ELABORATION OF TECHNICAL PROJECT CONCEPT OF THE FUEL ... · elaboration of technical project concept of the fuel switch to biomass in prokuplje including economical evaluation and

ELABORATION OF TECHNICAL PROJECT CONCEPT OF THE

FUEL SWITCH TO BIOMASS IN PROKUPLJE

INCLUDING ECONOMICAL EVALUATION AND

RECOMMENDATIONS FOR IMPLEMENTATION STRUCTURE OF

DISTRICT HEATING GRID

Prepared for:

Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH

Dag Hammarskjöld Weg 1-5

Postfach/ P.O.Box 5180

65760 Eschborn

Prepared by:

K.R.B. Consulting & agency

Starovlaška 89

32250 Ivanjica

September 2017

2

Table of Contents

1. EXECUTIVE SUMMARY ........................................................................................................... 8

2. INTRODUCTION .................................................................................................................... 11

3. PROJECT LOCATION ............................................................................................................ 13

4. EXISTING HEATING SYSTEMS............................................................................................. 16

5. BIOMASS MARKET ANALYSIS.............................................................................................. 35

6. TECHNICAL DESIGN CONCEPT ............................................................................................ 39

6.1 TECHNICAL SOLUTIONS AND SIZING THE BOILER ........................................................... 39

6.2 HEATING PLANT, LOCATION AND FACILITIES ................................................................... 44

6.2.1 HEATING PLANT ‘А’ ............................................................................................................ 44

6.2.2 HEATING PLANT ‘B’ ............................................................................................................ 46

6.3 CONCEPT OF DISTRICT HEATING NETWORK.................................................................... 48

6.3.1 CONCEPT OF DISTRICT HEATING NETWORK................................................................. 48

6.3.2 SCHEME OF DISTRICT HEATING NETWORK ................................................................... 49

6.3.3 CONCEPT OF HEATING SUBSTATIONS ........................................................................... 60

7. PRELIMINARY COST ESTIMATES ........................................................................................ 62

8. PRELIMINARY FINANCIAL ANALYSIS .................................................................................. 65

9. PROJECT EVALUATION ........................................................................................................ 67

10. LEGAL FRAMEWORK ........................................................................................................... 68

11. ENVIRONMENTAL IMPACT .................................................................................................. 69

12. ENERGY EFFICIENCY MEASURES AND CONCLUSION .................................................... 72

13. ANNEX .................................................................................................................................. 73

3

List of tables Table 1- Public buildings in Prokuplje ............................................................................................. 8

Table 2 - The structure of Prokuplje land ..................................................................................... 14

Table 3 - Data on population of Prokuplje from 1961 to 2011 ....................................................... 15

Table 4 - Data on population of the town of Prokuplje from 1961 to 2011 .................................... 15

Table 5 - Microclimate data for the City of Prokuplje .................................................................... 16

Table 6 - Data on buildings connected to the boiler room of Gymnasium ..................................... 17

Table 7 - Data on the building of primary school ‘Ratko Pavlović Ćićko’ ...................................... 20

Table 8 - Data on the buildings of Kindergartens ‘Biseri’ and ‘Bambi’ ........................................... 21

Table 9 - Data on buildings of the Municipality and Police station ................................................ 23

Table 10 - Data on the buildings connected to the boiler room in Technical school ...................... 24

Table 11 - Data on the building of primary school ‘9. Oktobar’ ..................................................... 26

Table 12 - Data on the Sports hall ................................................................................................ 27

Table 13 - Calculated capacity of future heating plants ................................................................ 28

Table 14 - Current situation, energy and fuel consumption, price, CO2 emission ......................... 31

Table 15 - Requirements for wood chips according to SRPS EN ISO 17225-4:2015 ................... 35

Table 16 - Classification of wood chips based on the moisture content according to

SRPS EN ISO 17225-4 ................................................................................................................ 35

Table 17 - Classification of bulk density of wood chips according to SRPS EN ISO 17225-4:2015

.................................................................................................................................................... 35

Table 18 - Requirements for wood chips according to SRPS EN ISO 17225-4:2015 ................... 36

Table 19 - Data on forests provided by SE ‘Srbijašume’, FE ‘Kuršumlija’ ..................................... 36

Table 20 - The energy potential of green chips from forestry, with wood waste from sawmill

industry, in the municipalities of Nova Varos, Priboj and Prijepolje ............................................... 38

Table 21 - The energy potential of biomass from FE ‘Kuršumlija’ ................................................. 38

Table 22 - Characteristics of wood chips depending on the percentage of moisture .................... 38

Table 23 - Unit price of wood chips depending on the percentage of moisture ............................. 39

Table 24 - Comparative analysis of the costs of currently used fuels in Prokuplje and costs of

biomass ....................................................................................................................................... 39

Table 25 - Overview of the areas and capacity of central biomass heating systems ‘A’ and ‘B’ .... 41

Table 26 - Calculated capacity of future heating plant .................................................................. 42

Table 27 - Sizing the pipe network by routes ................................................................................ 58

Table 28 - Calculation of operation point of network pump, heating plant ‘A’ ................................ 59

Table 29 - Calculation of operation point of network pump, heating plant ‘B’ ................................ 59

Table 30 - Working points of circulation pumps for heating plant ‘A’ and ‘B’ ................................. 59

Table 31 - Selection of substations in the facilities ....................................................................... 61

Table 32 - Investment costs ......................................................................................................... 62

Table 33 - Operational costs ........................................................................................................ 64

Table 34 - Costs of energy production ......................................................................................... 65

Table 35 - Unit costs of heating energy ........................................................................................ 67

4

List of figures Figure 1 - Location of the Toplica District ..................................................................................... 13

Figure 2 - Municipalities of the Toplica District ............................................................................. 13

Figure 3 - Energy consumption per fuel types - current situation .................................................. 31

Figure 4 - CO2 emission per fuel types, current situation .............................................................. 32

Figure 5 - Annual energy costs per fuel types, current situation ................................................... 32

Figure 6 - Unit price of energy per fuel type, current situation ...................................................... 33

Figure 7 - State and private forestsper Municipalities and Districts .............................................. 37

Figure 8 - Share of forest’s area in the total area of the Serbian municipalities ............................ 37

Figure 9 - Annual energy costs per fuel types - comparison with biomass ................................... 40

Figure 10 - Unit price of energy per fuel type - comparison with biomass ..................................... 40

Figure 11 - Diagram of the annual distribution of the heat capacity of the heating plants ............. 42

Figure 12 - Situation plan of heating plant ‘A’ ............................................................................... 44

Figure 13 - Situation plan of heating plant ‘B’ ............................................................................... 46

Figure 14 - Disposition of drawings of the heating network per numbers ...................................... 49

Figure 15 - Drawing No 1 of the heating network ......................................................................... 50








Figure 23 - Scheme of compact substation DSA 1 Mini Danfoss .................................................. 60

Figure 24 - Substation DSA - Mini Danfoss .................................................................................. 61

Figure 25 - Substation DSP – MAXI Danfoss ............................................................................... 61

Figure 26 - Emission of CO2 per a fuel type ................................................................................. 71

Figure 27 - Comparative analysis of costs of heating energy and savings ................................... 74

Figure 28 - Savings from fuel switch ............................................................................................ 75

Figure 29 - Operational costs and depreciation ............................................................................ 76

Figure 30 - Comparison of total costs of the existing system, new heating system and new system

supported by KfW Credit .............................................................................................................. 77

Figure 31 - Cash flow balance...................................................................................................... 78

5

List of photos Photo 1 - Building of Gymnasium ................................................................................................. 17

Photo 2 - Light fuel oil boilers, 3x550kW ...................................................................................... 17

Photo 3 - Insulated hot water collector ......................................................................................... 17

Photo 4 - Gymnasium .................................................................................................................. 17

Photo 5 - Gym hall ‘Sokolski dom’ ................................................................................................ 18

Photo 6 - Building of ‘Sokolski dom’ ............................................................................................. 18

Photo 7 - Building of National Museum Toplice ............................................................................ 18

Photo 8 - Panel radiator in the Museum ....................................................................................... 18

Photo 9 - Primary school ‘Nikodije Stojanović Tatko’ .................................................................... 19

Photo 10 - Movie Theatre, street view .......................................................................................... 19

Photo 11 - Movie Theater and Gymnasium schoolyard view ........................................................ 19

Photo 12 - Primary school ‘Ratko Pavlović Ćićko’ ........................................................................ 20

Photo 13 - Wood pellet boilers, 2x250kW .................................................................................... 20

Photo 14 - Insulated hot water collector ....................................................................................... 21

Photo 15 - Radiator without thermostatic valve ............................................................................ 21

Photo 16 - Kindergarten ‘Biseri’ .................................................................................................... 22

Photo 17 - Kindergarten ‘Bambi’ .................................................................................................. 22

Photo 18 - Boiler in Kindergarten ‘Biseri’ ...................................................................................... 22

Photo 19 - Underground fuel oil tank in the yard of Kindergarten ................................................ 22

Photo 20 - Damaged insulation of hot water collector .................................................................. 22

Photo 21 - Building of the Municipality ......................................................................................... 23

Photo 22 - Police station .............................................................................................................. 23

Photo 23 - Fuel oil boilers in municipal boiler room ...................................................................... 23

Photo 24 - Uninsulated hot water collectors in municipal boiler room ........................................... 24

Photo 25 - Underground oil tank in the yard of the Police station ................................................. 24

Photo 26 - Technical school ’15. maj’ and School gym ................................................................ 25

Photo 27 - Primary school ‘Milić Rakić Mirko’ ............................................................................... 25

Photo 28 - Fuel oil boilers in Technical school ............................................................................. 25

Photo 29 - Uninsulated hot water collectors ................................................................................. 25

Photo 30 - Underground fuel ........................................................................................................ 25

Photo 31 - Primary school ‘9. Oktobar’, main building .................................................................. 26

Photo 32 – Secondary building of the School ............................................................................... 26

Photo 33 - Fuel oil boilers in primary school ‘9. oktobar’............................................................... 26

Photo 34 - Hot water collectors in the School ‘9. Oktobar’ ............................................................ 27

Photo 35 - Underground fuel oil tank in the Schoolyard................................................................ 27

Photo 36 - Sports hall ‘Dr. Zoran Đinđić’ ...................................................................................... 27

Photo 37 - Sport court inside the Sports hall ................................................................................ 27

Photo 38 - LPG boiler .................................................................................................................. 28

Photo 39 - Circulation pumps ....................................................................................................... 28

Photo 40 - Locked LPG switch ..................................................................................................... 28

Photo 41 - LPG infrared heater .................................................................................................... 28

Photo 42 - Fenced underground LPG tank ................................................................................... 28

Photo 43 - Auxiliary facility of planned boiler room ....................................................................... 29

Photo 44 - Insulated connection ................................................................................................... 29

6

Photo 45 - Location of the heating plant ‘A’ .................................................................................. 44

Photo 46 - Pre-insulated pipes for the district heating network ..................................................... 48

7

List of abbreviations CAPEX - Capital Expenditure

CO2 - Carbon Dioxide

€ - Euro (currency)

(E) IRR - (Economy) Internal Rate of Return

(E) NV - (Economy) Net Present Value

FE - Forest enterprise

(F) IRR - (Financial) Internal Rate of Return

(F) NPV - (Financial) Net Present Value

LUC - Levelled Unit Costs

OPEX - Operating Expenditure

PVC - Polyvinyl chloride

RS - Republic of Serbia

SE - State enterprise

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1. EXECUTIVE SUMMARY

This study elaborates technical concept of a fuel switch in public buildings in Prokuplje municipality

and introduction of biomass as a fuel, as well as the installation of a biomass boiler and construction

of district heating network.

