Common myths about offshore wind power

Wind generation is often described as intermittent, as the wind doesn’t blow continuously.

Wind turbines have been continuously developed in order to improve reliability. It is now possible to expect that offshore wind turbines will operate for over 90% of the time that they are designed to be operating. Wind turbines need to be turning to generate electricity, and wind turbines require the wind to be blowing for them to turn.

A wind turbine will produce its maximum capacity of power at a wind speed of 30km/hr. On average and at a typical offshore location, wind turbines will produce about 40% of the total energy that they could produce compared to if the turbines were operating at full capacity continuously. This is known as its load factor. The load factor of conventional fossil fueledpower stations is on average 40 to 50%. Independent studies carried out on behalf of the Department of Trade and Infrastructure in the UK, recommend locating wind turbines offshore where load capacities are reaching their design figure of 37% to 40%. Compared to 20 to 30% load factors on land.

Offshore wind power is described as expensive.

Wind cannot compete with the cost of producing electricity from an existing power plant that has already been depreciated and paid for by tax payers and consumers. At good offshore sites however it is increasingly competitive with other new build technologies, especially given the dramatic rise in oil and gas prices. Oil, which influences the price of gas, has increased from an average of $14 in 1998 to $60 in 2006, to $140 in 2008.

A recent study concluded that if a cost of €30 per tonne of CO2 was applied to emissions from fossil fuel power stations, wind energy would be the cheapest form of power generation in Europe. Even without taking account of the external costs of damage to health and the environment from fossil fuel emissions and the disposal of nuclear waste.

If the wind farm is moved further out it will not affect its efficiency.

Contrary to the argument that the wind farm should be moved further offshore to the East, it is not feasible to do so for several reasons:

1. Water depth, current proven foundation technology for offshore wind farms does not permit economic development in water depths greater than 30m.
2. Seabed sediment to the East of the site mainly consists of mud unsuitable for foundation structures.
3. There are major shipping lanes to the East of the site into Greenore and Warrenpoint ports in Carlingford Lough.
4. Tidal current and wave conditions in the more exposed areas to the east are unsuited to wind farm construction and operation.
5. The argument that the wind farm should be located over the horizon where it will never be seen from shore is unrealistic as this would require the wind farm to be built in waters outside of Ireland’s territorial limits and exclusive economic zone at approximately 40km from the coast. The location for the proposed Oriel Windfarm is at the limit of Ireland’s territorial waters.

Contrary to the argument that the wind farm should be moved further South, Oriel Windfarm Ltd and its independent consultants examined the Southern part of the Foreshore Licence area and found that it is less suitable for the development of an offshore wind farm due to:

1. The Nephrops fishing ground present in the soft mud bottomed southern part of the Foreshore Licence area (approximately the area to the south of Latitude 53º 53’N).
2. The soft mud nature of the seabed and the deeper waters in this area being much less suitable for the construction of foundation structures.

Offshore wind farms will affect birdlife.

A recent study carried out by the Danish government using an infrared collision-detection system developed by Denmark's National Environmental Research Institute used a heat-activated infrared video camera that watches a wind turbine around the clock, recording the paths of sea birds around turbines. The first results, released this winter as part of a comprehensive $15 million study of Denmark's large offshore wind farms, show seabirds to be remarkably adept at avoiding offshore installations. "There had been suggestions that enormous numbers of birds would be killed," says Robert Furness, a seabird specialist at the University of Glasgow, who chaired the study's scientific advisory panel. "There's a greater feeling that marine wind farms are not going to be a major ecological problem, and therefore going ahead with construction is not going to raise lots of political difficulties.