Wind power is the kinetic①energy or energy extracted by wind turbines.
Wave power refers to doing useful work including ecectricity generation， desalination， and filling a reservoir with water after wave energy being formed on the surface of ocean wave power is a form of renewable energy. Though often co-mingled， wave power is physiologically distinct from the diurnal flux of tidal power and the steady gyre②of ocean currents which are powered by the earth’s rotation. Wave power generation is not a widely employed technology with only a few experimental sites in existence.
Tidal power is a means of electricity generation achieved by capturing the energy including mass water moving leading to tides， then absorb the energy contained in the tides to finish the whole process. Two types of tidal energy can be extracted③： the movement of tides brings kinetic energy of currents energy of currents due the tides and potential energy is produced by the difference in height (or head) between high and low tides.
Geothermal power is electricity generated by utilizing④ naturally occurring geological heat sources. It is a form of renewable energy， too.
① kineticadj. 运动的，运动引起的，活跃的
② gyren. 旋回
③ extractv. 采掘、提取、提炼
④ utilizev. ［书］利用
能源的种类
风能是风的一种动力能源，或者是通过风力机而制造提取的能量。
波能指的是波能在海洋表面形成后，能被用来去做有价值的工作，包括发电，去掉盐分，形成一个蓄满水的仓库。波能是一种可再生资源。虽经常被混为一谈，但是，波能与由于地球自转而导致的每日变化的潮汐能，和稳定回转的洋流有着生理学意义上的区别。波能发电还没有作为一个被广泛使用的技术来使用，因为只有少数几个试验点存在。
潮汐能是一种发电的途径，通过水量大规模的运动形成潮汐，再通过吸取潮汐中含有的能量而最终完成。两类潮汐能都可以被提取：潮汐运动带来水流的回旋能量，高低潮汐之间因高度差异产生潜在能量。
地热能利用自然存在的地热资源来制造电力，也是一种可再生资源。
