8.1 Cost Estimation for Rough Planning Stage a trial ...8.1 Cost Estimation for Rough Planning Stage When you are going to make a trial calculation of construction cost in Rough Planning

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Manual for Micro-hydro power Development Chapter 8

Study on Rural Energy Supply with Utilization of Renewable Energy in Rural Areas in the Republic of Indonesia

CHAPTER 8 COST ESTIMATION 8.1 Cost Estimation for Rough Planning Stage When you are going to make a trial calculation of construction cost in Rough Planning Stage, it can be calculated by the method shown in Table8.1.2. However, before calculating, it is necessary to carry out an easy field survey, and decide the item mentioned to Table8.1.1.

Table8.1.1 Items to make a trial calculation of construction cost Description Item

Plan Maximum Out Put (kW) Turbine Discharge (m3/s) Effective Head (m) Intake Facilities Height of Dam (m) Length of Dam (m) Headrace Length of Headrace (m) Penstock Diameter of Penstock (m) Distribution Number of Households (kk) Distance to the furthest house from P.S

In addition, since indirect costs, such as tax, contractor fee, design cost, and supervisor fee, are contained in the cost of construction calculated by Fig 8.1.2, when a part of these indirect costs can be omitted, examination is required separately.

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(Rp)No. Description Formulation Remarks(1) PREPARATORY WORKS {(2)+(3)+(4)+(5)}×0.1 Transportation, Clearing,

Temporally Works(2) CIVIL WORKS ①～⑦

① Intake Facilities Gabion Dam 210,000×(H×L)

H : Height of Dam(m)L : Length of Dam(m)

Stone Masonry Dam 785,000×(H×L)+850,000


Concrete Dam1,650,000×(H×L)


② Settling Basin Long or Mid-Penstock type 60,300,000×Q0.504

Q : Turbine Discharge(m3/s)(Back to System Layout : Page4-2)

Short Penstock type 54,200,000×Q0.794

Q : Turbine Discharge(m3/s)(Back to System Layout : Page4-1)

③ Headrace 435,000×Q0.18×L Q : Turbine Discharge(m3/s)L : Length of Headrace(m)

④ Head Tank 47,600,000×Q0.5 Q : Turbine Discharge(m3/s)⑤ Penstock Civil Works

775,000×φ0.571×Lφ : Daiameter of Penstock (m)L : Length of Penstock (m)

Pestock 15,000×(Unit waight)×L

L : Length of Penstock (m)

⑥ Power House Base 4,890,000×P0.456 P : Maximum Output(kW)(Include Tail race)

⑦ Power House Building 2,460,000×P+20,350,000 P : Maximum Output(kW)(3) 75,710,000×(P/√He)0.56 Closs flow Turbine T-13

P : Maximum Output(kW)He : Effective Head(m)

(4) DISTRIBUTION WORKS 14,300×X0.5541 X : Number of Household×Distance2

(5) CONSUMER CONNECTION 428,000X+31,900,000 X : Number of Household

(6) OTHERS {(2)+(3)+(4)+(5)}×0.05

TOTAL (1)+(2)+(3)+(4)+(5)+(6)

ELECTROMECHANICALWORKS

Table8.1.2 Method to make a trial calculation of construction cost in Rough Planning Stage

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Fig8.1.1 Cost of Intake facilities

Cost(R

p) = 78

5,000＊

(H×L) +

850,0

00

y = 210,000＊(H×L)

Cost(

Rp)

= 1

,650

,000＊

(H×

L)

0

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

60,000,000

70,000,000

80,000,000

90,000,000

100,000,000

0 10 20 30 40 50 60 70 80

H×L

Cos

t (R

p)

Concrete Dam

Stone Masonry

Gabion Dam

Notes: For a trial calculation of construction cost in Rough Planning Stage

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Fig8.1.2 Cost of Settling Basin

Long or Mid-length Penstock type

Cost(Rp) =60,300,000＊Q0.504

Short Penstock type

Cost(Rp) = 54,200,000＊Q0.794

0

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

60,000,000

70,000,000

80,000,000

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Q (m3/s)

Cos

t (R

p)


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Fig8.1.3 Unit Cost of Headrace

Unit Cost(Rp/m) = 435,000＊Q0.18

200,000

250,000

300,000

350,000

400,000

450,000

500,000

0 0.2 0.4 0.6 0.8 1 1.2

Q (m3/s)

Uni

t Cos

t (R

p/m

)


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Fig8.1.4 Cost of Head tank

Cost(Rp) = 47,600,000＊Q0.5

0

10,000,000

20,000,000

30,000,000

40,000,000

50,000,000

60,000,000

70,000,000

0 0.2 0.4 0.6 0.8 1 1.2

Q (m3/s)

Cos

t (R

p)


