Is wind power econonomically viable?

Wind energy technology is developing fast. Manufacturing is becoming cheaper and more efficient, and the productivity of newer designs has improved, so more electricity can be produced from more cost-effective turbines. As a result, the cost of electricity from wind is now on a level with conventional electricity costs. Since 1992, unit prices of electricity from wind power have come down from 11p to around 2p - a significant drop.

Wind turbines are often criticised as being inefficient. However, turbines are 97 to 98% efficient in extracting the available energy from the wind. By comparison, traditional coal/gas combustion plants are only 30 to 40% efficient.

Over the course of a year turbines typically produce 30% of their theoretical maximum capacity (this is called the 'load factor'). This is not the same as efficiency. Very few machines operate at their theoretical maximum load factor, for example a kettle is not on all the time and a car is not in constant use at maximum speed. There are no power stations that operate without interruption. Many, including nuclear stations suffer 'outages' either routinely or due to safety concerns. By comparison, the collective output of wind turbines throughout the country is virtually continuous in that where the wind may wane in one location it is still blowing in others. The power supplied by turbines does not need to be constant, as there are peaks and troughs in electricity demand through the grid, for example the morning is a peak time when people are having breakfast. Therefore a mix of technologies is needed to meet a fluctuating demand for electricity. In times of lower wind speed electricity supply is met by other sources, ideally other renewables such as tidal, solar and biomass. Studies undertaken by the National Grid have shown that our existing electricity grid can support 20% of electricity being provided by wind turbines and that any fluctuations in supply can easily be met by other sources (www.nationalgrid.com).

Ultimately each unit of electricity produced from wind means that one less unit needs to be produced from fossil fuels or nuclear energy. This means less pollution being emitted by burning fossil fuels; the production of less nuclear waste and in the long term and fewer conventional power stations will be needed to replace ones currently programmed for decommissioning.

It is worth noting that a 1994 briefing note from the Parliamentary Office of Science and Technology to the Welsh Affairs Select Committee identified that each unit of electricity produced from fossil fuels, such as coal, results in excess of 860g of carbon dioxide, 10g of sulphur dioxide and 3g of nitrogen oxides being produced.