Installation of a Solar Power System at La Valla – Phase One€¦ · The La Valla solar power project was initiated in 2008. The purpose of this effort was to help the institution

Installation of a Solar Power

System at La Valla –

Phase Two

LOVEWORKS

YOUTH & YOUNG ADULTS OFFICE

CHURCH OF SAINT MARY OF THE ANGELS

22 November 2011

Installation of a Solar Power System at La Valla – Phase 2

Date: 01 Nov 2010 2 of 25

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

Table of Content

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

2 Project Partners ................................................................................................................... 4

3 Project Execution – Phase Two .......................................................................................... 4

3.1 Project Schedule .......................................................................................................... 4 3.2 Scope of Work ............................................................................................................. 5

3.2.1 Installation of the 4.2kW System ......................................................................... 5 3.2.1.1 Approach ...................................................................................................... 5 3.2.1.2 Basic Components and Sizing ...................................................................... 7 3.2.1.3 Installation .................................................................................................. 10

3.2.2 Repair and Improvement of Previously Installed System.................................. 17 3.3 Equipment Details and Cost ...................................................................................... 19

4 Follow Up Work ............................................................................................................... 20

4.1 Follow Up Trip on Oct 2011 ..................................................................................... 20 4.2 Handover and Future Follow Up Work..................................................................... 22

5 Summary ........................................................................................................................... 22

Appendix 1: Circuit diagram for 4.2kW system ...................................................................... 23

Appendix 2: Updated circuit diagram for security lighting system ......................................... 24

Appendix 3: Project Partners ................................................................................................... 25


Date: 01 Nov 2010 3 of 25

1 Introduction

La Valla is a school for handicapped children run by the Marist Brothers, an international

Catholic organization that focuses on education. 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 living nearer are

transported daily from the surrounding areas.

The La Valla solar power project was initiated in 2008. The purpose of this effort was to

help the institution reduce its operating cost by tapping on solar powered energy. La Valla

School is located in a rural area near Takhmao in Kandal province and is not service by the

national electricity grid in the area at the time of this project. It depends on a second-hand

45kVa generator to supply electricity, mainly used for lighting in the school and hostel

located within the school compound, for powering the computer lab and running the water

pumps of a small swimming pool that is used for physiotherapy and recreation. Electricity is

used sparingly due to high cost of diesel; fuel cost for running the generator exceeds USD600

per month.

This project was divided into two phases. The objective of Phase 1 was for all parties to get

familiarized with the basics of installing, running and maintaining a solar powered system. A

small 500W system was installed to provide security lighting to the school at night; since the

generator is switched off every night at 9pm, the whole area there is in pitched black darkness.

A series of energy-saving light bulbs were installed across four buildings in the school. This

was carried out between November 2008 to April 2009 (see Phase 1 report for more

information).

In Phase Two, a 4.2kW system (consisting of twenty 210W panels and the supporting

equipment including batteries, inverters and wiring and other structures) was installed in La

Valla. Repair and re-wiring work were also carried out at the solar powered security lighting


Date: 01 Nov 2010 4 of 25

system installed previously. The planning for Phase 2 was carried out in the first two

quarters of 2010 and executed in June 2010.

2 Project Partners

The main sponsor for Phase 2 was Hexacon Construction Pte Ltd. Besides providing most of

the funds, Hexacon also provided two experienced construction specialist who advised on the

design and provided vital on-site supervision during the construction phase. The balance of

the funds came existing Loveworks fund.

The bulk of the building and construction works were mainly carried out by a group of highly

motivated students from the Environmental Science & Engineering Students’ Club (ESESC)

of the National University of Singapore. This group spent a significant amount of effort

before the trip to raise funds to finance their own air travel and accommodation costs required

to be in Cambodia to carry out the construction.

The design, planning and overall project coordination were carried out by Loveworks.

3 Project Execution – Phase Two

The work done during Phase Two is described here.

3.1 Project Schedule

The overall project schedule is shown in Table 1. The planning and design began several

months after the completion of Phase One. The actual construction was carried out between

12-22 June 2010.


Date: 01 Nov 2010 5 of 25

Table 1: Project Schedule

Activity Date

Phase One

Phase One 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

Second follow up for Phase One (changing

of batteries) 11 Aug 2009

Phase Two

Phase Two Pre-planning Dec 2009 – Jun 2010

Phase Two Execution 12 – 22 Jun 2010

Follow up visit 06 – 09 Oct 2011

3.2 Scope of Work

The main scope for Phase Two involved the setting up of a 4.2kW solar panel system,

consisting of twenty 210 watt polycrystalline PV panels, together with the accompanying

batteries, charge controllers and synchronizers, inverter, grounding and wiring works. This

took up the bulk of the time and budget.

