In a study using real wind farm noise data exhibiting significant Amplitude Modulation (AM) we have been able to test the efficacy of the AM noise condition proposed by RenewableUK. The summary of the findings are :
1.1. The proposed RUK AM condition would not be breached by recorded wind farm noise data with high levels of AM measured at Askam, a site widely recognised to be producing severe AM problems, and at Swaffham, from data where the AM is clear and significant in magnitude. By comparison, data from both the Askam and Swaffham sites would be in breach of the Den Brook AM condition.
1.2. We conclude from these facts that the RUK AM condition is manifestly inferior to the Den Brook condition and does not offer to wind farm neighbours any realistic or significant protection against AM disturbance.
REF has responded to the latest consultation by the Institute of Acoustics on the Supplementary Guidance Notes designed to accompany their Good Practice Guide to the Application of ETSU-R-97 for the Assessment and Rating of Wind Turbine Noise. The summary follows and access to the full text of the consultation response is below.
Read more: IoA Supplementary Guidance Notes on Wind Turbine Noise
REF publishes today a research paper by Dr Gordon Hughes, Professor of Economics at the University of Edinburgh, on the performance over time of wind farms in the United Kingdom and Denmark. The paper can be downloaded by clicking on the link below. The UK and Danish data used in the analysis is also available below. The following summarises the results of the research.
Read more: Analysis of Wind Farm Performance in UK and Denmark
REF has responded to the Insitute of Acoustics' consultation on their discussion document entitled “A Good Practice Guide to the Application of ETSU-R-97 for Wind Turbine Noise Assessment”.
This study, which can be downloaded below, discusses the government’s apparent assumption that the costs of the UK’s energy and climate change policies will be offset by energy efficiency measures, both in domestic households and in businesses, leading to a reduction in energy consumption (i.e. energy conservation).
This information note examines the revision to the ETSU-R-97 method of deriving noise conditions for wind farm planning permissions from background noise measurements, as proposed in an article in the Acoustics Bulletin of the Institute of Acoustics (IoA).[1] We have used actual wind speed data to model the impact of the revision on noise conditions and likelihood of noise complaints from neighbours.
The revision is designed to correct for site-specific wind shear that was erroneously assumed to be constant between two heights in the ETSU-R-97 guidance. The impact of this assumption is shown graphically in Appendix 1. However, in this note we show that the Acoustics Bulletin revision increases the uncertainty of the background noise curves and reduces confidence in the reliability of noise conditions based on them.
Read more: A Critique of the IoA Treatment of Background Noise for Wind Farm Noise Assessments
REFs study of the likely impact of climate change policies on the affordability of energy concludes:
1. Current renewable electricity policies intended to meet the EU Renewables Directive in 2020, will impose extra consumer costs of approximately £15bn per annum, which is roughly equivalent to 1% of current GDP. This annual total is comprised of approximately £8bn in subsidy, £5bn in grid integration, and a further £2bn in VAT charged on these extra costs.
The noise most commonly associated with wind farms, and frequently complained of, is the repetitive swishing beat occurring at turbine blade rotation frequency, which is known as Amplitude Modulation (AM) of the aerodynamic turbine noise.
Read more: The Den Brook Amplitude Modulation Noise Condition
As part of its research program, REF has carried out a study of the costs and implied oncosts of the UK Renewable Electricity subsidies, the results of which indicate that the total cost of the subsidies to renewable electricity generators would be in the region of £100bn by 2030.1
Read more: The Probable Cost of UK Renewable Electricity Subsidies 2002-2030
REF has assessed the UK Feed-in-Tariff for Renewable Electricity in the light of its performance in the first year, April 2010 to March 2011
In the recent April Operational Forum, National Grid revealed that substantial “constraint” payments were made to a number of Scottish wind farms in the first week of April1. A constraint occurs when the grid system or a section of the system is unable to absorb all the electricity being generated, and some generators that are contracted to generate must be asked to stand down.
The April event occurred because the Scottish grid network could not absorb all the energy being generated, and chose to constrain wind power off the system, paying very high prices to compensate wind generators for the lost income, in some cases as high as 20 times the value of the electricity which would otherwise have been generated. In total approximately £890,000 pounds was paid over a few hours to six wind farms, these costs being ultimately destined to pass on to the consumer.
Summary
• The United Kingdom failed to reach its 10% renewable electricity target for 2010, producing only 6.5% of electricity from renewable sources.
• This shortfall occurred in spite of a subsidy to renewable generators amounting to approximately £5 billion in the period 2002 to 2010.