Table 1 shows public buildings in Prokuplje and heating related data:

Institution Location of

existing boiler room

Type of fuel

Heating

area estimated capacity

m2 kW

1 Gymnasium

Gymnasium building

Light fuel oil

3,710 779

2 Gym hall ‘Sokolski Dom’ 574 145

3 National Museum Toplice 513 115

4 Movie Theatre 423 148

5 Primary school ‘Nikodije Stojanović Tatko’

1,360 272

6 Primary school ‘Ratko Pavlović Ćićko’ Own boiler

room Pellet 2,839 497

7 Kindergarten ‘Biseri’ Kindergarten ‘Biseri’

Light fuel oil

458 59

8 Kindergarten ‘Bambi’ 529 79

9 Building of the Municipality Building of the Municipality

Light fuel oil

2,518 466

10 Police station 954 143

11 Secondary Technical School ’15. maj’ Technical

school Light fuel

oil

2,790 446

12 School gym 780 196

13 Primary school ‘Milić Rakić Mirko’ 1,524 244

Heating plant "A" cadastral plot

2308/1 18,972 3,589

14 Primary school ‘9. oktobar’ Primary school Light fuel

oil 2,080 364

15 Sports hall ‘Dr. Zoran Đinđić’ Sports hall Electricity 2,070 767

Heating plant "B" cadastral plot

1704/1 4,150 1,131

TOTAL BIOMASS HEATING PLANTS 23,122 4,720

Table 1- Public buildings in Prokuplje

As shown in Table 1, public buildings currently have various heating systems and use different types

of fuel to obtain thermal energy. Almost all of these heating systems and boilers are functional, but

in a poor condition. These systems are economically and energy inefficient, expensive to

maintaining and servicing. Furthermore, they are big pollutants.

Offered technical solution envisages construction of following:

- Two Central boiler rooms with biomass (wood chips) heated boilers

- Two District heating network

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- Heating substations, where delivered heating energy would be measured, and which would

serve to managing consumption of heating energy in particular buildings.

Considering that public buildings in Prokuplje are spread all over the town, it is necessary

construction of two biomass-heating plants.

Heating plant ‘A’ is envisaged in the city zone, on cadastral plot 2308/1, that is location of former

landfill on left riverbank of the Toplica River. Pipeline is planned from the plant ‘A’ to central city

boiler rooms located in the buildings of Gymnasium, primary school ‘Ratko Pavlović Tatko’,

kindergarten ‘Biseri’, Municipality, and Technical school ’15. maj’. Capacity of the boilers in the plant

‘A’ is 2,000+2,500 kW. Facility with area of 680 m² is planned for boilers, equipment, and for storage

of wood chips sufficient for four days of operations. It is also planned central storage for wood chips

with area of 2,640 m² and with capacity of 5,270 m³, i.e. 1,580 t. Envisaged central storage of wood

chips has adequate capacity for annual supply of all of public buildings analysed in this study.

Heating plant ‘B’ is envisaged on cadastral plot 1704/1, in immediate vicinity of primary school

‘9 Oktobar’. There will be installed one boiler with capacity of 1,500 kW. Pipeline is planned from

the plant ‘B’ to the boiler rooms of primary school ‘9. oktobar”, and the Sports hall ‘Dr. Zoran Djindjić’.

In the building of Sports hall ‘Dr. Zoran Djindjić’, offices are heated by electricity, while the gym is

not heated, due to which fact its functioning and maintenance are jeopardized. Facility with area of

305 m² is planned for boilers, equipment, and for storage of wood chips sufficient for four days of

operations. For boiler operations during four coldest consecutive weeks in a year, it is necessary

wood chips storage with area of 100 m² and with capacity of 190 m³, i.e. 55 t.

Considering workforce requirements, it is planned engagement of two highly technically educated

employees and one manager in each plant. Workers with lower qualifications would be replaced

from existing assignments in the facilities that will be included in a fuel switch project.

Planned capacity of the district heating network is sufficient for the public buildings, as well as for

potential connection to additional, smaller consumers.

Full load hours in public buildings in Prokuplje is low (808 kWh/kW) due to the heating during working

hours only. The fuel switch project would enable better utilization of the facilities of the Sports hall

in terms of providing commercial services, such as renting, thus generating additional income.

There are forests at territory of the Municipality of Prokuplje and the Toplica District sufficient to

provide biomass for district heating plant. In addition, biomass can be purchased as residues from

orchards and private forests. In such way, local community could close the circle of production and

consumption of heating energy.

Estimated investment value for implementation of this project is 2,151,200 €. Expected period of

return of investment is 9 years from the start of operations.

If the investment was financed from KfW Bank's program, with grant of 20%, grace period of 5 years

and a repayment period of 10 years, the positive business results would be achieved after 7 years

from the start of operations.

The investment could be reduced by 70,000 € in case of construction of the storage of wood chips

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with area of 1,200 m2 instead of the planned 2,640 m2. However, the storage of 1,200 m2 would

have a capacity sufficient for 50% of annual consumption only.

Prerequisites for successful operations of the plant are following:

‒ Selection of an appropriate financing model (from own funds, credit line or public-private

partnership)

‒ Entering into long-term contracts for the supply of the biomass

‒ Ensuring sufficient fuel storage supply covering consumption in the coldest month of the

year

‒ During the construction phase, train personnel who would take over management and

maintenance of the boiler plant

‒ Ensure high quality maintenance of the specific equipment in cooperation with the supplier

of the equipment.

This investment will achieve the following benefits:

‒ Lower costs of heating energy

‒ Low emission of harmful substances in the exhaust gases

‒ Reduction of CO2 emissions – combustion of wood biomass releases CO2 ‘neutral’

‒ Raising the comfort of all future consumers of the Prokuplje district heating

Techno-economic indicators of the future energy system with wood chips are as follows:

Heat capacity of boilers Woodchips boiler 1,500 + 2,000 + 2,500 kW

Fuel

Woodchips

M30 according to

SRPS EN ISO 17225-1:2015, and

SRPS EN ISO 17225-4:2015

Annual production of thermal energy 3,815 MWhth /a

Annual fuel consumption Woodchips 1,578 t/a

Efficiency on the threshold of the heat plant 0.90 x 0.92

Annual reduction in CO2 emission 689 t/a

CAPEX 2,151,200 €

OPEX (the amortization period) 3,840,636 €

LUC 79.30 EUR/MWh

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2. INTRODUCTION

The program ‘Development of a Sustainable Bioenergy Market in Serbia’ (GIZ DKTI) is implemented

jointly by the KfW (financing component) and GIZ (technical assistance component). It is funded by

the German Federal Ministry for Economic Cooperation and Development (BMZ) under the German

Climate Technology Initiative (DKTI). The main implementing partner and beneficiary of the

technical assistance (TA) component is the Serbian Ministry of Agriculture, Forestry and Water

Management (MAFWM). The general objective of the project is to strengthen capacities and create

an enabling environment for the sustainable use of bioenergy in Serbia. The TA component includes

the following five activity areas:

1) Policy advice: Assessment of bioenergy potentials and regulatory framework for creating and

enabling environment for private sector investment in bioenergy projects etc.

2) Biomass supply: Accompany investments in biomass-fired district heating plants in up to

three pilot regions with TA to secure a reliable and cost-effective supply of biomass in a

sustainable manner.

3) Efficient firewood utilization at household level: Increase the efficiency of firewood

consumption for heating at household level through the promotion of firewood drying and

efficient stoves/ovens.

4) Project development: Support in cooperation with the national and international private sector

the development and the implementation of feasible bioenergy projects – from biogas or straw

combustion plants in the industry sector to wood based heating boilers in private and public

buildings.

5) EU-Project BioRES – Regional Supply Chains for Woody Bioenergy: BioRES aims at

introducing the innovative concept of Biomass Logistic and Trade Centres (BLTCs) in Serbia,

Croatia, and Bulgaria based on cooperation with technology leaders from Austria, Slovenia,

Germany, and Finland. The BLTCs as regional hubs will help increasing local supply and

demand for wood bioenergy products in these countries.

The development of a biomass supply is required only if there are liable regional consumers of

biomass. As a supporting institution, GIZ DKTI has received a Letter of Expression of Interest signed

by the mayor of Serbian municipality Prokuplje to declare their demand for guidance, legal and

technical assistance in the process of the development of a fuel switch of public buildings in

Prokuplje to biomass. Heating grid will have to be planned.

This fuel switch from existing fuels (electricity, wood, light fuel oil, heavy fuel oil) to biomass should

provide savings in the budget of the municipality by strengthening local incomes with local produced

wood fuel and should reduce emissions of the renewed heating system.

The aim of this study is to establish technical concept for switching to biomass heating, the

installation of a wood chip heating plant including storage recipient and design of the distribution

system including grid and substations.

In addition, it is necessary to estimate the investment costs of the plant, distribution system, perform

financial evaluation of savings from woodchip heating system (compared to current situation)

regarding fuel costs, efficiency, investment and operation costs, cash-flow analysis through savings

12

and sensitivity analysis regarding fuel prices, investment cost and boiler efficiency.

The study includes the following:

- Assessment of the current energy situation in public buildings in Prokuplje regarding

heated area, boiler capacity and current performance, energy consumption and cost

efficiency, condition of distribution system and connections.

- Techno-economic analysis of the proposed system for the production of thermal energy

by burning biomass (wood chips), and distribution system with heating grid and

substations which should include:

Proposal of a technical concept for central woodchip heating system including

boiler, feeding system, storage unit and grid installation taking into consideration

future efficiency measures in the buildings.

Financial evaluation of savings from woodchip heating system (compared to

current situation) regarding fuel costs, efficiency, investment and operation

costs, cash-flow analysis through savings and sensitivity analysis regarding fuel

prices, investment cost and boiler efficiency.

An assessment of CO2 emissions reduction.

The recommendation concerning the quality and availability of wood chips to

supply the plant in the future, taking into account the prices and local suppliers

of wood chips.

Technical concept and preliminary design for heating grid in Prokuplje,

substations and further necessary equipment, including losses, connected to

planned biomass plant.

Estimation of overall investment costs for the heating grid, substations and

further necessary equipment.

Financial evaluation of heat prices compared to current situation taking into

account fuel costs, efficiency, investment and operation costs

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3. PROJECT LOCATION

The Toplica District is situated in southern part of the Republic of Serbia, covering geographic and

historic area known as Toplica, located in the basins of rivers Toplica and Kosanica. Area of the

District is 2,231 km², and according to Census 2011, number of inhabitants is 91,754 with population

density of 41people/ km². Western border of the District is mountain massif of Kopaonik, and

northern border are mountains of Veliki and Mali Jastrebac. In the east of this District there is the

basin of Južna Morava River towards Niš, and its southern borders are mountains of Vidojevica and

Pasjača. Whole area, as well as the river flowing through this area, are named after numerous hot

water sources (Serbian: toplica, or banja) and spas that are known since the Roman era (such as:

Prolom, Lukovska, Kuršumlijska). The Toplica District consists of:

1. City of Prokuplje 2. Municipality of Blace 3. Municipality of Kuršumlija 4. Municipality of Žitorađa

1 2

City of Prokuplje with area of 759 km2 covers 34% of territory of the Toplica District and

encompasses 1 city and 106 settlements. Urban area is inhabited by 27,333 people, and 17,086

people inhabit the settlements. Main industry is food processing. Confectionery Company ‘Hissar’

is operating successfully after the privatization, while alcoholic beverage production company

‘Prokupac’ broke. It is also significant ‘Leoni’ Company, producing wires, optical cables and fibres;

as well as the Company ‘Nikodije Stojanović Tatko’, producing felt.

1 https://sr.wikipedia.org/sr/Топлички_управни_округ 2 Ibid

Figure 1 - Location of the Toplica District Figure 2 - Municipalities of the Toplica District

14

There is developed road traffic, and railway traffic to some extent. One of important routes in the

area is main road M- 25 between Niš and Priština. This main road connects Prokuplje to highway

E-75 Belgrade- Skopje. Local roads are not in a good condition.

Agriculture is important industry in Prokuplje. Most represented are growing crops, fruit (plums,

apples, cherries, grapes). The land is also suitable for the development of cattle breeding, due to

large area of meadows and pastures.

Surface area of fertile land ha 44,599

Arable land ha 30,567

Orchard land ha 5,954

Forest land ha 29,529

Meadow and pasture land ha 8,078

Table 2 - The structure of Prokuplje land3

Climate is moderate continental with cold winters. Basic meteorological data (average annual

values) of the Toplica District are following:

- Insolation: 145.5 hours/month, i.e. 1,746 hours/year

- The amount of rainfall: 590 mm/year

- Air temperature: 17.3°C, Relative humidity: 70.7 %

- Daily solar radiation on a horizontal surface: 3.62 kWh/m² day

- Atmospheric pressure: 95.2 kPa

- Wind speed: 2.0 m/s (measured at 10 m from the ground)

- Ground temperature: 11.1°C

- Degree day heating: 2,613

- Heating days: 179

- Average temperature during heating days: 5.4°C

Toplica River flows through Prokuplje. On the right bank of the River, there are industrial zone,

sports complex ‘Toplica’, hospital complex, and railway station. On the left riverbank, there is the

city core, which is not homogenous, but concentrated along main road M-25 Niš-Priština. In the

strict city core there are municipal and other public institutions, while schools’ buildings are spread

in the direction of main road. Except for the main City street and main directions to neighbouring

places, the streets in Prokuplje are narrow, not intended for frequent traffic. The relief is such that

the city extends from the slopes on the left riverbank of Toplica towards surrounding slopes of the

mountain Jastrebac. Except for several residential buildings, people live in family houses.

