自工業(yè)革命以來，人類主要依賴石油、煤炭和天然氣等化石燃料。然而，化石燃料被認(rèn)為是一種可燃燒的能源，其中一些，特別是石油，據(jù)說已經(jīng)達(dá)到了峰值產(chǎn)量。因此，我們可以肯定地預(yù)測它們的價(jià)格會(huì)隨著時(shí)間的推移而上漲。此外，化石能源產(chǎn)生的溫室氣體是全球變暖的主要原因之一，而氣候變化繼續(xù)成為全球現(xiàn)象。核能曾被認(rèn)為是化石燃料的重要替代品，被認(rèn)為是解決能源問題的良方。然而，在福島這樣可能發(fā)生嚴(yán)重災(zāi)難的情況下，核能已經(jīng)多次暴露為對人類的嚴(yán)重威脅，而且在處理其產(chǎn)生的放射性廢物方面也遇到了進(jìn)一步的困難。

與化石燃料相比，可再生能源作為“未來的可持續(xù)能源”引起了全世界的關(guān)注，在“第四次革命”或“綠色革命”的進(jìn)程中，隨著農(nóng)業(yè)、工業(yè)和工業(yè)的發(fā)展，這些能源的利用得到了極大的擴(kuò)展。因?yàn)槿毡疽淮文茉粗挥?%是國內(nèi)生產(chǎn)的。然而，可再生能源可以在日本國內(nèi)生產(chǎn)，并且可以作為替代化石燃料和核能等現(xiàn)有能源的替代品。此外，可再生能源幾乎不會(huì)產(chǎn)生溫室氣體排放，可再生技術(shù)的實(shí)施有望穩(wěn)定國內(nèi)和地區(qū)能源安全，創(chuàng)造就業(yè)機(jī)會(huì)，并為地區(qū)經(jīng)濟(jì)注入活力?？稍偕茉催€可用于生產(chǎn)各種形式的電，如非太陽能、風(fēng)能、地?zé)?、水力、生物量、地?zé)峄蜃鳛樯锶剂现械娜剂稀?/p>

盡管偶爾有人呼吁擴(kuò)大利用可再生能源，但日本的發(fā)電量仍僅占總發(fā)電量的10%左右，甚至包括圖1所示的大型水力發(fā)電設(shè)施。此外，2011年3月11日福島核事故發(fā)生后，日本能源政策尤其是核工業(yè)的氣候已經(jīng)完全改變。這一悲劇進(jìn)一步闡明了改變?nèi)毡局睾艘蕾嚹茉凑叩谋匾?，特別是考慮到日本所處的地理位置。此外，盡管短期內(nèi)依賴化石燃料是不可避免的，但不久的將來，化石燃料價(jià)格的高增長將迫使我們決定將現(xiàn)有的能源政策轉(zhuǎn)變?yōu)橐钥稍偕茉礊榛A(chǔ)的能源政策。

可再生能源項(xiàng)目，特別是太陽能發(fā)電項(xiàng)目，可以在相對較短的時(shí)間內(nèi)實(shí)施；因此，引入可再生能源可以作為災(zāi)后恢復(fù)措施發(fā)揮重要作用，也有助于能源安全和全球變暖預(yù)防。此外，可再生能源的應(yīng)用還表現(xiàn)出“越普及，價(jià)格越低”的特點(diǎn)，這在小規(guī)模分散技術(shù)中是很典型的?？稍偕茉醇夹g(shù)的一個(gè)顯著特點(diǎn)是，隨著經(jīng)濟(jì)的進(jìn)一步普及，可再生能源的性能提高，價(jià)格下降。換言之，與過去十年相比，下一個(gè)十年將見證可再生能源的迅速普及，從而導(dǎo)致成本的大幅下降。這將使在未來幾年內(nèi)以較低的成本同時(shí)引進(jìn)比目前速度更多的可再生技術(shù)成為可能。今后，日本各地區(qū)將采取以小規(guī)模分散可再生能源為重點(diǎn)的能源政策，使之成為災(zāi)后經(jīng)濟(jì)的支柱，實(shí)現(xiàn)100%可再生能源的潛在社會(huì)。這將通過靈活和戰(zhàn)略性的能源轉(zhuǎn)移來實(shí)現(xiàn)，目的是提供可自給自足的能源，同時(shí)緩解全球變暖，如圖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.