Accepted Manuscript

Title: In Search for Sustainable Globally Cost-EffectiveEnergy Efficient Building Solar System–Heat RecoveryAssisted Building Integrated PV Powered Heat Pump forAir-Conditioning, Water Heating And Water Saving

Author: Marija S. Todorovic Jeong Tai Kim

PII: S0378-7788(14)00689-6DOI: http://dx.doi.org/doi:10.1016/j.enbuild.2014.08.046Reference: ENB 5292

To appear in: ENB

Received date: 26-8-2014Accepted date: 27-8-2014

Please cite this article as: M.S. Todorovic, J.T. Kim, In Search for SustainableGlobally Cost-Effective Energy Efficient Building Solar SystemndashHeatRecovery Assisted Building Integrated PV Powered Heat Pump for Air-Conditioning, Water Heating And Water Saving, Energy and Buildings (2014),http://dx.doi.org/10.1016/j.enbuild.2014.08.046

This is a PDF file of an unedited manuscript that has been accepted for publication.As a service to our customers we are providing this early version of the manuscript.The manuscript will undergo copyediting, typesetting, and review of the resulting proofbefore it is published in its final form. Please note that during the production processerrors may be discovered which could affect the content, and all legal disclaimers thatapply to the journal pertain.

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In Search for Sustainable Globally Cost-Effective Energy Efficient Building Solar

System – Heat Recovery Assisted Building Integrated PV Powered Heat Pump for Air-

Conditioning, Water Heating And Water Saving

Marija S. Todorovic1 and Jeong Tai Kim2,*

1University of Belgrade, 2Department of Architectural Engineering, Kyung Hee University, Yongin

446-701, Korea, *Corresponding Author: J. T. Kim (jtkim@khu.ac.kr)

Abstract

Obtained as a research result of conducted project, this paper presents an innovative, energy efficient

multipurpose system for a sustainable globally cost-effective building’s solar energy use and

developed methodology for its dynamic analysis and optimization. The initial research and

development goal was to create a cost-effective technical solution for replacing fossil fuel and

electricity with solar energy for water heating for different purposes (for pools, sanitary water,

washing) in one SPA. After successful realization of the initial goal, the study was proceeded and as

a result, the created advanced system has been enriched with AC performance. The study success

was based on understanding and combined measurements and by BPS made predictions of AC loads

and solar radiation dynamics as well as on the determination of the synergetic relations between all

relevant quantities. Further, by the performed BPS dynamic simulations for geographically spread

buildings locations, it has been shown that the final result of the conducted scientific engineering

R&D work has been the created system of confirmed prestigious to the sustainability relevant

performance –globally cost-effective building integrated photovoltaic powered heat pump (HP),

assisted by waste water heat recovery, for solar AC, water heating and saving.

Keywords: energy efficiency, geographic cost-effectiveness analysis, multipurpose BIPV system,

BPS, solar air-conditioning, complex system dynamics, heat pump and waste water heat recovery

1. Introduction

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Industrialization associated with increasing consumption of resources, spurred on by the demands for

higher living standards from an exponentially growing population, are polluting the Earth ground, its

oceans and other surface waters, as well as its atmosphere denuding forests, depleting the ozone

layer of the stratosphere and creating more and more evident weather extremes and raising global

warming. Natural resources of energy and matter constitute the Earth's natural capital - essential for

human civilization and are classified mainly as: solar capital (99% of the energy used on the Earth)

and Earth capital (life support resources and processes including human). It is well known that

consuming natural resources of energy and raw materials and producing wastes is the way the industrial,

but also natural systems operate.

As the size of industrial systems increases, resources and sites availability for wastes disposal

become limited. The extracted materials in extreme cases amount even more than 10 tons per person

annually, in the most developed countries and approximately 94 percent of the extracted material is

converted to waste, with the rest of only 6 percent finalized into durable products ([1] - [3]). There

are too many examples, around the world, of dissipative uses of resources, products degraded,

dispersed to the environment, and lost from the standpoint of any kind of reuse or recyclability - food,

fuel, fertilizers, etc.

In addition, life support resources of oxygen and water (freshwater in the world's lakes and rivers

makes up a tiny fraction about 1 part in 10,000 of all the water on the Earth) a vulnerable global

heritage on the Earth in the past, today became under siege and progressive degradation. Serious

water shortage predicted 15 years ago ([1], [3]) was underestimated. The UN has identified more

than 70 trouble spots linked with water, from the Middle East to the Sahel, from the arid zones of

Latin America to the Indian subcontinent. River basins straddle national borders in 300 places around

the world. Some "water conflicts" are active and latent for decades, hundreds and thousands of years.

Water is at the heart of Arab-Israeli conflict - 2/3 of Israel's water comes from beyond the country's

1967 borders. Libya is pumping from non-renewable underground water supplies in the Sahara,

causing concerns in Egypt, Chad, Niger and Sudan [2].

There is deep synergy of the exponentially growing Earth population, energy resources increasing

demand and exhaustion as well as more and more often occurring weather extremes and related

catastrophic events. Consequently, on the global scale there are also exponentially growing needs for

more harmonious and sustainable social and economical development. To sustain weather extremes

and catastrophic events, people need better constructed, more resilient and healthy houses, better air-

conditioned with reliable controlled indoor environment quality.

