Indonesia’s energy infrastructure must serve a population and economy spread across thousands of islands. This geography has produced several large electricity systems, many smaller grids and numerous isolated networks rather than one fully connected national market. Java and Bali contain the largest concentration of consumers and generating capacity, while major energy resources are located across Sumatra, Kalimantan, Sulawesi, Papua and other parts of the country.
The central infrastructure challenge is therefore not simply building more power plants. Indonesia must connect energy resources with demand, improve reliability outside its main economic centres and expand transmission quickly enough to support industrial growth. At the same time, oil refineries, LNG terminals, gas pipelines and fuel-distribution networks must continue supplying a country where energy demand is rising faster than domestic oil production.
Indonesia Operates Several Power Systems Rather Than One National Grid
Indonesia had more than 100 GW of installed electricity generation capacity in 2024, but this capacity is distributed unevenly. The Java-Bali system is the country’s largest and most developed power network. It supplies Jakarta, major manufacturing centres and some of Indonesia’s most densely populated provinces. It also contains many of the country’s large coal-fired and gas-fired power plants.
Conditions are different outside Java and Bali. Sumatra, Kalimantan and Sulawesi have substantial regional systems, but connections between islands remain limited. Smaller islands may depend on diesel generators, compact local grids or a single major power plant. A failure at one generating unit, fuel terminal or transmission line can therefore have a greater local effect than it would within a large interconnected system.
This fragmentation also affects project development. A new power plant cannot be evaluated only by its generating cost. Developers must consider whether the local grid can absorb the electricity, whether transmission is available and whether regional demand is large enough to support the project. Indonesia can have surplus generation in one area while another region faces shortages because the two systems are not physically connected.
The state electricity company PLN remains the central institution in the sector. It operates much of the generation, transmission and distribution infrastructure, purchases power from independent producers and carries out national electrification programmes. Its investment decisions therefore influence almost every part of Indonesia’s electricity market.
Inter-Island Transmission Is Becoming a Strategic Priority
Indonesia’s renewable resources and electricity demand are often located in different places. Sumatra has large hydropower, geothermal and solar potential, while Kalimantan has significant hydropower opportunities. Java has the largest demand but fewer undeveloped sites for major renewable projects.
Inter-island transmission could reduce this imbalance. The planned Sumatra-Java connection is particularly important because it could transmit electricity from renewable projects in Sumatra to industrial and urban consumers in Java. High-voltage direct current technology is expected to play a major role because it is suitable for moving large amounts of electricity over long distances and through subsea cables.
Similar long-term concepts would connect Kalimantan with Java and Sulawesi, strengthen connections among the eastern islands and create a more integrated Indonesian power system. These links could allow PLN to balance electricity supply across wider areas, reduce the need for duplicate reserve capacity and make larger renewable projects commercially practical.
The current national electricity plan includes almost 48,000 kilometres of new transmission lines and associated substations through 2034. Nearly 198,000 kilometres of distribution infrastructure are also planned. These figures show that Indonesia’s electricity expansion is increasingly an infrastructure programme rather than only a power-plant construction programme.
The difficulty will be execution. Subsea cables are expensive, technically demanding and exposed to marine risks. Land acquisition can delay overhead lines, while transmission planning must keep pace with the location and timing of new generating projects. Building renewable capacity before the required grid connection is ready would leave valuable assets underused.
Industrial Development Is Moving Electricity Demand Beyond Java
Indonesia’s downstream mineral strategy is creating new centres of energy demand. Nickel processing, stainless-steel production and battery-material manufacturing have expanded rapidly in Sulawesi and parts of eastern Indonesia. Similar industrial development is planned in Kalimantan and other resource-producing regions.
These projects require large and stable electricity supplies. In some industrial parks, companies have developed captive coal-fired power plants because the regional PLN grid could not provide enough capacity quickly enough. This has supported industrial growth, but it has also created parallel power systems outside the main public grid and increased the carbon intensity of Indonesia’s mineral-processing sector.
Future infrastructure planning will need to connect industrial zones more closely with public transmission systems. Dedicated renewable generation, gas-fired capacity, hydropower and storage could gradually replace part of the dependence on captive coal. However, the required investment extends beyond generation. New substations, industrial feeders, transmission corridors and control systems will be needed to serve demand that can increase by hundreds of megawatts when a new smelter or processing complex begins operating.
