Wave power generation is relatively new in the world. In Europe, a Scottish company operates a few large scale projects off the Portuguese coast since 2007 and the UK government has just okayed a different type of wave power project to be moored on its coastal waters. There’s little activity in the US as yet on the wave power scene. So what are the advantages and what are considered challenges?
The new British project provides a few answers to these questions. Wave power is clean energy with great potential. In the US alone, it’s estimated that wave energy resources amount to 2,100 terawatt hours annually, which is half the US’ electricity consumption.
The UK project to capture energy from coastal waves involves massive rubber snakeslike devices. These are parked out on the waves and stretch for up to around 200m. At one end a turbine is attached and the other end is kept just under the surface as it’s pinned down to the sea floor. What happens is that when a wave comes rolling along, the end that’s just underneath the surface of the water, is squashed, causing the flexible rubber to form a bulge. The snake’s diameter is engineered in such a way that this bulge travels to the other side of the snake at around the same speed of the wave, ending up at the side to which a hydropower turbine, which converts the bulge into energy that’s fed to the power grid.
“Anaconda may be able to satisfy our insatiable demands,” the UK official newspaper The Register reports. It will take around three more years of lab testing before the rubber projectiles will first be seen in coastal waters. It is believed that one snake yields as much as one megawatt of energy when operating at peak levels.
The company that is linked with the academics, Checkmate SeaEnergy, has successfully obtained a patent on its bulge wave technology. The company, which collaborates with professors ate Engineering and Physical Sciences Research Council, named the Anaconda, which is quite appropriate. Even though Anaconda is the only project worldwide to run on bulge wave technology, there are a few more projects involving coastal waves, including Pelamis Wave Power, the Scottish company which in 2004 was the world’s first to develop wave technology off the coast of the Scottish Okney Islands. Pelamis last year commenced a big project in Portuguese coastal waters, operating three 750 kilowatt snakes whose metal cylinders weigh 770 ton and are 120m long.
In North America, there are only a handful of wave energy developers and they don’t use snakelike projectiles but focus on capturing tidal energy and buoys. They include Canada’s Finavera Renewables, Scotland’s, AWS Ocean Energy and Ocean Power Technologies of Pennington, NJ. OPT was reportedly testing bobbing buoy-type devices.
We’ ll have to wait until 2011 before we know if the British rubber snakes will finally prove if they’re worth all the effort, but the scientists involved say they are quite sure that they will be better than competing technology because the rubber is light and needs little maintenance. John Chaplin, a civil-engineering professor at the University of Southampton who’s involved in Anaconda, said “We don’t really know how Anaconda works in big waves yet, but intuitively, it seems likely that it’s going to be able to survive big waves,” in Technology Review earlier this month. One rubber snake weighs around 110 tons.
All sounds interesting enough. Wave power projects might have a future in the US too. The main drawback, it seems, is actually regulatory rather than technical, according to Roger Bedard of the Electric Power Research Institute, a not for profit think tank. He believes that pipes could be moored in US coastal waters too but only after they gain government support. Bedard also cited immense regulatory hurdles as a detterant for the time being.