Professor M. Jefferson: ‘English Wind Farm Efficiency’
Centre for International Business and Sustainability (CIBS)
http://www.londonmet.ac.uk/lmbs/research/cibsus
Working Paper Series No. 1
A Critical Note on the Efficacy Of The UK’s Renewable Obligation System as it Applies to Onshore Wind Energy Developments in England
Michael Jefferson1
Abstract
Although wind energy is a potentially useful renewable energy resource, insufficient emphasis is placed upon optimising its efficiency in operation under UK renewable energy policy and planning guidance. Exaggerated claims are made about its efficiency in terms of actual and likely capacity factors achieved. Noise and health impacts are understated in industry, and some government, literature. Impacts on residential property prices have still not been adequately assessed. The industry claims that the planning system in the UK presents more obstacles than in, for example, Denmark, Germany or Spain, are ill-founded. Underpinning this paper are the capacity factors achieved by wind energy developments in England in 2007, derived from official sources, and the rewards calculated to have been accumulated by developers. These rewards are largely the result of subsidies provided by business and domestic electricity customers in the UK, a fact that is not widely known – partly because both the industry and the government misleadingly claim, “there is no public subsidy for wind energy”. Recommendations are made for achieving a more open and challenging planning framework where technical and commercial claims can be properly tested.
Introduction
Wind energy should be considered as a significant renewable energy source with considerable potential for efficiency gains, if optimally located. But the relevant criteria should be based upon efficiency; seeking to maximise electricity generation and carbon emissions avoidance from the use of wind energy; minimising those social and environmental costs which are, or may be, associated with wind energy developments; and maximising the benefits of heavy consumer subsidies. This should be the basis of policy; yet little or no weight seems to be given to these criteria in UK practice. While it is correct to state that the UK has a relatively good wind resource, this is not uniform over England. Over much of Central England the wind resource is relatively weak, and this fact should be fully reflected in the allowance, or otherwise, of wind energy development applications. This paper examines the evidence from wind energy developments in England during 2007 to justify these criticisms. This paper does not, however, deal with another criticism made about the intermittency of wind and the resulting need for back-up generation.
The key criterion for gauging the efficiency of wind energy should be, ceteris paribus, the wind speed at a particular location where wind turbines are planned or in operation. By wind speed is meant the mean wind speed over, say, a period of the average year. Allowance needs to be given for start-up problems and the occasional operational difficulties with a turbine. Mean wind speeds are usually derived from the government’s NOABL wind speed database, to which information the results of readings from an anemometer mast are generally available to the wind energy developer involved. (It is a matter of serious concern that such readings are generally not made available to the public despite the fact that both domestic and business electricity consumers in the UK heavily subsidise wind energy developments through their electricity bills). The higher the mean wind speed [taking note that few wind turbines operate at speeds below 4 metres per second (m/s) or higher than 24 m/s] the greater the electricity generated and carbon emissions avoided. However, this progression is not straightforward. Wind speeds at a particular site can be plotted as a probability density distribution, but this distribution is skewed. The variation at a particular site is usually plotted as a Weibull distribution (sometimes the Rayleigh distribution is used). The power of the wind varies with the cube of the wind speed, so the higher the mean wind speed the greater the power weighted average of the wind speeds at that location will be. As a rule of thumb, a mean wind speed of 9 m/s at hub height will produce 2.5 times the electricity per year as a mean wind speed of 6 m/s at hub height (say about 2.4 GWh per year against 0.9 GWh per year, where GWh means gigawatt hours). There are other factors to be taken into consideration such as site characteristics (undulations, trees and hedgerows may affect what is called the roughness indicator); air temperature (affecting air density); the power curve of the particular turbine; and the height of the hub and the swept rotor area (the higher the first and the wider the second will usually increase power output).
