This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

IOP A community website from IOP Publishing

Powered by Movable Type 4.34-en

Renew your energy: August 2009 Archives

In a book to be published in Oct, Dr Nina Pierpont, a New York paediatrician, says she has identified a 'wind turbine syndrome' ('WTS') due to the disruption or abnormal stimulation of the inner ear's vestibular system by wind turbine infrasound and low-frequency noise, the most distinctive feature of which is a group of symptoms which she calls 'visceral vibratory vestibular disturbance', or VVVD. Evidently this can cause problems ranging from internal pulsation, quivering, nervousness, fear, a compulsion to flee, chest tightness and tachycardia - increased heart rate. Turbine noise can also trigger nightmares and other disorders in children as well as harm cognitive development in the young. However, Dr Pierpont made clear that not all people living close to turbines are susceptible.

That might explain why, as the British Wind Power Association (BWEA) noted in an initial response, 'an independent study on wind farms and noise in 2007 found only four complaints from about 2000 turbines in the country, three of which were resolved by the time the report was published'.

Nevertheless, it's wise to be cautious. Some small domestic scale machines, which being small have very high rotation speeds, can be noisy, but audible noise from large modern wind turbines is nowadays hardly an issue, with gearless, variable speed turbines being very quite, since the blade rotation speed is better matched to the changing wind speed, thus increasing energy transfer efficiency and reducing aerodynamic noise. But low frequency sound might conceivably be a problem for some people. The only way to find out if this is this case and then to assess it's significance, is to carry out research on a large scale – Pierpont's sample was tiny, evidently based mostly on interviews with just 10 families living near wind turbines – 38 people!

In 2006 DTI published a study by Hayes McKenzie, which investigated claims that infrasound or low frequency noise emitted by wind turbine generators was causing health effects. The report concluded that there was no evidence of health effects arising from infrasound or low frequency noise generated by wind turbines. But the report noted that a phenomenon known as Aerodynamic Modulation (AM) was in some isolated circumstances occurring in ways not anticipated by ETSU-R-972, the report which described the method of assessing the impact of the wind farm locally. So the Government commissioned Salford University to conduct a further work. This study concluded that AM is not an issue for the UK's wind farm fleet. Based on an assessment of 133 operational wind projects across Britain, the study found that, although the occurrence of AM cannot be fully predicted, the incidence of it from operational turbines is low. Out of all the working wind farms at the time of the study, there were four cases where AM appeared to be a factor. Based on these findings, the Government said it did not consider there to be a compelling case for more work into AM, but it would keep the issue under review.

Pierpont's views have attracted significant media attention, with for example, the normally pro-wind Independent even suggesting that 'there is a prudential argument for postponing the commissioning of land-based wind farms until they are shown to be safe'. A bit less radically, Pierpont has called for a 2 km safety zone.

The NHS website stepped in with a short critique, which noted that "The study design was weak, the study was small and there was no comparison group. There is also no information on how the group was selected in the first place and some uncertainty as to which countries these people come from." It concluded 'it is physically and biologically plausible that low frequency noise generated by wind turbines can affect people' but, 'this study provides no conclusive evidence that wind turbines have an effect on health or are causing the set of symptoms described'.

The BWEA, in a special Factsheet, then went on the offensive, noting that 'Dr Pierpont is a known anti-wind campaigner'. And it pointed to a peer reviewed study by Geoff Leventhall which had refuted the allegations about infrasound, concluding that they were " irrelevant and possibly harmful, should they lead to unnecessary fears".

The Pierpont study does sound very weak but, to clear the air, it seems that the issue has to be resolved once and for all by an authoritative independent study.


Geoff Leventhall 'Infrasound from Wind Turbines - Fact, Fiction or Deception?" Canadian Acoustics Vol. 34 No.2 (2006)


At the launch of the film 'The Age of Stupid' earlier this year, Ed Miliband, Secretary of State for Energy and Climate Change, commented "The government needs to be saying, 'It is socially unacceptable to be against wind turbines in your area- like not wearing your seatbelt or driving past a zebra crossing'."

