FAQ1. Self-Consumption – Net Energy Metering
- Self-consumption allows consumers to be efficient in the usage of electricity, through the installation of a renewable-based energy system on their property.
- Economically feasible IPP depreciates over 30 - 50 years with high operational fuel cost. The life of our solar PV system is similarly 30 to 40 years. (Search Google: Oldest photovoltaic array in operation)
- Electricity can only be generated during sunlight hours. However, here in Malaysia we have TNB as a backup. We are not on our own when we use our own electricity generated by solar PV.
- The most economical configuration for self-consumption is grid tie system, i.e., using grid tie inverter. The system synchronizes itself with TNB supply.
- TNB buys from IPP between 34.7 sen to 37.4 sen. If we amortize the capital cost over 25 years, our cost of electricity is only 16 sen.
- Current urban middleclass consumers subsidize low income electricity users. Residential consumers pay the marginal rate of 57.1 sen/kWhr whereas low income and rural consumers pay between 22 to 33 sen/kWhr.
- GST is applicable on all usage more than 300 units (kWhr). Hence, from 2015 April, there is an automatic increase of 6 % on your electricity bill.
- When our country goes through the next subsidy rationalize program, expected electricity rate will increase between 25 to 39 percent on the average. But the top end residential users are expected to pay an increase of say 40 percent on the marginal rate of 58 sen/kWhr, which is about 81.2 sen/kWhr.
- At 80 sen/kWhr, 1 Watt of system generates 365 x 3.8 x 0.80 = RM1.11 a year of electricity. Payback on RM5 a watt is less than 5 years, and you will have free electricity for the rest of the 20 years.
- To size the solar PV, you have to first determine how much power you use during the sunlight hours in a day. You will use this information to calculate the PV solar system. Sometimes, it is more accurate to use monitoring devices to help to do this over a period of time. This is especially true for commercial applications.
2. What does the PV Solar System comprise of? What does the inverter do?
- Comprises of Jinko PV modules, Trannergy inverters, junction box with circuit breakers and surge protection devices, cables and solar rack structure. Solar PV electrical output is DC.
- The inverter changes the DC into AC to suit the TNB grid AC input. It automatically syncs with the existing power supply so as not to clash with the existing power supply. Our inverter is a grid tie inverter, meaning that it will not work without TNB supply.
The AC circuit is connected into the house electricity supply so that it will supplement the TNB incoming power.
- Can I use the solar-generated electricity at night?
No. The PV solar system only generates electricity in the day using the sunlight. At night, we will solely depend on TNB for the supply of electricity.
- Can I only use electricity generated by my system, and not any from TNB?
- In theory this is possible. You can have a battery bank to store the electrical energy in the day and use it at night. However, the cost of such as system may be twice what it will cost you using it on a grid-tie system. The battery will come. Many hybrid products are already in the market. Talk to us about it.
- It is best to use the PV solar power to supply the most expensive part of the TNB supply. We recommend that you use the PV solar electricity to supplement the TNB incoming supply.
- We also supply stand-alone systems for remote use. We supply this system for fish farm in the open sea or for plantation. This system is independent from the grid.
- What other advantages are there in putting up the PV system on my roof?
- The PV solar system on the rooftop of your house protects the roof and results in a cooler environment in the building. Savings in cooling cost can be as much as 40 percent. Your roof will last longer, and you will have a cooler house.
- You will also save on your bill when using air-conditioning because the inside of the house will be cooler by the additional layer of roof material.
- What type of maintenance do the solar panels require? What about the rest of the system?
- The solar module may need some cleaning if they are dirty. Malaysia’s wet weather will help to wash away most of the dirt. This is the only maintenance you will need, maybe once or twice a year.
- You will not be required to oil or grease any part as the system can be considered as solid state. There is no moving part.
- If the system is not generating electricity, you will need to call your installer to check. Perhaps you may have a loose connection. PV solar system can generate as much as 1000V DC and is dangerous. Do not attempt to do anything on your own.
- The inverter has a warranty of 5 year or 10 years. It will last a good number of years after that. Trannergy inverters comes with a 10 year factory warranty.
- What is the life span of my PV Solar system?
- In Europe, the PV solar system has lasted more than 30 years. Your system will similarly last as long and maybe longer. The solar panel manufacturers generally give 25 years of yield warranty of 80 percent. They expect the system to last at least that number of years.
- PV modules will not just die. It will degenerate, and will last a very long time, however the output will deteriorate over time.
Is generating PV Solar electricity for self-consumption against the law?
The Electricity Supply Act 1990 subsection 54 provides the exemption from section 9 of the Act for the usage of PV solar for electricity generation and uses.
For a three phase system, at a voltage not exceeding low voltage with a capacity of up to 72kW;
- For a single phase system, at a voltage not exceeding low voltage with a capacity of up to 24kW.
- What is NET Metering?
- Net metering is a metering system implemented by the electricity distribution licensee (TNB) where the net amount of electricity between consumption and generation is read within a fixed period (monthly). For example, when an owner of a PV solar system monthly bill is a result of the difference between the amount of energy generated and the amount of energy consume.