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Hence, there is a great need in the whole world for sustainable buildings with energy efficiently

integrated and cost-effectively use of solar energy - the most uniformly distributed renewable energy

source around the world. Trying to contribute for answering to such need, this paper is devoted to

search for globally cost-effective energy efficient building integrated solar - waste water heat

recovery assisted building integrated PV powered heat pump for air-conditioning, water heating and

water saving.

2. Relevant System Model Background and Methodology

Utilization of energy sources, such as the sun, geothermal, water and wind, reduces reliance on

vanishing form of energy sources. Renewable energy technologies can contribute to the development

of sustainable buildings construction improving living, health and education conditions, especially in

remote countrysides.

The initial specific objective in the study ([5], [10]) was to find a technical solution for replacing

fossil fuel and electricity with solar energy for the heating of water for different purposes (for pools,

sanitary water, washing), and in addition to explore possibilities to improve indoor comfort by

introducing air-conditioning. Crucial aspects for the success of the study [5] was the understanding of

solar water heating system and air-conditioning dynamic behavior dependent on the TMY - Typical

Meteorological Year’s data [8], and synergetic relations between energy efficiency, solar radiation

availability and intensity, as well as sanitary water and air-conditioning demand dynamics

determined for a specific model Case Study. As a model Case study, SPA Rusanda in Serbia has been

selected. For its accommodation capacity of 400 patients, the consumption of sanitary hot water is

about 70 000 liters per day.

Water and water heating energy demand. Different water heating systems were studied by the

dynamic simulations applying TRNSYS program [7] as well as the own originally developed

software. Performance of the economic analysis has been determined implementing domestic and

European procedures as well as the powerful BLCC software [6]. For the Spa Rusanda, Site Location

Data are Latitude {45.85 0 N+ S-}, Longitude {20.80 0 W- E+}, Time Zone Relative to GMT 1.00

{GMT+/-}, Elevation 132m. For the SPA Rusanda climatic zone the thermo-technical systems -

HVAC systems relevant outdoor design conditions are:

For heating and HVAC system operation mode in winter:

Design air dry bulb temperature tsp = - 18C;

For cooling and HVAC system operation mode in summer:

Design air dry bulb temperature tsp = 33C, and relative Humidity = 33%.

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Thermal energy daily necessary for sanitary water heating is determined for the two ”nominal” water

consumption values: for 70 m3 daily from 14°C to 40°C eq. (1), and for 80 m3 daily from 14 °C to

40°C eq. (2).

Qtv V c Ttv Thv m c Ttv Thv 70000 4.186 4014 7618520kJ (1)

Qtv V c Ttv Thv m c Ttv Thv 80000 4.186 4014 8790600kJ (2)

The ”nominal” water consumption values have been determined using consumption data history and

measurements (presented on graphs in Figures 2. and 3.).

LTP - Long Term Performance Prediction of the solar water heating systems – SWHS, or more

generally of the solar energy utilization systems is of crucial importance for investors and that is the

most important and delicate task within the frame of designing an installation for active solar energy

utilization [4].

Figure 1. Mean daily profile (left) and daily profile with minimum daily consumption (right)

For the qualitative and quantitative analysis of the systems, particularly its cost-effectiveness, it is of crucial

importance to determine loads (sanitary water and air-conditioning demand and daily dynamics), as well as

systems energy efficiency related to both the fluid flow and heat flow/transfer in all system components and

parts. Leakages both of heat and water are to be identified and eliminated (see Fig. 2).

Figure 2. Conduit pipes detailed ultrasound flow-rate measurement (left) data (right) at different sections

The diameters of pipe lines are to be sized in the manner in which the reference to the corresponding heat

transfer fluid flow rates, pressure drops, the pump power and the electricity consumption will be kept at the

lowest possible level. When appropriate piping diameters are defined the electricity consumption of solar

water heating plants, including the energy demand of measuring and control instruments, is minimal, and

varies between 2.0 and 3.5 % of the total power input.

3. Wastewater Heat Recovery Assisted Heat Pump

The new original concept of solar energy utilization for water heating is here defined which is based

on the introduction of a very effective measure to increase energy efficiency, exactly nearly

maximum possible increase of energy efficiency of the final energy utilization by implementation of

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the waste water heat recovery system which can recover 80–90% of waste heat. After recovering

waste heat, the solar PV powered heat pump’s compression work through the release of condensation

heat in the heat pump condenser, heats earlier preheated fresh water in the heat recovery unit. Thus,

wastewater heat recovery is very effective means to reduce thermal energy consumption and increase

energy efficiency of sanitary water heating installation.

On the market, there are wastewater heat recovery systems in reliable and efficient operation. Based

on our previous experience for the wastewater heat recovery, for the case study as appropriate model,

the unit Menerga AquaCond wastewater heat recovery system [15] was selected. It incorporates

patented automatic heat exchanger cleaning in order to ensure continuity of operation and low

maintenance costs. Wide series of material specifications are foreseen to prevent different forms of

acid and alkali attack. Its scheme is given on Figure 3.

Figure 3. Wastewater heat recovery unit scheme: operation (left) and heat exchanger cleaning regime (right)

Its functioning description [15] is as follows: inside the unit, wastewater passes through the inner

tubes of the heat recovery unit and into the heat pump evaporator, while the same volume of fresh

water flows through the outer pipe of the heat recovery unit and enters into the heat pump condenser.

Within the heat recovery unit, a large proportion (80-90 %) of the heat held in the wastewater is

transferred directly to the fresh water. Inside the evaporator, further heat is recovered from the

wastewater, cooling it down to approx. 8 OC, which is below the temperature of the incoming fresh

water, and is an excellent inlet temperature for Air-Conditioning, the HVAC unit chiller.

