太阳能拯救我们吗？

爱思英语编者按：太阳是一种理想的燃料：无穷无尽，无处不在，而且清洁。肯定会有一天我们放弃依赖煤炭、石油和天然气----这些燃料对气候影响太恶劣，全世界分布也太不均衡----直接使用制造化石燃料的能源。在几个用电量很高的地方，像意大利和夏威夷，太阳能已经接近于有有竞争力。但是，在大多数地区，太阳到目前为止依然是最昂贵的电力来源----特别是在美国太阳能的成本是天然气和煤炭的好几倍----这就是为什么太阳还只是供应我们所需能源的一小部分的原因。

That won"t change fast unless governments give solar a big boost. President Barack Obama campaigned with a pledge to institute a federal "renewable portfolio standard" requiring utilities to generate a quarter of their electricity from renewables by 2025. Yet even if Congress enacted that ambitious law, coal would still dominate the nation"s electricity portfolio two decades from now, and solar energy would probably remain a minor contributor. Cap-and-trade legislation that sets a price on carbon emissions would not be a magic bullet for solar either. Both mandates would likely lead utilities to favor the cheapest renewables, like wind. Solar would make a sizable contribution only after 2025, once the expansion of wind energy had plateaued.更多信息请访问：http://www.24en.com/

Some advocates say we need to encourage solar more directly. European nations have done so with "feed-in tariffs," laws that require electric utilities to pay premiums to solar-power producers, be they commercial power plants or private homes that pump energy to the grid. Such tariffs have made Germany and Spain solar leaders, creating a market that has helped drive down prices. The billions of dollars of tax credits and loan guarantees in the Obama stimulus package may have a similar effect.

Another option is for the federal government to invest directly in solar—for example, says Ken Zweibel of George Washington University, by funding the construction of giant solar plants in the desert Southwest, along with the high-efficiency transmission lines needed to carry the power nationwide. In Zweibel"s version of the future, the sun would satisfy more than two-thirds of U.S. electricity needs by 2050, for an investment of about $400 billion. "Compared to what we just paid for the financial bailout, it"s pocket change," he says.

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