Certainly there has been a lot of invective hurled at so called NIMBY's- those who, while perhaps professing to be in favour of renewables generally, resist deployment of wind farms and the like near where they live. The NIMBY, Not In My Back Yard, concept has gained credence because national opinion surveys show overwhelming support for renewables, but when it comes to specific schemes there is often a lot of opposition to projects, wind farms in particular.

Of course it may be that in many cases this opposition is only from a noisy minority- aided and abetted by national anti wind lobby groups like Country Guardian. But there is no question that opposition to wind power has slowed its progress in the UK. So NIMBYs are seen as a major problem.

Thus the Danish company Vestas, when seeking to explain why it was closing its wind turbine blade manufacturing plant on the Isle of White, with the potential loss of over 600 jobs, saw local opposition to new projects around the UK as part of the problem- along with the recession and the local planning process ,which it said 'remains an obstacle to the development of a more favourable market for onshore wind power.' The British Wind Energy Association echoed these views: 'There is now a direct correlation between nimbyism and the curtailment of the economic benefits of wind power. A positive factor of this unfortunate crisis is that the public are now aware of the fact that the opposition to wind farms is affecting the economic opportunities available to this country.'

So are NIMBYs really the problem? A multi-University study funded by the ESRC and led by Dr. Patrick Devine-Wright (then at the University of Manchester, now at Exeter) aimed to deepen understanding of the factors underlying public support and opposition to renewable energy technologies. 8 case studies were undertaken covering 10 projects across 4 sectors - on and offshore wind, biomass and marine.

The research found little evidence of nimbyism - only 2% of the respondents to a survey of over 3,000 people fitted the stereotype of being strongly in favour of renewable energy in general, yet strongly against a local proposal.

Dr Patrick Devine-Wright, said: "We have identified what the key issues are that shape public concerns about new proposals. Developers and government should be acting to address these key issues, not labelling protestors as nimbies. They need to pay more attention to how the benefits or drawbacks of a proposal are perceived by local people." and "avoid the politically expedient term of nimby"

He added: "Government needs to do much more to make sure that planning decision processes are open, fully informed and fair. At the moment local people often feel disenfranchised as their concerns are not properly listened to or decisions end up being taken in a 'black hole' in London. Under such conditions local resistance can easily escalate."

The research summary notes that 'When opposition occurred this was characterised in particular by developers as emotionally based and outside of what they saw as 'rational' planning concerns. These conceptions of the public have a number of implications. First, for the design and engineering of technologies, with marine developers, for example, aware of the need to 'design in' potential public reactions from the beginning. Second, for the locational strategies of where projects are developed. Third, for public engagement practices. Here it was found that engagement has become routinised and not dependent directly on public responsiveness. Engagement was essentially conceptualised in terms of information provision and addressing public concerns'.

Overall, they say 'we found a range of supportive (38.1%), neutral (38.2%) and oppositional (23.7%) attitudes to specific projects. Marine energy projects tended to be most supported, whilst onshore wind projects tended to be least supported. Lack of trust in developers was consistently found, as well as strong concerns about the fairness of planning procedures. For example, in each of our Welsh case studies, there was substantial opposition to planning decisions being made in London. Only 2% (61 individuals) of survey respondents held the stereotypical NIMBY attitude of being strongly in favour of renewable energy generally, but strongly against a proposed project. We found no significant relationship between project support and personal characteristics commonly assumed to characterise opponents, including length of residence in the area, perceived proximity of home to project site, and age. Our analysis showed that project support was best explained by the perception of the local impact of the project (drawbacks vs. benefits); attitude to the technology sector; the perception that the developer listened to local residents; levels of trust in the developer and the perceived fairness of planning procedures'.