Most important of all for the purposes of this paper is the capacity factor (sometimes called load factor) which a turbine or total wind energy development achieves in a year. The capacity factor for a turbine is the actual annual electricity output divided by the theoretical maximum output. Therefore a 2 megawatt (MW) turbine will have a theoretical output of 17,520 MWh in a year: if the turbine achieves a capacity factor of 30% then it will produce 5,840 MWh in a year, and at 20% only 3,500 MWh. An array of 10 turbines of 2 MW each in the former case would produce just over 58,000 MWh per year, and in the latter case just over 35,000 MWh. In general, therefore, it is clearly advantageous to locate turbines where the mean wind speed is relatively high and the capacity factor achievable is optimised. The latter may not always be the maximum feasible figure, because at very high wind speeds or mean wind speeds there may be an advantage in using a smaller rotor blade for a given turbine size, which will tend to lower the capacity factor achieved but raise annual electricity production. However, in most circumstances the capacity factor figures given by relevant bodies (for example, the Office of Gas & Electricity Markets, Ofgem, for the UK) are key to understanding the contribution and efficiency of wind energy developments.
The British Wind Energy Association has long recommended that when making planning applications, or calculations of likely electricity generation or carbon emissions avoidance, wind farm developers and other interested parties should base their case on a 30 per cent capacity factor. The BWEA claims that: “At very good sites the capacity factor can be over 40%. At other sites the capacity factor may be under 30%.” The UK government states: “Capacity factors in the UK may generally fall anywhere between 20% and 50%, with 30% being typical in the UK.” [PPS 22 Companion Guide, page 165, para. 34] In 2007, in fact, less than one-third of wind energy developments in Scotland achieved a capacity factor of 30% or more; in Wales less than 20% of developments did so; and in Northern Ireland only about 25% did so. In England the figure was 15%, and this paper looks at the results in England in detail.
Wind Energy Data for England
Ofgem data for 2007 supplied to the non-governmental organisation CLOWD found in the Annex to this Note (but adjusted for obvious errors as noted in the Annex) have been analysed. [1.] It is interesting to observe that the mean capacity factor of 22.8 per cent achieved by the 81 onshore wind energy developments (wind farms) operational in England for most of 2007 fell far short of this, although rising to 24.5 per cent if weighted by wind farm capacity. Indeed, Figure 1 and the Appendix show that only 12 of the 81 developments exceeded this threshold. In other words, the great bulk of the developments fell short of it. The data have significant implications for weighing up the costs and efficiency of the UK’s Renewables Obligation scheme – introduced in 2002, and funded to a large extent by the UK electricity customer. Administered by Ofgem, which considers there are alternatives which would deliver more renewable energy and lower carbon emissions at lower costs to business and domestic customers, Renewable Obligation Certificates are issued for qualifying renewable energy produced (not just wind energy) at £x per GWh (currently about £53 per GWh, and in 2007 just over £45 per GWh). A figure of £45 per GWh for 2007 has been taken for the purposes of this paper.
Figure 1. The distribution of the Capacity Factor of On-Shore Wind Farms, in England, in 2007
Source: Renewables Obligation Register, Ofgem/CLOWD, 2008
It may be claimed (and is indeed strongly claimed by spokespersons for the British Wind Energy Association) that as the UK’s Renewables Obligation scheme (RO) only pays out for electricity actually generated, it is electricity generation that matters and not load factors. [2.] Unfortunately, such an argument does not account for the substantial social costs associated with getting planning permission; nor does it reflect the negative environmental, visual (and for those adversely affected, psychological and financial) impacts that wind farms can have on landscapes and property values. Admittedly, some of these impacts contain a subjective element, some of which are disputed by the various groups concerned. There has, for example, been a blurring of facts about noise and potential health impacts of wind turbines (both by the industry and the government – see BWEA and DECC – Department of Energy & Climate Change – websites), where because critics have complained about “low frequency noise” or “infrasound” their concerns have been dismissed by experts who recognise that “the problem noise from wind turbines is fluctuating swish” which can awaken people and keep people awake, on the ground that “this may be mistakenly referred to as infrasound by those with a limited knowledge of acoustics” . [3.] Research evidence from the UK (for example by Dr. Amanda Harry) and elsewhere (for example by Dr. G.P. van den Berg) points to noise and adverse health effects for occupants in houses up to at least 1.5 miles from a wind turbine. Noise and health impacts arise independently of capacity factors achieved, due to local landscape contours for example, but the RO scheme encourages developers and some other parties to distort evidence because of the large sums of money involved. The government claims that wind energy developments do not impact on property values “in a uniform way” and that “a significant minority of surveyors (40%) reported no impact from wind farms” in a small survey conducted by the Royal Institute of Chartered Surveyors in 2004. What this limited survey actually reported was that in South West England over 76% of respondents reported an adverse effect; and some 74% in the Midlands and Eastern region. Near Deeping St. Nicholas, in Lincolnshire, negative impacts on residential property values have now been incorporated in judicial decision. Yet the BWEA claims: “There is currently no evidence in the UK showing that wind farms impact house prices.”
