Indonesia has almost every physical resource needed for a diverse renewable energy system. Its volcanic geology supports large geothermal fields. Mountainous islands and heavy rainfall create major hydropower potential. Strong sunlight reaches the country throughout the year, while agricultural production provides biomass and biofuel resources.
Yet Indonesia’s renewable electricity sector remains relatively small compared with its potential. Renewable sources represented only about 15.75% of the national energy mix at the end of 2025, below the earlier target of 23%. Coal continued to dominate electricity generation, particularly across the large systems serving Java, Bali and major industrial regions.
The gap between natural potential and commercial development defines renewable energy in Indonesia. The country does not lack resources. It faces a more difficult combination of project risk, regulated electricity prices, utility procurement, fossil-fuel competition, grid limitations and the challenge of supplying an archipelago rather than one connected landmass.
Geothermal Power Provides Reliable Renewable Electricity
Geothermal energy is Indonesia’s most distinctive renewable resource. The country lies along the Pacific Ring of Fire, where volcanic activity creates high underground temperatures suitable for electricity generation. Estimated geothermal potential exceeds 23 gigawatts.
Installed geothermal capacity reached roughly 2.7 gigawatts by 2025. This places Indonesia among the world’s leading geothermal producers, but it still represents only a fraction of the available resource.
Geothermal plants offer an important advantage over solar and wind. They can normally operate throughout the day and provide steady generation with high capacity factors. This makes geothermal particularly valuable in a coal-dominated system where policymakers and the state utility, PLN, are concerned about reliability.
Projects are operating or under development in areas including West Java, North Sumatra, South Sumatra, North Sulawesi and Flores. State-owned companies such as Pertamina Geothermal Energy and PLN are important participants, alongside domestic and international private investors.
Development is slower than the quality of the resource might suggest. Exploration requires expensive drilling before developers fully understand the size and performance of a field. Projects may also be located in mountainous, forested or environmentally sensitive areas where roads, transmission lines and community agreements are difficult to establish.
Electricity tariffs must be high enough to cover these risks, but PLN also faces pressure to maintain affordable consumer prices. Government-backed exploration, risk-sharing mechanisms and clearer procurement can therefore be as important as the geothermal resource itself.
Hydropower Must Connect Distant Resources to Demand
Hydropower remains Indonesia’s largest source of renewable electricity. Major resources exist in Sumatra, Kalimantan, Sulawesi and Papua, but the strongest demand is concentrated in Java and in expanding industrial zones.
This geographic mismatch shapes project economics. A large hydropower plant is most valuable when it can supply a dependable market, but Indonesia’s islands do not share a single nationwide grid. New dams may require long transmission lines, local industrial demand or undersea interconnections to reach customers.
Hydropower can serve several roles. Reservoir plants provide electricity that can be controlled according to demand. Run-of-river projects use natural water flows with less storage. Small hydro and micro-hydro systems can supply rural communities that are costly to connect to a larger network.
Large projects may also support metal processing and other industrial activity. Indonesia’s nickel industry has expanded rapidly, creating major electricity demand in Sulawesi and Maluku. Renewable hydropower could reduce the sector’s dependence on captive coal plants, but major developments require long construction periods, high capital investment and careful management of land, rivers and local communities.
Climate conditions introduce another risk. Hydropower output may fall during dry periods, while extreme rainfall can affect construction and operations. A wider mix of geothermal, solar, wind, storage and interconnected grids would make the system less dependent on one resource.
Solar Power Is Finally Moving Beyond a Small Base
Solar energy has the largest theoretical renewable potential in Indonesia, but deployment remained limited for many years. Installed solar capacity reached approximately 1.49 gigawatts by the end of 2025 after the country added more than 500 megawatts during the year.
This remains a modest total for a country of Indonesia’s size, but the growth rate signals a possible change. Commercial and industrial rooftop systems have expanded as companies seek lower-carbon electricity and more control over their energy costs. Utility-scale and floating solar projects are also becoming more important.
Floating solar is well suited to Indonesia because reservoirs can provide available space without requiring large areas of new land. The Cirata floating solar project in West Java demonstrated the model at scale. Construction later began on another floating project at the Saguling Reservoir, with planned capacity of 92 megawatts peak.
