Indonesia advances vast solar buildout

Jakarta has moved to accelerate one of Southeast Asia’s most ambitious renewable energy programmes, preparing a 100-gigawatt solar power project that officials estimate will require about $71.3 billion in investment and reshape Indonesia’s electricity strategy over the next several years.

The Ministry of Energy and Mineral Resources is working with the Ministry of Agrarian Affairs and Spatial Planning, state electricity company PLN and other agencies to identify land, grid links and storage systems needed for the programme. About 24,000 hectares on Java Island have been earmarked for verification, with the authorities seeking to match project sites with transmission lines, PLN substations and battery storage capacity.

Deputy Energy and Mineral Resources Minister Yuliot Tanjung said the government’s first priority is to push ahead with an initial 17 GW phase, supported by around 33 GW of battery energy storage systems. The early phase is expected to test the country’s ability to turn a national target into bankable projects at scale, particularly in areas where land acquisition, grid connection and tariff design have slowed renewable energy investment.

The wider 100 GW plan is designed to reduce Indonesia’s reliance on diesel and gas-fired generation, particularly in regions where imported fuel and high operating costs have weighed on the state budget. Officials have estimated that converting fossil fuel-based generation to solar power combined with battery storage could cut electricity generation costs by up to Rp73.9 trillion, or about $4.18 billion, a year once implemented at scale.

The programme also reflects Jakarta’s attempt to close the gap between Indonesia’s large solar potential and its modest installed capacity. The country has abundant sunshine across its islands, yet solar has remained a small part of the electricity mix compared with coal, gas, hydro and geothermal power. Rooftop and utility-scale solar deployment has been constrained by regulatory uncertainty, procurement delays, grid limitations and the financial position of PLN.

Indonesia’s latest electricity supply plan for 2025-2034 calls for 69.5 GW of new generation capacity, with renewable energy making up a large share of future additions. Solar is expected to play a central role in that expansion, with PLN’s planning framework pointing to 17.1 GW of new solar capacity by 2034 alongside hydro, geothermal, wind and storage projects. The 100 GW programme goes beyond that planning baseline and signals a more aggressive policy push from President Prabowo Subianto’s administration.

A key feature of the solar strategy is its decentralised design. Earlier planning discussions have described a model that could combine large centralised solar plants with smaller village-level systems, many paired with batteries. Such an approach could help remote communities replace diesel generation, improve supply reliability and reduce exposure to fuel price volatility, while also creating demand for locally produced panels, batteries, inverters and grid equipment.

The proposed investment scale underlines the financing challenge. A $71.3 billion programme would require state support, PLN procurement commitments, private sector participation, concessional finance and possibly blended funding from climate-related investment platforms. Indonesia has already attracted international attention through its Just Energy Transition Partnership, but converting pledges into project-level funding has remained difficult, particularly because coal continues to dominate power generation and captive industrial power demand is rising.

Land availability will be another decisive issue. Java, the country’s most populous island and main electricity demand centre, offers stronger grid connectivity but also intense competition for land. The identification of 24,000 hectares is a first step rather than a final allocation, as each site must still pass verification covering ownership, spatial planning, environmental suitability and connection feasibility.

Grid readiness may prove equally important. Large volumes of intermittent solar power will require stronger transmission networks, flexible generation, storage systems and updated dispatch rules. Battery storage is central to the plan because solar output peaks during daylight hours while demand often rises in the evening. Without adequate storage and grid upgrades, high solar penetration could create curtailment risks and weaken project economics.

The programme could strengthen Indonesia’s industrial policy if it succeeds in building domestic solar manufacturing capacity. Officials have linked the plan to demand for locally produced panels, a move that could support factories, create jobs and reduce exposure to import barriers in global solar trade. The strategy comes as several countries seek to capture more of the clean energy supply chain, from polysilicon and wafers to modules and battery systems.

Indonesia’s energy transition remains complicated by its coal-heavy electricity system, long-term power purchase agreements and the need to provide affordable energy to households and industry. Coal plants still anchor baseload supply, while nickel processing and other industrial sectors have increased captive power demand. Those pressures make the solar programme both a climate policy instrument and an energy security strategy.

Work on floating solar projects, rooftop systems and village electrification schemes has already begun to build momentum. PLN’s Saguling floating solar project in West Java, scheduled for commercial operation in late 2026, is one of several projects intended to demonstrate technical and commercial viability. The larger 100 GW plan, however, will require faster procurement, clearer tariff rules and stronger coordination across ministries, PLN, regional governments and investors.