Proximity to fine landscapes and major historic assets is a major issue for many people, but one the industry seems rather casual about. Given a major rationale for wind turbines is the preservation of habitats from the longer-term effects of anthropogenic greenhouse gas emissions, one might have thought preservation of landscapes and heritage might be considered of outstanding importance. The battle over Carsington Pastures wind energy development in Derbyshire, bordering the Derbyshire Dales and Peak District National Park, is a case in point. The local planning authorities opposed this application on the ground of “unacceptable harm to National Park Landscape” and its “acceptance would create a precedent for unnecessary wind farms around the national Park.” However, the Planning Inspector on appeal rejected the opposing arguments on the ground that “whilst there would certainly be degrees of harm, notably to the landscape character and the setting of the two Conservation Areas, such harm was not of a scale of magnitude unheard of or unusual in wind energy cases.” It apparently did not strike the Inspector that it is not before time that such harm ceases to be heard of, and is halted. In November 2008, it was announced that the Peak District National Park and Derbyshire Dales authorities planned to appeal to the House of Lords against the Inspector’s decision. This is, of course, very costly for both these authorities and the general public.
Where planning authorities decide in favour of a wind energy development application, and local residents and communities consider they have sound reasons to continue to oppose that decision, individual members of the public may have recourse to judicial review – but at a cost generally well in excess of £40,000. Such a situation exists in the Milton Keynes area (where wind energy specialists consider the placing of wind turbines is “crazy” – see Ref. 2), at the Petsoe End site. There the mean wind speed is very low, visual intrusion to the east especially severe – the company involved (Your Energy) is principally funded by a China (Hong Kong) national whose longstanding oil transportation and bunkering business is registered in The Marshall Islands and whose investment company is registered in The Bahamas. But for the UK electricity consumers’ subsidies available, it seems unlikely that a situation would ever arise.
Similar concerns have been expressed in and around the Lake District National Park, where the developments at Kirkby Moor (overlooking the Duddon estuary); Lambrigg Fell (just east of Kendal); and Wharrels Hill (overlooking Bassenthwaite and Skiddaw) have aroused particular opposition. But the evidence is not clear-cut. Research conducted in 2002 suggested that in fact 74% of local residents around Lambrigg supported that development. About the same time over 90% of local residents opposed the Wharrels Hill scheme (94% in the local parish and 92% in adjoining parishes). Other wind energy developments in Cumbria at Haverigg, Askam (Far Old Park Farm), High Pow, Lowca, Siddick, and Winscales have not attracted significant opposition. Much of the difference of attitude is down to surroundings – most of the latter group of developments are in low-lying areas close to the coast. Mean wind speeds (according to the government’s wind speed database) are relatively high – over 7 m/s at 45 metres above ground level. And hub heights are relatively low (40m or 45m except for High Pow’s 60m). Capacity factors achieved at two of these near coastal sites have also indicated a high (although not always achieved) potential: Haverigg around 35%; and Lowca over 30% for those turbines operating (three have recently had operational problems). However, Askam (where capacity factors achieved have steadily fallen since a high of 30.3% in 2002), Siddick and Winscales have been consistently lower (one reason for Siddick’s has been poor site positioning). It is too early to judge the other sites in the county. As with the Fens, remoteness of surrounding obstacles is important. Indeed in the Fens, if the government’s wind speed database is to be believed, exceptionally high capacity factors are being achieved in some locations where mean wind speeds are relatively modest, for example, Red Tile 2 with 31.99% in 2007; Longhill (a single turbine) with 29%; and Glass Moor with 27.56%.
