Construction

Construction of the windfarm takes about six months. The tracks are laid and foundations dug for the wind turbines. The substation is built and connected to the electricity grid and finally the turbines are delivered and erected. Each turbine is normally erected in just one day and electricity can flow within a week or two.

The biggest disturbances during the construction of a windfarm are usually the lorry journeys bringing stone to make the tracks and the delivery of the wind turbines and blades.

There are several quarries in the nearby forestry which means the lorries will not have to come from far a field and will use little or none of the road network avoiding disruption to road users.

The wind turbines are delivered on large articulated lorries that have steerable rear wheels to get round bends easier. Often turbines have to be delivered through built up areas, as with the Ferndale windfarm, causing some disruption. Fortunately the turbines for Maerdy can be delivered from the Heads of the Valleys road, avoiding all towns and villages and using only good quality A roads. The delivery route is shown below.

Operation

The windfarm would operate for about 20-25 years. The turbines will be turning approximately 80% of the time. If the turbines do not turn for an extended period then they would be removed.

The wind turbines will turn round to follow the wind direction. The blades would start to turn with the slightest breeze. Once up to speed their rotation speed is limited - they do not go round faster and faster in stronger winds. If the wind gets too fast the turbines would be shut down automatically and feathered into the wind.

The turbines are monitored by computer from a remote centre. If the turbines detect anything unusual such as vibration they will shut down. A single maintenance engineer would look after the windfarm on a routine basis. The turbines are designed to operate for their life without major part replacement.

Decommissioning

Planning permission is sought for 25 years - the expected life of the wind turbines. After this either the turbines would be removed or if windfarms were still encouraged by Government a new planning application may be sought for a new windfarm.

When removed the project is decommissioned to cause minimal disturbance to the environment. The planning authority set the conditions for removal. Normally the turbines are removed, but the foundations left insitu and landscaped over. Overground cables are removed, but sometimes underground cables are left in place if it would cause more disturbance to remove them. Tracks are landscaped and encouraged to be taken over by nature again.