Public buildings are mostly heated by light oil fuel. Solid fuels or electricity are used to a lesser

extent. In particular buildings, there is ongoing modernization of heating systems and fuel switch to

wood pellets.

3 http://www.prokuplje.org.rs/images/content/file/profil%20zajednice.pdf

15

Population of the administrative municipality Prokuplje

Number Census year

of 1961 1971 1981 1991 2002 2011

Inhabitants: 60,075 57,315 56,256 52,969 48,501 44,419

Households: 13,639 15,543 16,806 16,641 16,204 15,119

Table 3 - Data on population of Prokuplje from 1961 to 20114

Population of urban zone of Prokuplje

Number Census year

of 1961 1971 1981 1991 2002 2011

Inhabitants: 13,679 20,104 25,602 28,303 27,673 27,333

Table 4 - Data on population of the town of Prokuplje from 1961 to 20115

The most significant energy potential, which would ensure sustainable development, is the use of

biomass as a fuel. Wood potential of forests and orchards, as well as developed agriculture;

represent a good basis for collecting biomass with the purpose of solving the energy needs of public

and residential buildings in the city. Solution for energy requirements of the buildings is based on

the development of district heating network and installation of biomass boiler.

Positive planning documents, i.e. Detailed regulation plan of the city heating plant from 2011,

consider the central heating source only, and omit the heating network. Therefore, the first step in

establishment of the heating system and a fuel switch to biomass would be to revise the planning

documents, to create a development strategy, and General regulation plan of Prokuplje.

4 The Census of Population, Households and Dwellings in the Republic of Serbia, 2011 http://popis2011.stat.rs/?page_id=2134 5 Ibid

16

4. EXISTING HEATING SYSTEMS

Public institutions in Prokuplje are located in separate buildings with individual radiator systems and

individual boilers using light fuel oil and coil. Qualified personnel manage the boiler rooms. In several

buildings, electric heaters are used.

Particular problem is the use of the fuel oil, which combustion produces negative environmental

effects. Under certain microclimate conditions, the allowed emission limits are exceeded, which

could lead to a closure of the heat source.

In all of the buildings, radiator-heating systems are designed for temperature regime of 80/60°C and

the outdoor design temperature for the region of Prokuplje is -14.5°C.

Microclimate data

Air temperature

Relative humidity

Daily insolation

Atmospheric pressure

Wind speed

Soil temperature

(°C) (%) (kWh/m2) (kPa) (m/s) (°C)

January 0.3 80.5 1.59 95.5 1.9 -1.6

February 2.0 74.2 2.42 95.3 2.0 0.1

March 6.6 66.0 3.41 95.2 2.5 5.3

April 11.8 64.4 4.13 94.9 2.2 10.8

May 16.9 66.0 5.08 95 2.0 16.7

June 19.9 66.9 5.75 95.1 1.8 20.6

July 22.2 63.1 6.00 95.1 1.9 23.2

August 22.1 62.1 5.42 95.1 1.8 23.3

September 17.5 68.7 3.95 95.3 1.7 18.2

October 12.4 73.3 2.67 95.5 1.8 12.0

November 6.1 78.2 1.62 95.4 1.9 4.8

December 1.7 81.4 1.28 95.5 2.0 -0.5

Year 11.7 70.4 3.62 95.2 2.0 11.1

Table 5 - Microclimate data for the City of Prokuplje6

6 RET Screen International & NASA Software, updated 2014

17

Analysis of heating systems connected to the boiler room in the building of Gymnasium

Several buildings are connected to distributive system of the boiler room located in the building of

Gymnasium. There are three light oil fuel boilers of 3x550kW.

No Institution Heated

area Heating capacity

Calculated consumption

(m2) (kW) (kWh/a)

1 Gymnasium 3,710 779 756,172

2 The gym ‘Sokolski Dom’ 574 145 66,531

3 National Museum Toplice 513 115 92,739

4 Movie Theatre 423 148 44,204

5 Primary school ‘Nikodije Stojanović Tatko’ 1,360 272 264,029

Total 6,580 1,459 1,223,675

Table 6 - Data on buildings connected to the boiler room of Gymnasium

Operations of the boilers are controlled by flow temperature

thermostats installed on the boilers. There are closed

expansion tank with compressor, water circulation pumps,

and collector for distribution of heating energy. Equipment

in the boiler room is outdated, but well preserved and

functional. There is two-pipe radiator heating system with

no thermostatic valves on radiators.

Photo 1 - Building of Gymnasium

Photo 2 - Light fuel oil boilers, 3x550kW Photo 3 - Insulated hot water collector

Photo 4 - Gymnasium underground fuel tank

18

Underground pipeline connects the boiler room in the building of Gymnasium to several other

buildings. First building on the route of underground pipeline is Gym hall ‘Sokolski dom’. It is used

for activities of Gymnasium and sports clubs. There is two-pipe radiator heating system without

thermostatic valves and ventilation system with air heated from the boiler room in the building of

Gymnasium. Ventilation system is used occasionally.

After the building of ‘Sokolski dom’, National Museum Toplice is connected to the pipeline. There

is two-pipe radiator heating system with panel radiators without thermostatic valves on radiators in

the Museum.

Photo 5 - Gym hall ‘Sokolski dom’ Photo 6 - Building of ‘Sokolski dom’

Photo 7 - Building of National Museum Toplice Photo 8 - Panel radiator in the Museum

19

Building of primary school ‘Nikodije Stojanović Tatko’,

also connected to the boiler room in Gymnasium, has

two-pipe radiator heating system without thermostatic

valves. Schoolwork is conducted in two shifts. School

building is modernized by reparation of the facade and

installation of PVC windows, which increased energy

efficiency of the building.

Photo 9 – Primary school ‘Nikodije Stojanović Tatko’

Movie Theatre is located in the building of Gymnasium. There is two-pipe radiator heating system

without thermostatic valves in Movie Theatre.

Photo 11 – Movie Theater and Gymnasium schoolyard view

Photo 10 - Movie Theatre, street view

20

Analysis of heating system in the primary school ‘Ratko Pavlović Ćićko’

Primary school ‘Ratko Pavlović Ćićko’ is heated from the boiler room located within the school

building. There are two wood pellet heated new boilers with power of 2x250kW, produced by

‘Šukom’, Knjaževac.




(m2) (kW) (kWh/a)

1 Primary school ‘Ratko Pavlović Ćićko’ 2,870 502 487,289

Total 2,870 502 487,289

Table 7 - Data on the building of primary school ‘Ratko Pavlović Ćićko’

Until the end of heating season 2016-17, the School was heated by solid fuel. In summer of 2017,

the heating system was modernized. Former boilers were dismantled, and there were installed two

modern biomass (wood pellets) boilers, produced by ‘Šukom’, model Šukoplam PR 250. These

boilers have additional ventilator for airflow through the boiler. There is ongoing installation of rail

transporters for delivery of wood pellets to the boilers. There are also installed new circulation pumps

and new hot water distributors.

Photo 13 – Wood pellet boilers, 2x250kW

Photo 12 - Primary school ‘Ratko Pavlović Ćićko’

21

There is two-pipe radiator heating system without thermostatic valves in the School building.

Schoolwork will continue in two shifts. Operations of the boilers, ventilator, and rail transporter are

automatized in accordance with output water temperature from the boilers.

Analysis of heating systems connected to the boiler room in Kindergarten ‘Biseri’

Kindergartens ‘Biseri’ and ‘Bambi’ are both heated from the boiler room located in the Kindergarten

‘Biseri’. Underground pipeline connects Kindergarten ‘Bambi’ to the boiler room. ,




(m2) (kW) (kWh/a)

1 Kindergarten ‘Biseri’ 458 59 48,460

2 Kindergarten ‘Bambi’ 529 79 64,887

Total 987 138 113,347

Table 8 - Data on the buildings of Kindergartens ‘Biseri’ and ‘Bambi’

There is two-pipe heating system without thermostatic valves in both kindergartens. Recently, there was

implemented energy rehabilitation of Kindergarten ‘Biseri’ by installation of thermal insulation and PVC

windows.

Photo 15 – Radiator without thermostatic valve

Photo 14 - Insulated hot water collector

22

Photo 16 – Kindergarten ‘Biseri’

Light oil fuel heated boiler is produced by ‘Sime’, model 2R 10, with

capacity of 200kW. There are circulation pumps and hot water

collector with damaged insulation. Equipment in the boiler room is

outdated and in a poor condition. There is underground fuel tank in

the yard of Kindergarten ‘Biseri’.

Photo 18 – Boiler in Kindergarten ‘Biseri’

Photo 20 – Damaged insulation of hot water collector

Photo 17 - Kindergarten ‘Bambi’

Photo 19 – Underground fuel oil

tank in the yard of Kindergarten

23

Analysis of heating systems connected to the boiler room in the building of Municipality

Building of the Municipality and Police station are heated from the boiler room located in the building

of the Municipality. Underground pipeline connects the Police station to the boiler room.




(m2) (kW) (kWh/a)

1 Building of the Municipality 2,518 466 313,161

2 Police station 954 143 244,646

Total 3,471 609 557,808

Table 9 - Data on buildings of the Municipality and Police station

There is two-pipe radiator heating system without thermostatic valves on radiators in these two

buildings.

Photo 21- Building of the Municipality

There are two light oil fuel boilers produced by ‘Toplota’, Zagreb, with capacity of 2x290kW. There are circulation pumps and hot water collector without insulation. Equipment in the boiler room is outdated and in a poor condition. There is underground fuel tank in the yard of the Police station. Photo 23 – Fuel oil boilers in municipal boiler room

Photo 22 - Police station

24

Analysis of heating systems connected to the boiler room of Technical school ’15. Maj’

Building of Technical school ’15. Maj’, the School gym, and primary school ‘Milić Rakić Mirko’ are

heated from the boiler room located in the building of the Technical school ’15. Maj’. Underground

pipeline connects these buildings to the boiler room.




(m2) (kW) (kWh/a)

1 Technical school ’15. Maj’ 2,790 446 432,930

2 School gym 780 196 89,932

3 Primary school ‘Milić Rakić Mirko’ 1,524 244 236,850

Total 5,094 886 759,711

Table 10 - Data on the buildings connected to the boiler room in Technical school

In all of above listed buildings, there are two-pipe radiator heating systems. In the School gym and

in primary school ‘Milić Rakić Mirko’, there are no thermostatic valves on radiators, while in Technical

school, thermostatic valves are installed. The building of Technical school was reconstructed and

energy rehabilitated by installation of thermal insulation and PVC windows. Schoolwork in both

schools is conducted in two shifts.

Photo 25 - Underground oil tank

in the yard of the Police station

Photo 24 - Uninsulated hot water collectors in municipal boiler room

25

There are two light oil fuel boilers with capacity of 2x750kW in the boiler room. There are circulation pumps and hot water collector without insulation. There is expansion tank with compressor. Installations in the boiler room are new, dated on recent reconstruction of the School building. Level of automatization of the boilers’ operations is low. Functioning of the boilers is regulated in accordance with temperature of water in the boiler. Underground fuel tank is located in the schoolyard.

Photo 30 - Underground fuel

oil tank in the Schoolyard

Photo 27 - Primary school

‘Milić Rakić Mirko’

Photo 26 - Technical school

’15. maj’ and School gym

Photo 29 - Uninsulated hot water collectors Photo 28 - Fuel oil boilers in Technical school

26

Analysis of heating system in the primary school ‘9. Oktobar’

Primary school ‘9. oktobar’ is heated from the boiler room located within the school building. There

are two oil fuel heated boilers with power of 2x400kW, produced by ‘Kran Inženjering’, Knjaževac.




(m2) (kW) (kWh/a)

1 Primary school ‘9. oktobar’ 2,080 364 353,333

Total 2,080 364 353,333

Table 11 - Data on the building of primary school ‘9. Oktobar’

Premises of primary school ‘9. oktobar’ are located in two buildings. Boiler room is located in main

building, and secondary building is connected to the boiler room by underground pipeline. In both

buildings, there is two-pipe radiator heating system without thermostatic valves on radiators.

Schoolwork is conducted in two shifts.

There are water circulation pumps and thermally insulated hot water collectors. Equipment is outdated, but functional. Underground fuel tank is located in the Schoolyard.

