地热能源产生的三个主要方面:很久以前,地球形成的时候质量的动能,撞上地球表面转化为热量。地球重力进一步压缩材料也产生一些热量,元素自然衰变引起核裂变产生的能量。同时,月亮、太阳的引力引起的期刊(稍微)扭曲地球上也产生一些热量虽然很少。在这些热源:地球形成过程停止,动能转化为热量不再有供应。重力压缩效应,产生热量已经不再重要,因为物质密度足够的地球。放射性元素在地球上只能消耗,但没有进一步提供空间;他们生产热量将越来越弱,当时间流逝。潮汐运动导致地球上的热量太少补偿损失的热量通过自然损耗。美国产生的热量从核心(20×10〗^ 12 w)不能补偿进行的热表面和消散到空间(美国44×10〗^ 12 w)。作为一个观察的事实,地球的总质量是冷却。 When there is no supply (or not enough supply) while there is a constant loss (natural energy dissipation) or accelerated loss (manmade energy dissipation by tapping into geothermal energy), it is a simple mathematical logic: the Earth’s geothermal energy is not sustainable --- don’t even mention renewable. Someone argue: the Earth is so big and we are so small, we use a little bit of geothermal energy, it doesn’t matter. OK, if this proportional difference can allow human to use the geothermal energy long enough to the time the Sun’s life span is going to end and start to swell and scorch the Earth, then it makes sense. Otherwise it is non-sense. Then how long it can last if we use geothermal energy? Here is some rough calculation (because in this case we only need some qualitative analysis to decide sustainability issue on geothermal energy): In 2006, human use 16 trillion w /s; Earth total mass: 5.9763×〖10〗^24kg; Mean density: 5517kg/M^3; Estimated average heat capacity: 700 J/kg ℃; Kilowatts/hour= 3.6×〖10〗^6Joule; 16 trillion w/s = 〖16×10〗^9kw×〖60〗^2s= 〖57.6×10〗^12kw/h; 1℃ down for Earth total mass: 5.9763×〖10〗^24kg×700 J/kg÷ (3.6 ×〖10〗^6Joule) =1162×〖10〗^18kw/h; How many years human use can cause 1℃ down for Earth total mass? 1162×〖10〗^18kw/h÷〖57.6×10〗^12kw/h×24h×7d×52w =2309year How many years human use can cause 200℃ down for Earth total mass? 2309year×200℃ = 461,800year How many years we taking off our descendants by using geothermal energy for one year by this rate? 2 billion year/461,800year≈4331year The heat inside the Earth is the living force that keeps the Earth alive --- the heat inside the Earth resist water be sipped into the Earth, keep the molten core flowing that maintain the magnetic fields of the Earth that protect all lives on it and that also protect the atmosphere not been blown away by solar wind, keep continental plates moving that make mountains which keep the Earth uneven to maintain weather and prevent all Earth surface be submerged into 50 meters of water… Earth with weakened geothermal energy will become another Mars.