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Fig8.1.5 Cost of Penstock (Civil Works)

Cost(Rp) = 775,000φ0.571

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

0.2 0.4 0.6 0.8 1 1.2 1.4

Daiameter of Penstock φ(m)

Cos

t (R

p)


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Fig8.1.6 Unit volume waight of Penstock

t=3mmy = 0.07417 φ + 0.00133

t=4mmy = 0.0989φ - 0.0021

t=5mmy = 0.1236φ + 0.0012

0

10

20

30

40

50

60

70

80

90

100

100 200 300 400 500 600 700 800

Daiameter of Penstock φ(mm)

Uni

t vilu

me

wai

gth

(kg/

m)

t=3mm

t=4mm

t=5mm


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Fig8.1.7 Cost of Power house Base

(Inc. Tail race)

Cost(Rp) = 4,890,000＊P0.456

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

0 10 20 30 40 50 60 70 80

P (kW)

Cos

t (Rp

)


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Fig8.1.8 Cost of Power house builiding

Cost(Rp) = 2,460,000P + 20,350,000

0

50,000,000

100,000,000

150,000,000

200,000,000

250,000,000

0 10 20 30 40 50 60 70

P (kW)

Cost

(Rp)


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Fig8.1.9 Cost of Electromechanical Works

Cost(Rp) = 75,710,000 (P/√He)0.56

0

50,000,000

100,000,000

150,000,000

200,000,000

250,000,000

300,000,000

350,000,000

400,000,000

0 2 4 6 8 10 12 14

P/√He

Cos

t (Rp

)


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Fig8.1.10 Cost of Distribution Works

Cost(Rp) = 14300x0.5541

0

100,000,000

200,000,000

300,000,000

400,000,000

500,000,000

600,000,000

700,000,000

800,000,000

0 50,000,000 100,000,000 150,000,000 200,000,000 250,000,000

x = (Number of Household) * (Distance) ^ 2

Cos

t (R

p)


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Fig8.1.11 Cost of Consumer Connection

Cost (Rp) = 428000 x + 31900000

0

50,000,000

100,000,000

150,000,000

200,000,000

250,000,000

300,000,000

350,000,000

0 100 200 300 400 500 600 700

Number of Household

Cos

t (R

p)


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8.2 Cost Estimation for Detail Design Stage

Construction cost consists of items as shown in Table8.2.1.

Table8.2.1 Construction Cost No. Item Cost Direct cost of construction

1 PREPARATORY WORKS Addition item 2 CIVIL WORKS Addition item 3 ELECTRO-MECHANICAL WORKS Addition item 4 DISTRIBUTION WORKS Addition item 5 CONSUMER CONNECTION Addition item

SUB TOTAL(A)

Indirect cost 1 DESIGN FEE 5～10% of SUB TOTAL(A) 2 SUPERVISOR FEE 5～10% of SUB TOTAL(A) 3 MANAGEMENT FEE 5～10% of SUB TOTAL(A) 4 TAX 12.5% of SUB TOTAL(A)

SUB TOTAL(B)

TOTAL

8.2.1 Items

Typical items of a direct cost are shown below. (1) Preparatory works

Preparatory works consist of item as follows. - Location setting out - Felling and measurement - Equipment & materials mobilization

(2) Civil works

Civil works consist of item as follows. - Intake facilities - Settling basin - Headrace - Head tank

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- Spillway - Penstock and foundation - Powerhouse base - Tailrace - Power house building - Finishing

(3) Electro-mechanical works

Electro-mechanical works consist of item as follows. - Turbine - Controller - Dummy load - Generator - Accessories, spare parts and tools - Set up and installation - Transportation and packing - Testing - Pre commissioning trial run

(4) Distribution works

Distribution works consist of item as follows. - Transmission pole - Cable - Transformer - Accessories

(5) Consumer connection

- Cable - Switch - Accessories

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8.2.2 Quantity In order to calculate direct cost of construction, it is necessary to calculate the quantity for every work or material based on design. For example, in case of headrace of masonry, quantity will be calculated for excavation, foundation rubble stone, stone masonry, backfill, and plaster like Fig 8.2.1.

Fig 8.2.1 The example of works which should be calculated（Headrace）

With a natural thing, these items change according to a kind and the quality of structure. For example, in Intake, the item that should calculate will be changed according to type of dam like Table 8.2.2. And in Headrace, the item which should calculate will be changed according to the quality of the material of Headrace like Table 8.2.3.

