The energy regulator and the Industrial Works Department are at loggerheads over the former's decision to allow solar rooftops to be operated without a factory permit granted from the latter.
Direk Lavansiri, chairman of the Energy Regulatory Commission (ERC), said applicants to the solar rooftop scheme and signers of power purchase agreements with the Metropolitan Electricity Authority (MEA) and the Provincial Electricity Authority (PEA) are not required to obtain a permit to produce electricity for sale.
By law, solar rooftops of up to 10 kilowatts' capacity have been considered electricity-generating power plants and require factory permits.
But Mr Direk yesterday said a solar rooftop cannot be considered a factory since it does not require equipment or change the purpose of the building space.
"Besides, solar power is a clean energy, with no water, air or noise emissions that can harm the environment like factories generally do," he said.
"Solar rooftops are thus not considered factories."
The ERC is the sole agency in charge of the country's energy security.
"As a result, a decision on whether an energy project is a factory should come under the authority of the ERC," Mr Direk said.
He said the ERC will inform applicants of the solar rooftop scheme as well as the MEA and the PEA to proceed with the proposed sales of solar power.
However, Nuttapon Nuttasomboon, director-general of the Industrial Works Department, accused the ERC of rushing to conclude the matter without discussing it with the department.
The department will ask the Office of the Attorney-General to rule which agency has authority over solar rooftop operation, he said in an interview with the Bangkok Post.