After recovering waste heat, the solar PV powered heat pump’s compression work through the

release of condensation heat in heat pump condenser, heats earlier preheated fresh water in the heat

recovery unit. Thus, wastewater heat recovery is very effective means to reduce thermal energy

consumption and increase energy efficiency of sanitary water heating installation.

Automatic flow regulation provides a constant flow rate of wastewater even under varying external

conditions e.g. reducing heat of water in wastewater tank. The wastewater heat recovery unit can also

be supplied with automatic heat exchanger cleaning (e.g. for shower water recovery Fig. 3 - right). In

order to prevent a build-up of bacteria growth and pollution by fats and soap, porous pellets are

forced through the wastewater pipework at regular intervals. The cleaning pellets detach sediment

and material building up on the heat exchanger walls. The cleaning pellets last for a long time and

can be easily replaced.

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4. PV Powered Heat Recovery Assisted Heat Pump (PV/HR&HP) System

Photovoltaic system. There are a plenty of different types of PV modules and the module type

selection depends on a number of factors, including: price from suppliers, product availability,

warranties, efficiencies, etc. The module efficiency depends primarily on the type of the cell used

(mono-Si, poly-Si, a-Si, CdTe, CIS). However, within each of these categories there are wide

variations in the module efficiency from manufacturer to manufacturer, depending on the

manufacturing processes used. PV modules performance data are to be determined by the dynamic

simulations and have to be used in sizing PV modules area.

Table 1. Photovoltaic module characteristics

For the selected PV modules characteristics (Table 1.), dynamic simulations of the solar PV system

operation have been performed and the monthly and annual sums of received and converted solar

radiation to electrical energy have been determined (see Fig. 4).

Figure 4. Monthly sums of PV produced electricity (kWh)

PV powered heat recovery assisted heat pump performance. Based on the simulations and

performance prediction results, the preliminary design has been made for the PV powered heat

recovery assisted heat pump system. Its Model encompasses PV (200 m2) and Heat Recovery

assisted Heat Pump - MPV200/HR&HP. With the reference to all calculations and determined daily

quantity of sanitary water used and waste water released, the Menerga unit 44 36.2 has been selected

with the following characteristics: water flow rate 3,6 m3/h (72 m3/h in 20 hours), compressor power

2x3,4 kW, operating power 8,96 kW, and maximum power of 20 kW. The price of the unit with the

automatic cleaner is 64.344 EUR. For the PV cost-effectiveness analysis relevant data are as follows:

PV module price 4.5 EUR/W (for power per module 110 W), and with inverter, cable etc., the

complete PV system investment is increased by 20 %). All costs values in the economic analysis

were in /10/ obtained using the final energy - grid electricity energy price - 0,057 EUR/kWh;

thermal energy –natural gas 0,03954 EUR/kWh. Determined value of the Simple Pay Back Period

(SPBP) of system has been 8.7 (relevant data are given in the Table 2).

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Table 2. SPBP calculation data

Air-conditioning with the MPV200/HR&HP cold wastewater. Table 3. presents maximum

and minimum sums of the SPA Rusanda Model’s cooling energy demand in kWh/m2in kW/m2 for

air-conditioning of indoor environment for the cooling season from June to September.

If the whole quantity (72.000 l) of cold waste water (8º C) after the heat rejection in the heat pump’s

evaporator, would be used as the ”chiller” outlet cold water, the cooling capacity of 33,5kW in 10

hours could be operational with a daily cooling effect of 335 kWh. Dividing 335 kWh and 0,61

(0.3412 to 0.8855) kWh/m2 (daily specific cooling demand estimated is the useful indoor area of 550

to 950 m2 , which could be air-conditioned with the cold wastewater. Further, calculations, according

to /10/ show that the corresponding electricity demand for air conditioning is 160 kWh daily, and

from June to September approx. 19,500 kWh (thus the amount of grid electricity substitution

utilizing the MPV200/HR&HP cold wastewater for AC would be increased by 58.5%, and its SPBP

value would be 5.4).

Table 3. Daily sums of cooling energy demand for HVAC/m2

In the preceded analysis, the used data on energy prices were given for the year 2010 (grid

electricity energy price - 0,057EUR/kWh/10/. For the current electricity price in Serbia of 0.096

EUR/kWh, SPBP would be 5.17 without AC and 3.21 with AC. When the BLCC economic

analysis is made taking into account all relevant economic parameters, the same system has the

lowest lifecycle costs, and its Payback Period is also the best - PP is 1, which means that the

investments return already in one year.

5. Global Dependence of the PV/HR&HP-AC System Cost-effectiveness

The next step in this investigation was to explore the dependence of the cost-effectiveness of the

PV/HR&HP-AC system geographically. With that aim, the Model case study building SPA Rusanda

has been virtually moved to several locations in the world (Belgrade, Moscow, Manama, Singapore

and Chicago), and detailed building’s and PV/HR&HP-AC’s system dynamic simulations have been

conducted. Obtained simulations results and calculated relevant quantities have been have been

compared. The comparison results are presented in the Table 4. It is clearly visible that the cost-

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effectiveness of the PV/HR&HP-AC’s system is remarkable high all around the world. Although

geographical conditions and solar radiation intensity and availability and related, AC loads and

electricity prices are very different, and SPBP in all locations is far better that in many other systems

and projects.

