LAST year, I installed a solar system under the net energy metering (NEM) scheme approved by the Sustainable Energy Development Authority (Seda). NEM is a mechanism which allows electricity consumers in Peninsular Malaysia and Sabah to sell excess electricity generated from their solar photovoltaic (PV) systems back to the grid.

I let the contractor do the entire justification and costing. Later, I found out that it was not really NEM because the energy buying rate from Tenaga Nasional Bhd (more than 50 sen/unit) was higher than the selling rate (31 sen/unit). Fortunately, the real NEM was implemented in January 2019 with identical buying and selling rates.

I also found out that some assumptions made by the contractor were not justifiable. He was trying to make the project look good by making the return-on-investment (ROI) period shorter. I was not happy with this and started to learn about the practical side of the system myself. I learnt that I had paid the contractor more than necessary and that ROI could be even shorter.

The system is actually quite simple and DIY (Do-It-Yourself) is possible for people who know basic electrical wiring. Normal electrical contractors can be engaged if they don’t.

With NEM, solar energy is generated for immediate use and also for export to TNB during the day. At night, energy is imported back. Any excess usage will be charged by TNB based on the normal tariff.

The issue is why must we use registered contractors who may impose exorbitant charges? I am sure there are many reasonable contractors out there, but why should we go through the lengthy process and wait for many months to get one?

I would like to propose to the Energy, Science, Technology, Environment and Climate Change Ministry (Mestecc) that NEM should be at the users’ option when they subscribe to TNB for electricity supply even if they may need to pay extra for meters that have energy import and export readings. Furthermore, solar energy generation from a house would not exceed its normal monthly electricity consumption. So, instead of submitting a special application for NEM, a simple registration should be adequate.

We should encourage more house owners to install solar systems. For typical households with electricity bills of RM400 per month, their daily usage is around 30 units (kWh). By installing a 3kW solar system, they can save more than RM150 per month. If they install a 5kW solar system, the saving is more than RM250 per month.

Over 10 years, the total saving is RM18,000 and RM30,000 respectively. ROI is within six years.

Instead of giving a discount, housing developers could bundle a solar system with the house they sell. It should be noted that solar panels will last at least 25 years, during which electronic equipment (controller and inverter) may have to be replaced.

A 5kW system requires about 30 sq m of roof space, which is less than half of a typical link house. If there are one million houses using the 5kW system, the total daily generated solar energy is around 16.5GWh, which is about a quarter of the daily energy generated by TNB (excluding independent power producers/ based on 2016 report).

This is a completely green energy, hence there would be a significant reduction of CO2 generation in the country.

I am sure there will be challenges for TNB if free-for-all-NEM is implemented, but I am confident that these can be addressed.

DR MOHAMED AWANG LAH

Fellow

Academy of Science Malaysia

Kuala Lumpur