More fundamental for the industry, one might suppose, are the increasing supply chain pressures that have intensified due to global demand. Supply delays for turbines, rotor blades and gearboxes are now in excess of three years. Placing, or seeking to place, many turbines in locations where relatively low load factors are achieved, will exacerbate these delays, with severe cost implications. Finally, the UK’s RO scheme pays insufficient attention to the interests of electricity consumers, who are obliged to subsidise wind energy developments since under the UK’s RO scheme the developer could claim a Renewable Obligation Certificate (ROC) of somewhat more than £45 per MWh in 2007, roughly doubling the average cost of conventional electricity generation in that year. [By mid-2008 ROCs were valued at around £53 per MWh].
The unadjusted data in the Appendix show that those wind energy developments in England achieving a capacity factor of over 30 per cent in 2007 attracted ROCs of a total estimated value of £8,319,285 – that is 24 per cent of the total subsidy (in the form of ROCs) paid by domestic and business electricity consumers to wind energy developments in England in 2007. The other side of this coin is that 76 per cent of electricity consumers’ subsidies went to wind energy developments in which capacity factors were less than 30 per cent, with 45 per cent of the value of the subsidy going to wind energy developments achieving a capacity factor of less than 25 per cent, and 10 per cent of the total subsidy to developments achieving capacity factors of less than 20 per cent. The optimal cut-off point for capacity factor may well be a minimum of 30%, to encourage a clear merit order for accepting wind energy proposals, to reward developers of operational ones, and to promote re-engineering of older developments where local conditions support this.
Adjustments have been made to the provisional Ofgem data in order to eliminate the more obvious discrepancies. Most of the latter arise from the use of incorrect figures of total installed rated generating capacity at four developments. The now almost infamous “three H’s” of Hare Hill, High Volts I, and Holmside I are the most obvious examples of this. Then there is confusion over Bambers Farm (installed in October, 2004), Bambers II Wind Park at nearby Mablethorpe Sewerage Treatment Works (installed in November, 2006), and the original development at Mablethorpe Sewerage Treatment Works installed in 2002 (all three operated by Ecotricity, but this is not accredited by Ofgem). The first two developments have installed rated capacities of 4.8 MW each, the third has two 1.2 MW turbines. Somewhere along the line confusion occurred in Ofgem, resulting in a greatly exaggerated capacity factor figure for Bambers Farm in 2007 of 60.2% (it was actually 30.1% as shown in the Appendix).
Policy Implications and Recommendations
Public policy should support the most efficient wind developments (when measured by capacity factor). Not only do these developments receive subsidies from electricity consumers. They are also, as pointed out regularly by such official organisations as Ofgem, using a mature technology and over-rewarding developers. To optimise policy the main focus should be on the most efficient developments at whatever level of subsidy exists. Indeed Figure 2 shows the ten highest earners (largest producers) are among the developments with the highest capacity factors. However, an analysis of those 61 developments that claimed ROCs valued at £500,000 or less shows a spread of capacity factors, ranging from under 5 per cent to just over 35 per cent (but for the adjustments to “the three H’s” the upper range would have extended to over 59%). Thus, among the smaller earners that make up the bulk of the developments, it would appear that the relationship between the capacity factor and earnings is randomly distributed.
Figure 2. Scatter of all English On-Shore Capacity Factors against ROC Payments, 2007
Source: Renewables Obligation Certificate Register, Ofgem/CLOWD, 2008
The policy implications of this analysis are:
- That the planning authorities should be much more rigorous in applying the 30 per cent threshold as a ‘marker’ for future developments. [4.] This requires that Key Principle 1(v) of Planning Policy Statement 22 (PPS22): “Renewable Energy” be amended to permit planning authorities to take full account of likely and confirmed technical feasibility of planned and performing developments [see proposal (6) below].
