Singapore is sunny — so why is its solar share so low?

Because Singapore has only 730 km² of land, and rooftops are effectively its entire 'land'. Solar capacity reached 2 GWp (2,093 MWp) in 2025, five years ahead of target, and the new goal of 3 GWp by 2030 still equals only about 20% of national generating capacity of roughly 15 GW. Meanwhile more than 95% of electricity still comes from natural gas (EMA), and frequent tropical cloud cover cuts real output further.

The binding constraint is geometry, not sunshine. Singapore's territory is just 730 km², much of it taken by industrial estates, housing, nature reserves and military installations, leaving very little open ground for large ground-mounted solar. The sun is the only significant natural resource the city-state can capture inside its own borders, and the surface available to capture it is mostly roof: public housing rooftops across the island total roughly 50 km². At that scale, 2 GWp means local PV output can approach or briefly exceed instantaneous demand on a clear midday — yet still supply only a small share of annual energy.

Within those limits, Singapore has moved fast. Installed capacity rose from 0.4 GWp in 2020 to 2 GWp in 2025, hitting the original 2030 target five years early, after which the Energy Market Authority (EMA) raised the goal to 3 GWp by 2030. The main instrument is the SolarNova programme, run jointly by the Housing & Development Board (HDB) and the Economic Development Board (EDB), which aggregates public-sector demand to achieve economies of scale. By 2025/2026 panels had been installed on more than 5,300 HDB blocks, powering lifts, lighting and water pumps, with surplus electricity fed back to the national grid.

To push past the rooftop ceiling, Singapore has turned water surfaces and building facades into generating surfaces. The Tengeh Reservoir floating solar farm spans 45 hectares with 60 MWp of capacity built from 122,000 double-glass modules (PUB, 2021); the cooling effect of the water lifts module efficiency 5%–15% above a hot rooftop, and its output is enough to power five local water treatment plants. Reservoirs and catchments across the island offer around 1,500 hectares of potential surface, theoretically supporting some 2 GW of floating PV. The Solar Energy Research Institute of Singapore (SERIS) is simultaneously developing building-integrated photovoltaics (BIPV) — solar material as the actual skin of a facade — and runs a network of more than 100 irradiance sensors and sky cameras that tracks cloud movement and warns grid operators minutes before an output drop.

Even with every roof and reservoir covered, domestic potential falls far short of national demand, which is why the fourth pathway is imports. In October 2024 the EMA granted conditional approval to the Sun Cable project: 1.75 GW of low-carbon power delivered from large solar farms in Australia's Northern Territory through a 4,300 km subsea cable, capable of meeting up to 9% of Singapore's total electricity demand after 2035. Under the ASEAN Power Grid framework, Singapore plans to import up to 6 GW of low-carbon electricity by 2035, with parallel projects in Vietnam and Indonesia. The answer, then, is not that Singapore lacks sun — it is that the fraction of that sun its own rooftops can physically catch is bounded.

Even if Singapore covered every rooftop and every reservoir with solar panels, national demand would still far exceed the ceiling of domestic solar potential.

This question is covered in depth in The Full Spectrum Every Energy Source Explained — A Singapore Perspective，第七章 7.SG / 第十一章 11.SG