The world’s first commercial wave farm went live at the end of September in Agucadoura, located off the coast of northern Portugal. Designed by
Pelamis Wave Power, the farm employs three Wave Energy Converters– snakelike, semi-submerged devices that generate electricity with hydraulic rams driven by waves. This first phase of the new renewable energy farm is rated at 2.25 MW with 3 machines, and the the second phase will add an additional 25 machines to bring the capacity to 21 MW – enough to power 15,000 homes!
We’ve been following the Pelamis Wave Power project since last year and are very excited to see it come to fruition. Each Pelamis Wave Energy Converter measure 140 meters long and 3.5 meters in diameter, so they do take up significant amount of space out in the ocean. Still, the potential from this energy source is huge – the world’s waves are estimated to generate 2 Terawatts of power. To put that in perspective, the US currently has a generating capacity of just over 1 TW.
Pelamis Wave Energy Converters are tethered to the ocean floor by cables and are pointed perpendicular to the coastline. Each device is composed of several sections connected with articulated joints. As the waves roll in past the device, each section is driven up and down, while the hydraulic rams inside resist the motion. This resistance pumps high pressure fluid through hydraulic motors, which drive electric generators, thereby producing electricity. This electricity is then transmitted via underwater cables to the mainland.
Naturally, the amount of electricity generated depends upon the power of the waves at any given time, so like wind and solar energy, the electricity generated is not on demand. It’s an exciting renewable resource however, and Portugal’s new wave farm marks an important first step towards proving the technology, creating demand, and driving down the price. Soon you might see these off your local beach, assuming the conditions are right.
America is getting its very first wave power farm!
Ocean Power Technologies, a New Jersey-based firm, is currently installing giant buoys off the coast of Reedsport, Oregon. Once all ten buoys are in place, developers hope to use them to harness the energy of wave motion and generate power for hundreds of area homes.
Each buoy will measure about 150 feet tall by 40 feet wide and weigh in at about 200 tons. A float on each craft rises and falls with the rolling of the waves, driving an attached plunger’s up-and-down movement. A hydraulic pump then converts that movement into a spinning motion, which drives an electric generator. The electricity produced by the generator moves from sea to land via submerged cables. Right now, developers are finishing up construction on the first buoy, and it will take about 60 million big ones to finish up all ten. Once the entire system is on place, about 400 homes will derive their power from Oregon’s coastal waters.
Construction of the first buoy is an encouraging development, but the system still has some challenges to overcome. For one, wave power currently costs about six times that of wind power (although once the technology is optimized it should see comparable prices, especially because waves are more predictable than wind or solar power). Secondly, keeping the buoys in place and free from damages caused by big waves can be tricky.
And so far, wave power’s history doesn’t paint the most promising picture: The world’s first commercial wind farmopened in 2008 in Portugal, but power production was suspended due to financial difficulties. Moreover, two years ago, a Canadian-produced wave power device sank off Oregon’s coast. Still, if engineers can master the art of cost-effective wind power, it would be a huge boon for the renewables field. Waves are both free and predictable, so harnessing them to generate electricity would be great. Other wind farm projects are currently underway in countries like Spain, Scotland, Western Australia and England. If all goes according to plan,Oregon's wind farm will see completion by 2012.
by "environment clean generations"
Posted in: 
0 comentarii:
Post a Comment