The state-run Electricity Generating Authority of Thailand (Egat) is planning to talk with power authorities in Cambodia and Myanmar to trade electricity from Thailand at a combined capacity of 500 megawatts.
Patana Sangsriroujana, deputy governor for policy and planning, said Egat has been ordered by Energy Minister Sontirat Sontijirawong to talk with the two governments about future power trading.
"The sales to Cambodia will happen quicker than Myanmar because some transmission lines have been developed in Cambodia," said Mr Patana.
"Myanmar requires new investment for power infrastructure."
He said the electricity trade to both countries should begin by 2023. The energy ministers of the three countries need to agree on a contract.
Mr Patana said the Laos government is also interested in trading power to Cambodia and Myanmar under its Battery of Asia policy.
After the talk ends, both buyers and sellers will study the feasibility in more detail such as power capacity, locations of transmission lines, power tariffs and periods of trade.
This new trade is another step after a power agreement between Laos, Malaysia and Thailand.
The three countries agreed to a second power purchase under the Laos, Thailand and Malaysia Power Integration Project (LTM-PIP) in September during the Asean Ministers on Energy Meeting and Associated Meetings (AMEM) in Bangkok.
Trade between the three countries has increased to 300MW, from 100MW in the first LTM-PIP.
Mr Patana said community-owned power plants will be developed from renewable resources under the government's Energy for All scheme, resulting in power generation of 500-1,000MW, which can be traded to neighbours in Southeast Asia.
In addition, representatives from Myanmar said during AMEM the country needs to widen power access to locals.
Some 50% of Myanmar's population cannot access electricity, which is obstructing its economic growth.
Mr Patana said Egat's preliminary study found Thailand can trade electricity to Myanmar through the immigration checkpoint at Mae Sot, Tak.
Mr Sontirat, the energy minister, said last week Thailand's power supply has a large surplus with installed capacity of 44,000MW.
Peak demand is 32,000MW, leaving plenty of room to trade power to neighbouring countries.
"A lot of new power plants are expected to begin operation over the next three years, increasing the capacity surplus to 30% from 27% now," said Mr Sontirat.