Thursday, April 06, 2006

Wind energy doesn't need traditional back-up - official

A new report nails one of the persistent inaccuracies levelled at renewable electricity in Britain - its unreliability.

It confirms that variable generation from wind and other renewable technologies need not compromise electricity system reliability at any level of penetration foreseeable in Britain over the next 20 years.

The UK Energy Research Centre (UKERC)'s report on the costs and impacts of intermittent renewable energy on the UK's electricity network is described as "the most comprehensive assessment of the evidence on intermittency ever undertaken, reviewing over 200 studies on the subject".

The Times reported it by saying: "Wind power is as reliable and cheap as electricity from fossil fuels and nuclear reactors and could easily be used to generate at least 20 per cent of the UK's electricity."

This implies that with the addition of other renewables and energy efficiency, there is no need for more nuclear power stations to replace the ones that are to be decommissioned over the next 15 years.

The report finds that:

  • Renewable energy, such as wind power, leads to a direct reduction in CO2 emissions
  • The output of fossil fuel plant will need to be adjusted more often to cope with fluctuations in wind output, but any losses this causes are small compared to overall savings in emissions
  • 100% ‘back up’ for individual renewable sources is unnecessary; extra capacity will be needed to keep supplies secure, but will be modest and a small part of the total cost of renewables.  It is possible to work out what is needed and plan accordingly
  • None of the 200+ studies UKERC reviewed suggested that the introduction of significant levels of intermittent renewable energy would lead to reduced reliability
  • If wind power were to supply 20% of Britain’s electricity, intermittency costs would be 0.5 - 0.8p per kilowatt an hour (p/kWh) of wind output. This would be added to wind generating costs of 3 - 5p p/kWh. By comparison, costs of gas fired power stations are around 3p p/kWh
  • The impact on electricity consumers would be around 0.1p p/kWh. Domestic electricity tariffs are typically 10 - 16p p/kWh.  Intermittency therefore would account for around 1% of electricity costs
  • Costs of intermittency at current levels is much smaller, but will rise if use of renewables expands
  • Wide geographical dispersion and a diversity of renewable sources will keep costs down.

Energy Minister Malcolm Wicks apparently agrees. He said: "Suggestions that wind power is excessively expensive, or that traditional power stations are needed to back-up the energy produced by all our wind farms, are just two of the myths that have been peddled by their opponents. The UK Energy Research Centre's study demonstrates that these claims have been exaggerated. I welcome the report’s contribution to the debate."

Commenting on it Richard Ford, Head of Grid and Technical Affairs at BWEA, said:

"There is no technical barrier to wind contributing 20% or more of our power, at a cost that is both quantifiable and reasonable. The clarity provided on the terminology should minimise future confusion on what is a complex topic."

The report’s chief author, Robert Gross, head of UKERC’s Technology and Policy Assessment function, commented:

“Reports that suggest it is highly costly, or restricts the role of renewables are out of step with the majority of expert analysis, reflect regional problems that the UK can avoid, or both. However, costs will rise to a degree, and we can quantify the factors responsible.”

It confirms earlier research, conducted by Oxford University's Environmental Change Institute for the DTI, showing that wind power is reliable and sufficient given the right planning and infrastructure support.

Key findings of that were:
  • The UK has the best wind resource in Europe. The recorded capacity factor for onshore wind energy in the UK is 27%, greater even than in Germany (15%) and Denmark (20%) where wind farms are currently most widespread.
  • Availability of wind power in the UK is greater at precisely the times that we need it - during peak daytime periods and during the winter.
  • The UK wind resource is dependable. The likelihood of low wind speeds affecting 90% of the country would only occur for one hour every five years.
  • The chance of wind turbines shutting down due to very high wind speeds is exceedingly rare - high winds affecting 40% or more of the UK would occur in around one hour every 10 years and never affect the whole country.

>> the UK Energy Research Centre (UKERC) report.

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