Offshore wind farms, like their oil platform cousins, have a major logistics problem. Building and maintaining underwater cables from each tower to a grid that then has to get the power back to shore is costly to maintain. While technically possible from deep water, there is substantial power loss while accomplishing that feat.
Would it be more efficient and cost effective in deep water situations to have each wind turbine platform a free standing unit that converts water to hydrogen? The units could be modular, wind turbine, converter, barge terminal, storage unit, etc which would simplify maintenance.
To minimize down time a modular section could be replaced with a spare while undergoing repairs. Better yet, modules could be rotated in and out for routine maintenance rather than taking an entire unit off line.
Modular barges could dock with the platform to haul the hydrogen to a terminal closer to shore. Designed properly the barges would be an integral part of the platform. The combined storage of the platform and the barge could be in excess of 1 months production to allow the unit to operate through storms. They could then move the cargo to an offshore terminal when water conditions were safer.
The central terminal could pump the hydrogen to shore and/or use it to run generators and the power could be sent to shore on a shorter set of cables. A key benefit that this layout would offer would be a more reliable power source. The hydrogen could be stockpiled for periods of low wind or peak power usage.
It also sets up nicely to support hydrogen powered vehicles as an alternative to gasoline. Even the barges could be hydrogen powered.
Siemens wind turbines in the North Sea off Denmark, fixed to the seabed. Siemens is among the companies developing ‘floating’ turbines.
US Energy Secretary Steven Chu and his UK counterpart Edward Davey are set to announce that the two countries will jointly develop offshore wind turbines that don’t require anchoring to the seabed. “Floating” turbines potentially cut maintenance and installation costs and allow operations further out at sea.
The agreement is the “initial focus” of a broader memorandum of understanding that the U.S. and UK will sign this week to collaborate in energy development, according to a press release from the UK’s Department of Energy and Climate Change (DECC).
“The UK and US will agree to collaborate in the development of floating wind technology designed to generate power in deep waters currently off limits to conventional turbines but where the wind is much stronger,” DECC said.
The UK has more offshore wind capacity than any other country. Davey, who heads DECC, said that he expects floating turbines to play a big role in Britain’s carbon-reduced future.
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British Energy Secretary Ed Davey (l) with Anders Eldrup, CEO of Danish wind and power provider Dong Energy, in February. Dong is a partner in the 367-megawatt Walney Wind Farm off northwest England - the world's largest operating offshore wind farm.
“Floating wind turbines will allow us to exploit more of our wind resource, potentially more cheaply,” Davey said in the press release. ”Turbines will be able to locate in ever deeper waters where the wind is stronger but without the expense of foundation down to the seabed or having to undertake major repairs out at sea.”
Floating turbine proponents say that maintenance crews will be able to tow turbines to dockside for repairs, rather than carrying out more expensive work at sea.
The technology could play a vital role in Britain after 2020, following development of shallower water sites, Davey said.
A UK government-industry partnership called Energy Technologies Institute is currently selecting companies to participate in a £25 million ($40 million) small demonstrator floating field that by 2016 would have a capacity of 5-to-7 megawatts (A fraction of a typical coal-fired utility and of some existing British offshore wind plants such as the 367-megawatt Walney Wind Farm 9 miles off the coast of northwest England, believed to be the world’s largest operating offshore installation).
ETI’s members include DECC and other government agencies as well as oil companies BP and Shell, Germany utility E.On, French utility EDF, Caterpillar and Rolls-Royce (the aerospace and engine company, not the car company). ETI expects to chose contractors by early next year.
In the U.S., the DOE’s recently announced $180 million program to fund offshore wind could including floating technology, the DECC release noted.
The broader US/UK pact, including floating wind, is called “Collaboration on Energy Related Fields.” It calls for joint efforts in power generation and in energy transmission, distribution and efficiency.
The US/UK announcement precedes Wednesday’s start in London of a 2-day gathering of energy ministers from 23 countries to discuss renewables, energy efficiency, electric vehciles, carbon capture, buildings, industry, smart grids and other themes. Chu and Davey are co-chairing the gathering, called the Clean Energy Ministerial.
“Ed Davey will sing a number of bilateral agreements with conterparts form other governemnt to work in collaboration over the coming years,” DECC states.
Other countries or regions attending the conference are: Australia, Brazil, Canada, China, Denmark, European Commission, Finland, France, Germany, India, Indonesia, Italy, Japan, Korea, Mexico, Norway, Russia, South Africa, Spain, Sweden and the United Arab Emirates.
Photos: Wind turbines from Siemens. Ed Davey, Anders Eldrup from DECC via Flickr.
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