- Secondly, subsidies to those developments achieving a load factor well below 30 per cent should be urgently reviewed, and reduced or withdrawn. One approach might be to offer a proportion of the full subsidy for developments achieving load factors between 25 per cent and 30 per cent (say 50 per cent); a lower proportion for those achieving a load factor between 25 per cent and 20 per cent; and nothing below that. This would increase the incentive for developers to focus only on those schemes expected to yield capacity factors certainly in excess of 25 per cent and preferably over 30 per cent. It would encourage ‘re-engineering’ of older developments on appropriate sites. It would also improve the cost/benefit ratio of the Renewables Obligation scheme, which Ofgem and other government agencies (UK and EU) have criticised as over-rewarding investors (especially bearing in mind that onshore wind energy developments are a mature technology), being very costly for electricity consumers, and incurring huge costs for carbon emissions avoidance – some £400 per tonne carbon, on a grid average basis, according to Ofgem. [5.] If the proposal made here had applied in 2007, the saving to electricity consumers would have exceeded £18 million in that year (out of total ROCs payments/subsidies of just over £34 million). This, and future, sums would be more optimally put towards schemes in higher wind speed areas, or towards other renewable energy schemes considered to be more in line with policy objectives.
- Such a reform would therefore encourage explicit focus on higher wind speed sites, thereby achieving – other things being equal – higher electricity generation and greater carbon emissions avoidance in line with government policy. However, even in a relatively high average wind speed area care should be taken in site selection – as can be seen over the years for Lowca and Siddick in Cumbria (a mere 2.3 kms. apart). The former has persistently achieved significantly higher load factors than the latter (although the former experienced some operational problems in 2007). There would be further advantages. The industry is facing severe supply chain difficulties [6.], with delays of up to ten years in the supply of some turbines – largely due to the strength of international demand. By focussing on higher wind speed sites these supply chain difficulties would be somewhat alleviated, and both electricity generation and carbon emissions would be enhanced.
- Wind energy developments with relatively low capacity factors tend to increase transmission problems and costs. Focussing on those developments which have been given greater encouragement to locate in higher wind speed areas, and which achieve relatively high capacity factors, would also serve to ease these problems and costs.
- The intermittency of wind is, of course, a real problem. However, this should not be used as an excuse for blocking the sounder wind energy developments. In the face of ‘the peak oil problem’ (only temporarily allayed by current recessionary forces) and concerns about anthropogenically-induced global climatic change, any significant contribution from renewable energy is to be welcomed. There are other possibilities, however: not least Concentrating Solar Power with high voltage direct current transmission.
- There is persistent exaggeration by the UK wind energy industry of load factors likely to be achieved and generally achieved; of electricity likely to be generated and carbon emissions avoided; and of households likely to be supplied with electricity from wind energy. Three steps would help to address these failings: (i) Key Principle 1 (v) of the government’s Planning Policy Statement 22 (PPS 22) should be withdrawn as mentioned above. This “principle” currently states: “Regional planning bodies and local planning authorities should not make assumptions about the technical and commercial feasibility of renewable energy projects (e.g. identifying generalised locations for development based on mean wind speeds). Technological change can mean that sites currently excluded as locations for possible types of renewable energy developments may in future be suitable.” Instead, regional and local planning bodies should be permitted to exclude whole areas from consideration for wind energy developments on the grounds of lack of adequate mean wind speed, based upon the government’s NOABL wind speed database. (ii) Would-be developers should be required to provide to the public their anemometer readings, and should not be permitted to plead commercial confidentiality as an excuse for withholding this information. And (iii) both the government’s and the industry’s (BWEA) websites dealing with alleged “myths” concerning the industry and its effects should be subject to official scrutiny open to the public. It is worth stressing that the industry’s complaint that the UK’s planning system is significantly more onerous for wind energy developers than those in Germany, Denmark or Spain (for example) is without foundation. [11.]
- The effect of the changes proposed in (6) would be to create “an exclusion zone” over most of Central England where wind energy development applications would not be permitted due to insufficient mean wind speeds. This would reduce the costs and other burdens on local and regional planning authorities and the tax paying public. It would reduce the social, environmental, and financial costs on the public at large. There is a strong case for ensuring that not only are wind energy development applications ruled out within, and in close proximity to, National Parks but that the official designations Area of Outstanding Natural Beauty and Area of Great Landscape Value (designations which were the product of decades of effort by local and national authorities) should be re-instated and reinforced with a view to excluding wind energy developments within or overlooking them.
- The subject of noise and health implications arising from the “swishing” of wind turbines within, at least, 1.5 miles of residential properties should be revisited as a matter of urgency and an open review undertaken.
