He has carried out extensive research into renewable energy sources.

他已经对再生能源进行了广泛研究。

Today, renewable energy sources generate 12 percent of electricity in the U.S..

如今，美国所需电能的12%是由可再生能源提供的。

The Villa employs onsite renewable energy sources for heating, electricity and water.

此别墅运用了自备的可再生能源进行供热、供电和供水。

But it isn't only solar that's down in cost. It's other renewable energy sources, too.

成本下降不仅表现在太阳能上，也体现在其他可再生能源上。

We will develop clean and renewable energy sources such as wind power and solar energy.

开发风能、太阳能等清洁、可再生能源。