Geothermal power is considered to be a key element in future renewable energy supply. It has been used since the beginning of the last century for electricity generation, and even longer for supplying heat from below the earth. New intensive research and development work is widening the potential of sites that could be used to produce power. Specific new developments include large underground heat exchange surfaces (Enhanced Geothermal Systems) and the improvement of low temperature power conversion, for example with the Organic Rankine Cycle. The economics of geothermal electricity will also be improved by advanced heat and power cogeneration plants and further development of innovative drilling technology.
For conventional geothermal plants, costs are expected to drop from 7 cents/kWh to about 2 cents/kWh. Enhanced Geothermal Systems presently have high costs (about 20 cents/kWh), but these are expected to come down to around 5 cents/kWh in the long term, depending on the payments for heat supply. These price reductions assume a global average market growth for geothermal power capacity of 9% per year up to 2020, leveling out to 4% beyond 2030.
Geothermal energy has a non-fluctuating supply and a grid load operating almost 100% of the time. Until now we have just used a marginal part of the geothermal heating and cooling potential. Shallow geothermal drilling could deliver heating and cooling at any time anywhere, and can be used for thermal energy storage.
employment in geothermal energy Geothermal energy could contribute a significant proportion of the world’s energy supply, quadrupling under the basic Energy [R]evolution scenario by 2030, and increasing 10-times in the advanced version, compared to the Reference scenario. This would correspond to triple the amount of jobs, around 120,000 (basic) and 270,000 (advanced) in 2030.