Photo 32 – Secondary building of the School

Photo 33 - Fuel oil boilers in primary school

‘9. oktobar’

Photo 31 - Primary school ‘9. Oktobar’, main building

27

Photo 34 - Hot water collectors in the School ‘9. Oktobar’

Analysis of heating system in Sports hall ‘Dr. Zoran Đinđić’

Sports hall ‘Dr. Zoran Đinđić’ has no heating system. In the building consisting of the sports hall,

utility rooms, and offices, there is two-pipe panel radiator heating system, and heating system of the

sports hall by air conditioning chamber.




(m2) (kW) (kWh/a)

1 Sports hall 2,070 767 325,180

Total 2,070 767 325,180

Table 12 - Data on the Sports hall

Photo 35 - Underground fuel oil tank in the Schoolyard

Photo 37 - Sport court inside the Sports hall

Photo 36 - Sports hall ‘Dr. Zoran Đinđić’

28

Electric boilers are heating 230 m² of business premises in the building, while the sports hall is not

heated. Annual consumption of electricity for heating business premises is 200 kWh/m2, i.e. 46,000

kWh. As temporary solution, there are three LPG (liquefied petroleum gas) boilers with capacity of

2x48kW and 1x36kW, and the system of pipeline, circulation pumps, and collectors. As part of this

temporary solution, there are infrared heaters installed in the Sports hall immediately by the roof

structure. There is underground tank of LPG at fenced location behind the Sports hall.

LPG switch between the tank and equipment in the hall (boilers and infrared heaters) is installed on

the facade of the building. Bulkhead valve of the LPG switch is locked and secured by the Fire

department. This temporary LPG heating system is not operational due to failure in meeting

requirements of fire protection.

Planned solution for the heating of the Sports hall was construction of the boiler room that would be

connected to the Sports hall by underground pipeline. Behind the Sports hall, auxiliary facility of the

boiler room was constructed, but the boiler room has never been constructed.

Photo 38 - LPG boiler Photo 39 - Circulation pumps Photo 40 - Locked LPG switch

Photo 41 - LPG infrared heater Photo 42 - Fenced underground LPG tank

Table 13 - Calculated capacity of future

heating plants

29

Photo 43 – Auxiliary facility of planned boiler room

Overall analysis

Based on the displayed, heating systems differ by fuel type and by the type and number of users.

Heating systems with electric heaters in buildings are not connected to a separate line of electricity.

Due to the complex heating system, it is not possible to collect data of energy consumption;

therefore, energy consumption is calculated according to the following:

yeHDDtt

QH

epi

C

24

H - Estimated consumption (kWh)

QC - Capacity of heating installation (kW)

ti - internal temperature (20°C)

tep - external project temperature (-14.5°C) HDD - Degree days of heating (2,613)

e - correction for the effect of wind and heating switch

y - correction for the effect of daily consumption profile

Photo 44 – Insulated connection

30

Based on these equations, calculated values are shown in the following table:

No Institution

Operation Calculated consumption

Type of time days A Q q

by by

energy from to Institution heat source

h h m2 kW W/m2 kWh/a kWh/a

1 Gymnasium

Light fuel oil

7 20 125 3,710 779 210 756,172

1,223,675

2 Gym hall ‘Sokolski Dom’

12 20 125 574 145 253 66,531

3 National Museum Toplice

10 20 135 513 115 224 92,739

4 Movie Theatre 18 22 125 423 148 350 44,204

5 Primary school ‘Nikodije Stojanović Tatko’

7 20 125 1,360 272 200 264,029

6 Primary school ‘Ratko Pavlović Ćićko’

Pellet 7 20 125 2,839 497 175 482,436 482,436

7 Kindergarten ‘Biseri’ Light fuel

oil

6 17 125 458 59 129 48,460

113,347

8 Kindergarten ‘Bambi’

6 17 125 529 79 149 64,887

9 Building of Municipality Light fuel

oil

7 16 125 2,518 466 185 313,161 557,808

10 Police station 6 22 179 954 143 150 244,646

11 Technical School ’15. maj’

Light fuel oil

7 20 125 2,790 446 160 432,930

759,711 12 School gym 12 20 125 780 196 251 89,932

13 Primary school ‘Milić Rakić Mirko’

7 20 125 1,524 244 160 236,850

13 Primary school ‘9.oktobar’

Light fuel oil

7 20 125 2,080 364 175 353,333 353,333

14 Sports hall Electricity

for offices

14 20 154 2,070 767 371 325,180 325,180

23,122 4,720 204 3,815,490 3,815,490

Table 13 - Overview of data on the analysed facilities and consumption

Facilities of public institutions are very energy-inefficient. This is presented by power density, which

is 204 W/m2. Reasons to that are building structure and purpose of the facilities. Facilities with higher

floor-to-floor heights, such as the Sports hall, Gymnasium and Museum, bear bigger thermal load

(over 210 W/m2). Compact buildings with smaller heights, with glass surfaces, smaller surface of

the façade and good thermal insulation, such as the kindergarten ‘Biseri’ and ‘Bambi’, bear thermal

load of 130 W/m2.

31

Energy costs per a type of fuel are shown in Table 14. Considering that only offices are heated in

the building of Sports hall, this analysis considers their consumption only. It is not considered

presumed consumption in case of heating whole space of the Sports hall.

Current situation Unit Type of fuel

Total Light Fuel oil Pellet Electricity

Energy consumption

Annual (kWh) 3,007,874 482,436 46,000 3,536,310

Unit (kWh/m2) 165 170 200 166

Emission of CO2 (kg) 842,205 0 15,180 857,385

Efficiency of system (%) 90% 90% 99%

Consumption of fuel (t, m3) 291 108

Heated area (m2) 18,213 2,839 230 21,282

Unit fuel price (€/t, €/kWh, €/m3) 1,020 180 0.09

Annual energy cost (€) 296,428 19,492 4,140 320,060

Unit price of energy (€/m2) 16.28 6.87 18.00 15.04

(€/MWh) 98.55 40.40 90.00 90.51

Table 14 - Current situation, energy and fuel consumption, price, CO2 emission

Figure 3 - Energy consumption per fuel types - current situation

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

Light Fuel oil Pellet Electricity Total

3,007,874

482,436

46,000

3,536,310

Consumption of energy (kWh)

32

Figure 4 - CO2 emission per fuel types, current situation

Figure 5 - Annual energy costs per fuel types, current situation

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000


842,205

0 15,180

857,385

Emmision of CO2 (kg)

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000


296,428

19,4924,140

320,060

Annual energy costs (€)

33

Demand for heating energy in any facility is determined by working hours of the tenant of the facility.

Due to the heating during working hours only, the full load hours of 808 kWh/kW is low. If the facilities

would be used longer than during working hours, full load hours would be over 1,618 kWh/kW, which

is extremely high value. Installation of thermal insulation in the buildings would increase energy

efficiency and enable more comfort with same amount of energy consumed.

Figure 6 - Unit price of energy per fuel type, current situation

According to energy efficiency indicators, local heating systems in Prokuplje are very inefficient.

Energy efficiency of local heating systems depends on efficiency of following systems:

- System for production of heating energy- heating energy source

- Pipe systems for distribution of hot water

- Heating systems in the buildings

- Energy efficiency of the buildings

Systems for production of heating energy with boilers that use light fuel oil, or electricity as a fuel,

are energy efficient, but economically unsustainable systems. Almost all of the buildings in

Prokuplje, except for kindergarten ‘Biseri’ and technical school ‘15 Maj’, are not thermally insulated;

there is neither the control of the heating system, nor the control of the air temperature, which makes

all of these buildings and their heating systems inefficient. It is recommended the implementation of

energy efficiency measures aimed to reconstructing thermal insulation of the buildings, which would

certainly result in reduced consumption of heating energy.

Boilers using light fuel oil, are inacceptable in central city area due to environmental pollution and

high CO2 emissions.

Increase of energy, economic, and environmental efficiencies of heating systems in public buildings

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

Light Fuel oil Pellet Electricity Averge

16.28

6.87

18.00 15.04

98.55

40.4

90 90.51

Unit price of energy (€/m2), (€/MWh)

(€/m2) (€/MWh)

34

in Prokuplje could be achieved through following activities:

- Installation of central boiler for the city, which will use cheaper fuel with low CO2 emissions

- Establishment of remote district heating system for all city zones

- Connection of larger number of buildings to the remote district heating system aimed to

better utilizing remote heating system used longer.

Using biomass as a fuel instead of fuel oil, coal, gas and electricity, will result in higher economic

efficiency of the system, as well as in decrease of environmental pollution.

35

5. BIOMASS MARKET ANALYSIS

Biomass represents a renewable energy source, which is defined as the organic matter of vegetable

or animal origin (wood, straw, vegetable residues from agricultural production, manure, organic

fraction of communal solid waste). Biomass is used in combustion process and converted in power

plants into the heat, electricity, or both- heat and electricity. Biomass is used for the production of

liquid and gas fuels. Only the biomass of wood origin in the form of wood chips will be considered

as a part of this study.

Biomass is one of the renewable sources of energy and as such is considered as CO2 neutral. Since

biomass combustion emits exact amount of carbon dioxide as the plant binds during the process of

photosynthesis during growth, in that sense coefficient of carbon dioxide emissions of biomass

equals zero. However, this information is valid only when exploitation of biomass is accompanied

by a forestation, otherwise CO2 emissions should be taken into account.

Wood chips are intended as the biomass for combustion in heating plants. The quality of wood chips

is defined by the standard for solid fuel SRPS EN ISO 17225-1:2015, and SRPS EN ISO 17225-

4:2015 determines the fuel quality classes and specifications of graded wood chips. The following

table shows the requirements defined by the standards in Serbia:

Table 15 - Requirements for wood chips according to SRPS EN ISO 17225-4:2015

M10 M15 W20 W25 W30 W35 W40

Moisture content %

M<10 10<M≤15 15<M≤20 20<M≤25 25<M≤30 30<M≤35 35<M≤40

Table 16 - Classification of wood chips based on the moisture content according to SRPS EN ISO 17225-4

Moisture (%)

8 < % < 18 18 < % < 25 25 < % < 35 35 < % < 45

Bulk density (bulk-kg/m3)

225< BD200 <250 250< BD250 <280 280< BD250 <320 320< BD300 <380

Table 17 - Classification of bulk density of wood chips according to SRPS EN ISO 17225-4:2015

Wood chips

Standard SRPS EN ISO 17225-1:2015

SRPS EN ISO 17225-4:2015

Particles size

Amax = 6 cm2

L = 10 cm (max 10% - 35cm)

Moisture content W10 – W60

suitable: 40% max

Bulk density < 350 kg/m3

Calorific value 2.80-3.40 kWh/kg

36

Dimensions (mm)

The fracture >60% by weight

Fine fracture Rough fracture Maximum particle length

P16 3.15 ≤ P ≤ 16 mm < 3.15 mm, < 15% <6%, > 31.5 mm < 45 mm

P31 3.15 ≤ P ≤ 31.5 mm < 3.15 mm, < 10% <6%, > 45 mm < 150mm

P45 3.15 ≤ P ≤ 45 mm < 3.15 mm, < 10% <10%, > 63 mm < 200mm

Moisture (%)

M10 ≤ 10%

Dried M15 ≤ 15% M20 ≤ 20% M25 ≤ 25%

Suitable for storage M30 ≤ 30%

M35 ≤ 35% Limited for storage

M40 ≤ 40%

M50 ≤ 50% Unsuitable for storage M55 ≤ 55%

M60 ≤ 60% Wet

Ash content (%)

A 0.5 ≤ 0.5%

A 0.7 ≤ 0.7%

A 1.0 ≤ 1.0%

A 1.5 ≤ 1.5%

A 2.0 ≤ 2.0%

A 3.0 ≤ 3.0%

Table 18 - Requirements for wood chips according to SRPS EN ISO 17225-4:2015

Total forest area in the municipality of Prokuplje is about 29,529 ha. The forest area covers 39% of

the territory of the city; the degree of utilization of resources is around the national average. State

owned forests represent 62%, and privately owned forests are 38% of total forest area of Prokuplje.

Forest enterprise ‘Kuršumlija’, Kuršumlija, manages following forest administration offices:

Kuršumlija, Prokuplje, Blace, with total forest area of 62,189 ha.

