Figure 1: Location of the Kilgarvan wind farm The site has a large number of wind turbines. The first wind farm to be built was Coomagearlaghy/Kilgarvan. This site was commissioned in 2006 and is operated by SWS. This site contains 15 Vestas V90/3000 turbines with a power of 3 MW each. The total rated power of the site is 45 MW. This section of the site is estimated at an annual production of 112 GW.h (equivalent to 2,500 hours at full load/year). Further turbines were built at Inchincoosh and Letercannon. This site contains 13 Nordex N90 turbines. This section of the wind farm is also known as Coomagearlaghy III. Each of these turbines has a power of 2.5 MW, bringing a total rated power for the site to 32.5 MW. The estimated annual production of this site is 81 GW.h. The site was commissioned in 2009 and is operated by Bord Gais Energy. Ten more wind turbines were commissioned in 2009 in the Sillahertane section of the site. This section of the wind farm is also known as Coomagearlaghy II. The turbines in this area are Vestas V52, each with a power of 0.85 MW. The total power of the site is 8.5 MW. The site is estimated to have an annual production of 21 GW.h. This part of the site is operated by Bord Gais Energy. Two substations are located on the site. On the day of our visit, we were at the Coomagearlaghy 110kV substation. This is connected to Clonkeen substation via 6 km of overhead lines. The table below summarizes the different areas of the Kilgarvan site. Site name Wind turbine type Number of wind turbines Individual production (MW) Total production (MW) Estimated annual production GW.hKilgarvan Vestas V90 15 3 45 112Sillahertane Vestas V52 10 0.85 8.5 21Inchiccoosh/ Letercannon ..... . middle of paper ...... ut of 2.5 MW for the Nordex N90s at this location occurs at a wind speed of 13 m/s. The wind speed in Sillahertane varies from 9 to 9.25 m/s at a height of 75 m. The turbines used in Sillahertane are the Vestas V52 which have an optimal power of 0.85 MW at 16 m/s. Figure 6 below shows wind speeds at different hub heights for Inchincoosh and Sillahertane. Figure 6: Average wind speeds at Inchincoosh and Sillahertane. The average wind across the entire site is approximately 9 m/s. Wind speeds of 7.5 m/s are considered economically viable. Wind speed can vary considerably on site. The wind speed was very low, at 3 m/s, when we were there and we were told during our site visit that wind speeds of up to 50 m/s were recorded at the site. To avoid damage, wind turbines stop at a certain wind speed. This is typically 25 m/s for on-site turbines.