Some effort was also spent upgrading and repairing the security lighting system that was

previously installed during Phase One. The things carried out here consist of rewiring works

to make it tidier, replacing the faulty inverter and repair of some of the switches and bulbs.

3.2.1 Installation of the 4.2kW System

3.2.1.1 Approach

The largest consumer of electricity in La Valla is the swimming pool water filtration system

(Fig. 1). This system is crucial in keeping the pool in a healthy condition. The pool is used


Date: 01 Nov 2010 6 of 25

for physiotherapy and recreational purposes for the students and staff. The power

consumption of individual items in the filtration system is showed in Table 2. The swimming

pool water filtration system has to pumps; the main pump and a smaller backup pump. The

backup pump is only used when the main pump is down. There are two chlorinators and both

of them are used at the same time.

Table 2: Swimming pool water filtration system's power consumption

Item Power (W)

Main pump 2,438

Small pump (backup) 1,612

Chlorinator (SCMax155, 0.9kW

each) 1,800

Total 4,238

Besides the water filtration system, other areas of power consumption come from lighting,

fans, refrigerators, several computers and an air-con in the computer room. The solar power

system we designed was focused mainly on supplying power to the water filtration system

since it was the biggest consumer of electricity. Provisions were also made to allow any

equipment within the vicinity of the solar power system to draw power from it. Due to

budget constraint, we could not put up enough panels to supply for the entire need of the

school. Hence the system was designed to provide enough power to significantly reduce the

school’s dependence on diesel but not enough to replace it altogether.

Figure 1: Swimming pool water filtration system


Date: 01 Nov 2010 7 of 25

3.2.1.2 Basic Components and Sizing

The basic components of the system are shown in Fig. 2.

Charge

Controller

To AC load

Charge

Controller

Synchronizer

Battery

Bank

Inverter

Figure 2: Basic components of the solar power system


Date: 01 Nov 2010 8 of 25

Load Calculation

AC Loads:

Main Pump – 10.6A x 230 Vac x 6 hr = 14,628 Wh

Backup Pump – 7.01A x 230Vac x 6 hr = 9,674 Wh

Chlorinator (two sets) – 1,800W x 6 hr = 10,800 Wh

Since at any time, only one pump is running we are taking the maximum requirement, 25,428

Wh.

Allowing for Pure Sine Wave Inverter efficiency (85%)

= 25,428Wh / 0.85 = 29,915.3 Wh

DC Load: none

Total for AC and DC loads = 29,915.3 Wh per day

Calculation for the Required Solar Input

Estimated peak sun hours in Takhmao = 6 peak sun hours per day.

Required input from solar panel bank

= (29,915.3 Wh / 6 hr) x 1.4 = 6980.2W

Note: 1.4 is a factor chosen to incorporate efficiency of around 70%.

Selection of Solar Panels

If we choose Kyocera solar panel module of 210 Watt,

Required number of panels = 6980.2W / 210W = 33.2 34 panels

Kyocera KD210GH-2P is chosen.

Maximum Power, Pmax = 210 W

Maximum Power Voltage, Vmpp = 26.6 V

Maximum Power Current, Impp = 7.9 A

However, due to budget constraint, we could only supply 20 panels. These panels were

arranged in series-pair in order to form 48V system, 2 for each pair, there are 10 lines in

parallel in total.

Selection of the Charge Controller

The rated short-circuit current of the 210W Kyocera panel is 8.58A each.


Date: 01 Nov 2010 9 of 25

We need to allow 25% extra capacity in the controller rating as solar panel can exceed their

rated output in particular cool sunny conditions (“cloud-edge effect”).

Current flowing from the solar panel bank to the charge controller

= 8.58 x 1.25 x 10 = 107.25 A

Charge controller that can handle such massive current is very expensive, thus for cost

effective measure, we need to divide the current into 2 lines, each handling only 53.625

Amps

Modular Power Management from Phocos is chosen.

2 x Modular Power Switch 48V, 80A

1 x Modular Central Unit 48V

1 x Modular Power Switch 48V, 80A (for load protection)

Selection of the Inverter

An inverter that is more than capable of carrying the maximum anticipated load has to be

selected.

