Tidal Energy
 

Anyone who has been caught in a nasty undercurrent knows the power of the tides. And just as windmills can covert the physical energy in a breeze into electricity, tidal turbines can do the same for the motion in the ocean. The engineering principle is no different — the steady currents found in coastal of water like Canada's Bay of Fundy turn the rotors of an underwater turbine. But tidal streams are far more predictable than wind, which means utilities using tidal don't have to worry about unexpected still days. The cost of putting equipment under water and concerns about the impact on the marine environment have kept tidal experimental, but that's beginning to change. Verdant Power recently completed a successful trial in New York City's East River, and the UK-based Marine Current Turbines is preparing for a 10.5 MW project off the coast of Wales.

Australia is almost uniquely situated to take advantage of the wave energy breaking on our shores. South Africa is another country that could benefit greatly from wave energy. Wave energy is truly without CO2 emissions, without the production cost of solar cells, and could be used to produce desalinated water - again without so called dirty energy cost. It is un-fathomable that the Australian government would not support it, yet they have not.
I hope they will in the future.

Some funding for wave but Carnegie was neglected??
 

Australia funds utility-scale wave power station

11 November 2009
Four renewable energy projects will receive AU$235 million from the federal government in Australia, including a 19 MW wave farm off the coast of Victoria.

The Australian subsidiary of Ocean Power Technologies has received AU$66.5m to build the wave power facility that will supply green energy to 10,000 homes. Construction will take place in three phases, starting in the second quarter of 2010.


The wave energy project will be a partnership with Leighton Contractors and conducted through Victorian Wave Partners, a company formed by Ocean Power Technologies Australasia and Leighton following an agreement signed in December 2008. It will be the first commercial-scale ocean energy project in Australia and will use OPT’s PowerBuoy technology.

"The PowerBuoy® is an offshore wave energy converter, most of which is submerged below the water's surface. Inside, a piston-like structure moves as the PowerBuoy® bobs with the rise and fall of the waves. This movement drives a generator, producing electricity, which is sent to the shore by an underwater cable. An OPT "power plant" will consist of an array of identical PowerBuoys® that are electrically connected to provide the desired power capacity."


Note:
It surprised quite a few investors that the Fed choose the little known Ocean Power Technologies over Carnegie Corporation's (ASX: CNM) "A Wave energy company that aims to produce electricity from fully submerged pumps which are anchored on the ocean floor. Wave energy is tapped to pressurise and pump seawater onshore where it spins turbines to generate electricity. The pressure can also delalinate salt water, using "reverse osmosis desalination" technology.


However OPT does have powerful backing with Woodside and Leighton's on-board.

This method of electricity generation relies on capturing the energy contained in the movement of water with the tides. There are two types of tidal energy. The first is the energy in the water current between the incoming and outgoing tide. The second is the energy in the rising and falling of the water between high and low tides.

Catalyst ABC - Good review of wave technology
 

Of late there seems to be some interest in wave technology...

I saw an interesting segment by Catalyst on the Carnegie technology indicating that they are approaching commercialization in 2012 - 2013.

"Carnegie Wave Energy Ltd is one of only three companies worldwide with a wave power plant currently in commercial pilot. If all goes well, and every indication so far is positive, CWE will by 2012 have proven that wave power is cheap, efficient and pollution free and can be used to produce either electricity or desalinated water - or both together in any combination - at a significant cost saving to any other renewable energy method for coastal cities."

See: http://www.powergenworldwide.com/index/display/wire-news-display/1412375476.html