EXPAT COUNSEL, Bangkok Post, 6 April 2014.
This week we continue our investigation of solar power in Thailand by highlighting some of the alternatives for installing solar technology in private homes. Could you really make your breakfast with just coffee grounds, water, two eggs, a slice of bread, a few appliances and the sun?
The decrease in manufacturing costs for solar photovoltaic (PV) cells is making solar energy an increasingly viable option for smaller scale use; whether to save money on electricity bills, to sell to the grid or as a carbon-footprint reducing lifestyle choice, there exist multiple options on the market. Prices for solar cells in Thailand are among the lowest in the world, ranging from 23 to 42 baht per watt. These are less than a quarter of the comparable prices just over a decade ago, and compare to European prices of €0.87 to €1.45 (39-65 baht) per watt. According to the Energy Regulatory Commission (ERC), every kilowatt of electricity generated by a solar rooftop requires an average investment of 60,000 baht (depending on manufacturer) and can generate revenue (or presumably savings) of 8,000 to 9,000 baht a year. No wonder solar panels are appearing more frequently on rooftops, car parks and roadsides throughout Thailand.
As mentioned last week, solar equipment capable of generating less than 3.87kW can be installed without a licence. For most homes this will be sufficient. There are many online tools that can be used to calculate exactly how many solar panels will be required to meet your needs. For example, energymatters.com.au states that a medium-sized Australian home with two or three people would be best served by a 3kW system. It will cover lighting, a fridge, a TV, a washing machine, a dishwasher, a computer and a small air-conditioner, with the balance of the electricity requirements being met from the grid. This website and others also provide detailed calculators into which the user puts precise data regarding their energy use and specific appliances, allowing a more finely-tuned result.
Once you have selected the appropriate size of solar power system, you’ll want to consult with an expert about your options. Several companies in Thailand specialise in solar installation solutions for your home. Among other things, they will want to know your budget, your location, the physical layout and orientation of your roof and your energy goals. The equipment you purchase will include solar panels, a solar controller, batteries, a solar inverter and cables.
A company employee will help you in the set-up of the equipment, being careful to optimise the position and angle of the solar panels to be in the full sun from 9am to 3pm if possible.
A typical solar power system will have solar panels on the roof connected to a charge controller which is then connected to a collection of external batteries (aka a battery bank). The charge controller sets the rate at which electric current is transferred to the batteries to prevent the batteries from overcharging, while the batteries store the electricity generated from the solar panels. The battery bank (which can also be directly connected to any DC appliances) is then connected to an inverter. The inverter converts direct current into alternating current which can then be connected to the power grid or directly to the electrical wiring of your home.
Not all houses and apartments can accommodate the size, weight and directional requirements of solar panels. A typical solar panel is 158cm x 80cm, and 3.5cm thick. For an installation of 1kW, six such panels are positioned side-by-side. For those living in apartments, smaller systems can be installed subject to the availability of space and access to sunlight. Weight is another issue. A single mono-crystalline silicon solar panel weighs between 15kg and 26kg, so a typical 1kW array of panels will add between 90kg and 156kg to your roof. You should certainly consult your contractor to determine if your home can bear the additional weight.
Those living in apartments, and those for whom the weight or size of larger solar panels is a concern, may also have the option of installing a solar-powered air-conditioning unit.
We are told that for the relatively low price of 12,000 baht your current air-con system can be retrofitted with a solar panel, potentially reducing its electricity consumption by up to 60%. Alternatively, a new solar-powered air-con unit can be fitted in your home, with prices starting at 18,000 baht.
Solar panels preheat the freon gas before it enters the compressor, reducing the work that the compressor must do before the freon is pumped into the system, thus reducing the power used.
Sadly, those wishing to have their solar installation connected to the grid for the sale of excess electricity might have to wait. As of October, 2013, the Metropolitan Electrical Authority was no longer accepting applications for participation in the programme. Based on the effectiveness of the current grid-connected systems, applications could reopen in coming months.
Given the attractive feed-in tariff and a possible 25-year contract period for each participant, more users in the domestic and corporate sectors are keen to participate.
Finally, last week we mentioned the ERC’s notification waiving the factory-
permit requirement for grid connections. The Department of Industrial Works, which is responsible for issuing permits, has suggested the ERC did not have the authority to make such a ruling, and have sought a determination by the Office of the Attorney-General. Stay tuned.