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Tag Archives: variabilty intermittencty

Too much wind

‘When storms come, some build walls, some are thrown by the wind, others build windmills’. So said Chinese philosopher Lao Tzu. But sometimes you can overdo it.

In my last Blog I reported on criticisms from, basically, anti wind power groups that there was not enough reliable wind. However, there are, perhaps perversely, also criticisms that there is sometimes too much wind- which means that, under current market and grid balancing arrangements, compensation is paid for the loss of potential earnings. For example, six Scottish wind farms were paid a total of nearly £900,000 to stop producing energy because the grid network could not absorb it, for several hours between April 5-6th.

£308,000 went to Scottish Powers Whitelee wind farm in East Renfrewshire, £265,000 to RWE/nPower’s Farr wind farm south of Inverness, £140,000 to SSE Renewables’ Hadyardhill in South Ayrshire, and £130,000 to Scottish Power’s Blacklaw in Lanarkshire, while the Millennium wind farm in the Highlands and Beinn Tharsuin, north of Alness, got £33,000 and £11,500 respectively.

The Renewable Energy Foundation (REF) said the payments ranged up to 20 times the value of the electricity that would have been generated if the turbines had kept running. That was for the Farr wind farm. The payments include compensation for the loss of the Renewable Obligation subsidy element. Dr Lee Moroney, planning director for the REF, which has criticised subsidies to renewables in the past, said: ‘The variability of wind power poses grid management problems for which there are no cheap solutions. However, throwing the energy away, and paying wind farms handsomely for doing so, is not only costly but obviously very wasteful. Government must rethink the scale and pace of wind power development before the costs of managing it become intolerable and the scale of the waste scandalous.’ -for-wind-farms-discarding-electricity-5th-6th-april-2011

The National Grid said ‘On the evening of the 5th into the 6th of April, the demand for power was low but the nuclear generating plants in Scotland were running as expected. There was also heavy rainfall, which mean hydro power plants were operating well too’. A fault in the transmission system also meant the surplus energy could not be transferred to England.

DECC described the incident as ‘unusual’ and said ‘In future we need greater electrical energy storage facilities and greater interconnection with our EU neighbours so that excess energy supplies can be sold or bought where required.’

The Scottish government said ‘electricity generated by renewables accounted for 27.4% of Scotland’s electricity use. National Grid is responsible for balancing the supply of electricity from all sources across the grid to match demand and generators will sometimes be required to reduce output as part of that process. At the same time, the Scottish and UK governments have been working with the National Grid and others in the industry to strengthen grid capacity and address access constraints’. That will certainly be necessary if Scotland is to achieve the new heroic target promoted by the SNP during the recent Scottish elections of getting 100% of electricity from renewables by 2020!

The basic problem is that turbines can be, and have been, built much faster than connectors, although payment for curtailment is common to all plants with similar supply and grid balancing contracts- fossil fired standby plants get paid when idle too. But under the ROC system wind gets larger basic payments and some projects have it seems negotiated good curtailment deals. Crucially, under current policies, the nuclear output is not curtailed. Maybe it should be, making room for wind. But then nuclear would be (even more?) uneconomic, and if it got a curtailment fee, (even more?) subsidised.

This problem will only get worse as more wind, plus other renewables, and more nuclear are put on the grid. The Climate Change Committee (CCC) has just outlined a possible strategy in which, by 2030, nuclear and renewables would each have about a 40% share. This would require an additional 2-3 nuclear reactors on top of those developers are already planning to build. The CCC do look to smart grids and storage to help deal with grid balancing, but much more will be needed- and ideally new market and contractual arrangements. But, even so, it is hard to see how we can avoid expensive curtailment events during low demand periods if we have large amounts of inflexible nuclear and variable wind both seeking to feed into the grid. Perhaps the new government White Paper on the Electricity Market Reforms, expected maybe in June, will have some answers.

The overall renewable energy target seem likely to remain in place, unless we re- negotiate it down with the EU, as a new report fro the right of centre Policy Exchange suggested. However, the CCC report suggested cutting back on offshore wind targets, as did the Policy Exchange- which claimed it was too expensive. The offshore wind target has already been drastically cut from the 30-32GW envisaged at one time, to around 13GW by 2020, as spelt out in last July’s UK National Renewable Energy Action Plan. Will even that now be viewed as excessive? And if so where is the compensating expansion? The new Renewable Heat Incentive is fine as far as it goes, although most of it won’t start until next year, and it’s just for heat. As for electricity, PV solar has just been savaged with FiT tariff cuts for large projects, the Marine Renewables Deployment Fund has been axed, and last year Lord Marlan said ‘there should be no dramatic increase’ in on-land wind generation above current targets. The White paper should make for interesting reading.

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