What the map shows
The map shows the long-term yearly average solar resource across Indonesia, from satellite records through 2018, at a resolution fine enough to read district by district.
It carries two layers. Global horizontal irradiation (GHI) is the total solar energy falling on a flat surface over a year — the raw resource. Photovoltaic power output (PVOUT) converts that resource into the electricity a standard solar installation would actually generate per kilowatt of installed capacity, after accounting for temperature, the sun’s angle and typical system losses. GHI tells you where the sun is strongest; PVOUT tells you where a plant earns the most.
Click anywhere to read the value at that point. Province boundaries and city labels can be switched on or off, and the layer can be laid over a plain, satellite, street or light base map. The data comes from the Global Solar Atlas 2.0, published by the World Bank Group and ESMAP with Solargis, under a CC BY 4.0 licence.
Planning solar expansion
Indonesia’s solar ambitions are measured in tens and hundreds of gigawatts. Where that capacity goes decides what it costs. The map is a first screen for siting: which provinces and districts combine strong output with nearby demand and grid access, and where a given budget buys the most generation.
Solar resource analysis
PVOUT gives the expected yearly yield per kilowatt installed — the number that drives a project’s revenue and levelised cost. Comparing it across candidate sites, or against the output of the diesel or coal plant a project would displace, is the starting point of any solar feasibility assessment.
Islands and off-grid systems
Much of Indonesia’s electricity outside Java–Bali still comes from small diesel and captive coal plants on isolated grids. The map shows where solar, paired with storage, can replace them — and where the resource makes that case strongest.
How to read it — and its limits
Read the map as a resource screen, not a site assessment.
The values are long-term yearly averages. They do not show seasonal swings, the monsoon months when output falls, or the year-to-year variation that an El Niño year such as 2026 produces. For those, a site needs hourly or monthly data for its exact location.
The map also shows sunlight, not buildability. It does not account for land status and forest designation, slope, flood risk, distance to a substation or the capacity left on the local grid, all of which usually decide a project before the resource does. Across most of Indonesia the resource differs less than these constraints — which is why the map is most useful when read against them.
Solar resource of Indonesia
Irradiation and PV output layers, province boundaries and city labels. Runs in the browser; the satellite, street and light base maps need an internet connection.
Reform of the power market, transition credits and decentralised renewables.
Where the solar work sits, including Achieving the 200 GW Solar Ambition and Decentralized Renewables.
Tripling renewables and doubling efficiency by 2030 in Indonesia.
Transition credits to shift captive, off-grid coal plants to renewables.