WATSAN COORDINATION MEETINGWATSAN COORDINATION MEETINGUNICEFUNICEF Kampala July 7,2005Kampala July 7,2005
SOLAR &SOLAR &DIESEL MOTOR DIESEL MOTOR PUMPSPUMPSAPPRAISALAPPRAISAL
Alessandro GaleotaAlessandro Galeota([email protected])([email protected])
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SOLAR PUMPING SYSTEMSOLAR PUMPING SYSTEM The solar system comprises: stationary
or tracking solar array; controller; electric motor and pump
The system pumps water with the use of power generated by the sunlight
Solar electric cells convert sunlight directly into DC power (photovoltaic process)
The controller converts the variable DC voltage into three phase voltage to run a brushless pump
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Aloi camp solar schemeAloi camp solar scheme
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DIESEL MOTOR DRIVEN PUMPDIESEL MOTOR DRIVEN PUMP
Diesel motorDiesel motor Discharge and Discharge and
drive head (1)drive head (1) Driveshaft (4)Driveshaft (4) Rotor/stator Rotor/stator
pumping pumping element (6)element (6)
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Pabbo camp diesel motorPabbo camp diesel motor
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STRENGTHSSTRENGTHS Solar systemSolar system
Ideal for remote & Ideal for remote & unattended locationsunattended locations::
• No fuel & little or no No fuel & little or no maintenancemaintenance
• No need of pump or No need of pump or motor attendantsmotor attendants
Solar pumping system are Solar pumping system are noise and pollution freenoise and pollution free
Reliability and ease of useReliability and ease of use
Diesel systemDiesel system
Little maintenance of the Little maintenance of the pumppump
Wide range of applicationsWide range of applications• Capacity 10-1700 l/minCapacity 10-1700 l/min• Total head 15 – 450 mTotal head 15 – 450 m
Ease of inspection & Ease of inspection & maintenance of motor maintenance of motor drive headdrive head
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WEAKNESSESWEAKNESSESSolar systemSolar system• High capital costHigh capital cost• Restricted daily Restricted daily
flowflow• Limited storage Limited storage
capacity due to capacity due to aboveabove
• Daily flow reduced Daily flow reduced with increase in with increase in total head total head
Diesel systemDiesel system• High O&M costsHigh O&M costs• No operation due No operation due
to shortage of fuelto shortage of fuel• Power losses Power losses
through drive head through drive head & shafting& shafting
• Greenhouse gas Greenhouse gas emissionemission
• Human factor Human factor
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OPPORTUNITIES OPPORTUNITIES for both systemsfor both systems
To address the water demand of To address the water demand of a large number of IDPsa large number of IDPs
To store waterTo store water To use tap stands with less effort To use tap stands with less effort
for collecting water and reduced for collecting water and reduced queueing timequeueing time
To increase access to safe To increase access to safe drinking waterdrinking water
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POTENTIAL THREATSPOTENTIAL THREATS
Solar systemSolar system• Lower flow rate Lower flow rate
due to rainy seasondue to rainy season• Theft of solar Theft of solar
modulesmodules• Broken modulesBroken modules• Disconnection of Disconnection of
electrical wiringelectrical wiring
Diesel systemDiesel system• Lack of Lack of
maintenancemaintenance• Theft of fuelTheft of fuel• Unavailability of Unavailability of
spare parts spare parts
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Steps towards solutionSteps towards solutionSolar systemSolar systemLower flow rate due Lower flow rate due
to rainy seasonto rainy season• GPS Tracking ArrayGPS Tracking Array• Additional array Additional array
oversizing (30%)oversizing (30%)• Increased water Increased water
storagestorage
Diesel systemDiesel systemLack of maintenanceLack of maintenance• Keeping a service Keeping a service
