Indonesia's RUPTL 2025–2034: 47,758 km of new lines and what they mean for testing

Indonesia's state utility PLN is now in the second year of its 2025–2034 electricity supply business plan, the RUPTL. Announced by the Ministry of Energy and Mineral Resources on 26 May 2025, the plan puts renewables and the transmission network at the centre of the country's energy transition.

What the RUPTL plans

According to a summary by law firm A&O Shearman, the plan includes:

• Generation: 17.1 GW of solar PV, 11.7 GW of hydro, 7.2 GW of wind, 10.3 GW of gas and 4.3 GW of battery storage, plus two small nuclear units.
• Transmission: 47,758 km of new transmission lines.
• Investment: about IDR 565.3 trillion (around US$35 billion) for transmission, alongside about US$185 billion for generation.

Much of Indonesia's renewable potential lies far from the load centres on Java. PLN plans a "green supergrid" of long-distance links between islands, with corridors such as Sumatra–Java and Java–Kalimantan under study. At TransTech ASEAN 2026 in Jakarta, PLN researchers presented work on multi-terminal HVDC and on the reactive compensation needed for the Sumatra–Batam–Bintan link (Southeast Asia Infrastructure).

What it means for testing

Nearly 48,000 km of lines means hundreds of new and extended substations across an archipelago, many of them in places where logistics are difficult and a failed test set cannot be replaced overnight. Three points stand out:

1. Commissioning across many islands

Each substation needs the full set of transformer, circuit breaker, CT/VT and protection tests before energisation. Rugged, portable and battery-powered instruments, with spares and local support, matter more than in a single dense network.

2. High-voltage cables and island links

Submarine and land cables on inter-island links and city feeders are tested with AC withstand tests after installation, typically using a series resonant test system, and need fast fault location when something goes wrong.

3. Insulation in a tropical climate

High humidity and temperature accelerate the ageing of insulation and the corrosion of contacts. Regular insulation resistance and PI, tan delta and contact resistance tests catch moisture and contact problems before they cause outages.

HUAC works with utilities, EPC contractors and industrial users in Indonesia and the wider region. Tell us about your project and we will suggest equipment that suits the voltage levels and site conditions.

Sources

• A&O Shearman, "Key takeaways from PLN's 2025–2034 electricity supply business plan", May 2025.
• Southeast Asia Infrastructure, "Southeast Asia's Grid Ambitions: Conference highlights of TransTech ASEAN 2026".