多年以来,美国电力需求增氏率约为7%。近几年由于阿拉伯石油禁运,其增长率降为3.5%,1978年则更降到3%以下。若按3%的年增长率计,本世纪末美国将要增加5亿千瓦的电力;如果按4%的年增长率计,则需要增加7.5亿千瓦。这一巨大的电能增加量,不能光指望常规热能和热核能,因为那将面对环境污染与安全威胁两大问题难以解决。而在下一个20多年中,太阳能、风能和地热能等也均难以满足这一增长要求,故只能对水能进行开发利用了。据美国联邦能源管理委员会最近估计,美国尚未被利 Over the years, the U.S. power demand growth rate of about 7%. In recent years, due to the Arab oil embargo, its growth rate has dropped to 3.5% and in 1978 to more than 3%. At 3% annual growth rate, the United States will have to increase its output by 500 million kilowatts by the end of this century. If it increases by 4% per year, it will need to increase 750 million kilowatts. This huge increase in electricity can not just count on conventional heat and thermonuclear energy, since it will be difficult to solve the two major problems of environmental pollution and security threats. In the next 20 years, solar energy, wind energy and geothermal energy are also difficult to meet the growth requirements, it can only be developed for the use of water. According to a recent estimate by the Federal Energy Regulatory Commission, the United States has not yet been profitable