Figure 5. Yearly sums of global solar radiation on the horizontal surface and electricity prices (left) and

Monthly Sums of AC Energy Demand – right

Table 4. Global dependence of the PV/HR&HP-AC system performance data

6. Cost-effectiveness and Water Saving Importance of PV/HR&HP-AC System

To elucidate further advanced innovative PV/HR&HP-AC system’s characteristic performance in

different geographical conditions, the case study of a residential building in Belgrade has been

selected (Fig. 6) and it has been virtually moved to Amman in Jordan. It is occupied by 80 families

with the average number of three persons per family. The building’s useful or floor area is 3276 and

the total area is 3756 sq. meters. The building’s energy efficiency has been analyzed with an aim to

be “deeply” energy refurbished (which means RES integrated refurbished). Crucial for the

refurbishment project success is the understanding of solar water heating systems and AC dynamic

behavior dependence on the TMY - Typical Meteorological Year’s data, and synergetic relations

between energy efficiency, solar radiation intensity and sanitary water consumption dynamics. The

averaged, monitored summer consumption of sanitary hot water in the building is 37968 liters per

day.

Main characteristics of Jordanian environment related to the fresh water supply are: very limited

natural fresh water resources, deforestation, soil erosion and desertification. Consequently, the

gravest environmental challenge that Jordan is facing is the scarcity of water. The deficit is covered

by the unsustainable practice of overdrawing highland aquifers, resulting in lowered water tables and

declining water quality.

Figure 6. Two direction views at the case study building in Belgrade virtually moved to Amman

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Jordan is a developing non-oil producing country, where its energy requirements are obtained by

importing oil from neighboring countries ([1] - [14]) creating a financial burden on the national

economy. Jordan imports oil for all of its needs and therefore it has been vulnerable to energy supply

fluctuations. Concerning the fact that electricity demand in buildings, including households is in

intensive growth particularly in developing economies, conversion of solar energy to electrical

energy is of extremely high interest. For buildings integration, especially existing buildings (solar

integrated refurbishment), PV technologies are considered a reliable alternative to fossil fuels, as

they can be implemented in a wide range of settings.

The solar energy potential in Jordan is characterized by the average daily solar irradiation of about

5.5 kWh/m2, while the sun shines approximately 2900 hours per annum. Despite this, apart from for

heating water for some households, solar energy is scarcely being used ([1] - [14]). The South of

Jordan receives a substantial amount of annual solar radiation per unit area, with an average annual

total radiation exceeding 2,5 MWh per year per square meter, which is much more than the average

annual radiation of about 1,4 MWh/m2 on horizontal surfaces in Serbia. Building Virtual Site

Amman Airport Location Data are

Latitude: {31.59 0 N}

Longitude {35.59 0 E}

Time Zone Relative to GMT 2.00 {JRD}

Elevation 766 m

For the Amman climatic zone thermo-technical systems - HVAC systems relevant outdoor design

conditions are: for heating and HVAC system operation mode in winter:

Design air dry bulb temperature is tdb = 1C, and for cooling and HVAC system operation

mode in summer relevant data are: design air dry bulb temperature is tdb = 35.3C, and

humidity ratio is HR= 16.3 g of moisture/kg of dry air.

Water Heating Load and Waste Water Heat Recovery in Amman. Assuming that the fresh water

temperature is 14 °C, and that the design sanitary warm water temperature is to be 40°C, the

necessary heat for heating 37,968 m3 daily from 14 °C. to 40 °C is as follows [16]:

kW861147kJ41322851440186437968TTcmTTcVQ cwhwpcwhwphw .. (3)

With the reference to conducted calculations and determined daily quantity of sanitary water used

and waste water released, and available capacities of the heat recovery assisted heat pump units –

commercially available, the Unit 4436.2 has been selected with the following characteristics: water

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flow rate 3.6 m3/h (for � 38 m3/h in 10.56 hours), compressor power 2x3,4 kW, operating power 8,96

kW, and maximal power of 20 kW. The price of unit with the automatic cleaner is 64.344 EUR. For

daily 10.56 hours operation of the heat pump 94.62 kWh (the result of 8.96x10.56) is necessary,

and annually 365 times more, which amounts 34535.42 kWh [16].

Air-Conditioning Loads and PV Performance in Amman TMY. By the dynamic building

performance simulations (BPS), for virtual residential building in Amman Typical Meteorological

Year (TMY) all year round hourly values and annual dynamics of the building’s air-conditioning

loads have been predicted [16]. The five days sample is shown in Fig. 7 and in the Table 1 are given

daily maximum values of cooling loads read from the diagram given in Fig. 7. Similar dynamics and

analysis have been conducted for global solar radiation, and determined are the values of

instantaneous incident solar radiation and related portions converted to electricity (all year round -

for 8760 hours), and relevant average values have been further determined, as well as daily, monthly

and annual sums per sq. meter and for total installed PV areas.

Figure 7. Specific cooling loads in five day periods in Amman’s case building

Matching Air-conditioning and water heating loads and energy demand with PV electricity.

Dynamics of variations of incident global solar radiation and of the selected PV’s produced

electricity, in Amman’s TMY, is predicted also by the dynamic simulations. In the Table 5 are

presented relevant PV features of selected modules necessary to predict PV arrays operation and

produced electricity. For grid connecting, PV system operational and cost-effectiveness optimization

criteria are different. As in Jordan they use the feed-in tariff system for PV electricity production,

there is clear interest to analyze PV panel-arrays integration at, the as more as possible bigger area of

the available building facades appropriately oriented towards the sun.

