Friday, April 08, 2011

A Cold Look at Big Wind in the UK 2008 to 2010

It is clear from this analysis that wind cannot be relied upon to provide any significant level of generation at any defined time in the future. There is an urgent need to re-evaluate the implications of reliance on wind for any significant proportion of our energy requirement. _UKWindReport PDF
Stuart Young Consulting has released a 28 page PDF review of UK wind power from 2008 to 2010 (via TheRegister), which contradicts many of the green talking points used to promote wind energy. Policy analysts and decision makers must have access to reliable facts and figures, if they are to help businesses and governments make the best possible decisions regarding vital energy supplies.
1. During the study period, wind generation was:
• below 20% of capacity more than half the time.
• below 10% of capacity over one third of the time.
• below 2.5% capacity for the equivalent of one day in twelve.
• below 1.25% capacity for the equivalent of just under one day a month.
The discovery that for one third of the time wind output was less than 10% of capacity, and often significantly less than 10%, was an unexpected result of the analysis.

2. Among the 124 days on which generation fell below 20MW were 51 days when generation was 10MW or less. In some ways this is an unimportant statistic because with 20MW or less output the contribution from wind is effectively zero, and a few MW less is neither here nor there. But the very existence of these events and their frequency - on average almost once every 15 days for a period of 4.35 hours - indicates that a major reassessment of the capacity credit of wind power is required.
3. Very low wind events are not confined to periods of high pressure in winter. They can occur at any time of the year.
4. The incidence of high wind and low demand can occur at any time of year. As connected wind capacity increases there will come a point when no more thermal plant can be constrained off to accommodate wind power. In the illustrated 30GW connected wind capacity model with “must-run” thermal generation assumed to be 10GW, this scenario occurs 78 times, or 3 times a month on average. This indicates the requirement for a major reassessment of how much wind capacity can be tolerated by the Grid.
5. The frequency of changes in output of 100MW or more over a five minute period was surprising. There is more work to be done to determine a pattern, but during March 2011, immediately prior to publication of this report, there were six instances of a five minute rise in output in excess of 100MW, the highest being 166MW, and five instances of a five minute drop in output in excess of 100MW, the highest being 148MW....
6. The volatility of wind was underlined in the closing days of March 2011 as this Report was being finalised.

• At 3.00am on Monday 28th March, the entire output from 3226MW capacity was 9MW.
• At 11.40am on Thursday 31st March, wind output was 2618MW, the highest recorded to date.
• The average output from wind in March 2011 was 22.04%.
• Output from wind in March 2011 was 10% of capacity or less for 30.78% of the time.

The nature of wind output has been obscured by reliance on “average output” figures. Analysis of hard data from National Grid shows that wind behaves in a quite different manner from that suggested by study of average output derived from the Renewable Obligation Certificates (ROCs) record, or from wind speed records which in themselves are averaged.

It is clear from this analysis that wind cannot be relied upon to provide any significant level of generation at any defined time in the future. There is an urgent need to re-evaluate the implications of reliance on wind for any significant proportion of our energy requirement.

Most people are unwilling to delve into the technical details of energy cost-benefit analysis, but it is the specific technical details of big wind energy which damn the entire enterprise.
Wind output is actually below 20 per cent of maximum most of the time; it is below 10 per cent fully one-third of the time. Wind power needs a lot of thermal backup running most of the time to keep the lights on, but it also needs that backup to go away rapidly whenever the wind blows hard, or it won't deliver even 25 per cent of capacity.

Quite often windy periods come when demand is low, as in the middle of the night. Wind power nonetheless forces its way onto the grid, as wind-farm operators make most of their money not from selling electricity but from selling the renewables obligation certificates (ROCs) which they obtain for putting power onto the grid. Companies supplying power to end users in the UK must obtain a certain amount of ROCs by law or pay a "buy-out" fine: as a result ROCs can be sold for money to end-use suppliers.

Thus when wind farmers have a lot of power they will actually pay to get it onto the grid if necessary in order to obtain the lucrative ROCs which provide most of their revenue, forcing all non-renewable providers out of the market. If the wind is blowing hard and demand is low, there may nonetheless be just too much wind electricity for the grid to use, and this may happen quite often...

...there is little point building more wind turbines above a certain point: after that stage, not only will they miss out on revenue by often being at low output when demand is high, but they will also miss out by producing unsaleable surplus electricity at times of low demand. The economic case for wind – already unsupportable without the ROC scheme – will become even worse, and wind will require still more government support (it already often needs large amounts [3] above and beyond ROCs).

The idea that pumped storage will be able to compensate for absent wind – meaning that there will be no need for full thermal capacity able to meet peak demand – is also exposed as unsound. The UK has just 2,788 megawatts of pumped-storage capacity and it can run at that level for just five hours. UK national demand is above 40,000 megawatts for 15 hours a day and seldom drops below 27,000. Pumped storage would have to increase enormously both in capacity and duration – at immense cost – before it could cope even with routine lulls hitting the planned 30-gigawatt wind sector, let alone rare (but certain to occur) prolonged calms. _TheRegister
Big wind without big storage becomes a big drain on the entire economy. But big, utility-scale storage is expensive to build, and not available everywhere.

It has been argued that hydro power provides a good backup to wind, but given what we are learning about big wind's unreliability and huge costs, why would anyone even bother trying to make big wind palatable? The underlying compulsion to build big wind and solar -- carbon hysteria -- rests upon unscientific claims and unreliable computer models.

Big wind is a huge and ruinously expensive house of cards, being built up for reasons both corrupt and emotional, not rational to the public purse which is called upon to prop up the faulty enterprise. It is long since time to call it quits.

More: See this GWPF article linking to this John Muir Trust coverage of the same report.



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