From the above requirement, maximum load

= 4,238W/ 0.85 = 4,985.9 Watt

5000W Inverter would be suitable.

Selection of the Batteries

For solar system, it is best to use GEL type deep cycle batteries. To ensure long battery life,

deep cycle batteries should not be discharged beyond 70% of their capacity, i.e. 30% capacity

remaining. Discharging beyond this level will significantly reduce the life of the batteries.

Battery sizing is based on maximizing the solar panels that are available. With 1-day storage

capacity, the battery sizing would be as follows:

Ah required = (17,640 Wh / 12 V) / 0.7 X 1.1 = 2,310.0 Ah

We choosed 12V, 200Ah battery for this system.

No of batteries required = 2310/ 200 = 11.55 batteries

We need to arrange the 12V batteries into series line, 4 batteries for each line.

Hence at least 3 battery lines are required. One additional battery line was added for buffer.

Hence, no of 200Ah 12V batteries required = 16


Date: 01 Nov 2010 10 of 25

3.2.1.3 Installation

The installation works were carried out from 12-22 June, 2010. We began by repainting the

stainless steel mounting frames for both the solar panels and batteries with several coats of

anti-rust paint (see Fig. 3). This was to protect them as long as possible from rust.

After they were dried, the mounting frames for solar panels were hoisted one at the time to

the rooftop and secured to the roof (see Fig.4). The mounting frames were then fastened one

at a time to the rooftop (Fig. 5)

Figure 3: Painting of mounting frames with several coats of anti-rust paint


Date: 01 Nov 2010 11 of 25

Figure 4: Hoisting of mounting frames to rooftop

Figure 5: Fastening of mounting frames on the rooptop


Date: 01 Nov 2010 12 of 25

The next step involved hoisting of the solar panels to the roof so that they can be attached to

the mounting frames. This step had to be carried out slowly as the panels were very heavy

and also very fragile (Fig. 6).

Figure 6: Mounting of solar panels in the mounting frames


Date: 01 Nov 2010 13 of 25

After physically mounting the solar panels on the mounting frames, every two panels were

wired up in a parallel arrangement, resulting in 10 such pairs, 5 pairs facing north and 5 pairs

facing south. Each of these pairs was then wired to respective junction boxes (see Fig 7).

There are two main junction boxes on the rooftop, one for the north panels and the other for

the south. The junction boxes were then connected to a room below (Fig. 8 and 9).

Figure 7: Wiring works beneath the panels on the rooftop

Figure 8: Wiring works under the solar panels


Date: 01 Nov 2010 14 of 25

There are two rooms that are used to house the solar power equipment. One room is used to

house the control boxes (isolaters, synchronizers, charge controllers) and battery rack

consisting of sixteen 200Ah batteries (see Fig. 10). Another room is used to house the 5kW

inverter (see Fig. 11).

Figure 9: Wiring works at the control box

Figure 10: Control box and battery storage area


Date: 01 Nov 2010 15 of 25

All the activities carried out on the rooftop left holes and these have to be patched up after all

the rooftop works have been completed (see. Fig.12). The completed rooftop can be seen in

Fig. 13.

Figure 11: 5kW inverter


Date: 01 Nov 2010 16 of 25

Figure 12: Roof repairing works being carried out

Figure 13: Rooftop, after all mounting and wiring works have been completed


Date: 01 Nov 2010 17 of 25

3.2.2 Repair and Improvement of Previously Installed System

Some works were also carried out to repair and improve the solar powered security lighting

system that was previously installed in 2008/2009.

The wiring connections that was carried out in 2009/2009 had quite a few loose connections

and the path where they were laid were not optimal. Some of these connections were coming

out at some points. They are also slightly inferior quality wires and had no wire casing.

Therefore, rewiring work was carried out mainly using excess good quality wires that were

left over from the 4.2kW system (see Fig.14). Flexible wire casing was also used to protect

the wires from the elements.

Figure 14: Rewiring works at the security lighting system


Date: 01 Nov 2010 18 of 25

Faulty light bulbs were also replaced with new ones. All switches fuse boxes and charge

controllers were packed neatly in a junction box and labeled (see Fig.16). The inverter was

also repaired.