In conclusion they say: 'The research found evidence of substantial social consent, both for renewable energy generally and for specific projects, and little evidence to support the continued use of the NIMBY concept to explain why some people oppose project proposals. We conclude that rather than trying to dismiss and undermine legitimate questioning and criticism of particular renewable energy projects, industry and policy makers should instead focus on protecting and nurturing social consent for what is a key part of a low carbon future. No simple formula will achieve this, as each place and context has distinctive characteristics, but our findings show the importance of factors such as enhancing local benefits; timely and meaningful engagement by developers; trust; and fair planning procedures'.

Project Summary Report

There may of course also be political aspects to opposition to wind projects. A Greenpeace survey found that between Dec 2005 and Nov 2008, Tory councils blocked 158.2MW of wind projects, approving just 44.7MW, while Labour councils fared only a bit better rejecting 62.6MW, while approving just 68.3MW.

It's also perhaps worth noting that local opposition is much less apparent elsewhere in the EU e.g. in Denmark, which now gets around 20% of its electricity from wind projects. One reason could be that, unlike in the UK, most of them are locally owned by farmers or wind co-ops. As the Danish proverb goes 'your own pigs don't smell'.

Hydroelectric plants generate about 17% of total world electricity and are the largest existing renewable source of electricity. However, many environmental/development organisations, including WWF, FoE, and Oxfam, while backing micro hydro, have opposed large hydro projects because of the large social and environmental impacts.

The social dislocation resulting from flooding areas for new reservoirs is an obvious issue, but there are also more subtle eco issues. For example a few years back the World Commission on Dams claimed that in some hot climates, biomass carried down stream was collected by the dam and can rot, generating methane, so that the net greenhouse emissions can be more than from a fossil plant of the same energy capacity. This effect is site specific, but its does indicate that in some locations hydro may not be quite such an attractive renewable source as some suggest.

Nevertheless, there is still a strong push m for more hydro. For example, The African Union (AU),The Union of Producers, Transporters and Distributors of Electric Power in Africa (UPDEA), The World Energy Council (WEC), The International Commission On Large Dams (ICOLD), The International Commission on Irrigation and Drainage (ICID), and The International Hydropower Association (IHA) have all recently agreed that hydro is an important answer for some if Africa's major problems.

They note that 'During the past century, hydropower has made an important contribution to development, as shown in the experience of developed countries, where most hydropower potential has been harnessed. In some developing countries, hydropower has contributed to poverty reduction and economic growth through regional development and to expansion of industry. In this regard, we note that two-thirds of economically viable hydropower potential is yet to be tapped and 90% of this potential is still available in developing countries. In Africa, less than 7% of hydropower potential has been developed'.

They say 'We firmly believe that there is a need to develop hydropower that is economically, socially, and environmentally sustainable. Regarding the environmental and social impact of hydropower, a number of lessons have been learnt from past experience. Governments, financing agencies and industry have developed policies, frameworks and guidelines for evaluation and mitigation of environmental and social impacts, and for addressing the concerns of vulnerable communities affected by hydropower development. Those guidelines must be adjusted to the relevant individual country context. We note that the key ingredients for successful resettlement include minimization of resettlement, commitment to the objectives of the resettlement by the developer, rigorous resettlement planning with full participation of affected communities, giving particular attention to vulnerable communities. The decision making process should incorporate the informed participation of the vulnerable communities and those negatively affected, who must in all circumstances derive sustainable benefits from the project. The costs of social and environmental mitigation measures and plans should be fully assessed and integrated in the total cost of the project'.

They point to giant potential projects like Grand Inga on the Congo river - 40 000 MW which could generate more energy than 280 TWh /year of exceptionally cheap electricity, at less than $ 0.01. For comparison diesel generators, widely used in Africa, costs from $ 0.15 to $ 0.30/kWh.

