Global revenues from clean tech businesses--including air and water purification, advanced materials, distributed power generation, renewable energy, and process controls, such as sensors to monitor air and water--now surpass 85 billion pounds, according to the Cleantech Venture Network, a for-profit membership group that connects venture and institutional investors with entrepreneurs.

FORBES

Wind power led among the renewable energy sources and accounted for about 3.5% of the overall power generation in 2012.

FORBES: Why People Should Care About Clean Power

For many of these states, offshore wind is the most abundant indigenous energy source and the only commercial option for renewable power generation, especially in southern states where land-based resources become scarcer with decreasing latitude.

FORBES: Turn Baby, Turn - Offshore Wind Power Poised for Major Growth in U.S.

As always, the Chinese government will head the list of economic drivers as it continues to make large investments in key sectors such as power generation, transportation, health care and renewable energy.

FORBES: China Investment Summit

For instance, the US National Renewable Energy Laboratory concluded in a 2008 analysis that Sudan has about 250 times the solar power generation potential as Gambia.

FORBES: More On Africa's Power Problems And Possible Solutions

Yet for all the hoopla that renewable energy receives, wind and solar account for just 6% of total U.S. power generation.

FORBES: Coal Is History. Or Is It?

Energy Secretary Chris Huhne has vowed to change the way the country produces energy, replacing old coal plants with gas-fired power stations and renewable sources as well as building a new generation of nuclear plants.

BBC: Debate on the government's green agenda

The CCC thinks as do ministers that a big expansion of renewable energy and the construction of carbon-capturing coal plants and new nuclear-power stations is the way to decarbonise electricity generation.

ECONOMIST: Energy and climate change