Published on 02/12/2013
Solar flair How to get the most out of the government's rooftop electricity scheme. All the talk about solar power's benefits has prompted the energy industry and even end-users to pin their hopes on a resource that Thailand enjoys in abundance _ sunlight.
More universities are encouraging students to design houses and buildings with solar rooftops. These are samples of designs from architectural students from Silpakorn University. COURTESY OF PROF SATTA PANYAKAEW, FACULTY OF ARCHITECTURE, SILPAKORN UNIVERSITY
But advocates warn many aspects still need to be sorted out, especially regarding the sought-after solar rooftops for residents. They say the solar-rooftop incentive scheme for residents should be extended, arguing that the application period was too short, regulations posed obstacles and the number of homeowners applying was quite low. Kawin Thangsupanich, secretary-general of the Energy Regulatory Commission (ERC), said the electricity buy-back policy for solar rooftops should be promoted amid the ongoing energy crisis and swelling electric bills. He notes that solar and wind are clean, free energy sources that will never run out as natural gas is likely to, probably within seven years. The cost of importing energy is high, meaning electric bills that rise and never go down.
Thailand's electricity production capacity is now just 30,000 megawatts, against up to 60,000 MW needed in the next decade. Solar is an alternative energy that homeowners can use or generate income by selling electricity at a rate of 6.96 baht a kilowatt-hour to the Metropolitan Electricity Authority (MEA) or Provincial Electricity Authority (PEA) under the scheme. Today's electric bill is 3.75 baht per kWh on average. After the solar-rooftop incentive scheme opened on Sept 23, total power production capacity submitted by homeowners was just 40 MW compared with a quota of 100 MW. The scheme ended on Nov 15, less than two months after it took effect, despite a wait of three years since subsidies from the adder tariff programme ended in 2010. The ERC expects a second round for the same scheme next year, said Mr Kawin. Under the scheme, a house selling electricity generated by a solar rooftop to the MEA or PEA must be categorised as residential service (Schedule 1) on the electric bill. Electricity production capacity must not exceed 10 kilowatts. Despite an attractive selling price of 6.96 baht per kWh, the scheme drew few homeowners, possibly due to the sign-up period being too short and many not knowing about the incentive. Another issue: installing a solar rooftop involves both a factory operating permit and city zoning laws. Any house wanting to generate more than 3.73 kW of electricity from solar must submit a factory operating permit (Ror Ngor 4) to the Industrial Works Department, according to the Factory Act. If located in a zone where factories are not allowed, the house must generate less than 3.73 kW. According to the ERC, every kilowatt of electricity generated by a solar rooftop requires an investment of 60,000 baht on average and can generate an income of 8,000 to 9,000 baht a year (an initial return rate of 10-12% and a break-even point within seven years). "We've known the problems since the [solar rooftop] policy was announced," said Mr Kawin. "Now the agencies that supervise the regulations are revising them to facilitate and boost solar rooftops in the housing sector."
Prof Dusit Kruangam, chairman of the Thai Photovoltaic Industries Association, maintains that each province is suitable for solar rooftops except those locations that are shaded or obscured by high buildings or mountains. The main equipment for a solar rooftop includes a solar module, support structure, inverter, AC panel, AC surge protector, electric metre, ground system and cables linking the solar cell to the inverter and the electricity pole outside the house. Online monitors should be installed in order to cross-check how many kilowatthours of power are generated each month with the MEA or PEA. Total cost for a solar rooftop, including equipment, online monitor and fees for survey, design and engineering: 70,000 to 80,000 baht per kW, said Prof Dusit. Thus, the break-even point is about nine years. He suggests a simple estimation of whether a house has potential as a solar rooftop. A one-square-metre solar panel weighs 15 kilogrammes. If three or four people whose weight is 70 kg each can walk on the roof, that roof can support solar panels. For best results, panels should face south. If not, east or west will do but north is not recommended. If the roof has a slope of less than five degrees, however, the north is suitable. Yearly maintenance and cleaning of solar panels costs about 1,000 baht. Dust on a solar panel's surface will reduce its efficiency. Prof Dusit, also managing director of Thai Solar Future Co, has a solar rooftop on his house under the previous adder scheme from 2009, which offered a selling rate of 10.50 baht per kWh. He spent 300,000 baht to install 15 sq m of solar modules that can produce 2 kW of electricity, generating an income of 2,200 baht a month. He said the solar rooftop not only cuts electric bills and generates income but also reduces heat on the roof and the temperature inside the house.