Certainly schemes like this have large potentials. The proposed £40bn Grand Inga hydro project could, its supporters say, double the amount of electricity available on the continent and jump start industrial development, bringing electricity to hundreds of million of people as well as exporting power to South Africa, Nigeria and Egypt, and even Europe and Israel. It would supply twice as much electricity as the world's current largest dam, the Three Gorges in China.

However ,not everyone is so keen. The Guardian reported (21/4/08) that environmental groups and local people have warned that 'it could bypass the most needy and end up as Africa's most ruinous white elephant, consigning one of the poorest countries to mountainous debts'.

Grand Inga was proposed in the 1980s but never got beyond feasibility studies because of political turmoil in central Africa. Now there seem to be prospects for it to go ahead and be completed by 2022. The big change is that banks and private companies can earn high returns from the emerging global carbon offset market and, in some cases, from the Clean Development Mechanism credits.

Terri Hathaway, Africa campaigner with International Rivers, a watchdog group monitoring the Grand Inga project, said that 'As it stands, the project's electricity won't reach even a fraction of the continent's 500 million people not yet connected to the grid. Building a distribution network that would actually light up Africa would increase the project's cost exponentially. It would be very different if rural energy received the kind of commitment and attention now being lavished on Inga.'

While it is clear that hydro has many attractions and that Africa needs power, there are also clearly counterviews about whether hydro, especially large hydro, is the best bet. Large projects are expensive and involve large companies who may not be that concerned about local impacts. Large centralised projects may in any case be the wrong answer for Africa - the very large distances involved make it unlikely that grids could ever cover the entire continent. As with the Grand Inga project much of the power seems likely to be exported on HVDC links to remote markets- not used locally. Local decentralised power may make more sense. That can be micro hydro, or wind, or biomass or solar, technologies which can be installed quickly with low local impacts and a potential for direct local involvement - and possibly for the creation of local manufacturing enterprises to build the equipment The debate over the way ahead continues.

For more see IRN:

Also see: Wind in Africa news_round_up/293874/kenya_to_build_africas_biggest_ windfarm.html

Critics say that wind turbines can't be relied on to provide secure grid power because of the variability of the winds, and will have to be backed up by conventional power plants. So no conventional plants will actually be replaced, costs will be excessive and there will be very few emissions saved net.

Views like this, regularly expressed by groups ranging from Country Guardian to the Renewable Energy Foundation, have just as regularly been challenged by detailed academic and agency studies- with for example a major review of the various studies being produced in 2006 by the UK Energy Research Centre and an overview Earthscan book Renewable Energy and the Grid in 2007. The debate nevertheless continues.

The latest batch of reports includes one entitled 'Managing Variability' for Greenpeace, Friends of the Earth, RSPB and WWF by energy consultant David Milborrow. He concludes forcefully that there are no major technological problems with dealing with variable wind inputs to the grid, just minor economic costs: 'If wind provides 22% of electricity by 2020 (as modelling for Government suggests), variability costs would increase the domestic electricity price by about 2%'.

Basically, this is to pay for the fact that some fossil fuelled plant would have to be run a bit more each year to balance out low wind periods. These 'standby' plants already exist- they are used to run up and down to full power on a daily basis to meet the standard demand peaks, and can also be used to cope when some other plant (e.g. a nuclear plant) shuts down unexpectedly. So there's very little extra cost in using this existing standby capacity a bit more, occasionally, to back up wind plant. And very few extra emissions would be involved by the extra use of these plants. Milborrow says that it would reduce the carbon emissions saved from having 20% of UK electricity supplied by wind by about 1%.

This issue, once sometimes cited by critics as a major problem for wind, now seems to have finally been resolved. As the House of Lord Select Committee on Economic Affairs put it in its review of the Economics of Renewable last year 'The need to part-load conventional plant to balance the fluctuations in wind output does not have a significant impact on the net carbon savings from wind generation'- a view subsequently accepted by the government.

