Borneo Futures is engaged in a number of projects where assessing the biodiversity impacts of non-renewable energy is the focus. Geothermal energy is generally considered to be a clean, reliable source of energy, with only minimal environmental and social impacts, even when compared with other renewable energy sources. One source of impacts, however, that remains relatively understudied and underreported is the environmental and social impact of geothermal development on forest environments, and especially high biodiversity value tropical forest areas.

One of the established geothermal energy plants in West Java, Indonesia visited during our study

In 2017, we conducted a Rapid Environmental and Social Assessment of Geothermal Power Development in Indonesia with The World Bank Energy Team in Jakarta.


Geothermal energy is an important form of renewable energy, potentially contributing positively to reducing greenhouse gas emissions and related global warming. In Indonesia, however, the fact that the majority of geothermal potential is located in mountainous areas, close to, or in forest areas has raised societal concerns about environmental and social impacts. These forest areas play an important role in supplying fresh water and harbouring endangered wildlife or have high cultural or religious values. Borneo Futures conducted a micro-and macro-level risk assessment of potential and existing geothermal project locations in Indonesia. The aim of this study was to identify tools to improve avoidance and minimisation of impacts to biodiversity and communities.


Through a micro-level assessment of 16 existing Indonesian geothermal projects, we developed an improved insight into the key impacts and risks typically associated with geothermal power development in forest areas. Key findings include that for each 100 MW of geothermal power generated per year, about 10 km of project roads and 30 ha of forest clearing is needed, while about 10 km2 of forest is indirectly impacted through the effects of road-facilitated hunting, illegal logging, use of fire, and other detrimental activities.

Findings from the micro-level assessment of potential infrastructure impacts from geothermal development footprint

Through a macro-level assessment of the officially published 330 geothermal area potential points for Indonesia, the environmental and social risk rankings for every individual point was determined. Each of these was characterized according to weighted environmental and social variables, including forest use status (conservation area type etc.); land cover; claims for social forestry; presence of indigenous people, traditional land claims, recent deforestation history; international biodiversity values (World Heritage site, Key Biodiversity Area, Important Bird Area); size of conservation area; and location of geothermal point in relation to conservation area boundary. Based on the cumulative weighted scores of these variables, they were categorized as Low, Medium, and High-risk sites.


The resulting risk assessment provides a simple screening tool for the Government of Indonesia and other key stakeholders to guide geothermal power projects towards the areas with the least environmental costs and lowest likelihood of societal concerns about these costs. This tool also helps the government, banks, other finance institutions and geothermal energy companies to avoid material and reputational risks that can be associated with geothermal energy development in high-risk areas.

Distribution of geothermal potential points and forest use status across Indonesia

We believe that this project is a good example of how we, as a company, develop innovative approaches to assist the private sector in more effectively reducing impacts on biodiversity  and social values, inherent in many development projects across the tropics.