Forest enterprise Forest area

Total wood volume

Annual growth

Annual return

Kuršumlija ha m3 m3/ha m3

Kuršumlija 33,795 6,202,228 4.8 90,130

Prokuplje 20,409 3,811,438 5.7 49,402

Blace 7,985 1,888,400 6.4 29,317

Total 62,189 11,902,066 16.9 168,849

Table 19 - Data on forests provided by SE ‘Srbijašume’, FE ‘Kuršumlija’7

7 http://www.srbijasume.rs/kursumlija.html

http://www.srbijasume.rs/kursumlija.html

37

8 9

Calculation of the potential of forest waste in the municipality of Prokuplje is based on the study

‘Potentials and Possibilities of Commercial Use of Wood Biomass for Energy Production and

Economic Development of the Municipalities Nova Varoš, Priboj and Prijepolje’. This Study was

carried out as the analysis of the availability of wood waste from the sawmill industry and forestry in

the municipalities of Nova Varoš, Priboj and Prijepolje. The results showed that following amounts

are available to meet energy needs:

8 ‘Potentials and Possibilities of Commercial Use of Wood Biomass for Energy Production and Economic Development of the Municipalities Nova Varoš, Priboj and Prijepolje’, 2009, author: Branko Glavonjić, PhD 9 ibid

Figure 8 - Share of forest’s area in the total area of the Serbian municipalities

Figure 7 – State and private forestsper Municipalities and Districts

38

Nova Varoš Priboj Prijepolje Total

Forest (ha) 22,400 30,400 44,000 96,800

Wood waste volume (m3)

Chips from forestry 3,100 4,300 5,400 12,800

Wood industry 9,364 1,194 11,739 22,297

Total 12,464 5,494 17,139 35,097

Wood waste mass (t)

Chips from forestry 1,813.5 2,515.5 3,159.0 7,488

Wood industry 5,477.9 1,137.2 6,867.3 13,482

Total 7,291 3,653 10,026 20,970

Annually available energy value (MWh/a)

Chips from forestry 4,003.2 5,532.2 6,950.0 16,485

Wood industry 15,901.6 3,308.2 19,932.6 39,142

Total 19,905 8,840 26,883 55,628

Table 20 - The energy potential of green chips from forestry, with wood waste from sawmill industry, in the municipalities of Nova Varos, Priboj and Prijepolje10

Calculated energy value of forest waste, without the waste of the sawmill industry of SE ‘Srbijašume'

and FE ‘Kuršumlija’ is shown in the table below:

Territory

Forest area

Volume of wood waste

Mass of wood waste

Annually available energy

ha m3 t MWh/a

Prijepolje, Priboj, Nova Varoš 96,800 35,097 20,970 55,628

Forest farm ‘Kuršumlija’ 62,189 22,548 13,472 35,738

Table 21 - The energy potential of biomass from FE ‘Kuršumlija’11

Biomass of wood origin in the form of pellets available on the market is not suitable for analysis due

to the high purchase price. Some of the benefits of wood chips compared to wood pellets are lower

prices and lower level of wood processing. Domestic market transactions are performed on a small

scale between manufacturers and wholesalers, where price reaches 180 €/t of wood pellets.

Depending on the time of purchase, end customers pay between 200 and 220 €/t. The advantage

of pellets is higher bulk density, which means lower transportation costs and smaller storage for the

same amount of fuel in terms of energy produced. Due to lower processing level, wood chips has

lower price, but higher moisture content, which affects its energy value, bulk density, and price.

Wood chips Moisture Energy value Bulk density Cost

(%) (kWh/m3) (bulk-kg/m3) (€/t)

30-40 940-1,200 300-350 45-60

Table 22 - Characteristics of wood chips depending on the percentage of moisture

10 ‘Potentials and Possibilities of Commercial Use of Wood Biomass for Energy Production and Economic Development of the Municipalities Nova Varoš, Priboj and Prijepolje’, 2009, author: Branko Glavonjić, PhD 11 Own calculation

39

6. TECHNICAL DESIGN CONCEPT

6.1 TECHNICAL SOLUTIONS AND SIZING THE BOILER

Aimed to decreasing fuel costs for heating public buildings in the Prokuplje municipality, it is

designed the concept of the construction of central boiler room with biomass- wood chips heated

boiler, remote district heating pipe system, and substations. Comparative analysis of annual fuel

costs in existing systems, and in case of using wood chips is shown in Table 24. The analysis does

not consider area of sports hall within the building of Sports hall ‘Dr. Zoran Đinđić’. In calculations

of total heating energy produced by future biomass heating system, the heating of this whole

building is included, which provides actual parameters of comparative analysis. Following Table

shows variation of energy value and unit price of energy, depending on percentage of moisture. Due

to large contact surface, wood chips easily exchanges moisture with environment, which affects its

energy value and unit price of energy.

Moisture

Caloric value

Unit price

(%) (kWh/t) (€/t) (€/kWh)

Biomass, wood chips

30 3,400 53

0.016

40 2,800 0.019

Table 23 - Unit price of wood chips depending on the percentage of moisture

Unit Fuel type

Biomass Light fuel oil Pellet Electricity Total

Energy consumption (kWh) 3,007,874 482,436 46,000 3,536,310 3,815,490

Emission of CO2 (kg) 842,205 0 15,180 857,385 0

Efficiency of system (%) 90% 90% 99% 0 83%

Increase for heating up the system

(%) 0% 0% 0% 5%

Consumption of fuel (t), (m3) 291 108 0 1,578

Heated area (m2) 18,213 2,839 230 21,282 21,282

Unit fuel price (€/t), (€/kWh),

(€/m3) 1,020 180 0.09 53

Annual energy cost (€) 296,428 19,492 4,140 320,060 83,631

Unit price of energy (€/m2) 16.28 6.87 18.00 15.04 3.93

Unit price of energy (€/MWh) 98.55 40.40 90.00 90.51 21.92

Table 24 - Comparative analysis of the costs of currently used fuels in Prokuplje and costs of biomass

Based on collected data, calculated annual fuel costs in buildings used by public institutions in

Prokuplje are estimated to be around 320,000 €. If the analysed facilities used biomass-wood chips

for heating, annual fuel costs would come to amount of approximate 85,000 €. The use of biomass

for the heating of analysed facilities can reduce annual fuel costs by the amount of 220,000-

250,000 €.

40

Figure 9 - Annual energy costs per fuel types - comparison with biomass

Figure 10 - Unit price of energy per fuel type - comparison with biomass

The program of switching existing fuels with biomass in buildings used by public institutions of

Prokuplje requires a complex analysis in order to select the best technical and economic solutions.

Facilities of public institutions are dispersed all around the town, so replacement of individual boilers

requires the construction of two new central biomass boiler rooms with pipe system for district

heating.

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000


296,428

19,4924,140

320,060

65,933

10,575 1,008

83,636

Annual energy cost (€)

Existing fuel (€) Biomass, ships (€)

0.00

20.00

40.00

60.00

80.00

100.00

Light Fuel oil Pellet Electricity Biomass

16.286.87

18.00

3.93

98.55

40.4

90.00

21.92

Unit price of energy (€/m2), (€/MWh)

(€/m2) (€/MWh)

41

Heating plant marked ‘A’ would be connected to public buildings in immediate city core. Heating

plant marked ‘B’ would be connected to the buildings of primary school ‘9. oktobar’, and Sports hall

‘Dr. Zoran Đinđić’, which are distant from the future heating plant ‘A’ app. 1 km. If these building

would be connected to the heating plant ‘A’, route of the pipeline would run through hardly

approachable streets on very unevened terrain. Furthermore, there are no other public buildings-

bigger consumers of heat energy on that route. In respect to these facts, connection of primary

school ‘9. oktobar’ and Sports hall ‘Dr. Zoran Đinđić’ to the heating plant ‘A’ would result in delay of

delivery of heating energy compared to consumers in the city centre, and in lower quality of the

system. Considering aforementioned, there will be constructed heating plant ‘B’ to satisfy

consumption of primary school ‘9. oktobar’ and Sports hall ‘Dr. Zoran Đinđić’.

Local boiler rooms Heating

area capacity

m2 kW

BOILER ROOM – HETAING PLANT - SYSTEM ‘A’

Gymnasium 6,580 1,459

Primary school ‘Ratko Pavlović Ćićko’ 2,839 497

Kindergarten ‘Biseri’ 987 138

Building of the Municipality 3,471 609

Technical School ’15. maj’ 5,094 886

TOTAL ‘A’ 18,972 3,589

BOILER ROOM – HETAING PLANT - SYSTEM ‘B’

Primary school ‘9. oktobar’ 2,080 364

Sports hall 2,070 767

TOTAL ‘B’ 4,150 1,131

Table 25 - Overview of the areas and capacity of central biomass heating systems ‘A’ and ‘B’

For each system (‘A’ and ‘B’) will be Construction district heating network which should enable the

connection of the considered public facilities, with the possibility of connecting others buildings in

the future. This district heating system represents an investment in infrastructure.

The required installed capacity of the boiler and level of efficiency of the heating system is calculated

using the formula:

C

B

QQ

QB (kW) Installed boiler capacity

QC (kW) Net consume (capacity)

η System efficiency

η = ηB · ηC

ηB Boiler efficiency

ηC Efficiency of district heating system

τ Simultaneity factor

42

The calculated heat demand would be covered by installing heating plant of nominal heat output

presented in the next table:

Table 26 - Calculated capacity of future heating plant

Figure 11 - Diagram of the annual distribution of the heat capacity of the heating plants

The number of hours of boiler operations can be determined using Sochinsky formula:

max

1

0

0

0

11 QQ

m

b

max

min0

Q

Q

maxQ

Qmm

Q - heating capacity at the time,

- time,

minQ - minimum heating capacity of boiler

maxQ - maximum heating capacity of boiler

mQ - required capacity

0

1000

2000

3000

4000

5000

0 500 1000 1500 2000 2500 3000 3500

kW

Working hours

Heating Capacity (kW) - Heat Load Curve

System "A" System "B"

System Capacity

Qc ηB ηC Τ

Calculate QB

Sizing of the boiler

(kW) (kW) (kW)

‘A’ 3,589 0.9 0.92 0.9 3,901 4,500

‘B’ 1,131 0.9 0.92 0.9 1,229 1,500

43

During winter, every heating system is a subject to great fluctuations that depend on the weather

and user’s habits. The maximum output power is utilized very shortly during periods of very cold

weather. Regularly, the boiler is operating for long intervals of time at low load. Therefore, it is

important for the boiler to be operated efficiently during off-peak periods. This can be achieved in

one of the following ways:

1. The biomass boiler can provide the maximum capacity, while a buffer (a hot water tank) covers

short-term load fluctuations and ensures that the boiler can be operated efficiently during off-peak

periods.

2. Combination of more biomass boilers. More boilers increase the reliability of supply and ensure

that the heating operates efficiently, even in off-peak periods.

Optimal model for biomass plant ‘A’ would be the solution with two wood chips heated boilers,

2,500kW + 2,000kW, and hot water tanks with 45m3 volume . One boiler would be used at higher

outside temperatures. In this way, the system would be efficient even in lower operating modes. For

biomass plant ‘B’, optimal model would be the solution with one wood chip heated boiler, 1500kW

and hot water tank with 15m3 volume. Existing boilers in aforementioned facilities would serve as a

backup solution.

Comparison of biomass and existing fuels is based on the full load hours of 808 kWh/kW. This

consumption value implies that the heating systems are in a maintenance mode after working hours

and in schools during winter holidays. According to this data, it is necessary to produce yearly

consumption of 3,815 MWh. The unit production cost of the heating energy, according to the solution

with wood chips as a fuel, is about 21.92 €/MWh. Current unit cost for buildings described in this

study, with existing heating systems, is up to 90.51 €/MWh.

44

6.2 HEATING PLANT, LOCATION AND FACILITIES

6.2.1 HEATING PLANT ‘А’

The plot intended for the construction of a new power plant is located on a part of cadastral plot

2308/1 CM Prokuplje with surface of 4,200m2. This location is on the site of the former landfill, on

the left bank of the Toplica River.

Figure 12 - Situation plan of heating plant ‘A’

Photo 45 - Location of the heating plant ‘A’

45

The heat source consists of two boilers capacity 2,000kW and 2,500kW, for combustion of biomass

with total nominal thermal capacity of 4,000 kW. In the plant with two boilers, stable operations are

ensured with low outdoor temperatures, as well as with higher outdoor temperatures. In cases of

higher outdoor temperatures, one boiler can provide sufficient heating, without the risk of cooling

entire system. The regime of the boiler temperature is 100/70°C. Maximum operating pressure is

6 bars. The minimum temperature return to boiler is 60°C. It is planned to install a buffer tank with

volume of 45 m3 in order to optimize the operation of the heat source. Circulator pumps are located

between the boiler and buffer tank, as well as three-way mixing valve in order to provide protection

for the cold parts of boilers.