The development of Nusantara, Indonesia’s planned capital in East Kalimantan, adds another major infrastructure requirement. The city will need dependable electricity, fuel, transport and digital systems while regional demand is already being reshaped by mining and industrial projects.
LNG and Gas Infrastructure Connect Regions That Pipelines Cannot Easily Reach
Indonesia is both a producer and consumer of natural gas, but the location of its gas fields does not always match domestic demand. Major gas production is located in areas such as East Kalimantan, Papua and offshore basins, while some of the largest consumers are in Java and Sumatra.
The country has a long history as an LNG exporter, with major liquefaction facilities at Bontang and Tangguh. At the same time, Indonesia increasingly uses LNG within its domestic energy system. Regasification terminals allow LNG to be shipped between islands and delivered to power plants or industrial customers in areas that cannot be served economically by long-distance pipelines.
This creates a flexible but complex gas supply chain. Gas may move from an offshore field to a processing facility, into an LNG plant, aboard a domestic carrier and through a floating or land-based regasification terminal before reaching a power station. The system offers an alternative to extending pipelines across difficult terrain and deep water, but it also introduces shipping, terminal and contract costs.
Indonesia’s gas pipeline network remains fragmented. Regional systems connect production areas with industrial consumers, cities and power plants, but there is no complete national gas grid. Expanding pipelines and city-gas networks could reduce dependence on imported liquefied petroleum gas and improve access to domestic gas, particularly in urban and industrial areas.
Refinery Expansion Is Intended to Reduce Fuel Import Dependence
Indonesia’s declining crude-oil production has made petroleum infrastructure increasingly important. The country now depends on imported crude and refined fuels to meet demand from road transport, aviation, industry and electricity generation in isolated systems.
Pertamina operates the main national refining and fuel-distribution system. Its refineries, storage depots, ports, pipelines and retail network must supply distant markets across the archipelago. Marine transport is especially important because many islands cannot receive fuel through pipelines or road networks.
The Balikpapan refinery expansion is one of the most important current projects. It is designed to increase crude-processing capacity from approximately 260,000 to 360,000 barrels per day while producing cleaner fuels and improving refinery complexity. The project should strengthen domestic supply, although it will not remove Indonesia’s need for imported crude or petroleum products.
Refinery projects have faced high costs, long development periods and changing commercial conditions. Their value depends not only on additional capacity but also on whether they can produce the fuel types required by Indonesia’s expanding transport market at competitive prices.
Electricity Access Now Depends on Quality as Well as Coverage
Indonesia has made major progress in connecting communities to electricity, but a national electrification rate does not show differences in service quality. Some remote communities receive power for limited hours, depend on small diesel systems or face high operating costs because fuel must be transported over long distances.
Extending the main grid is not always the most economic solution. Isolated solar systems, battery storage, microgrids and small hydropower plants can provide more practical service to distant islands and rural settlements. These systems can also reduce diesel consumption and exposure to fuel-delivery disruptions.
The next stage of electrification will therefore focus more heavily on reliability, affordability and productive use. Electricity must be sufficient not only for household lighting but also for refrigeration, communications, schools, clinics, agricultural processing and local businesses. Distribution networks and maintenance capacity will be as important as the initial installation of generation equipment.
The 2025–2034 Plan Tests Indonesia’s Ability to Deliver Infrastructure at Scale
PLN’s 2025–2034 electricity plan proposes approximately 69.5 GW of additional generating capacity. Renewable generation and storage account for most of the planned additions, including solar, wind, hydropower, geothermal power, pumped storage and battery systems. Gas and previously planned coal projects remain part of the programme, especially where firm capacity is considered necessary.
The plan estimates total investment requirements of about US$188 billion across generation, transmission, distribution, storage, smart grids and related costs. Independent power producers are expected to finance and construct a large share of the new generating capacity.
The scale of the programme creates opportunities for equipment suppliers, engineering firms, investors and local manufacturers. It also creates coordination risks. Power plants, transmission lines, substations, storage projects and fuel infrastructure must be completed in the correct sequence. Delays in one part of the system can reduce the value of investment elsewhere.
Indonesia’s energy infrastructure is entering a period in which geography, industrial policy and the energy transition are becoming closely connected. The country has enough generation potential to support continued economic growth, but its success will depend on whether it can move electricity and fuel efficiently between regions. Inter-island transmission, stronger regional grids, modern refineries, flexible LNG systems and reliable distribution will determine whether Indonesia develops a genuinely integrated energy market or continues operating a collection of separate systems.
