Worth more used than sold

Thailand will buy the surplus electricity from a home roof at ฿2.20 a unit. It has paid that price since 1 January 2021, and in September 2026 its energy policy council approved keeping it for twenty years.

The same household buys its electricity at up to ฿4.3583 a unit, before the fuel charge and VAT. A unit used at home is therefore worth about twice as much as a unit sold, and more once the fuel charge and VAT are added. Almost everything about who the scheme suits follows from that.

The price nobody has moved

Household solar buy-back began in 2019 at ฿1.68 a unit for ten years. Two annual rounds were each meant to buy 100 megawatts. They drew a little over 400 applicants and three to four megawatts between them, InfoQuest reported in 2022, which it put down to a price that did not tempt people. (The Energy Regulatory Commission’s own running total in June 2021 was 1,683 participants and 9.018 megawatts across 2019 to 2021.)

The National Energy Policy Council raised the price to ฿2.20 from 1 January 2021, for new applicants and for everyone already selling at ฿1.68. The target was cut to 50 megawatts that year and to 10 megawatts in 2022.

In 2026 the price stayed and the target grew. In April the council approved a new round of 500 megawatts at ฿2.20 for ten years, with no more than 5 kilowatts sold per meter. Both utilities opened applications on 1 July 2026, first come, first served; the Provincial Electricity Authority’s project page gives an end date of 30 November 2027.

On 18 September the council went much further. On the government deputy spokesperson’s account it approved:

• 10,000 megawatts in total, “or about a million households”, including the 500 already opened;
• panels on the ground and floating on water, not only on roofs;
• the same ฿2.20 a unit, for twenty years instead of ten;
• the same 5-kilowatt limit on what each meter may sell, though a household may install more for its own use.

The council told the regulator to write the rules, and told the agencies to find a way to extend existing ten-year contracts so that nobody has to cancel and reapply. On 6 October the Metropolitan and Provincial Electricity Authorities’ scheme pages still said ten years.

Used or sold

Thailand uses net billing, and the September decision kept it. The household uses its own power first. Only what is left over is sold, at the fixed ฿2.20. Under net metering, which campaigners such as Greenpeace Thailand have asked for, an exported unit would cancel an imported unit one for one. That is not the rule.

From the September 2026 bill, the regulator’s residential energy charge is no more than ฿3.00 a unit for the first 200 units, ฿4.1584 for units 201 to 400, and ฿4.3583 above 400. The fuel adjustment charge, 16.23 satang until December, and 7% VAT are added on top (article 72 Your bill is not broken sets out the bands). The buy-back price is a fixed ฿2.20.

So for a household whose bill reaches the top band, each unit it avoids buying is worth more than twice what a unit sold earns. For a household that stays under 200 units a month, the gap is smaller.

The Provincial Electricity Authority says this plainly. Its scheme page says the programme emphasises panels that produce power for the household’s own use, with what is left over sold. The project’s own assessment, as the deputy interior minister described it to Thansettakij, is that households with monthly bills of ฿3,000 to ฿4,000 or more benefit immediately. Earlier analysis by Kasikorn Research, reported by Thai PBS Policy Watch, said the same thing in another way: rooftop solar suits homes that use their power in the daytime.

That describes a household that is at home, with the power on, in the middle of the day.

Who may sell

On the utilities’ own pages, a seller must be:

• an individual, on the residential tariff;
• the owner of the electricity meter;
• selling no more than 5 kilowatts through that meter (the metropolitan authority requires an export-limiting device on any inverter over 5 kilowatts);
• using an inverter registered with the utility, with a wiring diagram signed by a licensed electrical engineer.

The provincial authority charges ฿2,140 to inspect the connection, and states that the applicant pays for the whole installation.

A tenant is not usually the meter’s owner. Thansettakij’s guide to the 2026 round says tenants cannot apply. The scheme, as written, is for whoever owns the meter.

