Thailand could significantly accelerate rooftop solar deployment by reforming its current incentive and regulatory framework, according to a new report from the Institute for Energy Economics and Financial Analysis (IEEFA).

The report argues that stronger rooftop solar incentives could reduce Thailand’s dependence on imported liquefied natural gas (LNG), improve energy security and reduce pressure on electricity costs.

Thailand’s Solar Market Is Growing — But Rooftops Are Lagging

Natural gas currently accounts for approximately 66% of Thailand’s electricity generation.

As domestic gas production declines, Thailand has become increasingly dependent on LNG imports, exposing the power sector to global fuel price volatility and potential supply disruptions.

The financial impact is already significant. By March 2026, Electricity Generating Authority of Thailand (EGAT) had accumulated more than THB36 billion (approximately US$1 billion) in losses from previous energy crises.

At the same time, Thailand has substantial solar potential.

By early 2026, the country had approximately 11.8 GW of installed solar capacity, including:

• 8 GW of ground-mounted utility-scale solar

• 3.6 GW of rooftop solar

The gap highlights a major opportunity for distributed solar.

Why Has Rooftop Solar Adoption Been Slow?

Despite years of policy support, several barriers continue to limit Thailand's rooftop solar market.

The IEEFA report identifies:

• High installation costs

• Low solar buyback rates

• Restrictive capacity quotas

• Policy uncertainty

• Self-consumption limitations

Thailand's rooftop solar installation cost is estimated at approximately US$936/kW, nearly 50% higher than comparable markets such as Pakistan, Malaysia and Vietnam.

Under the current "Solar for Thai People" net billing scheme, the buyback rate is approximately THB2.2/kWh, compared with average retail electricity tariffs of around THB3.88/kWh.

This economics results in residential rooftop solar payback periods of approximately six to seven years.

Capacity restrictions have also constrained market growth. The 90 MW residential quota established under Thailand's 2019 net billing scheme was originally intended to remain in place until 2030, but was already fully utilised by 2024.

Could Net Metering Change the Economics?

One of the report's key recommendations is to move from net billing toward net metering.

Under a net-metering structure, consumers could offset electricity consumption at retail electricity rates rather than receiving a lower compensation rate for exported electricity.

According to the report's estimates, this could reduce payback periods to approximately:

5.5 years for a 5 kW residential system

and

4.5 years for a 10 kW system.

The report also recommends:

• Increasing rooftop solar buyback rates

• Streamlining tax incentives

• Removing restrictive solar capacity limits

• Relaxing self-consumption thresholds

• Accelerating solar-plus-storage deployment

• 
  

These changes could improve project economics for both residential and commercial customers.

Pakistan Offers a Different Model

The report points to Pakistan as a potential reference case. Since 2018, Pakistan has deployed approximately 38 GW of solar capacity, supported by policies including reduced trade barriers, fewer capacity restrictions, attractive net-metering arrangements and higher buyback rates.

Combined with falling solar module prices and high electricity tariffs, these measures helped reduce payback periods for some net-metered systems to less than two years.

By the end of 2025, Pakistan had more than 350,000 solar connections.

Thailand's current framework is more fragmented, with different mechanisms covering residential rooftop solar, ground-mounted projects and community solar.

The contrast suggests that policy design can be just as important as solar resource availability in determining rooftop PV adoption.

Why BESS Could Become the Next Step

The report also highlights solar-plus-battery energy storage systems (BESS) as another potential pathway for Thailand's rooftop solar market.

Greater integration of batteries could allow households and businesses to consume more of their own solar generation rather than relying on export compensation.

This could be particularly relevant under Thailand's current policy structure, where self-consumption can deliver stronger economics than exporting excess solar electricity.

For the C&I market, the combination of:

Rooftop Solar + BESS + High Electricity Consumption

could therefore become increasingly attractive if policy barriers are reduced.

The Bigger Market Signal

Thailand's rooftop solar market is not constrained by a lack of solar resources.

The bigger issue is project economics and policy design.

If Thailand moves toward stronger incentives, higher buyback rates, fewer capacity restrictions and greater solar-plus-storage adoption, rooftop PV could play a larger role in reducing LNG exposure and strengthening consumer energy independence.

For solar and BESS developers, installers and equipment suppliers, the key opportunity may therefore lie not only in Thailand's existing 11.8 GW solar market, but in the 3.6 GW rooftop segment that still has significant room for expansion.