Thursday, 9 July 2009

Wind Power

The Energy Saving Trust (EST) has released a report this week about domestic wind generation, which could change how and where wind turbines are installed. The report, which sampled a number of homes across the UK, used predicted and actual average wind speed readings to map the UK and decide where the most appropriate location for wind turbine installations actually are. Although the ideal position and geographical location was no surprise, findings about return on investment (ROI) and home installations were revealing.

Manufacturers figures for domestic wind turbines suggest that on average, building mounted turbines make 10% of their ratings a year and free standing turbines make 17% of their ratings. If a turbine is rated at 1kW, this would equate to 100 Watts and 170 Watts respectively. In direct comparison, the large wind farms get closer to 30-40% of their rating on average, reaching 59% efficiency at peak output. The EST's findings revealed that building mounted turbines actually came closer to being 3% of their ratings, a difference of 7%. This would mean that a £4,500 1kW wind turbine would generate 262.8 kWh of power per year, which equates to £34. Therefore the ROI for a 1kW wind turbine mounted on a domestic house in an average area would be 132 years!! This therefore is not a very environmentally friendly method of power production! If they are located in an ideal location such as Scotland where it is windy, with few obstructions and either by the sea on on a hill, this average rises to 7.4% of the rating. This equates to 648.2 kWh for the same turbine per year or £84. This lowers the ROI to 53 years and 5 months!

On the other hand, due to the ideal location of free-standing turbines, they have a much higher efficiency and much lower ROI. Free standing turbines need a large area of open ground so that they are safely positioned and not a danger. They should ideally be in a high position with no trees or buildings obstructing the wind flow. In the EST's tests, the average load was 19% of the turbines rating which almost certainly is because of their location. The benefit of a free-standing turbine is that it can be larger than one that is building mounted. So for example, a 6kW free standing wind turbine costs £17,200 to buy. At 19% of its rating it will generate 9,986.4 kWh a year or £1,298. Therefore, the ROI would be 13 years 3 months. In perfect conditions either by the sea or on top of a hill, the efficiency rises to 30% which makes the ROI 8 years 5 months. After this period it will start giving you free electricity.

So what has this got to do with data centres I hear you cry? Reducing power costs in data centres is big money, and many new facilities are trying ways to make their data centres or computer rooms "green". One idea is to have private power generation through wind and solar generation, but as was discussed before in this blog, solar power generation is not at a level yet where the benefits can be gained in the UK. If you have a data centre or building located in a remote area which has high average wind conditions, installing 10 free standing wind turbines could power four 3kW racks. Although the ROI would be a major factor, for a domestic situation, the government will provide a grant of up to £1,000 per kW of turbine installed and similar incentives are provided for businesses. In Dubai a number of different designs are being considered by architects to build wind generation into new skyscrapers. These could produce 1,200,000 kWh of power a year, enough to power a 20 Rack data centre with cooling included. If every new building had this technology included in the design, the possibilities of "free power" are endless.

Making your Data Centre as efficient as possible will reduce your yearly power bill significantly. Some very small, often free changes can return 5-10% savings in power. Migration Solutions are specialist consultants who created their ERA, Environmental Report and Assessment, to help data centre and computer room operators save running costs and extend the life of servers and their support equipment. For more information visit or call 0845 251 2255

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