Table 8.2.2 Quantity of dam Gabion dam Masonry dam Concrete dam

- Excavation (m3) - Backfill (m3) - Gabion (m3)

- Excavation (m3) - Backfill (m3) - Foundation Rubble

Stone (m3) - Stone masonry (m3) - Plaster (m2) - Stoplog (m2) - Gabion (m3)

- Excavation (m3) - Backfill (m3) - Sand filling (m3) - Concrete (m3) - Plaster (m2) - Stoplog (m2) - Gabion (m3)

��

��

��

��

Excavation

Foundation rubble stone

Stone masonry Backfill Plaster

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Table8.2.3 Quantity of headrace Simple earth channel Masonry channel Concrete channel

- Excavation (m3) - Excavation (m3) - Backfill (m3) - Foundation Rubble

Stone (m3) - Stone masonry (m3) - Plaster (m2)

- Excavation (m3) - Backfill (m3) - Sand filling (m3) - Concrete (m3) - Plaster (m2)

This is the same for other structures too, and care is taken not to omit ay items that should be added up based on drawings.（Ref 8.1 Breakdown of Construction Cost of Pilot Project）

8.2.3 Unit Cost Table 8.2.4 shows standard unit cost of civil work of PU. “Unit Price” of Table 8.2.4 is price of Tana-Toraja. Since unit cost changes according to various situations of each area, it is desirable to perform unit cost setup enough in consideration of the local characteristics.

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Table8.2.4 Unit cost of PU (Toraja)

Koef. Unit Unit Price Unit Cost Remark(Rp) (Rp)

Excavation(m3) 22,500 unskill labour 0.625 man 15,000 9,375 foreman 0.062 man 17,500 1,085 tools 1.000 ls 12,000 12,000

Total 22,460Backfill (m3) 15,200 unskill labour 0.192 man 15,000 2,880 foreman 0.019 man 17,500 333 tools 1.000 ls 12,000 12,000

Total 15,213Sand Filling (m3) 50,400 sand 1.200 m3 40,000 48,000 unskill labour 0.150 man 15,000 2,250 foreman 0.010 man 17,500 175

Total 50,425Fondation Rubble Stone (m3) 108,000 stone 1.200 m3 50,000 60,000 sand 0.400 m3 40,000 16,000 unskill labour 1.125 man 15,000 16,875 skill labour 0.563 man 25,000 14,075 foreman 0.056 man 17,500 980

Total 107,930 Stone Masonry 1:2 (m3) 234,000 stone 1.200 m3 50,000 60,000 PC 3.520 zak 26,500 93,280 sand 0.380 m3 40,000 15,200 unskill labour 2.250 man 15,000 33,750 skill labour 1.125 man 25,000 28,125 chief labor 0.113 man 30,000 3,390 foreman 0.017 man 17,500 298



Total 208,613

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Koef. Unit Unit Price Unit Cost Remark(Rp) (Rp)

Surface Finish (m2) 19,100 PC 0.237 zak 26,500 6,281 sand 0.019 m3 40,000 760 meduam skill labour 0.286 man 20,000 5,720 skill labour 0.214 man 25,000 5,350 chief labor 0.021 man 30,000 630 foreman 0.020 man 17,500 350

Total 19,091Gabion (m3) 96,600 stone 1.200 m3 50,000 60,000 wire cage 3.500 kg 7,000 24,500 unskill labour 0.450 man 15,000 6,750 skill labour 0.200 man 25,000 5,000 foreman 0.020 man 17,500 350

Total 96,600Stoplogs (unit) 281,000 wood 0.048 m3 4,150,000 199,200 carpenter 1.000 man 25,000 25,000 labour 2.000 man 15,000 30,000 foreman 0.100 man 17,500 1,750 tools 1.000 ls 25,000 25,000

Total 280,950 Working floor (m2) 261,000 PC 3.956 zak 26,500 104,834 sand for concrete 0.550 m3 50,000 27,500 split/gravel 0.930 m3 75,000 69,750 tools 1.000 ls 15,000 15,000 labour 2.000 man 15,000 30,000 skill labour 0.500 man 25,000 12,500 chief labor 0.050 man 30,000 1,500 foreman 0.010 man 17,500 175

Total 261,259 Rainforce Concrete K225(m3) 2,211,000 PC 7.896 zak 26,500 209,244 split/gravel 0.810 m3 75,000 60,750 sand for concrete 0.490 m3 50,000 24,500 labour 3.000 man 15,000 45,000 skill labour 0.500 man 25,000 12,500 chief labor 0.050 man 30,000 1,500 foreman 0.110 man 17,500 1,925 con.+form tools 1.000 ls 75,000 75,000 steel bar concrete 175.0 kg 7,000 1,225,000 wire 2.000 kg 9,000 18,000 labour for steel concrete 6.750 man 25,000 168,750 chief for steel concrete 2.250 man 30,000 67,500 unskill labour 8.750 man 15,000 131,250 con.+form nail 4.000 kg 7,500 30,000 carpenter 5.000 man 25,000 125,000 chief of carpenter 0.500 man 30,000 15,000

Total 2,210,919

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[Ref. 8-1 Cross-sectional method to calculate quantity]

It is convenient to use the cross-sectional method when calculating complicated quantities such a headrace. When you want to calculate the quantity of excavation of headrace as shown in the following figure, first, you draw a sectional view for every changing point of cross-sectional form, and the excavation area for every section is calculated using planimeter, etc.

