自工业革命以来，人类主要依赖石油、煤炭和天然气等化石燃料。然而，化石燃料被认为是一种可燃烧的能源，其中一些，特别是石油，据说已经达到了峰值产量。因此，我们可以肯定地预测它们的价格会随着时间的推移而上涨。此外，化石能源产生的温室气体是全球变暖的主要原因之一，而气候变化继续成为全球现象。核能曾被认为是化石燃料的重要替代品，被认为是解决能源问题的良方。然而，在福岛这样可能发生严重灾难的情况下，核能已经多次暴露为对人类的严重威胁，而且在处理其产生的放射性废物方面也遇到了进一步的困难。
与化石燃料相比，可再生能源作为“未来的可持续能源”引起了全世界的关注，在“第四次革命”或“绿色革命”的进程中，随着农业、工业和工业的发展，这些能源的利用得到了极大的扩展。因为日本一次能源只有5%是国内生产的。然而，可再生能源可以在日本国内生产，并且可以作为替代化石燃料和核能等现有能源的替代品。此外，可再生能源几乎不会产生温室气体排放，可再生技术的实施有望稳定国内和地区能源安全，创造就业机会，并为地区经济注入活力。可再生能源还可用于生产各种形式的电，如非太阳能、风能、地热、水力、生物量、地热或作为生物燃料中的燃料。
尽管偶尔有人呼吁扩大利用可再生能源，但日本的发电量仍仅占总发电量的10%左右，甚至包括图1所示的大型水力发电设施。此外，2011年3月11日福岛核事故发生后，日本能源政策尤其是核工业的气候已经完全改变。这一悲剧进一步阐明了改变日本重核依赖能源政策的必要性，特别是考虑到日本所处的地理位置。此外，尽管短期内依赖化石燃料是不可避免的，但不久的将来，化石燃料价格的高增长将迫使我们决定将现有的能源政策转变为以可再生能源为基础的能源政策。
可再生能源项目，特别是太阳能发电项目，可以在相对较短的时间内实施；因此，引入可再生能源可以作为灾后恢复措施发挥重要作用，也有助于能源安全和全球变暖预防。此外，可再生能源的应用还表现出“越普及，价格越低”的特点，这在小规模分散技术中是很典型的。可再生能源技术的一个显著特点是，随着经济的进一步普及，可再生能源的性能提高，价格下降。换言之，与过去十年相比，下一个十年将见证可再生能源的迅速普及，从而导致成本的大幅下降。这将使在未来几年内以较低的成本同时引进比目前速度更多的可再生技术成为可能。今后，日本各地区将采取以小规模分散可再生能源为重点的能源政策，使之成为灾后经济的支柱，实现100%可再生能源的潜在社会。这将通过灵活和战略性的能源转移来实现，目的是提供可自给自足的能源，同时缓解全球变暖，如图2所示。
since the industrial revolution, human beings havedepended mainly on fossil fuels such as oil, coal, andnatural gas. however, fossil fuels are recognized asexhaustible energy sources, and some of them,especially oil, are said to have already reached peakproduction. as a result we can predict with certainty along term rise of their prices. moreover, the greenhousegas that fossil fuel energy produces is one of the majorcauses of global warming, while climate changecontinues to become a global phenomenon. nuclearenergy, which has been pointed out as a remedy toenergy problems, was once thought to be a seriousalternative to the fossil fuels. yet nuclear energy hasrepeatedly been exposed as aserious threat to the human beingsin the case of serious disasters thatcan occur like in fukushima, andthe further difficulties in handlingthe radioactive waste it produces.
in contrast to fossil fuels, renewableenergy has attracted worldwideinterest as the "sustainable energyfor the future", and the utilization ofthese energy sources has vastlyexpanded in the ongoing process of"the fourth revolution" or greenrevolution; following theagricultural, industrial, itrevolution. since only a mere 5% of japan’s primaryenergy is domestically produced. however, renewableenergy can be domestically produced in japan, and canbe used as an alternative to existing energy sources suchas fossil fuel and nuclear energy. furthermore,renewable energy produces almost no greenhouse gasemissions, and the implementation of renewabletechnology is expected to stabilize domestic andregional energy security, create jobs, and energize theregional economy. renewable energy can also be usedto produce electricity in various forms such asphotovoltaic, wind, geothermal, hydro, biomass,geothermal, or as fuel in biomass fuel.
although occasionally there have been calls for anexpanded utilization of renewable energy, the amountintroduced in japan is still only about 10% of total generated electricity, this even includes the large sizehydro power facilities as shown in fig.1. furthermore,the climate of japan’s energy policy especially thenuclear industry has changed completely after thedisaster on 11th march 2011 in fukushima. the tragedyfurther clarified the necessity to alter the heavily nucleardependent energy policy of japan, especiallyconsidering the geological position japan is locatedupon. additionally, albeit the inevitability to rely on thefossil fuels in the short term, the highly probable rise inprices of the fossil fuels in the near future will force usto decide to alter the existing energy policy to one basedon the renewable energy.
renewable projects, particularly those of solar powergeneration, can be implemented within a relatively shorttime frame; therefore, introducing renewables can playan important role as a post-disaster recovery measure aswell as contribute to energy security and globalwarming prevention. moreover, the "the morepopularization, the lower the price" characteristic,which is typical in small scale dispersed technology ispresent in the adoption of renewable energy. one of thepositive characteristics of renewable technologies is thatthe performance improves and price declines as theybecome more popularized. in other words, the nextdecade in comparison to the last decade will witnessmuch faster spread of renewable energy and thus adramatic price decrease in the cost. this will make it possible to introduce more renewable technologies inten years than the current speed at a lower costsimultaneously. from now on, the respective regions ofjapan are expected to adopt an energy policy thatfocuses on small scale and dispersed renewables notonly as to make it a mainstay of post-disaster economicrecovery but also to realize a potential society of 100%renewable energy. this will be achieved through adrastic and strategic energy shift aimed at supplyingstable and self-sufficient energy, while at the same timemitigating global warming as shown in fig.2.