Appendix
Wind energy developments in England, 2007. (ROCs received assumed at £45 sterling per MWh electricity produced in 2007 at development listed)
| Wind farm | Capacity Factor | ROCs Received (£) |
| Capacity factor over 30 per cent [12 developments] | ||
| Haverigg 3 | 35.09 | 235,170 |
| Haverigg4 | 34.99 | 234,495 |
| Drigg | 34.30 | 309,690 |
| The Greenhouse | 33.66 | 12,870 |
| Workington | 33.63 | 485,235 |
| Out Newton | 32.05 | 1,149,660 |
| Red Tile 2 | 31.99 | 1,260,990 |
| North Pickenham | 31.96 | 1,813,950 |
| Hedley Hope | 31.89 | 282,825 |
| Middlefields | 31.82 | 10,035 |
| Caton Moor | 30.83 | 1,944,270 |
| Bamber’s Farm [7] | 30.10 | 580,095 |
| Sub total ROCs | £ 8,319,285 | |
| Capacity factor between 25-29.9 per cent [21 developments] | ||
| Mablethorpe | 29.50 | 140,715 |
| Naylor Hill | 29.21 | 21,510 |
| Blood Hill2 | 29.07 | 206,280 |
| Longhill | 29.00 | 209,250 |
| Kirkstanton | 28.81 | 272,520 |
| Ovenden Moor | 28.75 | 1,042,740 |
| Trannack Downs | 27.66 | 98,145 |
| Glassmoor | 27.56 | 1,738,575 |
| Swaffham | 27.54 | 195,390 |
| Forestmoor | 26.99 | 191,475 |
| Deeping St. Nicholas | 26.77 | 1,688,220 |
| High Volts1 | 26.59 | 243,495 |
| Bears Down | 26.36 | 997,515 |
| Delabole | 26.02 | 410,355 |
| Holmside1[8] | 26 | 238,770 |
| Bristol Port | 25.78 | 255,600 |
| Kirkheaton | 25.74 | 182,610 |
| Lowca | 25.71 | 468,315 |
| Red House | 25.54 | 1,208,340 |
| Kirkby Moor | 25.42 | 480,960 |
| Ecotech | 25.21 | 149,040 |
| Sub-total ROCS | £10,439,820 | |
| Capacity factor between 20-24.9 per cent [ 25 developments] | ||
| East Town End | 24.87 | 194,130 |
| Newlands2 | 24.80 | 39,105 |
| St. Breock | 24.69 | 446,715 |
| Great Orton Airfield | 24.56 | 255,600 |
| Coldham | 24.07 | 1,517,850 |
| Harlock Hill | 24.05 | 237,015 |
| Great Orton | 23.93 | 124,515 |
| Winscales Phasse II | 23.74 | 636,480 |
| High Sharpley | 23.62 | 242,055 |
| Coal Clough | 23.32 | 882,315 |
| Cold Northcott | 23.18 | 621,225 |
| Lynch Knoll | 23.04 | 45,405 |
| Red Tile1 | 23.02 | 907,470 |
| Carland Cross | 22.94 | 542,475 |
| Burton Wold | 22.18 | 1,748,295 |
| Hare Hill (E.on) | 21.91 | 237,555 |
| Four Burrows | 21.76 | 386,010 |
| Dagenham | 21.72 | 308,295 |
| Hameldon Hill | 21.69 | 469,395 |
| Tow Law | 21.64 | 197,010 |
| Hare Hill | 21.6 | 198,360 |
| Stags Holt | 21.60 | 642,420 |
| High Volts2 | 21.38 | 463,590 |
| Nissan | 21.33 | 333,045 |
| Royd Moor | 21.06 | 539,640 |
| Sub-total ROCS | £12,215,970 | |
| Capacity factor below 19.9 per cent [ 23 developments] | ||
| Lambrigg | 19.86 | 508,995 |
| Royal Seaforth Docks | 19.67 | 279,180 |
| Wood Green | 19.29 | 15,705 |
| Goonhilly Downs | 19.25 | 424,980 |
| High Pow | 18.47 | 238,095 |
| Holmside2 | 18.34 | 181,890 |
| Far Old Park | 18.06 | 328,905 |
| Green Park | 17.92 | 141,300 |
| Siddick | 17.89 | 296,235 |
| St. Mary’s Road, Ramsey | 16.36 | 13,275 |
| Oldside | 15.95 | 339,615 |
| Blood Hill1 | 14.93 | 132,390 |
| Faccombe Estates | 12.86 | 15,210 |
| ECO Centre, Hebburn | 11.97 | 10,620 |
| Chelker | 11.09 | 52,470 |
| Wharrells Hill | 10.11 | 312,210 |
| Barnard Castle | 10.07 | 19,845 |
| Blyth Harbour | 9.57 | 101,880 |
| Dotterel Farm | 9.13 | 2,880 |
| Renewable Energy Centre [9] | 7.99 | 7,245 |
| Loftsome Bridge | 7.86 | 13,455 |
| West Beacon Farm [10] | 4.45 | 855 |
| Fen Farm | 3.99 | 21,375 |
| Sub-total ROCS | £3,458,610 | |
| TOTAL ROCS | £34,433,685 | |
Notes:
- Where much less than a full year’s operating data are available, developments have generally been omitted. For example, Fen Farm, Hull Waste Water Treatment, McCain Foods (Whittlesey), Ransom Moor, and Stags Holt. In the case of 14 developments where operational for 9 months or more (in some of which there were operational problems affecting longstanding sites) their performance was included. At four of these developments capacity (or load) factor achieved exceeded 30%.
