Potential and economics of Solar Irrigation Pumps in Pakistan

1. Solar PV Tube Well
Potential and Economics
March 2013
Akhtar Ali
Proplan Associates
akhtarali1949@gmail.com
1

2. Table 1 : Tube well irrigated land and
potential for Solar PV
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Total number of Farms+8.26 Million
Total Farm Area =52.91 Million Acre
Total Cultivated Area=42.6 Million Acre
o/w irrigated by canal and tube wells both=13.89 Million Acre
and irrigated by tube wells only=6.08 Million Acres
Estimated coverage of Tube wells=12 Million Acre
@0.5 kW per acre, Solar PV potential=6000 MW
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• Author’s Estimate, data source; Agricultural Census of Pakistan
2010
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2

3. Table 2 :Existing Tube Well Statistics and Solar PV Potential
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Total number of Tube Wells = 1 million plus
o/w Diesel based =834905(11000 MW)
and Electric =250,000(3000 MW)
Average HP per Tube Well=17 H.P.(12.68 kW)
Typical Capacities:10,15,20,22,25 HP
Diesel, number of days of operation=125 days per year
Electric, number of days of operations=184 days per year
Solar PV ,optimal number of days of operation=300 days per year
Estimated number of obsolete pumps(installed before1994)=400,000
Estimated Solar PV demand for 300 days of operations=8000 MW
Assumed Target 50% conversion in 10 years=4000 MW
Yearly conversion =400 MW(40,000 solar pumps)
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Author’s Estimate, data source; Agricultural Census of Pakistan 2010;Agricultural
Machinery Census 2004
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3

4. Micro-economics of Solar PV in Tube well visa-vis Diesel Engine
Case study of a 15 kW Solar Tube well replacing diesel engine
Item
units
Amount/Value
Solar PV capacity
kW
15
Capacity factor
hours
1600
Annual Electricity produced
kWh
24000
Replacement cost of Diesel
Rs/kWh
25
Annual Diesel replacement
Rs/yr
600000
CAPEX Solar PV and Pump
Rs
1800000
Investment Payback Period
years
3
Equity @30%
Rs
540000
Loan
Rs
1260000
Repayment period
years
10
interest rate
%p.a
14
Annual Debt servicng
Rs
$241,559
Annual saving for first 10 yrs
Rs
$298,441
Equity payback Period
yrs
$1.81
Present Value of 25 yrs saving
Rs
$5,446,224
Net Present Value @10%
Rs
$3,646,224
IRR
%
33.31
Electricity cost in1-10 years
Rs/kWh
$10.06
4

5. 5

6. 6

7. 7

8. 8

9. Pump Head or Power Calculations;
• : GPM x TDH / 3960 = WHP
• GPM = Gallon per minute at the best efficiency point
• TDH = Total discharge head (measured in feet), as shown on the
pump curve ; at the best efficiency point)
• WHP = Water horse power or the amount of horse power the
pump is generating.
• Doing the same thing in the metric system we would get:
• M3/ HR = Cubic meters per hour of capacity as measured at the
best efficiency point on the pump curve.
• TDH = Total discharge head, in meters, at the best efficiency point.
• WKW = Water kilowatts of power being generated by the pump
• Divide Water Watts by Pump Efficiency
9

10. PV Panel Selection
• The power of solar panel=power of pump X
1.3
• the voltage of solar panel=the voltage of
pump
• the controller should be matched
10

11. Pump kW calculations and PV
Panels
Pump#1
Daily Consumption
Pump#2
Pump#3 Pump#4
CM/d
1000
500
750
250
Number of hours per day hrs/d
8
8
8
8
Hourly Flow
CM/hr
125
62.5
93.75
31.25
Dynmic Head
Meters
10
20
20
15
Efficiency
%
60
60
60
60
Motor Power Reqd
KW
5.79
5.79
8.68
2.17
PV Panel Power
kW
7.52
7.52
11.28
2.82
Number of Panels@200
Watt
pcs
38
38
56
14
11

