Indonesian government has vastly underestimated solar potential

With Indonesian energy body the Dewan Energi Nasional considering revising the nation's clean energy targets, Jakarta-based thinktank the Institute for Essential Services Reform (IESR) has attempted to press the case for solar by claiming the government has hugely under-estimated the technology's potential.

The IESR says the current solar ambition–6.5 GW of generation capacity in 2025–is based on an estimate of Indonesia's maximum technical solar potential which is up to 95 times smaller than its own calculations.

Supported by peer the Global Environmental Institute of China, the IESR has used GIS mapping to calculate Indonesian land could host 3.4-19.8 TWp of large scale solar project generation capacity.

Technical limit

The Beyond 207 Gigawatts: Unleashing Indonesia's Solar Potential study claims the national solar potential of 205 GW estimated by the Ministry of the Environment and Mineral Resources is woefully out of date, although the IESR points out the technical maximum it has calculated pays no heed to policy, market or other economic limitations, solely to the availability of suitably sloping land.

Excluding rooftop and floating PV which, the IESR points out, are the subjects of other studies it has prepared, the report calculates Indonesia has 484,000km² of land which could host 19.8 TWp of large scale PV capacity. If agricultural land and forest plantations are excluded, the figure falls to 188,000km² and 7.7 TWp; and if populated areas are also left out, the results are 154,000km² and 6.31 TWp.

In a bid to show how unreliable the government's 207 GW estimate is, the IESR also excluded the most common bare land surface–dry shrub–from the figures, and still identified 82,800km² of suitable sites nationwide, which could host 3.4 TWp of solar capacity.

The report's authors also stressed their calculation was based on a “rather conservative assumption” of the energy density of the sites identified, with the figure of 410 kWp/hectare based on a 2013 study drawn up by the National Renewable Energy Laboratory in the U.S. Recent solar projects in Indonesia have had energy densities of 600-800 kWp/hectare, according to the IESR.

The report noted the eastern, western and central provinces of Kalimantan–the Indonesian territory on the island of Borneo– boast the largest technical solar potential, with the provinces of Riau, northern and southern Sumatra, eastern and Central Java and Papua also boasting significant suitable project sites.