Introduction

Geothermal is a heat energy from the Earth. In Indonesia and the countries in the Pacific Ring of Fire, the location of the geothermal resource is indicated by geothermal manifestations such as hot springs, fumaroles, and thermal grounds. In a high-temperature geothermal system there is heat transfer from a magmatic heat source to the reservoir rocks and the deeply infiltrating meteoric fluids. As parts of the Earth’s system, a geothermal resource can only be well located and characterized through an integrated Geoscientific studies.

Geothermal fluid is tapped by drilling production wells into geothermal fluid reservoir
(~ 2 km). The heat energy of the produced fluids is then converted to electricity through
an electricity generating system. Alternatively the hot fluid can also be directly utilized for example for heating in an industrial process.  A lot of different Engineering expertise is required for both geothermal fluid production and utilization including electricity generation.

Geothermal is an environmental-friendly energy because: 1) geothermal power generations discharge very significantly much lower pollutant compared to that of fossil fuels. 2) geothermal fluid whose heat has been extracted is re-injected back into the deep reservoir, such that no thermal fluid is let to contaminate the surface/near surface environment.

Geothermal is a renewable energy source because its heat source and recharge fluids are both naturally renewed. It is sustainable because geothermal systems are  long-lived, the produced thermal fluids is naturally recharged.  There is also an engineering strategy to ensure their sustainability, i.e., re-injection of the extracted fluids for maintaining the heat and mass balance of the geothermal reservoir.

Geothermal is an indigenous energy, meaning that it can only be directly utilized in place, and can not be transported elsewhere before being converted into electricity.  Being indigenous, producible geothermal resources in Indonesia should be able to contribute in elevating the prosperity to their surrounding community.

Indonesian archipelago is bestowed with abundant, high-temperature geothermal energy resources scattered in about 250 locations with a total potential of more than 20,000 MW. Being renewable, sustainable and indigenous therefore, geothermal energy is reliable, for its supply is independent from season and energy market situation outside the country.

With the increasing demand of energy in one hand and the shortage of fossil energy resources in another, Indonesia is now facing a challenge to the increase utilization of its geothermal resource to ensure its energy security. Consequently it has to accelerate the human resource capacity building as well as Research and Development activities in geothermal.