Gneeves Wind Farm
Introduction
This wind farm consists of 11 Vestas wind turbines giving a total capacity of 9.35MW. The site is located on the northeastern edge of the Derrynasaggart Mountain range approximately 3km from the R582 Millstreet to Macroom road. It lies approximately 6km southwest of Millstreet and 15km northwest of Macroom.
History
SWS started developing this site in 2002. There was an existing planning permission from 1999 for 13 wind turbines. After leases were secured with local landowners a number of planning permissions were submitted to improve the feasibility of the site. The site has a significant depth of peat throughout, with turbine foundations being more difficult to build the deeper the peat. By February 2004 a practical layout had been achieved and work began on the grid connection.
The wind farm had a number of options for connecting to the grid and the most practical consisted of an overhead line to an existing substation located at Rathmore, Co. Kerry. SWS signed a connection agreement with ESB in 2003 and proceeded to apply for planning permission and negotiate wayleaves to allow the line to be constructed.
Technical
By late 2004 all the necessary permits and approvals were in place. SWS placed a turnkey contract with Vestas to supply all turbines, foundations, roads and electrical equipment for the wind farm. ESB were responsible for the grid connection, some of which was on difficult ground through existing forestry. Construction took place in early 2005 and the turbines were erected during summer 2005 with first generation in the autumn.
The Gneeves wind farm is built around the Vestas V52 turbine. This is a solid workhorse of a wind turbine, with over 2500 installed around the world. Vestas were originally involved in making farm machinery and, indeed, the main components are not that dissimilar, consisting of a gearbox, hydraulic system, braking system and generator.
The rotor (3 blades and hub) has a smaller diameter, at only 52m, than the Kilgarvan wind turbines and hence the rotation speed is higher, at 26 rpm when at full power, maintaining approximately the same tip speed.An important part of building a windfarm is the measurement of the wind resource at the site. By knowing how much wind blows and from which direction the turbines can be spaced to extract the most energy.
There are also different classes of turbines which are suitable for windier sites. In order to estimate the wind SWS erected two guyed tubular steel towers 45m high and fixed a number of anemometers and wind vanes at different heights in order to get a good picture of the wind at the site. Air pressure and temperature are also recorded because the denser the air, the more power the wind turbines can extract. The data recorded for 1-2 years is compared with the longer term data recorded at Cork Airport for example, and a long term average is predicted for the site. This is the key criterion used in deciding whether or not a particular wind project is financially viable.
Environmental
How green is a wind farm? Gneeves wind farm should displace 25,000 tonnes of CO2 every year of its life. But that is only the headline number. There are also significant savings in other emissions from power stations.
For example the Moneypoint power station on the Shannon is a coal based plant from which sulphur dioxide emissions caused acid rain over the susceptible Burren landscape for many years. Even with the recent introduction of scrubbers it will not be allowed to generate past 2016 when more strict air pollution rules from the EU are introduced.
Moneypoint has currently nearly 900MW of generation, but already in only a few short years of development, the wind industry has built 700MW of wind farms. This is set to increase to 1300MW by 2010. This should result in 15% of Ireland's electricity being generated from renewables.