Wind turbine FAQs
- Why did Glyndebourne want to build a wind turbine?
- Are wind turbines reliable and efficient energy providers?
- What happens when too much or too little electricity is produced by the turbine?
- Why not use other sources of renewable energy?
- Why doesn't Glyndebourne take other measures to reduce its impact on the environment?
- How big is the wind turbine?
- Where is the turbine located?
- What is the visual impact of the turbine?
- What environmental assessments has Glyndebourne undertaken?
- Where can you see the turbine from?
- How far is the turbine from the nearest footpath?
- Does the turbine make a noise?
- Is there any light or TV disturbance?
- Does the turbine affect radar?
- Has Glyndebourne considered the views of the general public?
- Going green?
- How can I obtain more information?
Glyndebourne recognises the enormous impact of climate change on the world and feels that it should do all that it can to protect the planet for future generations. It is our hope that, as an international organisation, our commitment to renewable energy might encourage similar initiatives globally.
Glyndebourne is committed to reducing its impact on the environment and developing the turbine was the single most significant action that we could take in order to reduce its carbon dioxide emissions. The results of the first year of energy production by the wind turbine are available here.
Glyndebourne currently uses similar amounts of electricity and gas, but electricity is by far the greatest contributor of carbon dioxide. Any serious attempt to reduce carbon dioxide emissions by the use of renewable energy must, therefore, commence with those technologies which generate electricity.
Glyndebourne engaged independent local experts to assess the impact of the wind turbine; a bird survey, a bat survey, archaeological, ecological, visual impact, shadow flicker, noise and traffic generation studies were all completed, and photomontages were prepared showing how the turbine would appear in the landscape.
Wind turbines generate electricity from a 'fuel' which is free and will never run out, but which is not available all the time. There is often confusion between 'efficiency' and 'intermittency'.
A wind turbine’s annual energy output is determined by its design specification and the average wind speed at its location. The annual mean wind speed at Mill Plain is estimated to be 6.8 metres per second. Generally wind turbines produce electricity 70-85% of the time; however, there will be times when the turbine is not turning, times when it is generating electricity but not at full load, and times when it is generating its maximum potential output. These variations in output can be averaged out and, taking into account site specific wind speed, expressed as an annual 'load factor'. The Glyndebourne turbine load factor is estimated to be 28.1%. This load factor has been used to assess the viability of the turbine.
'Efficiency' is a term normally associated with the conversion of fossil or nuclear fuel into electricity. For example, modern gas fired power stations have an efficiency of around 50% and 'waste' half of the energy value of their fuel as low grade heat, which is dumped into the atmosphere by cooling towers. In contrast to wind and other renewables, conventional fuel supply is not intermittent and the load factors of nuclear and gas power stations can be much higher, typically around 85%.
It is very difficult to make meaningful simple comparisons between renewable and conventional sources of electricity. Wind turbines are very efficient converters of wind energy into electricity, but their output will always be subject to the availability of the wind itself. A key difference between electricity generated from wind and conventional sources is that wind power leaves behind no legacy of carbon dioxide or nuclear waste.
The turbine’s maximum output is during the winter months and during Glyndebourne’s summer season output is lower. The turbine is connected to the grid so that surplus output can be used elsewhere. Conversely at times of high usage of power, electricity is supplied from the grid. However, over the year the turbine would supply enough electricity from renewable sources to equate to Glyndebourne’s annual consumption.
Glyndebourne did consider alternative sources of renewable energy, but in the Glyndebourne context, only wind power is capable of making significant carbon dioxide footprint reductions and of being developed economically.
It would not be possible to deploy photovoltaic panels (solar) to convert sunlight into electricity at Glyndebourne on a scale that would make more than a token contribution towards annual electricity demand. The use of biomass as a fuel for electricity generation (combined heat and power plant) would also not be practical because it would produce surplus heat during the summer when cooling is the primary requirement. Dumping the surplus heat would require condensing and cooling equipment using electricity and, in effect, the plant would be a small power station.
Glyndebourne is currently considering the recommendations of a Carbon Trust study. Low energy lighting and a gas fired condensing boiler have been installed, and energy saving changes have been made to the air conditioning system. Steps are being taken to reduce water usage; a paper baler has been installed to improve the recycling of all waste paper, cardboard and plastic and for many years, a bus service has been made available to take staff and opera-goers to and from Lewes train station.