Figure 15: One of the security lights, after rewiring and tidying

Figure 16: Junction box in progress. It houses all the switches and charge controller of the

security lighting system


Date: 01 Nov 2010 19 of 25

3.3 Equipment Details and Cost

The cost of the equipment and other supporting cost (non-equipment) for the project are

shown in Table 3 and 4 respectively. The total project cost came up to S$36,939.37.

Table 3: Equipment Cost

Note: Conversion rate for USD to SGD used is 1.3949

No Items Quantity Total (S$)

1 Kyocera Solar Panel 210W, 24V 20 $18,161.19

2 Solar rack on the roof 20 $418.46

3 Cable 1 x 6mm2 = 120m from Solar panels to Junction box 120 $125.54

4 Junction box for Solar 20 x 20mm 2 $13.95

5 Set Connection and accessories 1 $69.74

6 Apollo S 219C ( 5.0KVA / 48 Vdc ) 1 $5,858.45

7 Haze HZY-SL 12-200 16 $7,141.73

8 Battery connectors ans isolators 15 $104.62

9 Battery cable 10m = 50mm2 10 $125.54

10 Cable # 6 AWG ( 2x 16mm2 ) Thailand 60 $376.61

11 Cable # 14 AWG ( 2x 2.5mm2) KTC 100 $111.59

12 Cable # 14 AWG for ground ( 1x 2.5mm2) KTC 100 $46.03

13 Ground pole 4 pcs,conector,ground road 1 x 16mm = 20m 1 $111.59

14 Delta Lightning Protection Arrestor 2 $237.13

15 Breaker 2P 60A 4 $75.32

16 Breaker 2P 150A 1 $64.16

17 AC circuit breaker 1 $13.95

18 Transportation to Takhmao 1 $48.82

19 Phocos Charge Controller Package 1 $1,251.90

20 Repair and correction of security lighting system 1 $585.84

21 Hardware shop purchases in Takhmao 1 $349.41

22 Voltmeter 1 $70.00

23 Miscellaneous 1 $348.72

SGD 35,710.29

Table 4: Supporting costs

No Items Total (S$)

1 Communication costs (Cambodian sim cards and top ups, Phoenix 1516 prepaid) $96.60

2 Transportation $777.11

3 Bank transfer charge $61.92

4 Manual filing for equipment $7.80

5 Post trip event $214.90

6 Customs related processing $70.75

SGD 1,229.08


Date: 01 Nov 2010 20 of 25

Table 5: Summary of Cost

Cost Amount

Equipment Cost SGD 35,710.29

Supporting Cost SGD 1,229.08

Total Cost SGD 36,939.37

Hexacon Construction Pte Ltd sponsored S$35,000 of this project. The remainder of the cost

for the project came from Loveworks (see Table 6).

Table 6: Funding for project

Cost Amount

Cost borne by Hexacon Construction Pte Ltd SGD 35,000.00

Cost borne by Loveworks funds SGD 1,939.37

Total Cost SGD 36,939.37

4 Follow Up Work

4.1 Follow Up Trip on Oct 2011

A follow up trip was made on October 2011. Here are the findings from the trip.

The 4.2kW system installed in June 2010 is being fully utilized since its installation. It has

been working well for more than a year and does not have any issues at all.

As for the security lighting system, in the interim between the June 2010 and the follow up

trip, the school extended the security lights to a new building; one new series of lightings was

added for the workshop building (see Appendix 2 for updated plan). See Table 7 for details.


Date: 01 Nov 2010 21 of 25

Table 7: Updated security lighting details

Security lighting details

Number of buildings covered 5

Total number to lights 18

Power requirement of each light bulb 8 watts

Estimated consumption a day (based on 8 hours) 1,152Wh

The battery bank configuration of four 12V 100Ah batteries installed in June 2010 did not

turn out well. This was partly because two of the batteries used in the bank were slightly

older than the other two and this led to problems. The battery bank was replaced with two

12V 200Ah batteries. This time, 200Ah batteries were used instead of 100Ah batteries; this

reduced the number of batteries required, therefore reducing unnecessary connection

imbalances and losses.

The wooden racks made for the batteries in the previous trips were replaced by a stainless

steel rack. The cost for works carried out during the follow up trip can be found on Table 8.

The budget for this came from existing Loveworks fund.

Table 8: Cost for work carried out during follow-up trip.

