Geothermal technology is an emerging renewable energy source across the world. It is generally used for power generation as well as other thermal applications such as an industrial heat input.
Geothermal energy is the heat that comes from the sub-surface of the earth. It can be used to generate clean electricity or used for cooling and heating purpose. A geothermal power plant usually has around 90% capacity utilisation.
Several geothermal technologies are available today to convert hydrothermal fluids to electricity such as dry steam, flash steam and binary cycle. The conversion is totally based on the state of the fluid, i.e. steam or water and its temperature.
Geothermal energy offers several environmental advantages similar to other renewable energy sources- hydropower, wind, and bioenergy. Geothermal energy has various benefits including low emissions, no liquid contamination from re-injection, and reducing reliance on fuel.
Despite these advantages, the geothermal energy is still not accessible due to some major constraints such as:
Another significant restriction with the geothermal industry is that the heat cannot be transported. It has to be used where it is found and is often too far from end-users.
One of the main reasons why geothermal growth has failed to keep pace with wind and solar industries in recent decades is the shortage of high-temperature resources.
In comparison to solar and wind, high geothermal resources are only available where a strong flow and favourable hydrological occurrence exists. The geothermal industry contains risks as it requires proper exploratory drilling and testing (like oil and gas industry) to comply with the resource presence.
The geothermal market is slowly increasing with an estimated geothermal energy output of around 630 petajoules in 2018. It produced around 89.3 TWh in the form of electricity. In 2018, an estimated 0.5GW of new power generating capacity was added to the total cumulative capacity make the total to around 13.3GW.