In 2009-10 energy policymakers asked investors to apply for solar farm licences. Licences for 2,537 MW were granted to solar farms, but only 1,083 MW have started under a commercial operation date, with another 400 MW under construction. This leaves 1,054 MW held by inactive investors, said PEA's governor Numchai Lorwattanatrakul.
"We believe only 500 MW from those inactive licences will come online, with the remainder expiring," said Mr Numchai.
Last week the National Energy Policy Council set a deadline for solar farm and solar rooftop licence holders to begin operating by the end of next year, paving the way for state utilities to start the second phase of solar power development.
The inactive licence holders will have a feed-in tariff of only 5.66 baht per unit on top of the electricity rate if they start producing electricity, while those operating or under construction will receive an adder rate at 6.5 baht on top of average power rate.
For the solar rooftop programme, another 867 MW is targeted for development.
He said PEA would support the rooftop scheme for commercial buildings instead of residences because of higher demand from the former.
Last year commercial building investors requested rooftop licences for over 300 MW, but the quota was set at 100 MW. The household sector requested only 33 MW.
Investors can no longer relocate their rooftop construction sites for existing licences, and if companies have access to transmission lines the licence may be invalid, he said.
A source said the next phase is expected to open for investors, with licences of 2,000 MW for the next two years at a new feed-in tariff rate in line with the new technology that helps lower the cost per unit.
Meanwhile PEA signed a memorandum of understanding yesterday with China-based CYG Sunri Co to upgrade the transmission system at PEA's pilot substation at Nong Ki in Buri Ram, allowing improvements for a smart grid in the future.