Redesign and Install Grid Tied 5KW Inverter for PKH Aoral

In January 2019, we removed all the stand alone photovoltaic systems in Aoral (1kW & 600W) and Trang ( 450W & 450W) and rewire and relocate them in PKH Aoral to make a Grid Tied 5KW Inverter system since Aoral has government electricity.

The Grid Tied 5KW Inverter system has 10 solar panels connected in series (180Vdc) and 4 batteries connected in series (48Vdc).

In operations, the sun charges the battery and the government supply electricity to PKH Aoral Training Centre when it is cloudy.

 When is sun is shinning brightly, the solar provides electricity to the PKH Centre and also feed back electricity to the grid.

When the government electricity supply is cut-off, the centre uses the solar power.

When the sun is shinning brightly, electricity from the solar charges the battery and also supply electricity back to the grid.

Solar Electricity for a Farm

In May 2018, I visited a farm overseas and installed a Photovoltaic System (900W) on the farm. They have no grid electricity supply.

Photovoltaic System for the Farm

The system proposed is a 900 Watts Photovoltaic System that can provide up to 2 KW of electricity to the farm. The daily usage has to be budgeted to ensure that the batteries storage is not fully discharged by excessive electricity usage.

System Specifications:

900 Watts Photovoltaic System (6 pieces of 150W Solar Panels)

Power Inverter, 24Vdc to 230Vac, 2,500 Watts

Lead Acid Batteries 12Vdc 200 AH – 4 pieces (Operating at 24 Vdc)

Budgeted Daily Energy Usage: approx 2,600 Watt-Hour per Day

Standby Battery Storage: 3 days

 

The Schematics for the Photovoltaic System is shown below.

The estimated energy usage for the farm based on their daily operations using the following electrical equipment and appliances:

1. Water Pump (500 watts) uses 3 hours daily
2. LED Lamps (10W x 5 pieces) uses 6 hours at night
3. Fan (40W x 2 pieces) uses 10 hours at night
4. Spot Light (10W) operate 12 hours at night for security

If the farm restricts the energy usage to the above duration, the photovoltaic system will be able to provide their daily energy needs.

The ampere meter shows the solar charging current of 18.7 Amps into the lead acid batteries.

A change-over switch between generator and solar allows easy switching between the two systems.

Donation of the Photovoltaic System.

• Photovoltaic System Cost – SGD 4,500
• Tools (Hammer Drill & Battery Operated Hand Drill) – SGD 160

In July 2018, the inverter had died. It was brought back to Singapore and send back to the shop to repair. It was found that all the fuses and MOSFET were burned. Still trying to understand what caused the inverter to die.

In October 2018, I bought a new inverter online, 2500W pure sine wave solar power inverter DC 12V 24V 48V to AC 110V 220V digital display. It cost me SGD$213.73.

Manage to get someone to bring over and install the inverter. The system is working again.

Mission Solar Repair/Maintenance for Lisu Churches at Pai (Sai Ngam & Nam Plamong) Thailand

On 31 March 2018, I visited Pai, Thailand on mission work to repair and maintain solar lighting for the Lisu Anglican churches at Nam Plamong and Sai Ngam. While in Pai, I visited Pastor Nippon and his wife Amanda, and their children Sunny, Rosie & Gracie. They build their own house at Pai.

I went to Nam Plamong to repair the solar lighting at the church. It was reported that lightning has damaged the electronics of the solar equipment. The charged controller is damaged and the battery was dead. I replace a new charge controller and new battery. I have also replaced the CFL lamps with LED lamps (8 Watts) which are more efficient and brighter. The system is up and running and operations has return to normal. The Pastor San Ti Suk and his family were very pleased to see the solar working again.

While I was at Sai Ngam, I did some maintenance work on the solar lighting. I cleaned the solar panels with detergent and water as it was dirty. I have also replaced the CFL lamps with LED lamps (8 Watts) which are more efficient and brighter. I have also rewired the toilet lights with new LED lamps.

St Paul’s Church members visited Sai Ngam church and teaches the members and leaders on bible lessons. George Ong, Tang Shin Yong, Christina Chng & Jin Rong Sim.