bookbook• Check of service Check of service
bookbookTheft of fuelTheft of fuel• Limited storage & Limited storage &
proper planning of proper planning of delivery delivery
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Steps towards solutionSteps towards solutionTheft of solar Theft of solar
modulesmodules• Solar array placed Solar array placed
on high stand and on high stand and connected with connected with large size bolts large size bolts
Broken panelsBroken panels• Solar assembly Solar assembly
metal backed. No metal backed. No grid is suggestedgrid is suggested
Availability of spare Availability of spare partsparts
• Local authorized Local authorized distributors and distributors and dealersdealers
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Steps towards solutionSteps towards solutionDisconnection of Disconnection of
electrical wiringelectrical wiring• The wires are The wires are
placed inside iron placed inside iron pipespipes
MONO PUMP COMPUTER AIDED SOLAR MONO PUMP COMPUTER AIDED SOLAR SIMULATIONSIMULATION
Country : Uganda System size : 1200 WattsLocation :Tororo (Latitude 0° 60' / Longitude 34° 20') System efficiency : 56%Static head : 35 m Array type :Tracking
TYPICAL PERFORMANCE AT 1000 W/ m 2
Daily FlowHorizontal I rradiation
KWh/ m2 day44,4 5,643,1 5,543,4 5,639,9 5,238,2 5,037,1 4,934,4 4,736,0 4,942,7 5,544,0 5,642,4 5,444,7 5,640,9 5,3Average
OctoberNovemberDecember
September
MonthJ anuaryFebruary
AugustJ uly
MarchAprilMayJ une
Average flow rate for JanuaryAverage flow rate for January(Mono Pump solar simulation)(Mono Pump solar simulation)
0102030405060708090
100
7.00 A
M
8.00 A
M
9.00 A
M
10.00
AM
11.00
AM
12.00
AM
1.00 P
M
2.00 P
M
3.00 P
M
4.00 P
M
5.00 P
M
Flow rate (l/min)
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Aloi camp solar schemeAloi camp solar scheme(oversized solar array)(oversized solar array)
POWER SUPPLY
220
410 410 410 410
240
140
050
100150200250300350400450
7.30AM
8.00AM
12.00AM
4.00PM
5.30PM
6.00PM
6.30PM
TIME
WAT
TS
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Cost-Benefit AnalysisCost-Benefit Analysis System’s daily flow of 40 mSystem’s daily flow of 40 m33
System’s lifetime of 10 yearsSystem’s lifetime of 10 years Benefit: revenue from water feesBenefit: revenue from water fees Capital cost and Operation & Capital cost and Operation &
Maintenance costsMaintenance costs Life-cycle costs and benefits are Life-cycle costs and benefits are
discounted to the discounted to the present valuepresent value using 10% discount rateusing 10% discount rate
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O&M costs breakdownO&M costs breakdownDiesel pumpDiesel pump: Fuel consumption 1 l/h – : Fuel consumption 1 l/h –
Discharge rate 10 mDischarge rate 10 m33/h/h• Cost of dieselCost of diesel (216,000 USh/month)(216,000 USh/month)• Cost of lubricant Cost of lubricant (15% of fuel)(15% of fuel) (32,400 USh/month)(32,400 USh/month)• Wages of two pumps operators Wages of two pumps operators (150,000 (150,000
USh/month)USh/month) • Kit of spare parts for pump – Kit of spare parts for pump – over 3 yearsover 3 years (gland (gland
packing, vee belts, drive shafting assy, rubber column packing, vee belts, drive shafting assy, rubber column stabilizer, final connecting shaft) stabilizer, final connecting shaft) (122,467 USh/year)(122,467 USh/year)
• Engine service kit Engine service kit (2000 hours) (2000 hours) (363,658 USh/year)(363,658 USh/year)
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O&M costs breakdownO&M costs breakdownSolar pump: Solar pump: replacement of replacement of
pump & controller after 5 years pump & controller after 5 years of serviceof service
SOLAR PUMP LIFE-CYCLE COSTS
YEARCAPITAL
COST
OPERATION & MAINTENANCE
COSTS
TOTAL COSTS (EURO)
PRESENT VALUE FACTORS
(discount rate 10% )
PRESENT VALUES OF
TOTAL COSTS0 13432 0 13432 1,00 134321 0 0 0,91 02 0 0 0,83 03 0 0 0,75 04 0 0 0,68 05 0 0 0,62 06 2320 2320 0,56 12997 0 0 0,51 08 0 0 0,47 09 0 0 0,42 0