- See: http://www.bwea.com/media/news/070830.html. The Chief Executive of the British Wind Energy Association has described “claims” about capacity factors (as supplied to, and by, the UK government agency The Office of Gas & Electricity Markets or Ofgem) as: “These claims about low capacity factors are absolute nonsense, capacity factors are irrelevant … a stream of factual inaccuracies, bogus pseudo-science … we can refute them all with valid evidence.” Another leading figure in the industry, has on at least two occasions commented adversely about proposed wind energy developments in “the Milton Keynes area” (on the basis that mean wind speeds are relatively low), claiming: “It’s crazy!” Faced with comments about resultant low capacity factors achievable he has regarded such comments as “stupid” and “akin to imposing a Communist-style command economy.” [As reported in "The Scotsman", Friday, 31 August, 2007, by Ian Johnston.]
- See Dr. Geoff Leventhall’s report to DEFRA: “A Review of Published Research on Low Frequency Noise and its Effects”, (2003); and his paper “Infrasound from Wind Turbines – Fact, Fiction or Deception”, geoff@activenoise.co.uk. The research findings of Dr Amanda Harry from her patients living within 1.5 miles of turbines is most revealing of the potential health risks from “swishing”. ["Wind Turbines, Noise and Health", February, 2007.] The recent experience at Deeping St. Nicholas reinforces noise and health concerns. But perhaps the most disturbing aspect of this debate is contained on the government’s website (www.berr.gov.uk/energy/sources/renewables/explained/wind/myths) where it is claimed a DTI-commissioned report by Hayes McKenzie concluded: “there is no evidence of health effects arising from infrasound or low frequency noise generated by wind turbines. In fact despite concluding this, it stated that although this was “the common cause of complaints” the actual cause is “the audible modulation of the aerodynamic noise, especially at night… once awoken the audibility of this noise can result in difficulties in getting to sleep.” [Hayes McKenzie: "Noise arising from Wind Farms"]
- The British Wind Industry Association has for years claimed that a 30% capacity factor should be the basis for calculation. However, the BWEA’s Director of Communications wrote on November 22, 2007, in a complaint to the BBC, that this figure is: “an arbitrary and inaccurate threshold”. This “confession” comes rather late in the day.
- For example, as detailed in Ofgem Report: “Reform of the Renewables Obligation 2006: Ofgem’s response”, Ref: 11/07, 2007, www.ofgem.gov.uk. See also: “Ofgem’s response to BERR consultations on reform of the Renewables Obligation”, Ref: 222/07. The Carbon Trust and the UK’s National Audit Office also made it clear they favour the Feed-in-Tariff system as applied in Germany (”Policy Frameworks for Renewables”, July, 2006, www.carbon-trust.org.uk; and “Renewable support policies in selected countries”, Report prepared for The National Audit Office”, January, 2005, www.nao.gov.uk). The Feed-in-Tariff system is not above criticism, having permitted many wind energy developments in inland areas without sufficient wind – Germany’s average load factor for wind energy in 2007 was barely 21%. Recent studies suggest UK wind energy projects are getting 40% more than they would under a German-styled REFIT Feed-in-Tariff. I am grateful to Professor Dave Elliott, of The Open University, Milton Keynes, UK, for this point.
