OAKLAND, Calif. — Global clean-energy markets are expanding rapidly, according to a new study. Just four sectors are projected to more than triple over the next decade, growing to $254.5 billion by 2017.

According to Clean Energy Trends 2008, produced by Clean Edge (and co-authored by GreenBiz.com executive editor Joel Makower), revenues in four benchmark sectors -- biofuels, wind power, solar photovoltaics, and fuel cells -- are up 40 percent in one year, to $77.3 billion in 2007. The report finds that for the first time, three leading clean-energy technologies each surpassed $20 billion in revenue.

According to the report, global production and wholesale pricing of biofuels reached $25.4 billion in 2007 and is projected to hit $81.1 billion by 2017. The global biofuels market last year consisted of more than 13 billion gallons of ethanol and more than 2 billion gallons of biodiesel production worldwide. Wind power is expected to expand from $30.1 billion in 2007 to $83.4 billion in 2017. Last year's global wind power installations reached a record 20,000 megawatts (MW), equivalent in size to 20 conventional fossil-fuel power plants.

Clean Edge also found that solar photovoltaics (including modules, system components, and installation), which totaled $20.3 billion last year, will more than triple to $74 billion by 2017. Annual installations in 2007 were just shy of 3,000 MW worldwide.

New global investments in energy technologies -- including venture capital, project finance, public markets, and research and development -- have expanded by 60 percent from $92.6 billion in 2006 to $148.4 billion in 2007, according to New Energy Finance. In the U.S., venture capitalists invested $2.7 billion in the clean-energy sector, representing almost 10 percent of total venture capital activity.

The report also outlines five trends poised to make an impact on the markets this year. They describe how small start-ups are powering markets for electric vehicles; how sustainable cities are being designed and built from the ground up; why overseas players are powering the U.S. wind market boom; why geothermal energy is experience a global renaissance as a clean-energy resource; and ho new technologies are helping oceangoing ships take a cleaner tack.

"Clean energy has moved from the margins to the mainstream and the proof is in these numbers," said Clean Edge Co-founder and Principal Ron Pernick. "Amid last year's plummeting housing prices, rising foreclosure rates, and record high oil prices, clean energy continued to provide a bright spot in an otherwise sluggish economy."

The free report can be downloaded at www.cleanedge.com.