(Note: USD to SGD conversion rate at 1.2776)

Items Amount

Narada 12V 200Ah gel batteries (2 units) SGD 830.44

Battery rack SGD 76.66

Bank transfer charges SGD 20.00

Discount (SGD 12.78)

Total Cost SGD 914.32

Grid electricity finally arrived at La Valla in the middle of 2011 when a temporary

connection to the power grid was made, about a year after the installation of the 4.2kW

system. However, the solar power equipment is still being utilized quite fully and continues

to help reduce the electricity cost for the school. The security lighting system continues its

role in providing security lighting that is immune to power outages.


Date: 01 Nov 2010 22 of 25

4.2 Handover and Future Follow Up Work

A complete documentation folder containing all information was transferred over to La Valla

School after the June 2010 trip. Training for also provided for key personnel in La Valla

School as the project was being implemented with the aim that they will be able to run and

maintain the system as independently as possible. The solar power vendor that we worked

with in this project is based in Phnom Penh and should be able to provide support to the

school when needed.

In the future, Loveworks will continue to provide support and make follow up trips as and

when requested by the school.

5 Summary

The La Valla School Solar Power Project was carried out with the objective of providing an

alternative source of electricity to the school to reduce its running cost. At the time when the

project was implemented, electricity from the grid was not available in the area and the

school depended on a second hand diesel generator for its electricity needs.

The project was divided into two phases. In the first phase, a small solar power security

lighting system was installed to provide night lighting to the school. A 500W system was

installed together with a series of power saving light bulbs in four buildings in the school and

this was carried out in 2008-2009. One of the objectives of the first phase was for all parties

to get familiarized with the installation and maintenance of solar powered systems before

embarking on a larger scale system. The second phase of the project was implemented from

2009 to 2010 and this involved a much larger 4.2kW system. Although grid electricity has

arrived at the area recently, the existing solar power systems continues to help the school

reduce its operating cost.


Date: 01 Nov 2010 23 of 25

Appendix 1: Circuit diagram for 4.2kW system Circuit diagram Single line 48 Vole

wire 6 mm2

les them 15 m use wire16 mm2

Use breaker better them use fuse because

fuse some time cut some time not cut

if not cut became burn fuse leg .

Battery wire 50 mm2

Narada battery 200Ah 16 units

AC to Load 220V

210 W 8.75 A

24 V

210 W 8.75 A

24 V

210 W 8.75 A

24 V

210 W 8.75A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

J. Box, with

or with out Fuse 10 A x 5

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75 A

24 V

210 W

8.75A

24 V

210 W

8.75A

24 V

210 W

8.75A

24 V

210 W

8.75A

24 V

210 W

8.75A

24 V

210 W

8.75A

24 V

CB 60Am

Charge controller

45 Am , 48V

CB 60Am

Charge controller

45 Am , 48V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

+ -

BATT 12V

Inverter 5 Kg 48 V

_

MCB 150Am

CB 60Am CB 60Am

J. Box, with

or with out Fuse 10 A x 5

Appendix 2: Updated circuit diagram for security lighting system

Appendix 3: Project Partners

Hexacon Construction Pte Ltd (Main sponsor)

Mr. Micheal Tai – Sponsor/Project Advisor

Mr. Tan Chee Wah – Project Advisor

Mr. Mohd Zulkifli bin Baderon – Project Advisor

Environmental Science & Engineering Students’ Club (ESESC)

Law Yi Hui

Emily Seow Pei Hoon

Seow Jun Chyi

Lim Jinwen (Joann)

Selina Patra

Chua Jia En (Alex)

Chua Kun Lin

David James Chua

Siah Tong Shie

Sim Yi Lin, Ivie

Phey Giap Seng

Goh Liang Kuang

Wong Jia Shou (Isaac)

Rachel See Xiu Qun

Poh Wei Peng

Loveworks

Sigit Purnamo – Technical IC

Augustine Quek – Technical Support & Student Liaison

Terence Chin – Project IC

Contact Information

LOVEWORKS,

Youth and Young Adults Office,

Church of Saint Mary of the Angels,

Email: [email protected]

Attn: Terence Chin

Visit us at:

Website: www.stmary.sg/loveworks

Blog: http://simplyloveworks.wordpress.com/

A special thanks to the parishioners of St Mary of the Angels for making this project

possible through their support of Loveworks’ fundraising events and donations.

mailto:[email protected]

http://www.stmary.sg/loveworks

http://simplyloveworks.wordpress.com/

Documents

Installation of a Solar Power System at La Valla – Phase One€¦ · The La Valla solar power project was initiated in 2008. The purpose of this effort was to help the institution