For the purposes of technical calculation, the documentation was used made by ‘Topling-heating

Beograd’, including additional mechanisms for feeding fuel, extracting exhaust gases and ash. For

the purposes of circulation in the distribution system, circulation pump with inconstant flow and

pressure sensors are planned.

Construction of following facilities is envisaged at the site of future heating plant ‘A’:

Building A:

- Space to install biomass boilers with area of 250 m2 is needed for installation of following

boilers:

a) one boiler with capacity of 2,000 kW. Space necessary for operations of such boiler has

following dimensions: width x length x height = 6.8 x 9.2 x 5.8m

b) one boiler with capacity of 2,500kW. Space necessary for operations of such boiler has

following dimensions: width x length x height = 8.0 x 10.2 x 6.3m

The rest of a space is manipulative space for access to maintaining and safe passage.

- Space to install daily tank of woodchips with surface of 250 m2 and capacity of 100 m3,

i.e. 30 t, and space for daily fuel storage sufficient for 4 days of operations.

- The area of processing equipment (buffers, pumps, collectors) of 130 m2

- Office space of 50 m²

Building B:

- Wood chips storage for whole heating season and for both heating plants (‘A’+’B’), with

area of 2,640 m2 and minimum useful height of 7 m. Capacity of this storage is 5,270 m3 or

1,580 t of wood chips, which is sufficient for the needs of both heating plants to provide

energy for the heating of all public buildings.

Total area of buildings of the heating plant ‘A’ is 3,320 m2 (250+250+130+50+2,640 m2) and the

degree of availability of cadastral parcel is 80%.

46

6.2.2 HEATING PLANT ‘B’

The plot intended for the construction of a new power plant ‘B’ is located on a part of cadastral plot

1704/1 CM Prokuplje with surface of 1,500m2. The location is behind primary school ‘9. oktobar’ and

Sports hall ‘Dr. Zoran Đinđić’.

Figure 13 - Situation plan of heating plant ‘B’

The heat source consists of one boiler capacity 1,500kW, for combustion of biomass, and hot water

buffer tank with volume of 15 m3 in order to optimize the operation of the heat source. In the plant

with boiler and hot water buffer tank, stable operations are ensured with low outdoor temperatures,

as well as with higher outdoor temperatures. In cases of higher outdoor temperatures, one boiler

can provide sufficient heating, without the risk of cooling entire system. The regime of the boiler

temperature is 100/70°C. Maximum operating pressure is 6 bars. The minimum temperature return

to boiler is 60°C. Circulator pumps are located between the boiler and buffer tank, as well as three-

way mixing valve in order to provide protection for the cold parts of boilers.

For the purposes of technical calculation, the documentation was used made by ‘Topling-heating

Beograd’, including additional mechanisms for feeding fuel, extracting exhaust gases and ash. For

the purposes of circulation in the distribution system, circulation pump with inconstant flow and

pressure sensors is planned.

Construction of following facilities is envisaged at the site of future heating plant ‘B’:

47

Building A:

- Space to install biomass boilers with area of 150 m2 is needed for installation of a boiler

with capacity of 1,500 kW. Space necessary for operations of such boiler has following

dimensions: width x length x height = 6.8 x 9.2 x 5.8m

The rest of a space is manipulative space for access to maintaining and safe passage.

- Space to install daily tank of wood chips with area of 55 m2 and capacity of 22 m3 or 6.5 t

that is sufficient for 4 days of operations

- The area of processing equipment (buffers, pumps, collectors) with area of 50 m2

- Office space of 50 m²

Building B:

- Wood chips storage with area of 100 m2 and minimum useful height of 7 m. Capacity of

this storage is 190 m3 or 55 t of wood chips, which is average 4 weeks consumption in the

coldest period of a year. This storage would be supplied by wood chips from central storage

located in the complex of heating plant ‘A’

Total area of buildings of heating plant ‘B’ is 405 m2 (150+55+50+50+100 m2) and the degree of

availability of cadastral parcel is 27%.

48

6.3 CONCEPT OF DISTRICT HEATING NETWORK

6.3.1 CONCEPT OF DISTRICT HEATING NETWORK

Heating network is designed to connect aforementioned public buildings. The pipe network consists

of pre-insulated steel pipes that are installed directly in the prepared soil. Distribution network will

contain chambers with bulkhead valves.

Photo 46 - Pre-insulated pipes for the district heating network12

The quality of the pipes corresponds to 1.0254 i.e. P235

TR1 according to EN10217 T1 (or St.37.0 of the technical

requirements and delivery conditions according to

DIN1626). The operating temperatures at the threshold of

the heat source are:

- The flow temperature is 100℃,

- The return temperature is 70℃

The difference in altitude between the highest point of the

town (on the outskirts) and the lowest point is less than

30 m, so the lowest required operating pressure in the

pipeline is 6 bar.

Route of the pipeline runs through main streets, or through land plots owned by the City or by other

state body/ company. An example is cadastral plot No 5686, owned by Public Water Management

Company ‘Srbijavode’, necessary for connection of Technical school ’15. maj’ to the heating

network.

Before designing the heating network, it is necessary preparation of a document at the municipal

level, which will define the Prokuplje construction strategy and direction of the future development

of the city centre.

Concept plan of the heating network is preliminary, and designed for the planning of the budget

expenditures.

12 Source: Website of the company Konvar d.o.o., Belgrade

49

6.3.2 SCHEME OF DISTRICT HEATING NETWORK

Based on the position of public institution buildings, as well as on the position of the main town

streets, residential buildings and individual houses, heating network plan would be as follows:

Figure 14 - Disposition of drawings of the heating network per numbers

50

Figure 15 - Drawing No 1 of the heating network

51


52


53


54


55


56


57


58

Dimensions of heating pipes for the network calculated with the planned reserve for future additions to the network:

Within the analysis, heating network is divided by the routes and transparent points, as shown on the drawings:

Type Route Distance Capacity of Unit price of network

of from to heat substations Dimension Total

route (m) (kW)

main A B 90 2200 DN150 310 27,900

main B C 95 2700 DN200 465 44,175

main C D 285 2900 DN200 465 132,525

main E E1 350 900 DN100 220 77,000

main F F1 100 500 DN80 175 17,500

main G G1 100 1000 DN125 265 26,500

connection A1 100 700 DN100 220 22,000

connection A2 160 1500 DN125 265 42,400

connection B1 110 500 DN80 175 19,250

connection C1 60 200 DN50 130 7,800

connection E1 10 900 DN100 220 2,200

connection F1 10 500 DN80 175 1,750

connection G1 10 1000 DN125 265 2,650

TOTAL 1,480 423,650

Table 27 - Sizing the pipe network by routes

According to the prices of units needed to construct a network of pre-insulated pipes, the costs of

the construction of heating network are estimated to 424,000 €. The additional costs of the

construction of the chamber with necessary fittings and installation of the fittings increase estimation

for 10%, leading to total costs of the heating network of 470,000 €.

Q - The amount of heat transported by the pipeline

w - Velocity of flow of the working fluid

ρ - Density of the working fluid

cp - Specific heat capacity

Δθ - Temperature difference

p

incw

QD

4

59

Calculation of operating point of the network pump is shown in the following Tables:

Table 28 - Calculation of operation point of network pump, heating plant ‘A’

Table 29 - Calculation of operation point of network pump, heating plant ‘B’

The operating point of the network pump (or a pair of network pumps, depending on the solution

adopted in the preliminary design) is as follows:

Heating plant ‘A’ Heating plant ‘B’

Flow l/h 95,000 50,000

Pressure drop kPa 87 55

Table 30 - Working points of circulation pumps for heating plant ‘A’ and ‘B’

The operating point is selected on a basis of the pressure drop in the hydraulically least favorable

heating substation.

Aimed to saving electricity for pumping the working fluid, it is necessary to incorporate the engine

frequency controls in order to optimize the operation of network pumps and synchronize it with the

actual required thermal energy to be delivered to the consumer.

Flow Lenght Speed

from to diemeter wall unit total friction local TOTAL

kW l/h m mm mm m/s Pa/m kPa kPa kPa

D C 2.900 85.508 90 219,1 5,9 0,704 22,08 1,987 3,603 5,590

C B 2.700 79.611 120 219,1 5,9 0,656 19,20 2,3 1,5 3,761

B A 2.380 70.175 150 168,3 4,5 0,979 58,36 8,8 3,2 12,001

A A2 1.500 44.228 190 139,7 4,0 0,902 63,05 12,0 2,8 14,741

MAX: 85.508 SUM: 36,1

10% 8.551 Security increase: 25% 9,0

Total for calculate: 94.059 heat excanger: 30

Adopted va lue: 95.000 (l/h) reserve: 10

Total for calculate: 85,1

Adopted for ca lc. (kPa): 87

Route Dimension of pipe Pressure dropCapacity

60

6.3.3 CONCEPT OF HEATING SUBSTATIONS District heating transfer stations provide the link between district heating suppliers and the customers’ systems. They incorporate the necessary equipment to tailor the supplied heat to the needs of the user. Indirect connections (in which district heating and in-house systems are hydraulically isolated) incorporate components to separate the systems (heat exchanger), to limit the flow volume, regulate the secondary supply temperature and measure the energy consumption. Substations are designed for installation in already existing boiler rooms. The existing boilers will be reviewed in terms of functionality. Those that do not meet the minimum requirements for safe operations will be removed from the substations (i.e. from the existing boiler rooms). Those that meet the minimum technical requirements will remain as a backup heat source in case when, for any reason, the heating system goes into breakdown of operational mode; or to serve as back up heating source if there is an increase of heat consumption that cannot be foreseen at this moment. The operating pressure in the primary part of the substation will be up to 6 bars max., and will correspond to the parameters of the heating network, while the temperature range will be 100/70℃ in the primary part and 80/60℃ in the secondary part. The further development of the heating system, with a focus on the connection of residential buildings, would involve the installation of heating substations of the packet type in each building, with identical operating parameters as for heating substations in public institutions or business facilities.

1- External sensor 2- Thermometer 3- Manometer 4- Sensor 5- Air vent 6- Drainage 7- Prim. Connection DHW 8- Safety thermostat 9- Connection to expansion 10- Controller 11- Strainer 12- Heat meter 13- Ball valve 14- Safety valve 15- Heat exchanger

Figure 23 - Scheme of compact substation DSA 1 Mini Danfoss13

13 www.danfoss.com

http://www.danfoss.com/

61

14 15

Substations models DSP-MAXI are designed for power stronger than 100 kW. Substations DSA1-Mini are designed to power up to 100 kW and can be mounted on the wall. Heat substation should be dimensioned according to the size of the heat loss of the building. The reconstruction of the existing boiler rooms should be executed in a way that does not change the working fluid distribution system and the heating substation is connected to the existing supply and return collectors. The existing circulation pumps should be replaced by more energy-efficient units with motors of variable frequency, in order to achieve savings in power consumption and reduce heat dissipation in the buildings.

No Institution Position on the

drawing

Type of No of subst. Power Price

substation

(kW) (€)

1 Gymnasium A-2 DSP-MAXI-32 3 500 18,000

2 Primary school ‘Ratko Pavlović Ćićko’

B-1 DSP-MAXI-22 2 250 11,000

3 Kindergarten ‘Biseri’ C-1 DSP-MAXI-22 1 200 5,400

4 Building of the Municipality A-1 DSP-MAXI-31 2 350 11,800

5 Technical School ’15. maj’ E-1 DSP-MAXI-32 2 450 12,000

6 Primary school ‘9. oktobar’ P-1 DSP-MAXI-32 1 500 6,000

7 Sports hall ‘Dr. Zoran Đinđić’ R-1 DSP-MAXI-32 2 500 12,000

TOTAL: 76,200

Table 31 - Selection of substations in the facilities

14 www.danfoss.com 15 Ibid

Figure 25 - Substation DSP – MAXI Danfoss Figure 24 - Substation DSA - Mini Danfoss

http://www.danfoss.com/

62

7. PRELIMINARY COST ESTIMATES

The task of this study has a number of levels:

‒ Fuel switch to biomass of existing heating systems in public buildings in Prokuplje, by

construction of the central biomass heating plant

‒ Construction of district heating distribution system to connect the public buildings

Fuel switch to biomass of heating systems in public buildings in Prokuplje should provide lower costs

of heating energy, reduce CO2 emissions, contribute to environmental protection, and enhance local

economic development in terms of growing and processing biomass. Implementation of the project

should provide savings in the Prokuplje municipal budget, and thus a quick return of the investment.

