installation of a solar power system at la valla – phase one · la valla is a school for...

Installation of a Solar Power

System at La Valla –

Phase One

LOVEWORKS

YOUTH & YOUNG ADULTS OFFICE

CHURCH OF SAINT MARY OF THE ANGELS

9 JULY 2009

Installation of a Solar Power System at La Valla – Phase 1

Date: 09 July 2009 2 of 14

Installation of a Solar Power System at La Valla – Phase One

Table of Content

1 Introduction ........................................................................................................................ 3

2 Background of La Valla School ......................................................................................... 3

3 Project Execution – Phase One ........................................................................................... 5

3.1 Equipment Details and Cost ........................................................................................ 6

3.2 Installation ................................................................................................................... 7

3.3 Optimization ................................................................................................................ 9

4 Recommendations for Phase Two .................................................................................... 10

4.1 La Valla’s Power Requirements ................................................................................ 10

4.2 Scope for Phase Two ................................................................................................. 10

5 Summary ........................................................................................................................... 12

Appendix 1: Circuit Diagram for Phase One ........................................................................... 13

Appendix 2: Other information ................................................................................................ 14


Date: 09 July 2009 3 of 14

1 Introduction

La Valla is a school for handicapped children run by the Marist Brothers located in the

rural district of Takhmao, Kandal Province, Cambodia. The area where the school is at

does not have access to electricity and a diesel generator is used for the school’s power

needs. The overall objective of this project is to install a solar power system with enough

capacity to replace all or a significant part of La Valla’s total power needs. The project

has been separated into two phases.

The objective of Phase One is to install a small pilot solar power system in La Valla to

achieve the following:

(a) Gain expertise in solar power systems, especially in the areas of hardware

installation, electrical system integration and optimization

(b) Gain familiarity with the electrical system at La Valla

(c) Obtain more accurate electrical consumption data at La Valla

Phase One was carried out over two trips to Cambodia, in December 2008 and March

2009. A proposal for Phase Two is given here based on the information and experience

gained from Phase One.

2 Background of La Valla School

La Valla is a school for children and young people with various physical disabilities. It is

located in Takhmao, Kandal Province in Cambodia. It was set up and run by the Marist

Brothers, an international Catholic organization that focuses on education.

Figure 1: La Valla School during morning assembly


Date: 09 July 2009 4 of 14

Students there range from the ages of 11 to about 18 or 19 years old and are from poor

families. Because of their disability and their poverty they have not been able to attend

their local elementary school or, perhaps they have started at school but have not been

able to continue. The main objectives of the school are to provide them with basic

elementary education and build self-reliance so that they will be able to lead meaningful

lives when they leave the school. Most of the students who are from the countryside live

in the boarding house within the school while the rest are transported daily from the

surrounding areas.

Figure 2: Faces of La Valla

The school is located in a rural area as the cost of land there is far cheaper than in the

capital, Phnom Penh. The power grid is not connected to the area and it will likely

remain so for the foreseeable future. As such, the school depends to a diesel generator to

supply its power needs. The school is made out of about 9 buildings. These include two

administration blocks, two classroom blocks, an ablution, a workshop, a kitchen and

canteen, and the principal’s residence. There is also a plantation/farm and fish pond

towards the eastern edge of the compound.


Date: 09 July 2009 5 of 14

The school houses a small swimming pool that is used for physical therapy for the

handicap and also leisure swimming for the students and staff. The bulk of the power

consumption of the school comes from the pumps at the swimming pool. Due to water

maintenance issues, the pump has to be turned on for at least 8 hours a day.

Figure 3: Swimming pool inside the school compound

3 Project Execution – Phase One

The execution of Phase One was carried out with the help of undergraduates from the

National University of Singapore (NUS) under Operation Orion, a volunteer organization

within NUS Civil Engineering Club. Project funding for Phase One was by NUS and

Loveworks.

A 500W solar power system consisting of four 125W panels, two 100Ah gel type

batteries, a charge controller and a sine wave inverter was installed. Since the school has

a security lighting problem at night, a series of security lightings consisting of 8W power

saving light-bulbs with the accompanying switches and wiring were also installed at four

of the main buildings there. La Valla’s generator is never switched on after ‘lights-out’ at

9pm every night. Hence, the whole compound is dark and vulnerable to buglary.