12. Table :Tubewells by HorsePower Capacity and power source(2004)
Pakistan
Capacity(H.P.)
Diesel
Electric
< 10
5760
20340
>10<15
122575
27793
>15<20
586097
20363
>20<22
13165
391
>22<24
14107
289
>25
93207
16701
Total
834911
85877
RoG %p.a.upto2004
7%
2.96%
Wt.Avg.HP
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14
Provincial Distribution
Punjab
697156
109097
Sindh
64128
31793
KpK
4223
12335
Balochistan
11872
23716
Total
777379
176941
Total
26100
150368
606460
13556
14396
109908
920788
6.12%
17
806253
95921
16558
35588
954320
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13. USE AND RENTING OUT TIME OF PRIVATE ELECTRIC & DIESEL TUBEWELLS/LIFT PUMPS
DURING LAST 12 MONTHS
Average use of
time
Total
Administrative No. of
Days
Hours
Unit
tubewells/
per
per
lift pumps
year
day
Punjab:
Electric
Diesel
Sindh:
Electric
Diesel
KPK:
Electric
Diesel
Balochistan:
Electric
Diesel
Pakistan:
Electric
Diesel
Renting out
time
Number Average
of
Average
tubewells/ Hours
Hourly
lift pumps rented
rate
per year
(Rs.)
61931
771642
183
124
6
5
22174
143308
619
315
110
114
3449
42691
151
123
7
6
513
6502
468
311
112
111
9829
11020
152
108
4
5
2350
2583
431
380
106
122
10659
9552
227
189
7
5
681
611
532
259
120
121
85868
834905
184
125
6
5
25718
153004
597
316
110
114
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14. PRIVATE TUBEWELLS & LIFT PUMPS BY
PURPOSE OF INSTALLATION
Source : Pakistan Agricultural Machinery Census - 2004.
Number of Tubewells/Lift pumps by Purpose of
Installation
Replacement
of
Supplementing
Irrigation of
Barani/Sailaba
Unit/ Type of tubewells/
Canal water
land wells/karezes
r
Tube-Wells lift pumps Number
% of Number
% of Numbe % of
Total
Total
Total
Total
Administrativ number of
e
Punjab:
Tubewells
Lift Pumps
Sindh:
Tubewells
Lift pumps
KPK:
Tubewells
Lift Pumps
Balochistan:
Tubewells
Lift Pumps
Pakistan:
Tubewells
Lift Pumps
829437
5415
.
38330
7809
587146
731
70.78
13.50
194765
3811
23.48
70.37
57681 6.95
914 16.87
34125
6877
89.02
88.06
4055
713
10.57
9.13
283 0.73
260 3.32
18705
2186
3289
379
17.58
17.33
14630
1551
78.21
70.95
925 4.94
263 12.03
19172
1134
637
170
3.32
14.99
9912
767
51.70
67.63
9296 48.48
203 17.90
905644
16544
625197
8157
69.03
49.30
223362
6842
24.66
41.35
68185 7.52
1640 9.91
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15. DIESEL TUBEWELLS BY TYPE OF
PUMP
TABLE NO 57.
TOT
AL
ADMINISTRATIVE CENT
RIUNIT
FUGAL
GOVERN
MENT
TUR- WELL
CENT
CENT
RITUR- WELL RITUR- WELL
BINE WITH FUGAL BINE WITH FUGAL BINE WITH
PUMP
1
PAKISTAN
N.W.F.PROVINCE
2
3
4
784006 21572 12199
PUMP
5
6
7
277
120
2920
2850
6
14
PUNJAB PROVINCE 744303 15501
5196
111
25
SINDH PROVINCE
BALOCHISTAN
PROVINCE
2957
PRIVATE
32763
915
1556
139
-
3983
2236
2597
21
81
PUMP
8
9
10
75783729 21452 12124
2
2951
2906
2848
13744192 15476
5183
- 32624
60
3962
915
1556
2155
2537
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16. PRESENT DEPTH OF
WATER TABLE
1
PAKISTAN
UPTO 10 FEET
11 TO 20 FEET
21 TO 30 FEET
31 TO 40 FEET
41 TO 50 FEET
51 TO 75 FEET
76 TO 100 FEET
10
1 TO 150 FEET
15
1 TO 200 FEET
201 FEET AND ABOVE
TOTAL *
TUBEWELLS
2
22466
125382
224027
188707
116750
94999
59965
31053
11053
12378
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17. APPENDIX
INDIAN SOLAR PV TUBE WELL SPECS
MNRE INDIA
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18. Description Model I
Solar
PV 1200 Wp
array
Model II
1800 Wp
Motor pump
Submersible
set type
electronic
with
controller
Max.
Model III
3000 Wp
with Submersible
Model IV
4800 Wp
Submersible
with Submersible
electronic
controller
controller
controller
50 metres
total 50 Metres
electronic electronic
80 Metres
with
80 Metres
dynamic
head
Module
MS hot dipped
MS hot dipped
MS hot dipped
MS hot dipped
mounting
galvanised, three
galvanised,
galvanised, three
galvanised, three
structure
times manual
three times
times manual
times manual
tracking facilities
manual tracking
tracking facilities
tracking facilities
200 sq. Metres
facilities
Required
45 Sq. Metres
75 sq. Metres
120 sq. Metres
Water
34,000 Litres per
51,000 litres per
51,000
Output *
day from a
shadow free
area
head
metres
of
total day from a total
30 head
metres
of
day
litres
from a
per 82,000
total day
30 head of 50 metres
litres
from a
per
total
head of 50 metres
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19. Description
Model-I
Model-II
Model-III
Solar PV array
900 Wp
1800 Wp
2700 Wp
Motor pump set
type
Motor capacity
Centrifugal DC
monoblock
1 HP
Centrifugal DC
monoblock
2 HP
Centrifugal DC
monoblock
3 HP
Operating
voltage
Suction Head
60 V DC (nominal)
60 V DC (nominal)
90 V DC (nominal)
7 metres
7 metres
7 metres
Max. total
dynamic head
10 metres
15 metres
25 metres
Module
MS hot dipped
MS hot dipped
MS hot dipped
mounting
galvanised, three times
galvanised, three
galvanised, three
structure
manual tracking
times manual
times manual
facilities
tracking facilities
tracking facilities
30 sq. Metres
75 sq. Metres
120 sq. Metres
Required
shadow free
area
Water Output *
77,000
litres
per
day
154,000
litres
per
115,000
litres
per
from a total head
day from a total head
day from a total head
19
of 10 metres
of 10 metres
of 20 metres

