This is a neat idea: wind turbines that use LIDAR (akin to RADAR, using light) to anticipate the strength of wind, and prepare for it in advance:
Dr Mikkelsen and his colleagues worked out that they could use lidar to scan incoming wind and determine how it was behaving before it struck the turbine. To try this idea out, they first placed lidar devices at the base of 120-metre-tall wind turbines at Hovsore, the Danish test site for such devices. The lidars scanned the approaching winds with a laser that produced infra-red light with a wavelength of 1.55 microns. Reflected light was detected by a device so sensitive that it could pick up one returning photon (the quantum-mechanical particles of which light is composed) out of every thousand billion fired by the laser. The device measured wind movement at 40, 60, 80, and 100 metres above the ground, and 100-200 metres in front of the turbine. The data it collected were then compared with wind measurements taken by cup anemometers (the sort that spin when struck by wind, to record its speed) in order to calibrate the lidar. That done, the computer which analyses the lidar data can be connected to the motors that adjust the pitch of the turbine blades, in order to maximise energy production and reduce damage.
Such technologies could help deal with minute-to-minute changes in wind speed, improving the reliability of wind farm output.
Wind forecasting
And now, the electricity forecast
Energy: New forecasting techniques make wind power more predictable and thus more practical for widespread use
Jun 10th 2010
WHEN Mitsubishi Power Systems Europe, a subsidiary of a Japanese industrial conglomerate, announced on February 25th that it was investing £100m ($145m) to establish a new wind-turbine research and development facility in Britain, the deal was heralded as another step forward for wind power. But the timing was in some ways unfortunate. Although Britain is indeed a good place to put wind turbines, the wind, like the weather, is notoriously variable. And according to data from the Met Office, Britain’s national weather service, February 2010 was in fact the least windy month for seven and a half years.
Wind power is widely seen as the source of renewable energy with the best chance of competing with fossil-fuel power stations in the near term. The European Union has committed itself to getting 20% of its electricity supply from renewable energy sources, mainly wind power, by 2020. In America the Department of Energy reckons that wind could provide a similar proportion of the country’s electricity by 2030. China recently tripled its wind-capacity target to 100GW by 2020.
But capacity does not equal electricity. For all those turbines to be worthwhile, the wind has to blow in specific places at specific strengths for specific periods of time. What if it doesn’t? Such questions are at the root of a growing interest in the field of wind forecasting. It can help developers of new wind farms decide where to build, and help operators of existing ones forecast output more accurately.