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Next, you can make the next table from the relation between the area of each section, and distance.

This cross-sectional method is applicable not only to excavation area but also to calculation quantities of backfill or masonry.

Section name Excavation Area Average Area Distance Volume① ② ③ ②×③

Total 12.73m3

2.690m3

4.125m3

3.735m3

2.180m3

E - E

2.00m

3.00m

3.00m

2.00m

A - A

B - B

C - C

D - D

1.37m21.375m2

1.245m2

1.12m2

1.090m2

1.06m2

1.345m21.31 m2

1.38m2

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[Ref. 8-2 The example of bill of quantity] No Unit Quantity Unit Price Amount Total Price

Rp Rp RpI

II1 Intake Facilities include setling basina. Excavation m3

b. Backfill m3

c. Foundation rubble stone m3

d. Stone Masonry 1 : 2 m3

e. Plaster m2

f. Gabions m3

g. Stoplogs (80w x 100h) cm2 unith. Flushing Gate (60w x 210h) cm2 uniti. Screen m2

sub total2 Headrace

a. Excavation m3

b. Backfill m3



e. Plaster m2

f. Stoplogs (80w x 100h) cm2 unitsub total

3 Head Tanka. Excavation m3

b. Backfill m3



e. Plaster m2

f. Gate (60w x 200h) cm2 unitg. Screen m2

sub total4 Spillway Channel

a. Excavation m3

b. Backfill m3



e. Plaster m2

sub total5 Penstock and Foundation

a. Excavation m3

b. Reinforced Concrete m3

c. Working floor m3

d. Sand filling m3

e. Plaster m2

f. Penstock set work m1

g. Welded steel m1

h. Butterfly valve unitI. Reducer pipe unitj. Clamp penstock pcsk. Bend degree angle pcsl. Anchor bolt pcs

sub total

Description

CIVIL WORKS

PREPARATORY WORKS

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No Unit Quantity Unit Price Amount Total PriceRp Rp Rp

6 Power House Base + Tail Racea. Excavation m3

b. Backfill m3

c. Sand filling m3

d. Working floor m3

e. Reinforce Concrete m3

f. Foundation rubble stone m3

g. Stone Masonry 1 : 4 m3

h. Surface finish m2

sub total7 Power House

a. Building m2

sub total8 Finishing

a. Penstock painting m1

b. Building Painting lsc. Service Walkway m1

sub total

III1 Crossflow Turbine

a. Turbine T13 bo. 600 mm unitb. Turbine base frame unitc. Pulley of turbine unite. Flexible Coupling unit

f. Plummer Block Bearing Set unitg. Flat belt unith. Fence Guard unitI. adapter pipe unitj. Dynamic Balancing lsk. Heat treatment lsl. Pressure gauge unit

sub total

2 Electronic Load Controller unitsub total

3 Ballast Loada. Air Heater (54 kVA) unitb. Housing Ballast unit

sub total4 Generator

a. Syncronous Generator Stamford unitb. Generator base frame unitc. Pulley of generator unit

sub total

5 Accessories, Spare parts & Tools unitsub total

6 Set up & Installation lssub total

7 Transportation & Packaging lssub total

8 Testing (welding) lssub total

9 Pre commissioning Trial Run lssub total

Description

MECHANICAL & ELECTRICAL

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No Unit Quantity Unit Price Amount Total PriceRp Rp Rp

IVa. Transmission pole pcsb. Twisted Cable 4 * 70 mm2 m1

c. Twisted Cable 4 * 35 mm2 m1

d. Twisted Cable 2 * 16 mm2 m1

e. Accessories lsf. Installation expense ls

Va. NYM Cable 2 * 1.5 mm2 m1

b. NYM Cable 3 * 1.5 mm2 m1

c. Electric Socket pcsd. Series Switch pcse. Single Switch pcsf. Connector pcsg. Service Wedge Clamp pcsh. Cable Clam packi. Plafond Fitting pcsj. Hanger Fitting pcsk. Rosset Wood pcsl. Cellophane Tape pcsm. Screw packn. T - dus pcso. MCB and housing unitp. Twisted Cable 2 * 10 mm2 m1

q. Grounding unitr. Installation Expense units MCCB Group unit

TOTAL Rp

CONSUMER CONNECTION

Description

DISTRIBUTION WORKS

Documents

8.1 Cost Estimation for Rough Planning Stage a trial ...8.1 Cost Estimation for Rough Planning Stage When you are going to make a trial calculation of construction cost in Rough Planning