Table 5. Selected PV modules characteristics

When the PV array is mounted on a wall, the required area should not exceed the surface available

on the wall. For building facade’s integration – building integrated PV (BIPV) arrays inclination

angle will be the same as the certain building wall inclination angle is. This seldom corresponds to

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an optimum in terms of energy production, but can reduce significantly installation costs by

eliminating the need for costly cladding and a support structure, or may be more desirable from an

aesthetics standpoint. For virtual building located in Amman have been assumed and analyzed two

characteristic sizing cases of PV arrays integration [16]:

a) Application of PV panels on the horizontal roof surface inclined by 32 degree North

b) latitude (an optimal angle for Amman’s geographic location), and sized to provide enough

power and PV electricity to run heat pump all year round.

Operational power of the selected heat recovery assisted heat pump is 8.96 kW, and for its

daily 10.56 hours operation 94.62 kWh is necessary (result of 8,96x10,56), and annually 365 times

more is necessary, which is 34535,42 kWh.

c) Specified maximum power of heat pump is 20 kW, and if autonomous regime of system is to

be foreseen, then PV arrays area is to provide the 20 kW power, when necessary.

d) Implementation of PV panels on all available surfaces, with an aim to estimate technical

potential of distributed PV electricity generation, substituting as more as possible fossil fuelled

produced grid electricity, and in addition supplying the grid with own surplus electricity: application

of PV panels on the horizontal roof, as in the case a) but using the whole available surface, and

integration in vertical façades East and West oriented, also using whole available surface areas.

Using maximally available buildings surface areas for PV installation, PV modules performance data

(Table 4) and locally relevant solar radiation data (Amman’s TMY), obtained are the values of

maximally possible installed PV power (Table 5).

Based on complete air-conditioning loads and energy demand, as well as on solar radiation and PV

electricity production data presented, defined are three Amman Case Study Models A, B, and C, and

cost-effectiveness has been analyzed for these three models - of the “PV powered solar air-

conditioning, water heating and water saving via heat recovery assisted heat pump system in

Jordan”. Dynamic simulations, for 8760 hours of Amman’s Typical Meteorological Year (TMY)

determined the values of instantaneous incident solar radiation and related portions converted to

electricity and further have been determined relevant average values, as well as daily, monthly and

annual sums of relevant quantities per sq. meter and for total installed PV areas.

In Table 5. are presented values of available areas for PV integration on differently oriented building

facades surfaces, corresponding areas of maximally possible installed PV arrays, and related installed

powers. Total installed PV arrays area is 2929,38 sq. meters, and total installed PV power amounts to

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432 kW, which corresponds to an average efficiency of 14.7%. The series of results of virtual

Amman buildings dynamic simulations are presented in Tables 5, and 6.

Table 6. Available areas, max-installed PV areas and PV power

Table 7. Monthly and daily mean AC energy demand [MWh/month] and [MWh/day]

Calculations, using maximally available buildings surface areas for PV installation, PV modules

performance data (Table 4) and locally relevant solar radiation data (Amman’s TMY), gave the

values of maximally possible installed PV power (Table 5). Based on complete air-conditioning loads

and energy demand, as well as on solar radiation and PV electricity production data (Table 7), cost-

effectiveness have been defined and analyzed for three models of the “PV powered solar air-

conditioning, water heating and water saving via heat recovery assisted heat pump system in

Jordan” for three cases - A, B and C.

Case - A. For the defined sizing case a) to operate heat pump system, daily energy demand is

94.62 kWh, monthly (case 30 days - 2838,6 kWh, and 31 days - 2933,2 kWh). Depending on the

monthly available PV electricity two extreme monthly values will determine necessary PV arrays –

December (Monthly minimal sum), and August (Monthly maximal sum). Hence necessary PV

arrays area for August is 98.6 and for December 185.9 sq. meters.

Approving acceptance of larger area will ensure PV solar sanitary water heating even in December

and air –conditioning using cold wastewater. In addition will be available certain surplus electricity

for more grid electricity substitution in households (for lighting and some of appliances, or

eventually partial space heating in less cold periods than December) or surplus can be sent to the grid.

Case – B. Use of maximally possible roof area of 308,3 sq. meters to install PV arrays, optimally

inclined, will result in installed power of 45,6 kW, and potential PV surplus for sending to the grid in

certain periods will increase.

Case – C. In this case, implementation of maximum possible PV arrays areas is on the roof surface,

and East and West oriented facades. Multiplying resulting values of produced PV electricity

(kWh/m2) with the related surface areas (m2), and summing is predicted potential annual PV

produced electrical energy amount of 535139,802 kWh in Amman’s TMY. It is the final sum of three

bolded values in Table 5 multiplied with related areas, as follows:

(294.433x308,3+106.286x1310,54+232.785x1310,54).

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Cold waste water use as the chiller water for air-conditioning. In all three cases, there is, at the

outlet of heat pump evaporator, the daily quantity of 37968 dm3 water at 8 oC. If the whole quantity

(37968 dm3) of cold waste water (8 oC) is used as ”chiller” outlet cold water, following cooling

capacities could be operational, depending on the cold waste water temperature increase (T) during

the process of heat rejection of AC air (AC air cooling) in the corresponding heat exchanger, as

follows: T=13-8=5 oC (daily cooling capacity Qdc=190 kWh; T=14-8=6 oC (daily cooling capacity

Qdc=228 kWh); T=15-8=7oC (daily cooling capacity Qdc=319 kWh); T=16-8=8 oC (daily cooling

capacity Qdc=365 kWh; T=18-8=10 oC (daily cooling capacity Qdc=456 kWh); andT=20-8=12oC

(daily cooling capacity Qdc=547 kWh).

