Asahan I — Indonesia

Asahan I is a 180 MW hydro power station in North Sumatra, Indonesia. It is operated by PT Bajradaya Sentranusa (China Huadian Corporation 70% + PJB 26.5%+Nusa Konstruksi Engineering 3.5%). Based on its capacity (estimated), it can supply roughly 180k homes (estimated). It ranks #202 of 401 Indonesia power plants by installed capacity. Commissioned in 2011, it is around 15 years old — relatively modern. As a non-combustion source, it has no direct CO₂ emissions from generation. In context, hydro supplies about 7.3% of Indonesia's electricity; the national grid averages 680 gCO₂/kWh (18.1% low-carbon) (2024).

Plant data: WRI Global Power Plant Database (CC BY 4.0), id WRI1000737.

Data provenance

Source of the capacity and fuel values:

capacity: GEM · 2026 · L100000602099; fuel: WRI GPPD

In context: how this plant compares

At 180 MW, Asahan I is well above the median hydro plant in Indonesia (30 MW). Technically it is described as conventional storage. Hydropower converts the energy of falling or flowing water into electricity; output depends on rainfall and reservoir level, and large dams also provide grid balancing and storage.

Capacity comparison computed from the WRI Global Power Plant Database; fuel-type context is general engineering background.

Key facts

Share of Indonesia hydro capacity

3.9% of 4,561 MW across 41 plants in this dataset

Age among peers

14 of 15 dated hydro plants in Indonesia are older

Calculated from the capacity and generation records in this dataset (WRI Global Power Plant Database (CC BY 4.0)).

Capacity vs largest hydro plants in Indonesia

Installed capacity (MW), WRI Global Power Plant Database (CC BY 4.0).

Owner

Operated by PT Bajradaya Sentranusa (China Huadian Corporation 70% + PJB 26.5%+Nusa Konstruksi Engineering 3.5%).

Local climate & thermal context

This hydro plant converts the energy of falling or flowing water through hydro turbines. It sits in a tropical rainforest climate (Köppen Af) — Northern Hemisphere, latitude 2.5°N — which shapes how much energy it can produce and how its output varies through the year.

Monthly mean temperature

This site has effectively no heating season (tropical/equatorial climate), so winter heat loss is not the driver here. The thermal concern shifts to year-round process heat and humidity/heat-driven corrosion of hot equipment.

Climate normals: WorldClim 2.1 (1970–2000 monthly normals, 10 arc-min, CC BY 4.0); zone: Köppen-Geiger world climate classification (Kottek et al. 2006, 0.5° grid). Degree-days & heat-demand index computed by PowerAtlas — a modelled heat-demand proxy, not a measured site figure.

Site climate & environmental severity

This site sits in a corrosive environment (estimated ISO 9223 class C4 — High), with humidity / wetness the leading environmental stress.

Indicative estimate via the ISO 9223:2012 informative method (atmospheric corrosivity from temperature, time-of-wetness and airborne salinity), using WorldClim climate normals, the Köppen-Geiger class and coast distance. Indicative, not a measured corrosion rate.

How it compares & nearby plants

The #8 largest hydro power plant of 41 in Indonesia by capacity.

Indonesia has 41 hydro power plants in this dataset, together about 4,561 MW of capacity.

Nearby power plants

• Sigura gura (asahan II) · Hydro · 286 MW · North Sumatra
• Tangga (asahan II) · Hydro · 317 MW · North Sumatra
• Batubara power station · Gas · 4,800 MW · North Sumatra
• Kuala Tanjung Inalum captive power station · Coal · 950 MW · North Sumatra
• Kuala Tanjung-2 power station · Coal · 450 MW ·
• Lamhotma power station · Coal · 200 MW ·

Location

Coordinates 2.5113, 99.259 from WRI Global Power Plant Database (CC BY 4.0). View on OpenStreetMap.

Frequently asked questions