The 100 gigawatt solar programme starts at Gilimanuk with fourteen sites and 5.3 gigawatt peak

President Prabowo Subianto launched the 100 gigawatt peak solar programme on 25 August 2026 at the PLTS site in Gilimanuk, Jembrana Regency, Bali. The programme opens with 14 installations spread across six provinces and totalling 5.3 gigawatt peak, and the government has set a three year horizon for reaching the full target.

The President was direct about the ambition. He said the government would build 100 gigawatts, that it was serious, and that the target was 100 gigawatts within three years. For scale, Indonesia's total installed generation capacity across all sources sits at roughly 88 gigawatts, which means the programme as stated would more than double the national fleet with a single technology.

Where the first fourteen sites sit

The opening phase is distributed as follows. West Java holds five installations. East Java holds four. Riau Islands holds two. Central Java, Bali and Bangka Belitung Islands hold one each.

The named locations in the first tranche are revealing. In West Java they include Saguling, Purwakarta, Jatiluhur, Cirata and Jatigede. Central Java contributes Gajah Mungkur. East Java contributes Karangkates, Madura, Pasuruan and Banyuwangi.

Anyone familiar with Indonesian water infrastructure will recognise most of that list. Saguling, Jatiluhur, Cirata, Jatigede, Gajah Mungkur and Karangkates are reservoirs, several of them already hosting hydropower.

The concentration in Java is also worth noting. Nine of the fourteen sites sit in West, Central or East Java, which is where demand is heaviest and where the transmission network is densest. Starting where the load already is reduces the amount of new transmission the first phase has to justify. The remaining sites in Bali, the Riau Islands and Bangka Belitung serve island systems, where the alternative supply is usually diesel and where the economics of displacing it are correspondingly stronger.

Reservoirs are doing quiet work here

The choice of sites is the most interesting engineering decision in the announcement, and it has not received the attention the headline figures have.

A reservoir that already supports hydropower comes with things a greenfield solar site does not. The land is already committed to a public purpose, so there is no competition with agriculture, settlement or tourism. A grid connection already exists, sized for the hydropower plant. Access roads exist. Operating staff are on site. Water cools the panels, which modestly improves their output in a tropical climate, and panel shading reduces evaporation from the reservoir surface.

The result is that floating solar on an existing reservoir sidesteps the two constraints that most often slow Indonesian solar, which are land acquisition and transmission access. Bahlil Lahadalia, Minister of Energy and Mineral Resources, described the rollout as using several deployment models together, including utility scale ground mounted arrays, floating installations, rooftop systems and installations in remote areas.

Land and grid connection are the two things that slow solar down in Indonesia. A reservoir that already generates power has solved both before the first panel arrives.

Bali's own allocation follows a different logic. PLN is developing five solar clusters in the province totalling 1,000 megawatt peak, supported by 3,300 megawatt hours of battery storage, with 300 megawatt peak of that at Gilimanuk itself. The heavy storage component reflects an island system where solar output and evening demand do not coincide.

What the programme is expected to return

The government has published a set of projections alongside the launch.

Total investment is put at approximately USD 73 billion, equivalent to more than Rp1,140 trillion. One wire report gives the dollar figure as USD 71.3 billion against the same rupiah total, and the difference is worth noting rather than resolving silently, since it most likely reflects different exchange rate assumptions.

Employment is projected at roughly 5.52 million jobs, broken down as 3.465 million in construction and 2.053 million in manufacturing. The split matters, because the manufacturing share depends on how much of the supply chain is built domestically rather than imported.

On emissions, the programme is projected to cut 140 million tonnes of carbon dioxide a year, with associated carbon value estimated at Rp6.31 trillion annually. That reduction figure assumes the full 100 gigawatt peak is built and operating, so it describes the programme at completion rather than anything the first phase delivers on its own.

Part of the mechanism behind both the emissions and the subsidy numbers is the replacement of diesel generation. Diesel plants are the most expensive electricity on the system and the most emissions intensive per unit delivered, and they are concentrated in exactly the island and remote systems the programme targets. Displacing them produces a larger saving per megawatt installed than displacing grid connected coal or gas would, which is why the subsidy projection is as large as it is relative to the capacity involved.

The figure with the most immediate fiscal relevance is the projected saving of Rp73.9 trillion a year in subsidy spending. Set against the Rp272.9 trillion energy subsidy allocation in the 2027 draft budget, of which Rp130.1 trillion is electricity, a saving of that size would be a material change to a recurring commitment rather than a one off gain.

Sirkularium's read for government and public institutions

Three observations follow.

The first concerns the site selection principle. Choosing reservoirs that already host generation is the same logic that makes geothermal bottoming units and rooftop solar attractive, which is that reusing committed land and existing grid connections is faster and cheaper than securing new ones. This principle deserves to be applied systematically rather than opportunistically. A national inventory of reservoir surfaces suitable for floating solar, ranked by existing grid capacity, would identify the next tranche before it is needed.

The second concerns the manufacturing share of the jobs projection. The 2.053 million manufacturing jobs are the part of the estimate most sensitive to policy. They materialise only if module, inverter and mounting production is established domestically at scale. Local content requirements, industrial estate readiness and workforce training determine whether that share is realised or whether the programme becomes primarily a construction and import exercise. Public institutions have direct leverage here and a narrow window in which to use it.

The third concerns absorbing the output. Adding capacity of this magnitude to a system of roughly 88 gigawatts places considerable demands on transmission, on storage, and on the flexibility of existing thermal plant. Bali's 3,300 megawatt hours of storage against 1,000 megawatt peak of solar suggests the planners are aware of this. The same ratio applied nationally would be a very large storage programme in its own right, and it would be prudent for provincial and national planning to treat storage and transmission as parallel commitments rather than as follow on work.

What to watch next is the construction progress of the first 5.3 gigawatt peak, the tender arrangements for subsequent tranches, and whether domestic manufacturing capacity expands in step with installation.