10 0 0 0,39 0
Remark: 14731
368
TOTAL LIFE-CYCLE COST
UNIT OUTPUT COST (Euro/ m3)The unit output cost is attained dividing the total life-cycle cost by 40 m3, which is solar pump's daily flow with a given 35 m of total head
Solar Pump Life-Cycle CostsSolar Pump Life-Cycle Costs
Diesel Pump Life-Cycle CostsDiesel Pump Life-Cycle Costs
YEAR
CAPITAL COST
OPERATION & MAINTENANC
E COSTS TOTAL COSTS
(EURO)
PRESENT VALUE
FACTORS (discount rate
10% )
PRESENT VALUES OF
TOTAL COSTS0 7607 0 7607 1,00 76071 2394 2394 0,91 21792 2394 2394 0,83 19873 2394 2394 0,75 17964 2394 2394 0,68 16285 2394 2394 0,62 14846 2394 2394 0,56 13417 2394 2394 0,51 12218 2394 2394 0,47 11259 2394 2394 0,42 1005
10 2394 2394 0,39 934
22306
558
(SOLAR PUMP UNIT OUTPUT COST: 368 Euro/ m 3 )
TOTAL LIFE-CYCLE COST
UNIT OUTPUT COST (Euro/ m3)Remarks: The unit output cost is attained dividing the total life-cycle cost by 40 m3 which is diesel motor pump's daily flow with a given 80 of total head
YEAR BENEFITS
CAPITAL COST
(EURO)
OPERATION &
MAINTENANCE COSTS
TOTAL COSTS
CASH-FLOW (BENEFITS -
TOTAL COSTS)
PRESENT VALUE
FACTORS (discount
rate 10% )
DISCOUNTED CASH FLOW
0 0 13432 13432 -13432 1,00 -134321 6636 0 0 6636 0,91 60392 6636 0 0 6636 0,83 55083 6636 0 0 6636 0,75 49774 6636 0 0 6636 0,68 45125 6636 0 0 6636 0,62 41146 6636 2320 2320 4316 0,56 24177 6636 0 0 6636 0,51 33848 6636 0 0 6636 0,47 31199 6636 0 0 6636 0,42 2787
10 6636 0 0 6636 0,39 2588
26014
Remarks:1 litre of water is assumed to cost 1 USH
40000 litres x 1 USH x 365 days = 14600000 / 2200 = 6636 Euro
NET PRESENT VALUE
DISCOUNTED CASH-FLOW DISCOUNTED CASH-FLOW FOR SOLAR PUMPFOR SOLAR PUMP
YEAR BENEFITS
CAPITAL COST
(EURO)
OPERATION & MAINTENANCE
COSTS TOTAL COSTS
CASH-FLOW
(BENEFITS - TOTAL COSTS)
PRESENT VALUE
FACTORS (discount
rate 10% )
DISCOUNTED CASH FLOW
0 0 7607 7607 -7607 1,00 -76071 6636 2394 2394 4242 0,91 38602 6636 2394 2394 4242 0,83 35213 6636 2394 2394 4242 0,75 31824 6636 2394 2394 4242 0,68 28855 6636 2394 2394 4242 0,62 26306 6636 2394 2394 4242 0,56 23767 6636 2394 2394 4242 0,51 21638 6636 2394 2394 4242 0,47 19949 6636 2394 2394 4242 0,42 178210 6636 2394 2394 4242 0,39 1654
18439
Remarks:1 litre of water is assumed to cost 1 USH
40000 litres x 1 USH x 365 days = 14600000 / 2200 = 6636 Euro
NET PRESENT VALUE
(Net present value of solar pump: 26014)
DISCOUNTED CASH-FLOW DISCOUNTED CASH-FLOW FOR DIESEL PUMPFOR DIESEL PUMP
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ConclusionsConclusions Solar system is Solar system is sustainablesustainable and and
reliablereliable: : no fuel, no need of operator, no fuel, no need of operator, pump and controller are maintenance-pump and controller are maintenance-freefree
Solar system is Solar system is cost-effective: cost-effective: 4 times 4 times the hand pump’s daily flow with the hand pump’s daily flow with negligible recurrent costnegligible recurrent cost
Diesel system has high pumping & lift capacity: 3 times the solar system’s daily flow
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ConclusionsConclusions Over 10 years of service, unit output Over 10 years of service, unit output
cost of diesel pump is higher than cost of diesel pump is higher than solar: 558 Euro against 368 Eurosolar: 558 Euro against 368 Euro
For a better analysis of field data (i.e. For a better analysis of field data (i.e. maintenancemaintenance), the appraisal should ), the appraisal should be extended over a longer period of be extended over a longer period of service-timeservice-time
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PUMP PERFORMANCEPUMP PERFORMANCE GrundfosGrundfos: : (H(HTT=6 Kwh/m=6 Kwh/m22 day day 20° northern latitude) 20° northern latitude) H(m)=30~Q(mH(m)=30~Q(m33/day)=26 H=60~Q=16 H=80~Q=13 /day)=26 H=60~Q=16 H=80~Q=13
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PUMP PERFORMANCEPUMP PERFORMANCE Mono diesel pump mod. 620Mono diesel pump mod. 620 Pump Pump speed 1200 rpmspeed 1200 rpm H=30~Q=3.55 H=60~Q=3,48 H=80~Q=3,3H=30~Q=3.55 H=60~Q=3,48 H=80~Q=3,3