- For example, as reported in: BVG Associates for British Wind Energy Association: “UK Offshore Wind: Moving up a gear”, December 2007. Curiously, the BWEA’s Press Release of 7th December, 2007, failed to acknowledge this aspect of the report’s solid work. (www.bwea.com/media/news/071207.html). See also John Vidal in ‘The Observer’, October 19, 2008: “Wind farm plans on brink of failure” where supply delays of up to 10 years are reported.
- The original provisional Ofgem figure of 60.2% for Bamber’s Farm looks much too high given it was 35.79% in 2006; 32.56% in 2005; and 31.89% in 2004. This is an obvious ‘odd’ number in the listing. The reconciliation of the actual likely load factor (30.7%) and possible conflation with nearby Bambers II Wind Park or Mablethorpe (extension) is explained in the text. In 2007, the month of January was very windy, but in October there were eleven days (arguably twelve) when low wind speeds were recorded at around 90% or more of the 64 Met. Office sites at the same hour, and at various other hours of those days. The latter may be regarded as invalidating published research results which claim, on the basis of 34 years’ data, that this occurs “around one hour every five years”.
- Holmside I claimed (or Ofgem did on its behalf) to have high capacity factors between 2005 and 2007: 45.04%, 40.55% and 59.15%, respectively. Nearby Holmside II has achieved 22.76%, 17.16% and 18.34% in the same period. Ofgem’s subsequent accreditation list (May,2008) for both Holmside and High Volts contained errors.
- Renewable Energy Systems “pioneering low-carbon headquarters in Hertfordshire embodies the company’s sustainable approach and commitment to corporate citizenship.” [RES website statement.]
- Also known as Beacon Energy: “Our site at West Beacon Farm is often described as being one of the world’s best examples of sustainable energy utilisation.” [Beacon Energy website statement.]
- Butler, Lucy and Karsten Neuhoff: “Comparison of feed-in tariff, quota and auction mechanisms to support wind power development”, ‘Renewable Energy’ 33 (8), pps. 1845-1867. The authors state: “Data from a range of sources suggests that the difficulties involved in the UK planning process may be overemphasised … The planning process takes a similar period of time in Germany, and significantly longer in Spain. Comparing countries, the process is regarded as slightly more risky in Denmark than in the UK.” (p. 1860)
ACKNOWLEDGEMENTS:
The author would like to thank Professor John Sedgwick, Director of the Centre for International Business and Sustainability at the London Metropolitan Business School, for his helpful comments on an earlier draft of this Note, and for providing the Charts; Martin Alder, for pointing out some errors in an earlier draft; and Allan Tubb for providing the raw data which inspired this closer look at what might be derived from it.
1 Michael Jefferson is Professor of International Business and Sustainability at the London Metropolitan Business School – Contact: m.jefferson@londonmet.ac.uk. Michael is a former Deputy Secretary-General, Director of Policy Development, and Director of Studies of the World Energy Council; Chief Economist of The Royal Dutch/Shell Group; Head of Oil Supply Strategy and of Planning in Europe for Shell Internationale Petroleum Mij.; Head of Oil Pricing in Shell International Petroleum Supply and Marketing; and a Director of Oil Supply and Trading in Scandinavia. He has been a Lead Author, Contributing Author, Review Editor, and Expert Reviewer for the Intergovernmental Panel on Climate Change. He wrote the energy policies chapter in the UN’s “World Energy Assessment” (2000). He was the first lead consultant for the G8 Renewable Energy Task Force. For many years he was Chairman of the Policies Committee of the World Renewable Energy Network/Congresses, and an Associate Editor of the journal “Renewable Energy”. He is a member of the Technical Advisory Group of the Renewable Energy Foundation.