Comparison of these results with the data given in Table 6. (monthly and daily mean AC energy

demand [MWh/month] and [MWh/day] for different indoor air temperatures – 26 oC, 28 oC and 30oC, shows that cold waste water temperature and waste water daily quantity by different temperature

increase T, enables building air-conditioning by controlling its temperature and cooling indoor

space to the significant degree.

Taking into account daily dynamics of AC loads (clearly visible in Fig. 6), implementing cold

wastewater storage (Cold Thermal Energy Storage - CTES) further optimization of indoor spaces

temperature control is possible.

Table 8. Monthly sums of incident solar radiation on PV arrays and produced electricity (kWh/m2)

Dynamic simulations results presented in Table 7. show potential renewable PV electricity

production by the same building if all available areas for PV integration would be used. In the future,

a detailed analysis is to be done of all building loads, aimed to determine which amount of the

available electricity will be a pure surplus.

7. System Investment And Operation Costs

The investment and operation cost analysis is conducted with the reference to described

simulations/calculations and determined daily quantity of sanitary water used and cold waste water

released in virtual Amman case building (capacity of the heat recovery assisted heat pump unit Type

44 36.2 [13], with relevant characteristics and price); with 0.8 EUR/installed PV Watt and grid

electricity price of 0.08 EUR /kWh, as well as Feed-in tariff electricity price in Jordan of 0,11

EUR/kWh. The results are presented in Table 8.

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Table 9. Investment and operational costs data

8. Conclusions

1. Based on the obtained results of the conducted research project in Serbia, aimed to find an

optimal way to replace imported gas with solar energy for sanitary and pool water heating, a

study has been conducted with the specific objective to determine sustainable, energy

efficient and cost-effective solution for replacing fossil fuel and electricity for water heating

and air-conditioning, particularly in the cooling regime. The study success was based on

understanding and combined measurements and by BPS made predictions of AC loads and

solar radiation dynamics as well as on determination of the synergetic relations between all

relevant quantities. Further, by the performed BPS dynamic simulations for geographically

spread buildings locations, it has been shown that the final result of the conducted scientific

engineering R&D work has been the created system of confirmed prestigious features

relevant to the sustainability – globally cost effective building integrated photovoltaic

powered heat pump (HP), assisted by waste water heat recovery, for solar AC, water heating

and saving.

Finally, a description is given for the investigation approach and results of performed dynamic

simulations of the virtual case building’s air-conditioning loads, related energy demand, available

solar global radiation and potential PV electricity production for the hydro-meteorologically relevant

TMY for Amman in Jordan. Cost-effectiveness has been defined and analyzed for three models of

the “PV powered solar air-conditioning, water heating and water saving via heat recovery assisted

heat pump system in Jordan” for three cases A, B and C.

Simple Pay Back Period SPBP of the increased investment analysis confirmed extremely high cost-

effectiveness of this inventive system. Relevant SPBP values for the three best models with the

reference to the referential case are as follows A – 0.92 less than one year B – 2.41 years and C –

5.93 years. Case A is focusing on the original - inventive system, however systems B and C also

deserve attention, as these system show how, by spread investment in distributed BIPV energy

generation, very significant, large-scale PV electricity production within urban areas can be reached,

and at the same time, deficient water sources may be saved.

REFERENCES

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[1] M. Todorovic (1988). Long Term Performances (LTP) of solar water heating systems, CNRE SWHS Workshop, published in Proceedings, Naxos, Greece, 84-96.

[2] Technology for a Sustainable Future - A Framework for Action, U.S. Environmental Technology Strategy Staff, Los Alamos National Laboratory, New Mexico, 1995.

[3] Cook P. J., D. Sheath, World Mineral Resources and some Global Environmental Issues, Nature Resources, UNESCO, pp. 26-33, 1997.

[4] M. Todorovic, Sustainability research and education via interdisciplinariness and harmony, in: International Conference on Advances in Infrastructure for Electronic Business, Science, and Education, Proceedings, No. 161, Scuola Superiore G. Reiss Romoli, 2000.

[5] VEA-INVI. Ltd, Feasibility Study With Preliminary Design For Solar Energy Utilization For Heating In Special Hospital Of The Spa Rusanda, SEEA - EAR, Belgrade, 2006.

[6] BLCC - Building Life Cycle Cost Program, National Institute of Standards and Technology (NIST).

[7] TRNSYS - TRaNsient SYstems Simulation Program, University Wisconsin.

[8] International Weather for Energy Calculations, IWEC – ASHRAE Weather files, Version 2.0.

[9] KMA – Korean Meteorological Administration, http://web.kma.go.kr/eng/index.jsp.

[10] M.Todorovic, O.Ecim and I.Zlatanovic, Building Integrated PV Air-conditioning and Water Heating in Special Hospital of the SPA Rusanda, Passive and Low Energy Cooling Conference, Creta, 2007.

[11] Building a Jordanian-Israeli Virtual Library for Renewable Energy Renewable Energy in Jordan South Jordan as a Case Study, iGREENs, 2011.

[12] Ali Sawarieh, Geothermal Water in Jordan, Workshop for Decision Makers on Direct Heating Use of Geothermal Resources in Asia, UNU-GTP, TBLRREM and TBGMED, Tianjin, China, May, 2008.