Phase One was carried out over two trips. The first trip consisted of 3 Loveworks

members and 15 undergraduates from NUS from 13-20 Dec 2008. The system design

and supervision was carried out by Loveworks while installation works was carried out

mainly by the NUS students.


Date: 09 July 2009 6 of 14

Figure 4: Briefing session on the first day upon arrival

The second trip was a follow up trip to inspect, make corrections and optimize the system.

A wooden housing was also built for the batteries, charge controller and inverter. It was

carried out by 3 members of Loveworks from 21 – 24 Mar 2009. Important dates are

listed below in Table 1.

Table 1: List of important dates for Phase One

Activity Date

Pre-planning Jun – Nov 2008

Phase One Execution (main installation) 13 – 20 Dec 2008

Follow up for Phase One (inspection,

correction and optimization) 21 – 24 Mar 2009

Phase Two 2010

3.1 Equipment Details and Cost

The list of equipment and their cost are shown in Table 2. A total of S$5,942.97 was

spent on the equipment. Approximately 75% of the cost was borne by NUS while the

remaining 25% was funded by Loveworks. Non-equipment related cost by Loveworks

was S$638.50.


Date: 09 July 2009 7 of 14

Table 2: List of equipment installed and their cost (inclusive of 7% GST where relevant)

Item Description Quantity Cost (S$)

Solar Photovoltaics (125W per unit, polycrystalline) 4 units 3,531.00

Charge controller (12/24V, 40 amp) 1 132.68

600W Inverter (full sine wave, 24 V DC, 220AC)) 1 548.91

Sealed Lead acid Battery (gel-type, 100Ah, 12V DC) 2 492.20

Wire (10 amp rated, 360metres) 360 m 54.57

Switches 20 45.00

Light bulbs ( 8W, flurorescent, white) + holders 20 45.00

Aluminium mountings for solar panels 2 sets 620.60

Ohoya Lead Acid Battery, 100Ah, 12V (backup battery) 1 128.35

Etrack 1P2C Energy Tracking Device 1 200.00

USB interface for Charge Controller 1 71.69

High loading wires (2 core 4mm SQ Neoprene Cable) 11m 58.85

Miscellaneous electrical components -- 14.12

Total cost S$5,942.97

3.2 Installation

The lights are installed on the exterior of four main buildings in La Valla, powered by

solar photovoltaic (PV) panels and batteries. There are two gel type batteries that provide

the necessary charge to the light bulbs at night; these are charged up by the solar panels

during the day. The solar panels are currently mounted on the roof of administrative

north (AN) building (see Appendix 1). The library storeroom currently houses the other

pieces of equipment: batteries, charge controller and inverter.


Date: 09 July 2009 8 of 14

Figure 5: Wiring works for the security lightings under way.

The batteries provide charge to the bulbs through a DC to AC pure sine wave inverter,

which converts the DC current from the batteries to AC current, which is supplied to the

bulbs. There are a total of 16 light bulbs on four buildings closest to the main gate. Each

building has 4 light bulbs, one on each side of a building. Each building also has a switch

for these four lights. Lastly, there is a master switch for all 16 lights in the AN building.

These lights serve as security lighting at night, lighting up the immediate area around

these four buildings and deterring intrusion and theft. This solves the problem of night-

time theft within the school premises.

Figure 6: Carrying out of wiring works at the rooftop area


Date: 09 July 2009 9 of 14

Figure 7: Mounting of the four panels on rooftop

3.3 Optimization

Programming of the charge controller was carried out at the final stage. The appropriate

controller settings were selected based on the manufacturer’s recommendations. The

system currently has the potential to power many more appliances as the capacity the of

500W system is not yet fully utilized. At present only 25.5% (estimated) of this power is

utilized everyday. The two batteries can provide up to 100Ah on a full charge.

