It is practically six,500 kilometers (4,000 miles) from the surface to the center of the Earth, and the deeper you go, the hotter it gets. The outer layer, the crust, is 3 to 35 miles thick and insulates us from the hot interior.
For dry steam sources either atmospheric exhaust turbines or condensing steam turbines are employed. New developments of Enhanced Geothermal Systems (EGS) are focusing on enhanced systems, utilizing current deep reservoir resources Deep Drilling Projects (DDP) in a depth Draft TNA Geothermal of four to five km. The aim of such projects (i.e. in Iceland and New Zealand) is the exploitation of supercritical fluid reservoirs with steam temperatures up to 400-600°C.
A couple of wind energy stations are operating in Queensland. Windy Hill Wind Farm in the Atherton Tablelands consists of 20 wind turbines creating 12MW of green electricity. The other is owned by Ergon and positioned at Thursday Island. Two wind turbines meet ten% of the remote community’s electrical energy needs, reducing their total dependence on diesel energy.
Geothermal power plants, like wind and solar power plants, do not have to burn fuels to manufacture steam to turn the turbines. Generating electrical energy with geothermal power aids to conserve nonrenewable fossil fuels, and by decreasing the use of these fuels, we lower emissions that harm our atmosphere. There is no smoky air around geothermal energy plants – in fact some are constructed in the middle of farm crops and forests, and share land with cattle and nearby wildlife.
As the temperature of geothermal wells in the country ranges among 20°C – 100°C direct use applications are most appropriate. North-East Bulgaria (Moesian plate) and South Bulgaria (Rila-Rhodopes massif) host most of the geothermal sources. Direct thermal water use in Bulgaria concentrates on balneology (biggest share with 60%), space heating, air-conditioning, greenhouses, ground source heat pumps, direct thermal water provide, bottling of potable water and soft drinks and for some technological processes.