The government has no plan to buy renewable power from 2018-2023, saying the country has enough reserved power for the medium term.
Energy Minister Siri Jirapongphan said the state will not buy more renewable-based electricity from small power producers and very small power producers, nor will it purchase from local or overseas plants.
He said the cost of renewable power would make Thai consumers pay a higher power bill, 20-25 satang more per kilowatt-hour.
Moreover, the government has its Quick Win projects that include 12 solid waste power plants with a total capacity of 77.9 megawatts (MW).
"We are confident there will be no effect to power used by local households, with the power bill decreasing the next few years because the cost of renewable power plants is relatively higher than fossil-based plants," said Mr Siri.
Thailand's power development plan for 2015-2036 saw energy policymakers set the proportion of renewable power at 20% of the total power-generating system, or 19,634MW by 2036.
The figure is relatively high compared with the current 7,490MW.
He said state utilities will pay a feed-in tariff to private power producers of 2.40 baht per kilowatt-hour, the same rate Electricity Generating Authority of Thailand pays now.
Renewable power was offered to Thai investors in 2007 through a government support scheme for new development with adder rates (the rate state utilities pay operators) of 8.5 baht per kilowatt-hour for solar panel-generated electricity.
Over the past decade, renewable power has expanded in capacity from 100MW to almost 10,000MW at present.
Mr Siri said the government will continue to promote biomass power plants in the Deep South -- Yala, Pattani and Narathiwat -- with total capacity of 300MW as it aims to solve power shortages in this part of the country over the next 3-5 years.
The government expects to implement the Pracha Rat scheme to develop the biomass power plants in those three provinces.
These projects are scheduled to be finished by the third quarter this year. The South has biomass power plant capacity of 50MW at present.
Mr Siri said energy policymakers have agreed to postpone a scheduled commercial operation date for solid waste power plants in eight locations, including the 12 Quick Win projects from 2019 to 2021.