目前有两种方法来提取地热能源:一个主流,一个仍然在实验/示范级。(波拉克et al(2010))[1]估计全球geoethermal热损失在44岁TW(相比之下,文明的能源消耗速度大约是20 TW)。当[美国能源部指出][2],所有方法依赖于三个因素的结合:- * * * *地下热,- * * * *液体表面的热量,* *,* *渗透率允许流体流动。# # #主流地热方法接近板块边界。水库的热液体了,把热的液体表面。一般液体的温度超过100摄氏度;,并且可以用于发电,取暖。# # #实验方法是干热岩即增强型地热系统或EGS)。帕维尔诉评论说,这是在(驾驶在捷克共和国)[3],在其他地方,并允许地热开采的地方不近板块边界。从该链接:>的设计深度…钻孔是2100至2500米。 The drilling diameter ranges from 393,7 mm for the starting upper section to 152 mm at the borehole bottom One tube is placed inside another, inside the borehole. Water can be injected down the inner tube, and returned up through the gap between tubes, or the other way around. That paper reproduces the following chart from Šafanda, J., Dědeček, P., Krešl, M., Čermák, V. [2007] Report from geothermal research for PVGT-LT1 (in Czech): ![enter image description here][4] As you can see, these temperatures are much lower, so are unsuitable for electricity generation, because one must accept very low efficiencies (Carnot's Law). They are used for space- and water-heating. [1]: http://dx.doi.org/10.1029/93RG01249 [2]: http://www1.eere.energy.gov/geothermal/powerplants.html [3]: http://geomedia.cz/data/GMLitVal.pdf [4]: http://i.stack.imgur.com/iwWqD.png