Figure 8: Installation of the battery, charge controller and inverter (left). A wooden casing was built to

house these components (right)


Date: 09 July 2009 10 of 14

An additional socket for the plucking in of additional electrical appliances to use up the

remaining 75% power was initially considered but not provided in the end in order to

prevent over usage to the extend that that there will be inadequate power for the security

lightings to last throughout the whole night. Full utilization of this pilot system will be

dealt with in Phase Two.

4 Recommendations for Phase Two

A recommendation and cost estimation for Phase Two based on La Valla’s power needs

are given here.

4.1 La Valla’s Power Requirements

The area where La Valla resides is not serviced by the electricity grid. Hence, electricity

is provided by a 45kVA diesel generator. The largest consumer of electricity in La Valla

is the swimming pool water filtration system; it has a 1.5kW water pump that has to be

kept on for at least 8 hours a day in order to maintain the water in the pool. Therefore,

the swimming pool water filtration system itself consumes at least 12kWh of electricity a

day. Besides the pump, other electrical appliances are mainly light bulbs, several fans,

one refrigerator, several computers and an air con in the computer room.

Figure 9: Water filtration system for the swimming pool at La Valla

4.2 Scope for Phase Two

Phase Two will focus on providing a 2.75kW solar power system for the swimming pool

water filtration system. This will relieve the load on the school’s diesel generator by a


Date: 09 July 2009 11 of 14

significant amount and result in substantial savings through the reduction of fuel

consumption. The system to be installed is a dual system; the water filtration system can

be switched between using solar power or the diesel generator. This is important so that

backup power is available in the event of a failure in the solar power system.

A breakdown of the equipment and cost is shown in Table 3. Similar to Phase One,

125W panels are chosen because their dimension allows them to be check-in to the

airplane without any hassle. Efforts to scout for solar power related equipment in Phnom

Penh so far have shown that it is much more economical to fly them in from Singapore

rather than to buy it in Cambodia.

Table 3: Phase Two – Breakdown of equipment and cost

Item Description Quantity Cost (S$)

Solar Photovoltaics (125W per unit, polycrystalline) 20 units 18,000

Charge controller (12/24V, 40 amp) 3 400

3000W Inverter (full sine wave, 24 V DC, 220AC)) 1 1,600

Sealed Lead acid Battery (gel-type, 100Ah, 12V DC) 8 2,000

Wires (high loading rated wires) 200 m 1,000

Controller box (integrated, w/ circuit breakers) 1 500

Mounting Brackets 8 sets 3,500

Switches and miscellaneous electrical components -- 200

Total Cost S$27,200

The appropriate site for the installation of the solar power system for Phase Two has

been identified. It will be on the roof area above the canteen (see Fig.10). The

mentioned roof area is large enough to accommodate the solar panels, and also high and

central enough in the school compound to make any theft of the panels difficult. A

vacant store room at the canteen will be used to house the batteries, inverter and charge

controller.


Date: 09 July 2009 12 of 14

Phase Two is set to commence in 2010 should funding be available by then.

Figure 10: The canteen area has been identified as the site for the installing the solar power system for

Phase Two.

5 Summary

In Phase One, a small solar power system of 500W has been installed at La Valla

between December 2008 and March 2009. Security lightings and the accompanying

network of wiring and switches were also installed in four main buildings around the

school. These are powered by the 500W solar power system. For Phase Two, a 2.75kW

solar power system providing for the swimming pool’s water treatment power

consumption is been recommended. This system will cost approximately S$28K.


Date: 09 July 2009 13 of 14

Appendix 1: Circuit Diagram for Phase One

+ +

- - 25 - 39V

AN

AS CN

CS

220V

Inverter

Charge

Controller


Date: 09 July 2009 14 of 14

Appendix 2: Other information

Loveworks Project Team Members

Principle Engineers:

Sigit Kwa

Augustine Quek

Project IC:

Terence Chin

Contact Information

LOVEWORKS,

Youth and Young Adults Office,

Church of Saint Mary of the Angels,

5 Bukit Batok East Avenue 2,

Singapore 659918

Email: [email protected]

Website: www.stmary.sg/loveworks

Attn: Terence Chin

mailto:[email protected]

http://www.stmary.sg/loveworks

installation of a solar power system at la valla – phase one · la valla is a school for...

Documents