[13] Jordan Energy Situation, https://energypedia.info/index.php/Jordan_Energy_Situation, 2011.

[14] Mohammed S. Al-Soud, Eyad S. Hrayshat, A 50 MW Concentrating Solar Power Plant for Jordan, Journal of Cleaner Production, www.elsevie r. com/locate/jclepro, 2008.

[15] Heat Recovery Assisted Heat Pump Performance Data, AquaCond Waste water heat recovery unit with recuperator and heat pump, Menerga air–conditioning technology, 2012.

[16] M. Todorovic and O.Ecim Djuric, Innovative Pv Powered Solar Air - Conditioning, Water Heating And Water Saving Via Heat Recovery Assisted Heat Pump For Jordan, Jordan 4th Jordanian IIR International Conference on Refrigeration and Air Conditioning, Amman, August, 2012.

NOMENCLATURE

Q daily heat for water heating (kJ/day)

V daily water consumption (l/day)

T temperature (oC)

c specific heat(kJ/kg oC)

ρ specific density (kg/dm3)

Subscripts

hw hot water

p pressure

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cw cold water

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Table 1. Photovoltaic module characteristics

MSW 110 Modul Parameters

Power (± 5%) [W] 110 ± 5.5

Output current [A] 6.47

Output voltage [V] 17

Nominal voltage [V] 12

Short circuit current [A] 7,46

Open circuit voltage [V] 21,6

Length [mm] 1.321

Width [mm] 676

Height [mm] 38

Type of cells (p/s - pseudo square) p/s 103.5 mm cell

Configuration 72 (6x12)

Mass [kg] 10.7

Table 2. SPBP calculation data

Investment costs: 531.844 EURInvestment increase: 231.844 EURAnnual consumption of thermal energy: 389 – 718.361= 3.781.028 kWhAnnual saving of thermal energy use: 718.361 kWhValue of thermal energy saving: 28.404 EURAnnual consumption of electrical energy: 720.072 – 33.316 = 686.756 kWhPV produced electrical energy: 33.316 kWh Total annual energy costs: 201.007 EURTotal annual costs of thermal energy: 149.502 EURTotal annual costs of electrical energy: 39.145 EURAnnual maintenance costs: 270 EURAnnual value of saving energy: 215.222 – 188.646= 26.576 EURSPBP – Simple Pay Back Period of increased InvestmentSPBP = 231.844/26.576 = 8,7 year

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Table 3. Daily sums of cooling energy demand for HVAC/m2

Min Max Ave.Month

[kWh/m2]

June 0.3050 0.9761 0.6406

July 0.3548 0.9859 0.6704

August 0.3412 0.8855 0.6134

September 0.1706 0.7552 0.4629

Table 4. Global dependence of the PV/HR&HP-AC system performance data

Relevant quantity Belgrade Manama Moscow Singapore Seoul Chicago

WMO Station 132720 411500 276120 486980 471120 725340

Latitude N 44° 49‘ N 26° 16 N 55° 45‘ N 1° 22 N 37° 34' N 41° 46'

Longitude E 20° 16 E 50° 39 E 37° 37‘ E 103° 58‘ E 127° 00' W 87° 45'

GMT +1.0 Hours +3.0 Hours +3.0 Hours +8 Hours+9.0

Hours -6.0 Hours

Elevation m 99 2 156 16 86 187

Standard Pressure at Elevation Pa

100141 101301 99465 101133 100487 99099

MDB Temperature °C34.0 °C

on Jun 15

41.9 °C

on Jul 21

30.6 °C

on July 13

33.8 °C

on Apr 23

32.7°

on Jul 23

37.2

on Jul 1

MDB Temperature °C-19.0 °C on

Dec 24-10.2 °Con Jan 12

-25.2 °Con Feb 15

21.0 °Con Sep 8

-11.8 °Con Dec 16

-23.3°Jan 27

Solar energy incident in horizontal plane

annually (kWh/m2)1347,3 972,8 1705,8 1819,3 1540 1500

PV Power (W/m2) 166,58 138,1 204,1 208,1 205.3 204,6

Produced PV electricity (kWh/yr )

33316 24054 42118 41145 41060 40920

Grid elctricity price EUR/kWh

0,096 0,162 0,042 0,4762 0,498 0,0945

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Grid electricity substituted

by PV/HR&HP-AC (kWh)

52816 35364 100828 102180 64875 61380

SPBP 8,7 7,64 12,42 4,59 4,85 8,9

Table 5. Selected PV modules characteristics

Conergy PowerPlus 240P

Power (± 5%) [W] 240 ± 5.5Output current [A] 8.15Output voltage [V] 29.7

Nominal voltage [V] 26.98

Short circuit current [A] 8.62Open circuit voltage [V] 36.48Length [mm] 1651Width [mm] 986Height [mm] 46Type of cells (p/s -pseudo square) p/s 103.5mm cellConfiguration 72 (6x12)Mass [kg] 19.6

Table 6. Available areas, max-installed PV areas and PV power

Surface orientation Surface area PV modules PV area Installed power[m2] number [m2] [kW]

South 311 190 308.3 45.6East 1313.8 805 1310.54 193.2West 1313.8 805 1310.54 193.2

Table 7. Monthly and daily mean AC energy demand [MWh/month] and [MWh/day]

Indoor air26oC

Indoor air 28oC in shaded cells

Indoor air 30oC in shaded cells

MonthMonthly Daily

meanMonthly Daily

meanMonthly Daily mean

IV 4.895 0,163 4.895 0,163 4.895 0,163

V 9.702 0,312 9.702 0,312 9.702 0,312

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VI 27.150 0,905 17.770 0,592 9.786 0,326