Solar can also support smaller island systems that rely on diesel fuel. Combining panels with batteries can reduce fuel imports, transport costs and exposure to oil-price movements. These projects may provide greater local value than simply adding another plant to an already well-supplied grid.
The main barriers are not solar resources or technology costs. They involve procurement limits, rooftop regulations, PLN’s role as the main electricity buyer, local-content requirements, grid readiness and uncertainty over how much new generation each regional system can absorb.
The Archipelago Requires More Than One Transition Model
Indonesia cannot apply the same renewable strategy everywhere. Java-Bali is a large interconnected electricity market with extensive coal capacity. Remote islands may depend on small diesel systems. Mining and processing zones often use privately operated captive power plants, while some rural areas still require basic improvements in electricity access.
On small islands, distributed solar, batteries and local microgrids may provide the most practical route. In volcanic areas, geothermal can supply stable regional power. Hydropower may support larger grids or industrial centres. Bioenergy may have a role near agricultural and forestry operations where residues can be collected sustainably.
Transmission investment remains essential. The 2025–2034 electricity plan includes major construction of power lines, substations and storage. Without these assets, planned renewable projects may remain isolated from demand.
Indonesia must also decide how to treat its fast-growing captive-power sector. Industrial estates, especially those connected to nickel processing, have built large amounts of their own coal-fired generation. Captive capacity reached almost 26 gigawatts in 2024, with more than three-quarters powered by coal.
Replacing or reducing this generation will require renewable plants, storage, stronger regional grids and contracts that give industrial customers confidence in reliable supply. It will also require financing at a scale separate from the public PLN system.
Biofuels Link Renewable Policy to Palm Oil
Renewable energy in Indonesia extends beyond electricity. The country has used mandatory biodiesel blending to reduce petroleum imports and create domestic demand for palm oil.
Indonesia moved from a B35 blend to B40, meaning diesel fuel contained 40% palm-based biodiesel. The government plans to introduce B50 in July 2026. Officials expect the higher blend to reduce fuel-import costs and increase domestic biodiesel demand.
Biofuels can improve energy security and support agricultural processing, but the environmental outcome depends on how feedstocks are produced. Expansion that causes deforestation, peatland damage or land conflict can weaken the climate benefits of replacing petroleum. Certification, traceability and higher productivity on existing plantations are therefore central to the long-term credibility of the programme.
Used cooking oil and other waste feedstocks may also support sustainable aviation fuel. Indonesia has begun developing this market, although production volumes and regulations remain at an early stage.
The 2034 Plan Is Ambitious but Back-Loaded
Indonesia’s Electricity Supply Business Plan for 2025–2034 proposes 42.6 gigawatts of new renewable capacity and 10.3 gigawatts of storage. Solar is expected to provide about 17 gigawatts, followed by hydropower, wind, geothermal and bioenergy.
The planned scale is substantial, but much of the renewable construction is scheduled for the second half of the ten-year period. Fossil-fuel capacity continues to play a large role during the earlier years, including new gas and previously committed coal projects.
This sequencing creates a delivery risk. Delays during the early period would leave an even larger volume of renewable projects to be financed, permitted and constructed after 2030. Indonesia has missed earlier renewable targets, so the credibility of the new plan will depend on procurement rather than headline capacity alone.
The government and PLN will need to provide bankable tariffs, predictable tenders, land and permitting support, transmission access and clear rules for private investors. International climate finance may help, but funding will not solve projects that lack workable commercial structures.
Indonesia’s Renewable Energy Outlook
Indonesia’s resource base can support a much cleaner and more diverse energy system. Geothermal and hydropower provide firm electricity, solar can expand quickly, and distributed systems can reduce diesel dependence across smaller islands.
The central issue is execution. Indonesia must turn technical potential into projects that can secure finance, connect to customers and compete within a system still built around coal. Progress will depend on whether the 2025–2034 plan changes the pace of procurement, transmission construction and private investment.
Indonesia’s renewable future is therefore not limited by the availability of energy. It will be determined by how effectively the country links its resources, islands, industries and electricity institutions.