- We recommend you to visit www.seda.gov.my for more information.
- Financials related to PV Solar
- What is the rate of consumer electricity tariff?
How do I calculate the payback for my investment?
As an example, we use 1 kW PV solar system as a basis. Say the cost of buying a fully setup system is RM5000. The electricity generated a year is
· In the recent articles on electricity tariff in Malaysia by the Association of Water and Energy Research (AWER), after the coming rationalization exercise at the end of 2015, we expect the price of electricity tariff to increase between 24 percent and 39 percent. If the rise is 24 percent, the new tariff is Rm0.71, and the yearly value of electricity generated is RM907, and the payback is thus (5000/907) 5.5 years. This is about 15 percent return on investment.
How much is my electricity cost from solar PV generation?
This is another way to look at the cost and return on investment. By using the same assumptions above, a 1kW PV solar system cost RM5000. The system will easily last 25 years with guarantee 80 percent power output at the end of the 25 years period. As indicated in another part of this site, the system lifetime is more than 30 - 40 years. The power output over the system lifetime is as follows:
· Cost of electricity generated is (RM5000/31000 kWHr) = RM0.16/kWHr
· Compare your electricity generation cost to the IPP price sold to TNB
· Genting Sanyen 375MW 35.3 sen/kWHr
· Segare Energy 1.3 GW 36.3 sen/kWHr
· TNB Pasir Garden 275 MW 37.4 sen/kWHr
· TNB Prai 1.07 GW 34.7 sen/kWHr
· My own PV solar system 16 sen/kWHr
Be your own IPP!
- What are the factors that will affect my power generation?
- Factors which affect your PV power generation are shadow, temperature and incident angle of solar irradiance. Shadow falling on any part of a solar panel will affect the whole system for a normal home rooftop. Therefore, it is important that the area surrounding your PV solar system is clear of shadows during the day.
- The hotter the surface of the solar module, the lower is the generation of electricity. Therefore it is important that there is sufficient space between the panel and the top of the roof for aeration purposes.
- In western countries, some solar PV system is built to track the sun to allow it to collect more solar irradiance. Our rooftop normally is about 20 degrees tilt and is not a very ideal slope for collecting sun energy compare to the rooftop of common metal deck on factory top.
- Can PV solar panels be installed on all roof types?
- This is generally true. It can be installed on any relatively flat surfaces. The flatter the roof, the better the solar irradiance collection.
- Will installing PV solar panels cause roof leakage?
- Generally this is not true, unless of course the installer is careless and damages something along the way. In fact, having a layer of solar module on the roof will make your roof last longer.
- What is the best roof orientation?
- The best orientation is the slope to face north-south. When the sun travels across the sky in the day, both sides of the roof will be evenly exposed.
- How many hours of sunshine do we have in a day?
- In most parts of Malaysia, we have about 4.5 Hrs. of peak sun hours. We have more in drier places like Kedah and Perlis which maybe close to 5 Hrs or more.
20. Stand Alone System
- Stand Alone system uses battery to store the electricity to be used after sunshine hours.
- In a Stand Alone system, we need to balance the load, generation and storage. Hence, a good understanding of the load is important in the design of a Stand Alone system.
- Because of the relatively high total cost of the system, we cannot use the cost of grid supply electricity to justify a Stand Alone system. Hence, Stand Alone system is only useful where infrastructure cost is high. Stand Alone system cost about 2 to 2.5 times that of standard grid tie system.
- However, when we compare Stand Alone PV system with diesel generator, the operational cost of using diesel generator is prohibitive. A PV Stand Alone system is much more desirable.
- Vanadium battery is a new class of battery with close to unlimited battery life. The battery is the weakest link in a Stand Alone system.
- In a Stand Alone system, the common solar charger is PWM charger and MPPT charger. The PWM charger function is to protect the battery while the MPPT charger optimizes the sun light harvest. MPPT charger is generally more expensive.
- The more efficient way is surely by DC. However, because of the range of products available running in AC, we have to cater to the need by using an AC inverter.
21. Solar Hybrid System
- Generally, a solar hybrid system refers to a system using solar PV, battery and diesel generator. However, in our urban setting, we can design an on-grid hybrid system.
- As in the hybrid system using diesel generator, an on-grid hybrid uses TNB as our back-up.
- Advantage of this system is we can use more of the power we generate for ourselves and use a UPS (Uninterrupted Power Supply) as a back-up to our system. In Malaysia, this is a luxury, because TNB is generally dependable.
22. Our Products:
- World class solar PV panel from Jinko Solar, 1st in the world list in the NYSE.
- Solar panel makes up about 50 percent of the cost of the system.
- World class supplier for inverters, Trannergy. Product is sold in the USA, Australia and Europe.
- High quality balance of system according to international standard. We use name brands such as Schneider and Hager.
- Lapp DC cables according to solar PV industry standard.
- Amsolar Sdn Bhd extended 36 months warranty, including health checks and service. We follow the Malaysian Standard for all our assembly processes.