It finds that dedicated back-up for wind is unnecessary. Only modest extra reserve capacity is needed to keep supplies secure. Output from fossil fuel plant will need to be adjusted more often to cope with fluctuations in wind output, but any efficiency losses this causes are small compared to the overall carbon dioxide emissions savings from wind plant.
"It is clear that intermittent generation need not compromise electricity system reliability at any level of penetration foreseeable in Britain over the next 20 years, although it may increase costs," states the report. If wind were to supply 20% of the UK's electricity needs, the intermittency costs would be just £0.005-£0.008/kWh, with an impact on consumers of around £0.001/kWh- -- only 1% of electricity costs. But at current penetration levels the costs are much lower. Wide geographical dispersion and a diversity of renewable energy sources will keep costs down, the report adds.
The government and wind industry welcomed the findings. "Suggestions that [renewable energy] 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," says energy minister Malcolm Wicks, adding: "The UKERC's study demonstrates that these claims have been exaggerated."
Richard Ford, head of grid and technical affairs at the British Wind Energy Association, says the clarity provided by the report should minimise future confusion on this complex issue. "I hope that this landmark report will be used as a benchmark for future research and policy direction on intermittency."