<P> Small - scale EGS have been installed in the Rhine Graben at Soultz - sous - Forêts in France and at Landau and Insheim in Germany . </P> <P> Geothermal power requires no fuel (except for pumps), and is therefore immune to fuel cost fluctuations . However, capital costs are significant . Drilling accounts for over half the costs, and exploration of deep resources entails significant risks . A typical well doublet (extraction and injection wells) in Nevada can support 4.5 megawatts (MW) and costs about $10 million to drill, with a 20% failure rate . </P> <P> In total, electrical plant construction and well drilling cost about € 2--5 million per MW of electrical capacity, while the break--even price is 0.04--0.10 € per kW h . Enhanced geothermal systems tend to be on the high side of these ranges, with capital costs above $4 million per MW and break--even above $0.054 per kW h in 2007 . Direct heating applications can use much shallower wells with lower temperatures, so smaller systems with lower costs and risks are feasible . Residential geothermal heat pumps with a capacity of 10 kilowatt (kW) are routinely installed for around $1--3,000 per kilowatt . District heating systems may benefit from economies of scale if demand is geographically dense, as in cities and greenhouses, but otherwise piping installation dominates capital costs . The capital cost of one such district heating system in Bavaria was estimated at somewhat over 1 million € per MW . Direct systems of any size are much simpler than electric generators and have lower maintenance costs per kW h, but they must consume electricity to run pumps and compressors . Some governments subsidize geothermal projects . </P> <P> Geothermal power is highly scalable: from a rural village to an entire city . </P>

Fossil fuels geothermal energy and hydroelectric energy as a source of electrical energy