WC Archive

Micro-Wind Power

Micro-micro-wind Nature News reports on the development of a tiny wind turbine (about 10cm in diameter) able to produce a surprisingly large amount of power for its size. The reason? Instead of the wind turning a conventional generator -- which, at that size, would be able to convert at best about 1% of the wind energy into electricity -- the system uses a piezoelectric generator, converting turbine vibrations into electricity using piezoelectric materials, which produce power when under mechanical stress. This gives the tiny turbines an efficiency of about 18%, comparable to much larger systems. In turn, these micropowerhouses can be used to power wireless sensor networks.

(As noted in the comments, the Nature News story has been changed from free access to premium-only, and sites with more information than a link back to Nature were hard to find. I found one, though: INDOlink, a site focusing on news for Non-Resident Indians. Their article, Shashank Priya Invents Wind-Powered Wi-Fi, has a somewhat deceptive title -- the power from the piezoelectric turbines is not likely to be enough for standard wifi networks -- but gives most of the details of the Nature News story.)

Home Wind Turbine BBC's The Magazine asks, Can a home wind turbine make money? The answer is a qualified "maybe," which is about as good as you're going to get right now. Wind intermittency is the greatest factor -- even turbines built in blustery areas will fall victim to extended calm periods. People who build home turbines shouldn't do so expecting to be able to live off the grid; instead, home wind power lets users cut their overall power bill by covering some portion of home use and, where allowed, selling excess power back to the grid. Regular readers will not be surprised to learn that the best thing one can do to increase the return of a home turbine is to increase the efficiency of energy use.

Large-Scale Wind Power

Floating Offshore Wind Traditional offshore wind farms are less-than-ideal for a few reasons. They are arguably visually unattractive, and may put shore birds at risk (depending upon turbine placement and height). Moreover, it's just not very efficient -- winds are less powerful close in to shore than they are in the open ocean. That's why Thomas Lee has designed a floating wind turbine platform intended for use dozens or even hundreds of miles out to sea. The turbines could be used to produce hydrogen or electricity cabled back to land, and would be able to move out of the path of major storms. This is still very much a paper design, not something currently being built; however, the US National Renewable Energy Laboratory has done a preliminary evaluation of floating platform wind farms (PDF), and concluded that they would be able to produce power for as little as $0.05/kWh.

Vertical Turbines Deep-offshore wind still too conventional? A company called Terra Moya Aqua has come up with a vertical axis wind turbine (VAWT) design that they claim is somewhat more efficient than equivalent horizontal axis wind turbines (HAWT) -- 43-45% efficient, compared to the 20-40% of conventional systems. The TMA design is supposed to handle high winds better than conventional HAWTs, be quieter, and result in fewer bird kills (as they will be more visible than spinning horizontal blades, apparently). The first production model is supposed to be available by next summer; TMA claims that commercial models should produce power at a cost of $0.025-$0.035/kWh.

VAWT designs aren't new, and previous iterations have fallen victim to higher mechanical stresses than traditional HAWT systems. I'm encouraged to see that TMA doesn't claim outrageous efficiency numbers or that this VAWT design will replace traditional towers. It remains to be seen how the TMA version will fare, but I look forward to hearing the results. (Via Treehugger)

Wind Potential

Guandong Wind Power The Worldwatch Institute has just published a lengthy examination (PDF) of the wind power potential for the Guandong region in China, near Hong Kong. Using studies from Stanford University and the UN Environment Program (probably SWERA), Worldwatch estimates that Guandong could build 20 GW of wind energy capacity by 2020, supplying about 17% of the region's demand. To accomplish this, Guandong would have to install a bit more than a gigawatt of wind power, on average, every year -- a rate that's slower than is typical for many similarly-sized European nations.

UK Wind Power Oxford’s Environmental Change Institute has now completed a study of the wind power potential in the United Kingdom, and has good news: it's the best in Europe. Jolly good!

According to the report, wind turbines in the UK produced around 27% of their maximum possible energy, compared to 20% in Denmark and only 15% in Germany, the country with the greatest wind power use. Moreover, the wind coming in off the Atlantic was extremely predictable and dependable, and the likelihood of either wind calms or overly-high winds causing wind farm shutdowns across the UK was extremely low (one hour every five years and one hour every ten years, on average, respectively). More importantly, peak wind availability coincides with peak demand periods in the evening and in the winter.