The tax break: worth most to those who pay most

The Revenue Department issued its rules on 30 September 2026, under a Royal Decree in force since 3 March. On its Director-General’s Announcement No. 470:

• up to ฿200,000 of what was actually spent on the equipment and its installation is exempt from personal income tax;
• the contract and the request to connect to the grid must both fall between 3 March 2026 and 31 December 2028, and the exemption is claimed in the tax year the connection succeeds;
• one system, one claim, per person, over the whole period;
• the claimant must be the registered electricity user and the person who applied to connect, on the residential tariff, with no more than 10 kilowatts installed;
• the evidence is an electronic tax invoice from a VAT-registered seller, naming the buyer’s tax number and saying it is for solar equipment. The claimant must tell the utility they intend to claim, and the utility reports to the Revenue Department by 15 January of the following year.

An exemption is worth whatever tax it removes. On the Revenue Department’s rate table, the first ฿150,000 of net income is untaxed, and the rate then rises in steps from 5% to 35%. Taking ฿200,000 off a net income of ฿300,000 saves ฿7,500. Taking it off ฿1 million saves ฿40,000. Taking it off ฿6 million saves ฿70,000. For anyone whose net income is ฿150,000 or less, it saves nothing. (This is Bangkok Lad’s arithmetic from the published rates.)

That last group is most filers. In the 2024 tax year, 12.57 million people filed personal income tax returns and 7.43 million of them, 59.1%, owed nothing, on House budget committee figures reported by Krungthep Turakij. Only 5.14 million paid any income tax at all.

A law lecturer writing for InfoQuest has also read the decree’s wording strictly. It exempts “income paid” for the system. On that reading, money borrowed to buy the system is not income paid, and instalments paid after the year of connection do not count. That is one academic’s reading, not a ruling, and the Revenue Department’s announcement does not address it directly.

The grant: proposed, not yet approved

The government has proposed a cash grant of ฿50,000 per household. As the deputy interior minister described it on 2 October, reported by Thansettakij:

• ฿75 billion, for 1 million households and then a further 500,000, from the ฿400 billion emergency borrowing decree;
• the site must already have an electricity meter, and the system must be at least 5 and at most 10 kilowatts, on a roof, on the ground or floating;
• state welfare card holders may take part;
• low-interest loans at 2.5% for about seven years from three state banks (the Government Housing Bank, the Government Savings Bank and the Bank for Agriculture and Agricultural Cooperatives), with sale proceeds paid straight to the lender;
• a free smart meter, and installers who must be registered with the utilities;
• registration was expected on 1 November. The finance minister had earlier said mid-October.

As of that report, the proposal was before the committees that screen spending from the borrowing decree. The energy council and the regulator were still to amend their rules so that sale income could be paid directly to a lender. It is not yet approved, and nobody can register for it yet.

If it goes ahead as described, it is the first part of the system that reaches people the tax break cannot, including welfare card holders. It still requires a meter, room for at least 5 kilowatts, and the rest of the installation cost, which has not been published. Whether a tenant can take part has not been addressed in what has been reported.

What this adds up to

The buy-back is a published price, fixed for twenty years. That is what lets a bank lend against it and take the proceeds. On this site’s first finding, a standard and a published price are what make a system work. Here the state publishes the price below every band it charges, and at about half the top one. The system works, but for using power, not for selling it.

The subsidies follow the second finding. The tax break is drawn around income-tax payers, and is worth more the higher the bracket. The right to sell is drawn around people who own the meter. As article 89 The wrong way round put it, the category is drawn around people who already had options.

The proposed grant is the first part that tries to reach beyond them. Whether it does will depend on rules that have not been published yet.

Nothing in this article is advice on whether to install panels, apply, borrow or claim.

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Common misconceptions

“The state buys solar power at the same price I pay.” It buys at ฿2.20 a unit, fixed. Households pay up to ฿4.3583 a unit before the fuel charge and VAT.

“The meter runs backwards.” Thailand uses net billing. Power is used at home first, and only the surplus is sold, at ฿2.20.

“The contract is now twenty years.” The energy council approved twenty years on 18 September 2026. The regulator’s rules and the utilities’ pages still said ten years on 6 October.

“Everyone gets ฿200,000 back.” It is an income-tax exemption on up to ฿200,000 of spending. It saves nothing for anyone whose net income is ฿150,000 or less, and at most ฿70,000 at the top rate.

“I can get ฿50,000 now.” The grant is a proposal. Registration was expected on 1 November, subject to approval.

“A tenant can sell power from the roof.” The seller must own the meter. The utilities’ rules are written for the owner.