VII 33.840 1,092 23.380 0,754 14.140 0,456

VIII 36.780 1,186 26.010 0,839 16.350 0,527

IX 26.670 0,889 17.320 0,577 9.284 0,309

X 11.960 0,359 11.960 0,359 11.960 0,359

Annual 150.997 111.037 76.117

Table 8. Monthly sums of incident solar radiation on PV arrays and produced electricity (kWh/m2)

South oriented inclined (32o) on horizontal roof surface

Positioned at vertical (90o) façade wall oriented West

Positioned at vertical (90o) façade wall oriented East

MonthSolar radiation

Produced electricity

Solar radiation

Produced electricity

Solar radiation

Produced electricity

January 126.75 18.193 37.25 5.248 85.53 12.154February 144.84 20.842 48.95 6.912 112.79 16.092March 159.3 23.026 63.68 9.052 110.14 15.753April 181.53 26.415 76.4 10.925 139.69 20.143May 188.7 27.556 81.06 11.647 145.27 21.132June 201.72 29.661 92.03 13.326 171.22 25.032July 195.71 28.893 87.87 12.782 147.15 21.642August 201.02 29.74 81.34 11.843 164.3 24.026September 190.33 28.119 63.64 9.232 161.37 23.334October 163.52 23.996 44.15 6.353 152.4 21.249November 153.05 22.211 33.79 4.794 160.28 20.734December 109.91 15.78 29.59 4.172 80.38 11.496�um 2016.38 294.433 739.75 106.286 1630.5 232.785

Table 9. Investment and operational costs data

Investment costs A B C

IC1 Heat recovery assisted heat pump (HRHP) EUR 63344 63344 63344

Installed PV watts W 20000 45600 432000

IC2 PV arrays cost for PV price 0,8 EUR/W EUR 16000 36480 345600

IC1 + IC2 79344 99824 408944

Operational annual costs A B C

HRHP system annual electricity demand kWh 34535,42 34535,42 34535,42

OC1 HRHP grid electricity use at the 0,08EUR/kWh EUR 2762,83 2762,83 2762,83

PV produced electricity

PV inst. A&B (roof 185,9&308,3), C max. avail. kWh 54735,09 90773,69 535139,8

PV produced electricity sent to grid value EUR 6020.86 9985.11 58865,38

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Feed-in profit (FIP) 3258,03 9722,28 56102,55

Referential case investment costs

IC1 Heat recovery assisted heat pump (HRHP) EUR 63344

IC2 Air cooled AC unit, cooling capacity 130kW EUR 13000

IC1 + IC2 EUR 76344

Referential case annual operational costs

OC1 HRHP grid electricity use at the 0,08EUR/kWh EUR 2762,83

Mean Air-Conditioning cooling demand kWh 111037

Air cooled AC electricity demand (COP=3,09) kWh 35934,31

OC2 Air cooled AC operation using grid electricity EUR 2874,74

OC1 + OC2 EUR 5637,57

HRHP + PV Increased investment costs (HRHP+PV) EUR 3000 23480 332600

Simple Pay Back Period HRHP+PV/FIP Year 0,92 2,41 5,93

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0

2

4

6

8

10

12

14

16

18

1 3 5 7 9 11 13 15 17 19 21 23

m3

0

1

2

3

4

5

6

7

8

9

10

1 3 5 7 9 11 13 15 17 19 21 23

m3

Figure 1. Mean daily profile (left) and daily profile with minimal daily consumption (right)

Figure 2. Conduit pipes detailed ultrasound flowrate measurement (left) data (right) at different sections

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

0 1000 2000 3000 4000 5000 6000 7000

m3

Paviljon 9,7,2

Paviljon 9,7,2-2

Paviljon 8

Paviljon 8 -2

Paviljon 1

Bl. terapija

Bl. terapija-2

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M

heat

reco

very

hot water 18°C

compressor

fresh water 10°C

condenser

evaporator

waste water 31°C

cleaning elements

flowrate control

waste water 18°C

M

flowratecontrol

heat

reco

very

condenser

evaporator

Figure 3. Wastewater heat recovery unit scheme: operation (left) and heat exchanger cleaning regime (right)

0.0

2000.0

4000.0

6000.0

8000.0

10000.0

12000.0

14000.0

16000.0

18000.0

20000.0

Ele

ctric

al e

nerg

y [k

Wh

]

1 2 3 4 5 6 7 8 9 10 11 12

Month

Figure 4. Monthly sums of PV produced electricity (kWh)

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Figure 5. Yearly sums of global solar radiation on horizontal surface and electricity prices (left) and Monthly Sums of AC Energy Demand – right

Figure 6. Two direction views at the case study residential building in Belgrade virtually moved to other case cities

0

5

10

15

20

25

30

35

40

1 11 21 31 41 51 61 71 81 91 101 111

Hour [h]

Spec

ific

cool

ing lo

ad

[W/m

2]

MayJuneJulyAugustSeptember

Figure 7. Specific cooling loads and a five days periods in Amman’s case building

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Highlights

Innovative multipurpose system.

With the reference to the global energy and water resources sustainability concerns created is prestigious – globally cost effective building integrated photovoltaic powered heat pump assisted by waste water heat recovery, for solar AC, water heating and saving.

Relevant dynamic analysis and optimization methodology presented.