There is not yet a realistic pipeline leading to zero-carbon forms of power, just MegaJoules of passion. Take wave technology. Environmental sustainability, yes. The issue is cost. As it is with a lot of alternative energy sources, it’s a matter of watch-this-space.
However, according to proponents offshore wave energy has the potential to be one of the most environmentally benign forms of electricity generation with a minimal visual impact from the shore. 
For more, this may be useful, by Peter Marsh at the FT.
Wave energy pioneer courts big engineers
http://www.ft.com
Three of Britain’s biggest engineering groups are being sounded out in an effort to find a “UK solution” to the conundrum of how to finance one of the world’s most advanced suppliers in the fledgling wave energy sector. The company up for sale is….
While the technology is considered one of the most promising areas of renewable energy, the costs of producing Pelamis’s hardware are 5-10 times higher than they need to be before the machines can rival conventional forms of power, such as gas turbines.
