Floating solar could play a crucial role in the Association of Southeast Asian Nations’ (ASEAN) regional target of 35% renewable energy in the installed power capacity by 2025, according to a report published by National Renewable Energy Laboratory (NREL).

The report identified 7,301 water bodies —88 reservoirs and 7,213 natural water bodies — as potentially suitable for floating solar deployment in Southeast Asia.

Overall, the floating solar potential ranges from 134–278 GW on reservoirs and 343–768 GW on natural water bodies.

The report states that the potential for floating solar installations is more significant on reservoirs in Laos and Malaysia.

At the same time, it is higher on natural water bodies in Brunei, Cambodia, Indonesia, Myanmar, the Philippines, Singapore, and Thailand.

In Vietnam, the potential remains relatively consistent regardless of the type of water body.

Brunei

Brunei, which relies heavily on natural gas (78%) and coal (21%) for its electricity generation,  aims to generate 30% of its electricity from renewable sources by 2035. Unlike its neighboring Southeast Asian countries, Brunei lacks the installed capacity and significant potential for hydropower, which limits its ability to integrate floating solar with existing hydropower infrastructure.

According to the report, Brunei has no technical potential for floating solar on artificial reservoirs. However, the assessment identified 18 natural water bodies that show promise for future floating solar projects.

The potential capacity for floating solar on these water bodies ranges from 137 to 669 MW, depending on the assumptions made about the distance from the shore.

Cambodia

Cambodia has set a target for its installed capacity mix by 2030, aiming for 55% hydropower, 6.5% biomass, and 3.5% solar, while fossil fuels are expected to make up for the remaining 35%.

Currently, hydropower is the primary source of electricity, accounting for approximately 45% of the total generation as of 2020.

Estimates suggest Cambodia has a floating solar potential of 15-29 GW on reservoirs and 22-46 GW on natural water bodies.

Indonesia

With an abundance of renewable resources and an ambitious goal of achieving net-zero emissions by 2060, Indonesia’s power generation mix currently relies heavily on coal (60%), followed by natural gas (18%), renewables such as hydropower, geothermal, and biofuels (17%), and oil (3%).

Although Indonesia possesses substantial wind and solar resources, these technologies have not yet been widely deployed.

PT Perusahaan Listrik Negara, the state-owned utility in Indonesia, plans to add approximately 21 GW of renewable energy capacity between 2021 and 2030, accounting for slightly over half of the new capacity additions. Hydropower is expected to contribute 4.9 GW within this planned capacity, while solar power is projected to contribute 2.5 GW.

According to the report, a total of 1,858 water bodies (including 19 reservoirs and 1,839 natural water bodies) were identified as potentially suitable for floating solar projects. The technical potential estimates indicate a broad range of floating solar capacity, spanning from 170 to 364 GW.

Laos

By 2025, Laos aims to achieve 30% of its total energy consumption from renewable sources.

According to the report, unlike most other ASEAN countries, Laos exhibits a higher potential for floating solar installations on reservoirs than natural water bodies. This is likely due to the country’s significant domestic hydropower resources.

Considering the three reservoirs assessed in the report, Laos has an estimated floating solar potential of 5-10 GW. For natural water bodies, Laos possesses an estimated floating solar potential of around 2-5 GW.

Combined with the potential on reservoirs, this amounts to a substantial range of 9-15 GW. However, after applying a transmission filter that excludes water bodies more than 25 km away from the nearest transmission line, the potential remains the same for reservoirs while decreasing by approximately 8.4-10.1% for natural water bodies, depending on the assumptions made about the distance from the shore.

Malaysia

By 2030, Malaysia has plans to increase its renewable energy capacity to 4 GW. Additionally, the country has set a target of achieving 31% of its installed electricity generation capacity from renewable sources by 2025.

Like Laos, Malaysia demonstrates a higher potential for floating solar installations on reservoirs, estimated to be within the range of 23-54 GW, compared to natural water bodies, which have a potential of 13-30 GW. As of 2021, Malaysia’s total installed electricity generation capacity was 39 GW.