However some of the other issues are still fiercely debated. The critics insist that there will be times when there is no wind at all over the whole of the UK. In which case, as consultant Denis Stephens put it in a critical review of a recent Carbon Trust report on wind, in which he drew on a study produced by Oswald for the Renewable Energy Foundation, 'for every megawatt of output from wind turbines there has to be an equivalent backup facility of conventional power generation'.

Milborrow by contrast insists that 'numerous studies have shown that, statistically, wind can be expected to contribute to peak demands', although he accepts that the amounts it can reliably supply then (its capacity credit) will be much less than the full rated capacity. However he notes that 'system operators do not rely on the rated power of all the installed wind farms being available at the times of peak demand, but a lower amount- roughly 30% of the rated capacity at low penetration levels, falling to about 15% at high penetration levels'. He does accept that wind variation adds an extra uncertainty into the management of the grid, although this ' is not equal to the uncertainty of the wind generation, but to the combined uncertainty of wind, demand and thermal generation', which is already dealt with by existing balancing measures. It simply adds a bit to the costs, and these can, if necessary, be reduced by a range of new measures.

He notes that ' Improved methods of wind prediction are under development worldwide and could potentially reduce the costs of additional reserve by around 30%. Most other mitigation measures reduce the costs of managing the electricity network as a whole. 'Smart grids', for example, cover a range of technologies that may reduce the costs of short-term reserves; additional interconnections with continental Europe, including 'Supergrids' also deliver system-wide benefits and aid the assimilation of variable renewables. Electric cars hold out the prospect of reduced emissions for the transport network as a whole and could act as a form of storage for the electricity network - for which the electricity generator would not have to pay.'

This view is shared by National Grid, who have produced a new consultative report, which includes a look at some of these ameliorative balancing options. Overall they seem to think that there should be no major problems in balancing the grid: 'As wind generation increases, so does geographic dispersion of the wind farms and we believe that this combined with ongoing improvements in wind forecasting will allow us to minimise the reserve requirements for wind going forward.' They admit that 'The need to carry operating reserve means the effective 'capacity credit' for wind output of 15% of capacity will therefore be less than 15%, but say that 'National Grid's view at this stage is that for 2020, a wind generation output assumption of up to 15% of capacity at times of peak demand is reasonable'.

The debate continues, although the emphasis now seems more on the costs rather than the technical viability. For example, in a new report on the 'Impact of Intermittency' in the UK and Ireland , Poyry Energy Consulting have opened up a new issue, claiming the problem is not so much the familiar short term variations in wind availability, but annual variations. It looked at the period 2000-2007 and found that annual levels of wind generation output varied by almost 25% in the Irish market and 13% in the British market. As a result there could be significant economic problems facing fossil fuel back-up capacity: 'plant may only operate for a few hours one year and then hundreds of hours the next year', making revenue planning hard.

Overall they say that grid interconnectors will be important for grid balancing, especially for Ireland, but as National Grid and Miborrow argue, there are also other technological adjustment that could change the situation- not just interconnectors but also pumped hydro storage and load management techniques like smart metering.

In addition we could use other non-variable renewable plants for balancing, not just hydro plants, but also biomass fired plants and possibly geothermal generation as well. A recent German study showed that it was possible to use biomass generation to balance wind and PV solar over the year on a national basis, despite weather cycles and demand cycles, and new enhanced geothermal systems are being developed in Germany and elsewhere which can provide firm power outputs.

What's interesting for the present is that the Poyry study shows that, given some inter-connection, Ireland can cope reasonably well without nuclear power. Indeed Poyry note that their assumption that there would be new EPR nuclear plants in the UK 'had the expected impact of increasing response requirements' i.e. from backup fossil plant, given expected nuclear plant fault levels. So having nuclear on the grid makes it even harder to balance wind!

Milborrow report:

National Grid report:

Pöyry report : http://

Oswald et al. 2008 Energy Policy Vol 36 Issue 8 Aug pp3202–3215.