The preliminary cost estimates includes annual investment and operating costs. Investment would

include the purchase of equipment and boilers, necessary construction works, mechanical works,

and electrical works on the construction and installation of a new boiler, the heating network, heating

substations; and connecting the buildings to the new distribution system.

Position Investment costs – Description (€)

1. Access road and landscaping plots for the new building and for the route of new pipeline.

60,000

2. Construction of the heating plants (‘A’+’B’) buildings with boiler room, equipment space and office, the total area 985m2

250,000

3. Construction of the fuel storage facility area 100+2640m2 55,000

4. Energy plant, mechanical and electrical equipment works (except boilers) 140,000

5. Biomass boilers and associated equipment 1500+2000+2500 kW 750,000

6. Chimneys 180,000

7. Construction of heating grid - distribution network 470,000

8. Heating substations for public administration buildings 76,200

9. Adaptation of spaces for heating substations in public buildings 35,000

10. Drum wood chipper 15,000

11. Documentation, construction management, commissioning of the plant and heating grid

80,000

12. Unforeseen costs 40,000

CAPEX (Capital Expenditure) 2,151,200

Table 32 - Investment costs16

The composition of operational costs (OPEX) is diverse and affected by many factors. In order to

calculate operational costs, there will be reviewed analysis of all annual expenses.

After reconstruction, energy rehabilitation and modernization of the buildings, it is expected

reduction of annual energy consumption for 0.1%.

16 Own calculations

63

Based on the forecast of the World Bank17, expected variations of fuel prices in a period of 10 years

are following:

- Liquid fuels: 57% - Wood chips 23%

Description Unit 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

Heat energy consumption

(MWh/a) 3,815 3,812 3,808 3,804 3,800 3,796 3,793 3,789 3,785 3,781

Wood chips consumption

(t) 1,578 1,576 1,575 1,573 1,572 1,570 1,569 1,567 1,565 1.564

Price of wood chips (€/t) 53 54 55 57 58 59 61 62 63 65

Unit price of energy from wood chips

(€/MWh) 21.92 22.41 22.92 23.44 23.97 24.51 25.06 25.63 26.21 26.80

Light fuel oil price (€/t) 1,020 1,078 1,140 1,205 1,273 1,346 1,422 1,504 1,589 1,680

Pellet (€/t) 180 184 188 192 197 201 206 210 215 220

Electricity price (€/MWh) 0.09 0.09 0.09 0.10 0.10 0.10 0.10 0.11 0.11 0.11

Unit price of energy from existing fuels

(€/MWh) 90.51 95.44 100.65 106.14 111.95 118.08 124.56 131.40 138.62 146.25

Maintenance of equipment and installation

% CAPEX / a 0.50 0.50 0.50 0.50 0.50 1.00 1.00 1.00 1.00 1.00

Cost (€/a) 7,181 7,181 7,181 7,181 7,181 14,362 14,362 14,362 14,362 14,362

Insurance % CAPEX / a 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

Cost (€/a) 9,841 9,608 9,381 9,162 8,948 8,742 8,542 8,349 8,163 7,984

Electricity - costs of the plant

kWhel / MWhth

2 2 2 2 2 2 2 2 2 2

Cost (€/a) 687 703 720 737 755 773 792 811 830 850

Labour costs (€/a) 20,000 20,300 20,605 20,914 21,227 21,546 21,869 22,197 22,530 22,868

Removal and disposal of ash

(t/a) 31.6 31.5 31.5 31.5 31.4 31.4 31.4 31.3 31.3 31.3

Cost of removal and disposal of ash

(€/a) 947 960 973 987 1,001 1,015 1,029 1,043 1,058 1,073

Chemical treatment of circulating water

Volume (m3) 180 180 180 180 180 180 180 180 180 180

Losses (m3 / a) 5 5 5 5 10 10 10 10 10 15

Unit price (€/m3) 3.00 3.03 3.06 3.09 3.12 3.15 3.18 3.22 3.25 3.28

Cost (€/a) 27 27 28 28 56 57 57 58 58 89

Depreciation of equipment and installations

% / a 3 3 3 3 3 3 3 3 3 3

Cost (€/a) 43,086 41,793 40,501 39,208 37,916 36,623 35,331 34,038 32,745 31,453

Depreciation of buildings

% / a 1 1 1 1 1 1 1 1 1 1

Cost (€/a) 4,900 4,851 4,802 4,753 4,704 4,655 4,606 4,557 4,508 4,459

17 World Bank Commodity Forecast Price Data, July 2015

64

Description Unit 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

Heat energy consumption

(MWh/a) 3,778 3,774 3,770 3,766 3,762 3,759 3,755 3,751 3,747 3,744

Wood chips consumption

(t) 1,562 1,561 1,559 1,558 1,556 1,554 1,553 1,551 1,550 1,548

Price of wood chips (€/t) 65 66 67 67 68 69 69 70 71 72

Unit price of energy from wood chips

(€/MWh) 27.07 27.34 27.61 27.89 28.17 28.45 28.74 29.02 29.31 29.61

Light fuel oil price (€/t) 1,697 1,714 1,731 1,748 1,766 1,783 1,801 1,819 1,837 1,856

Pellet (€/t) 222 225 227 229 231 234 236 238 241 243

Electricity price (€/MWh) 0.12 0.12 0.12 0.12 0.13 0.13 0.13 0.14 0.14 0.14

Unit price of energy from existing fuels

(€/MWh) 147.74 149.24 150.75 152.28 153.83 155.39 156.97 158.57 160.18 161.81

Maintenance of equipment and installation

% CAPEX / a 1.50 1.50 1.50 1.50 1.50 2.00 2.00 2.00 2.00 2.00

Cost (€/a) 21,543 21,543 21,543 21,543 21,543 28,724 28,724 28,724 28,724 28,724

Insurance % CAPEX / a 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

Cost (€/a) 7,811 7,645 7,485 7,332 7,186 7,047 6,914 6,789 6,669 6,557

Electricity - costs of the plant

kWhel / MWhth

2 2 2 2 2 2 2 2 2 2

Cost (€/a) 870 891 913 935 957 980 1,003 1,027 1,052 1,077

Labor costs (€/a) 23,211 23,559 23,912 24,271 24,635 25,005 25,380 25,760 26,147 26,539

Removal and disposal of ash

(t/a) 31.2 31.2 31.2 31.2 31.1 31.1 31.1 31.0 31.0 31.0

Cost of removal and disposal of ash

(€/a) 1,088 1,103 1,118 1,134 1,150 1,166 1,182 1,199 1,216 1,233

Chemical treatment of circulating water

Volume (m3) 180 180 180 180 180 180 180 180 180 180

Losses (m3 / a) 15 15 15 15 20 20 20 20 20 20

Unit price (€/m3) 3.31 3.35 3.38 3.41 3.45 3.48 3.52 3.55 3.59 3.62

Cost (€/a) 89 90 91 92 124 125 127 128 129 130

Depreciation of equipment and installations

% / a 3 3 3 3 3 3 3 3 3 3

Cost (€/a) 30,160 28,868 27,575 26,282 24,990 23,697 22,405 21,112 19,820 18,527

Depreciation of buildings

% / a 1 1 1 1 1 1 1 1 1 1

Cost (€/a) 4,410 4,361 4,312 4,263 4,214 4,165 4,116 4,067 4,018 3,969

Table 33 - Operational costs18

Estimation of operational costs (OPEX) predicts that after first 10 years, prices will stabilize and achieve small growth of 1% annually. In following 10 years, it is expected wood chips price increase up to 65€/t, and pellet price increase up to 220€/t. After this period, the price would continue growing per 1% annually. For the price of electricity, it is foreseen annual growth at a rate of 2.5%. Insurance costs are estimated for all of facilities, equipment, and installations built by the investment. Considering workforce, it is planned engagement of two highly technically educated employees and

one manager. Workers with lower qualifications would be replaced from existing assignments in the

facilities that are the subject of this study. Salaries costs would increase per annual rate of 1.5%.

Costs of cleaning exhaust systems and ash disposal are proportional to quantity of ash (2%) in

burned wood chips. Unit price of these costs would increase per annual rate of 1.5%.

18 Own calculations

65

8. PRELIMINARY FINANCIAL ANALYSIS

Sustainability of the plant will be analysed for a period of 20 years. Variations of operational costs

according to the structure for a period of 20 years are shown in tabular form. Analysis of operational

costs considers forecasts of price variations for each item.

Preliminary financial analysis consists of the table of costs of energy production, and following

figures, (enclosed in the Annex): comparative analysis of costs of heating energy and savings;

savings resulted by a fuel switch; operational costs and depreciation; comparison of total costs of

the existing and a new heating system; and cash flow.

2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Biomass - wood chips 83,631 85,436 87,280 89,163 91,087 93,052 95,060 97,111 99,206 101,347

Ash 947 960 973 987 1,001 1,015 1,029 1,043 1,058 1,073

Electricity 687 703 720 737 755 773 792 811 830 850

Water 27 27 28 28 56 57 57 58 58 89

Summary 85,292 87,127 89,001 90,915 92,899 94,897 96,938 99,023 101,153 103,359 Employee – Labor costs 20,000 20,300 20,605 20,914 21,227 21,546 21,869 22,197 22,530 22,868

Maintenance 9,906 9,906 9,906 9,906 9,906 18,177 18,177 18,177 18,177 18,177

Insurance costs 9,841 9,608 9,381 9,162 8,948 8,742 8,542 8,349 8,163 7,984

Summary 39,747 39,814 39,892 39,981 40,082 48,465 48,588 48,723 48,870 49,028

Depreciation 47,986 46,644 45,303 43,961 42,620 41,278 39,937 38,595 37,253 35,912

Total costs 173,025 173,585 174,195 174,857 175,600 184,640 185,463 186,341 187,276 188,299

2028 2029 2030 2031 2032 2033 2034 2035 2036 2037

Biomass - wood chips 102,258 103,178 104,105 105,041 105,985 106,938 107,899 108,870 109,848 110,836

Ash 1,088 1,103 1,118 1,134 1,150 1,166 1,182 1,199 1,216 1,233

Electricity 870 891 913 935 957 980 1,003 1,027 1,052 1,077

Water 89 90 91 92 124 125 127 128 129 130

Summary 104,306 105,262 106,227 107,202 108,216 109,209 110,212 111,224 112,245 113,276 Employee – Labor costs 23,211 23,559 23,912 24,271 24,635 25,005 25,380 25,760 26,147 26,539

Maintenance 26,993 26,993 26,993 26,993 26,993 36,899 36,899 36,899 36,899 36,899

Insurance costs 7,811 7,645 7,485 7,332 7,186 7,047 6,914 6,789 6,669 6,557

Summary 58,015 58,197 58,390 58,596 58,814 68,951 69,193 69,448 69,715 69,995

Depreciation 34,570 33,229 31,887 30,545 29,204 27,862 26,521 25,179 23,838 22,496

Total costs 196,891 196,687 196,505 196,344 196,235 206,022 205,926 205,851 205,798 205,767

Table 34 - Costs of energy production19

Financial analysis shows that future plant can generate positive cash flow after the period of 9 years

from the start of operations. Such long period needed to achieving the sustainability of the project

is caused by high initial investment costs and by low full load hours (808 kWh/kW) in public buildings.

19 Own calculations

66

Low biomass price, compared to currently used fuels, would enable better utilization of public

buildings - the Sports hall ‘Dr. Zoran Djindjić’ and Movie Theatre, to the general benefit of local

community.

Offered technical solution provides to the municipality the establishment of a sustainable heating

system, which would increase the quality of life, and create a positive impact to the environment.

If the investment was financed from KfW Bank's program, with grant of 20%, grace period of 5 years

and a repayment period of 10 years, the positive business results would be achieved after 7 years

from the start of operations.

67

9. PROJECT EVALUATION

Evaluation of the project is based on the collected and calculated data; costs of the construction of

the biomass plant with two wood chips heated boilers and district heating system; and operational

costs (OPEX). Analysis included variations of fuel prices and operational costs throughout whole

period of analysis.