A separate study conducted on six specific locations in Malaysia indicated that floating solar projects could generate approximately 14.5 GWh/year.

The report expands on that finding by considering all feasible water bodies in the country, suggesting that floating solar projects have the potential to generate an estimate of 47-109 GWh/year.

Myanmar

By 2025, Myanmar aims to achieve a target of 20% of installed electricity generation capacity from renewable sources. According to Myanmar’s 2015 Energy Master Plan, the goal is to increase the contribution of hydropower from 50% of electricity generation in 2021 to 57% by 2030.

The report indicates that Myanmar’s floating solar potential on reservoirs is comparatively lower, ranging from 18 to 35 GW. In comparison, the potential on natural water bodies is estimated to be within the range of 21 to 47 GW. When combined, this potential capacity exceeds Myanmar’s total electricity generation capacity, which stood at approximately 7.6 GW as of 2021.

After applying a transmission filter that excludes water bodies located further than 25 km from the nearest transmission line, the potential capacity experiences a decrease of 1.7-2.1% for reservoirs and a decrease of 9.7-16.2% for natural water bodies, depending on the distance assumptions made from the shore.

Philippines

The Philippines has set several priorities in the electricity sector, including meeting the growing electricity demand, achieving universal electricity access by 2022, and installing 15 GW of renewable energy capacity by 2030.

In 2019, the Philippines successfully launched its first floating solar project, and subsequent construction on other projects commenced in the following years. The potential assessment reveals a significantly higher capacity range for floating solar installations on natural water bodies, estimated to be within the range of 42-103 GW, compared to reservoirs, which have a potential capacity of 2-5 GW.

When applying a transmission filter that excludes water bodies located further than 25 km from the nearest transmission line, the technical potential capacity remains unchanged for reservoirs. At the same time, it decreases by approximately 1.7 to 5.2% for natural water bodies.

Singapore

Singapore has outlined renewable energy goals that involve installing 2 GW of solar capacity by 2030 and meeting 30% of its energy needs through low-carbon electricity imports by 2035.

The report identifies one reservoir and six natural water bodies in Singapore, with the technical potential ranging from 67-153 MW on the reservoir and 206-381 MW on the natural water bodies. These figures are in comparison to the country’s total installed electricity generation capacity of 12 GW as of 2021.

Singapore shows significant interest in offshore and nearshore floating solar projects, and in that regard, the nation has constructed a 5-MW floating solar project off its coast.

Thailand

Thailand is planning to build over 2.7 GW of floating solar projects on nine different reservoirs by 2037. The report suggests a significant floating solar potential of 33–65 GW on reservoirs and 68–152 GW on natural waterbodies, compared to a total installed electricity generation capacity of 55 GW in 2021.

When the transmission filter is applied (excluding water bodies further than 25 km from the nearest transmission line), the potential capacity decreases by 1.8–2.5% for reservoirs and decreases by 3.9-5.9% for natural water bodies.

Vietnam

Vietnam has set an ambitious goal to deploy 31-38 GW of solar and wind capacity by 2030, aligning with its broader objective of achieving carbon neutrality by 2050.

Given Vietnam’s substantial reliance on hydropower, the country presents a favorable environment for both standalone and hybrid floating solar projects. Among the Southeast Asian nations, Vietnam boasts the highest number of reservoirs suitable for floating solar installations, totaling 22. These reservoirs hold an estimated floating solar potential of approximately 21-46 GW.

Similarly, the technical potential for floating solar on natural water bodies in Vietnam falls within the range of 21-54 GW.

Upon applying a transmission filter that excludes water bodies situated further than 25 km from the nearest transmission line, the technical potential capacity remains unchanged for reservoirs while experiencing a decrease of less than 0.5% for natural water bodies.

In May this year, Blueleaf Energy and SunAsia Energy were awarded contracts by the Philippine government to construct and manage what is claimed to be the world’s largest floating solar project with a combined capacity of 610.5 MW.

According to an earlier report by NREL, the addition of floating solar projects on the top of water bodies, which already have hydropower stations, can annually generate around 7.6 TW of clean energy from the solar photovoltaic systems alone.