20. Mounting Structure
• The modules support structure shall be mild steel, hot
dipped galvanized (120 micron) iron for holding the PV
modules. The size of angle iron should not be less than
50x50x5 mm.
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• Each panel frame structure shall be so fabricated as to be
grouted on ground or roof on its legs. It will withstand
severe cyclone/ storm with the speed of 150 Km/Hr.
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• Each panel frame structure shall have provision to adjust its
angle of inclination to the horizontal between 10 to 40
degrees with a step of 10 degree, so that the inclination can
be adjusted at the specified tilt angle whenever required.
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21. Motor Pump type
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I.
II.
III.
IV.
Surface mounted DC motor pump-set
Submersible DC motor pump set
Submersible AC motor pump set
Floating DC motor pump set
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22. PV Panel Specs
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Modules supplied with the SPV water pumping systems should have certificate as per IEC 61215
specifications or equivalent National or International/ Standards.
Modules must qualify to IEC 61730 Part I and II for safety qualification testing.
The efficiency of the PV modules should be minimum 13% and fill factor should be more than 70%.
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The terminal box on the module should have a provision for “Opening” for replacing the cable, if required.
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– Each PV module must use a RF identification tag (RFID), which must contain the
following information:
• Name of the manufacturer of PV Module
• Model or Type Number
• Serial Number
• Month and year of the manufacture
• I-V curve for the module
• Peak Wattage of the module at 16.4 volts
• Im, Vm and FF for the module
• Unique Serial No and Model No of the module
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23. APPENDIX
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24. Pakistan Solar Insolation Map
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