Based on investment costs (Table 32) and operating costs for the period of 20 years (Table 33)

economic indicators are given in the Table 35 above. Economic indicators necessary for the

investment plan are following:

‒ (F) IRR - (Financial) Internal Rate of Return ‒ (E) IRR - (Economy) Internal Rate of Return ‒ (F) NPV - (Financial) Net Present Value ‒ (E) NPV - (Economy) Net Present Value ‒ DR - Discount Rate

Unit cost heat energy Unit Value

The investment value – Capex € 2,151,200

Annual production of heat energy (first year of operation) MWh / a 3,815

Total heat production (20 years) MWh 75,859

The operation value (20 years) – Opex € 3,840,636

LUC - Levelized Unit Costs € / MWh 79.3

NPV € 1,755.475

DR % 1

IRR % 6.470

Sensitivity to changes in the price of fuel (biomass) IRR%

Price biomass is less 5% 6.606%

Price biomass increased 5% 6.258%



Table 35 - Unit costs of heating energy20

Based on the results of the analysis of techno-economic indicators, it is concluded that the

investment in the construction of a new biomass plant with district heating system for public buildings

in Prokuplje is acceptable.

IRR = 6.470% > DR = 1 %

Financial indicators of sustainability are stable related to change of the price of biomass. Increase

of the price of biomass even up to 15% would not affect sustainability of the project, and such

increase would not significant prolong a period of the return of the investment. High increase of the

prices, than anticipated, of fossil fuels and of electricity would affect shortening a period of the return

of the investment to less than 9 years.

20 Own calculations

68

10. LEGAL FRAMEWORK

EU Directive 2009/28/EC promotes the use of energy from renewable energy sources. It sets

binding national goals for the overall share of energy from renewable sources in final energy

consumption (less than 20%), as well as the share of RES in transport (10% of energy from

renewable sources in transport by 2020).

In order to support investments in renewable energy sources, the Republic of Serbia adopted a

number of laws and bylaws related to the use of biomass and other renewable energy sources.

These are the following acts:

- Energy Law (Official Gazette of the Republic of Serbia 145/2014)

- Energy Sector Development Strategy of the Republic of Serbia for the period by 2025 with

projections by 2030 (Official Gazette of the Republic of Serbia 101/2015)

- Solid biofuels – Fuel specifications and classes SRPS EN ISO 17225-1,4:2015

- Law on Planning and Construction (Official Gazette of the Republic of Serbia 72/2009,

81/2009-corr, 64/2010 – Decision of the Constitutional Court, 24/2011, 121/2012, 42/2013 –

Decision of the Constitutional Court, 50/2013 – Decision of the Constitutional Court, 98/2013

– Decision of the Constitutional Court)

- Law of efficient energy consumption (Official Gazette of the Republic of Serbia 25/2013)

- Law on Environmental Protection (Official Gazette of the Republic of Serbia 135/2004,

36/2009, 36/2009 and other law, 72/2009 and other law, 43/2011 – Decision of the

Constitutional Court, and 14/2016)

- Law on The Strategic Assessment of Environmental Impact (Official Gazette of the Republic

of Serbia 135/2004 and 88/2010)

- Law on Integrated Prevention and Control of Environmental Pollution (Official Gazette of the

Republic of Serbia 135/2004, 25/2015)

- Law on Waste Management (Official Gazette of the Republic of Serbia 36/2009, 88/2010,

14/2016)

- Law on Air Protection (Official Gazette of the Republic of Serbia 36/2009, 10/2013)

- Law on the Ratification of the Kyoto Protocol to the UN Framework Convention on Climate

Change (Official Gazette of the Republic of Serbia – International Contracts, 88/2007 and

38/2009- other law)

‒ National Renewable Action Plan of the Republic of Serbia (Official Gazette of the Republic of Serbia 53/2013).

69

11. ENVIRONMENTAL IMPACT

Implementation of the project affects the area where the biomass is collected, prepared for

transportation, and transported at territory of Prokuplje and at territory of the immediate

surroundings. The environmental impact may be registered as noise, vibration, emissions of

particulate matter from the exhaust gases, etc.

During the construction of the plant, adverse impacts on local environment may occur due to

construction and installation works. Particularly negative impact would produce preparation works

for the construction of the boiler room and storage of wood chips where it would be necessary to

clear and level the ground. Construction works will cause noise and vibration generated by using

construction machinery, as well as increased dust emissions due to the works on the excavation of

foundations, leveling the ground, and the construction of access roads. All of the effects listed above

are of low intensity, and relatively short in duration. The construction site will be surrounded by the

fence, so adverse environmental impacts outside of the fence will be negligible.

Prior to the beginning of works, the Investor is required to prepare a study on the organization of the

site which will display the work areas, corridors for internal transport, temporary storage of

equipment and materials, temporary site landfill, manner and place of storage of flammable and

hazardous materials. The study will show the connection to the outside infrastructure and

installations, usage of protective agents, the method of disposal of solid and liquid waste and other

specific measures, which will be implemented to reduce risks to health and safety of the personnel

engaged; as well as environment protection actions.

During the operations of the energy block, the harmful substances contained in the exhaust gases

will exert the highest impact on the environment. In addition to dust from the fuel, the exhaust gas

also contains solid particles. Adding a cyclone device as a part of a boiler for combustion of biomass

would have effects on the following:

- Nitrogen oxides (NOx) in the case of combusting low moisture biomass: the temperature of

combustion is high in this case, and NOx content is significantly higher than in case of

combusting biomass with high percentage of moisture

- Sulfur oxides (SOx) are low because of the low sulfur content in the biomass

- Carbon dioxide (CO2) is considered neutral because the biomass is a renewable energy

source, so that the entire amount of the carbon emitted in the exhaust gas has been previously

taken from the environment in which the tree grew

- Carbon monoxide (CO) in practice does not occur due to the structure of the boilers and

constant monitoring of the combustion process.

In any case, the planned biomass plant should replace the existing local boilers which use fuel oil,

wood and electricity, and which are extremely unfavorable for the environment.

The heating plant itself does not require a significant amount of water. While in operation, the heating

plant does not have losses and uncontrolled water runoff except in the cases of emergencies

(failures). Such situations are extremely rare with this type of plants, so it is safe to say that there

70

is no risk of environmental pollution, as well as of pollution of surface and/ or groundwater.

The existing sewerage system is able to accept the wastewater that may be of atmospheric origin;

from washing facilities and equipment with a negligible content of oils and grease; waste and

sanitary sewage. In the cases of discharging the installations, a coolant tank is used with a grease

separator, and after the deposition, water is discharged into the sewer system.

The exhaust gases contain solid particles of ash, which are retained in the cyclone device prior to

entering the chimney and discharged into the atmosphere. A metal cartridge is placed into the

cyclone where the separated ash is deposited. In addition, the boiler unit has a cartridge for the

disposal of ash that occurs as a solid residue of the combustion process. The total amount of ash

deposited is 31 t/a, i.e. between 150 and 200 kg per day during the heating season. The ash will be

disposed in a safe place and once a week transported to the landfill under a contract with the local

utility company. The amount of ash is relatively small and does not represent a risk to the

environment.

The operations of the boilers and electric motor drives in the boiler room represent a source of

constant noise and vibration. All equipment that emits noise and vibration is located within the area

of the boiler room so that the sound is quite absorbed by the walls of the building. After

commissioning the boiler room, the measures will be implemented to eliminate or reduce the noise

to the acceptable level according to the Law on the protection of environmental noise21. According

to this Law, the maximum allowable noise level is 35 dB (A) during the day and 30 dB (A) during

night.

The user of this space will implement specific measures to minimize the negative impact on the

environment. These measures will be applied to the control of air emissions, as well as to the

management of wastewater, solid waste and noise.

Thermal energy for public institutions in the municipality of Prokuplje is obtained from different

types of fuel, so the production of CO2 is different for each heat source. Existing heating systems

in public buildings in Prokuplje produce up to 850 t of CO2 annually.

21 Official Gazette of the Republic of Serbia No 36/2009 and 88/2010

71

Figure 26 - Emission of CO2 per a fuel type

If the biomass for combustion were obtained by deforestation and without reforestation, an emission

of CO2 by biomass combustion would be 6 times less than from the combustion of existing fuels. If

the biomass for combustion were provided from wood waste or from forestation, then reduction of

CO2 emissions would be lower for 650 t per year.

0

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Ave

rage

Emission CO2 (kg), Comparasion to fuel

Emision CO2 (kg) - Existing fuel Emision CO2 (kg) - Biomass

72

12. ENERGY EFFICIENCY MEASURES AND CONCLUSION

Public buildings in the Prokuplje municipality are heated by electric heaters-boilers, biomass pellet

and light fuel oil, in individual boiler rooms located in the buildings. These heating systems require

high fuel expenses and a lot of engagement on purchase and storing the fuel; as well as on regular

maintenance and servicing.

Heating system that use pellet as a fuel (Primary school ‘Ratko Pavlović - Ćićko’) is a good example

of using biomass as a fuel. The pellet boiler system in the Primary school ‘Ratko Pavlović - Ćićko’

is new and was built during the year 2017. These boilers have a good automatic boiler control

system. Despite the automatic management of such systems it is necessary to regularly clean and

maintain, which is their fault if there are more such systems in a small area.

Heating systems that use light fuel oil have high level of automation in terms of maintaining water

temperature. In spite of high efficiency, they are big pollutants, and the fuel expenses are high for

such systems.

Facilities heated by electricity are energy very inefficient, even though the heating is easily

managed, and desired air temperatures are easily reached.

In respect to the above, the existing heating systems in public buildings in Prokuplje are energy

inefficient, and they require high expenses related to the following: the purchase of the fuel;

maintenance; servicing. Furthermore, these systems are big environmental pollutants.

Construction of two central boiler rooms, with biomass heated boilers of 6 MW and of heating

network will enable sustainable, cheaper, more reliable, manageable, and ecologically acceptable

heating system to public buildings in Prokuplje. Heating systems in the buildings would be connected

to the district heating network in the heating substations, which would enable measuring of delivered

heating energy and management of consumption in accordance with the requirements of specific

facility.

Construction of biomass heating plant and of district heating network will enable following:

‒ lower costs of the heating,

‒ reduction of fuel consumption,

‒ reduction of CO2 emission,

‒ reduction of environmental pollution,

‒ increased comfort, and increased quality of services,

‒ decrease of a fuel expense and of maintenance costs.

There are forests at territory of the Municipality of Prokuplje and the Toplica District sufficient to

provide biomass for district heating plant. In addition, biomass can be purchased as residues from

orchards and private forests. In such way, local community could close the circle of production and

consumption of heating energy.

73

13. ANNEX

74

Figure 27 - Comparative analysis of costs of heating energy and savings

2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

Existing fuels x 103 345,3 363,7 383,2 403,7 425,4 448,3 472,4 497,8 524,7 553,0 558,0 563,1 568,3 573,5 578,7 584,0 589,4 594,8 600,2 605,7

Wood chips x 103 83,63 85,43 87,28 89,16 91,08 93,05 95,06 97,11 99,20 101,3 102,2 103,1 104,1 105,0 105,9 106,9 107,8 108,8 109,8 110,8

Saving x 103 261,6 278,3 295,9 314,6 334,3 355,2 377,3 400,7 425,4 451,6 455,8 460,0 464,2 468,4 472,7 477,1 481,5 485,9 490,4 494,9

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

Comparative analysis of cost heat energy and saving - (€)

75

Figure 28 - Savings from fuel switch

0

50,000

100,000

150,000

200,000

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300,000

350,000

400,000

450,000

500,000

2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

Saving x 103 261, 278, 295, 314, 334, 355, 377, 400, 425, 451, 455, 460, 464, 468, 472, 477, 481, 485, 490, 494,

Saving from fuel switch - (€)

76

Figure 29 - Operational costs and depreciation

0

50,000

100,000

150,000

200,000

250,000

2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

Operational costs and Depreciation - (€)

Biomass - wood chips Extra energy Employee – Labor costs Maintenance & Insurance costs Depreciation

77

Figure 30 - Comparison of total costs of the existing system, new heating system and new system supported by KfW Credit

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

Total costs of Existing sistems - CAPEX+OPEX - KfW Credit (€)

Existing heating sistems CAPEX+OPEX KfW Credit

78

Figure 31 - Cash flow balance

2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038

TotalCashFlow x103 -2,19 -1,99 -1,77 -1,53 -1,27 -994, -692, -365, -13,0 366,7 747,7 1,133 1,525 1,922 2,324 2,727 3,136 3,550 3,969 4,394

-3,000,000

-2,000,000

-1,000,000

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

Cash flow balance - (€)

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ELABORATION OF TECHNICAL PROJECT CONCEPT OF THE FUEL ... · elaboration of technical project concept of the fuel switch to biomass in prokuplje including economical evaluation and