The 850kW turbine consists of a tubular tower 44m high and a three bladed rotor with a diameter of 52m. It has an overall height to blade tip of 70m and a base diameter of about 3m. The turbine is pale grey with a semi- matt finish. At the end of the wind turbine’s 25 year lifetime it will be removed from the site, which will be reinstated.
It is difficult to make comparisons between the scale of wind turbines and other structures. The turbine cannot be compared to a 24 storey block of flats for example, as a block of flats has a solid, angular aspect to it and is lit. In contrast, the turbine is a slender structure with a sculptural feel to it and is not lit. The Heathfield Television Mast (150m high) is about twice the height of the proposed turbine.
A location for a wind turbine was sought on the Glyndebourne Estate which would have a good wind resource and, at the same time, would have ready access, minimise environmental impact and provide a clear visual linkage between the turbine and the opera house. Mill Plain is the only location on the estate which met the site selection criteria. This location is within the South Downs Area of Outstanding Natural Beauty.
Mill Plain has a lower sensitivity to the development of a single turbine than the higher Downs to the west of the Ringmer to Glynde New Road. The turbine presents a simple image within a generally open, large scale landscape, located at the end of a long low ridge. It can be more easily accommodated within such a setting than within a small scale complex landscape. The turbine sits comfortably within the landscape when viewed from most middle and far distant viewpoints and does not appear to be out of scale with the ridgeline. Views of the turbine from the lower lying areas are restricted by intervening trees, hedgerows and buildings. The cabling required by the turbine is underground and there are no overhead pylons.
Glyndebourne engaged independent local experts to assess all aspects of the potential impact of the wind turbine. The site is not subject to any ecological designations and surveys have demonstrated that the turbine will not result in any negative impacts. Neither does the turbine have any direct impact on any listed buildings (of special architectural or historic interest), conservation areas or areas of local archaeological interest. It will be seen in relation to some listed buildings and from the Ringmer Conservation Area. However, the turbine does not have any negative impacts in relation to cultural heritage and archaeology.
The planning application contains a map showing the area over which it may be possible to see the turbine. Views of the turbine will be limited by the presence of woodland, buildings and the Downs. After a distance of about 4 to 5km the turbine, when visible, will become a small and incidental feature in the landscape.
There are three public footpaths crossing Mill Plain which converge close to the old post mill. The turbine is sited about 90m away from the closest section of footpath.
The noise assessment concludes that the wind turbine should not cause annoyance for any surrounding residential properties with one exception; an estate cottage, (occupied by a Glyndebourne estate employee). This is the closest property to the turbine (400m away), where, in high winds, the predicted noise level may slightly exceed one of the Government’s guideline figures.
Shadow flicker and electromagnetic interference have been evaluated and are likely to affect a handful of properties on the Glyndebourne Estate only. Mitigation measures will be undertaken if necessary.
The turbine will not have a detrimental impact on aviation, although it may be within 'line of sight' of radar which serves Gatwick Airport. The MoD had no concerns regarding the proposal.
In advance of submitting the planning application, Glyndebourne made best endeavours to alert the local community to the proposal. During October 2006, some 250 people specifically came to see the four day wind turbine exhibition, together with a further 150+ people attending a performance at Glyndebourne. In addition a seminar on the project was held for some 50 students of Ringmer Community College. A leaflet describing the project and advertising an exhibition was distributed to the majority of households in Ringmer and Glynde and there have been details on the Glyndebourne website since October 2006, along with a response form. Glyndebourne also invited the South Downs Society and the CPRE for meetings to discuss the proposals.
People attending the exhibition were asked to complete a response form. A total of 215 response forms were returned indicating that 85% of respondents supported the project. A further 10% were opposed to the project and 5% were undecided. The response form asked for the respondent’s postcode details. Of those who included this data, 113 lived in Ringmer. Of those identified as living in Ringmer, 73% were in favour of the turbine, a further 18% were opposed to the project and 9% were undecided. While most of those living in Ringmer who were opposed to the proposal were within sight of the turbine, three times as many who also expected to be able to see it, were in favour.
Glyndebourne is committed to an energy-saving programme which reflects Glyndebourne’s long-term desire to ultimately become carbon neutral.
The British Wind Energy Association: www.bwea.com
The Government’s 'Planning for Renewable Energy': www.communities.gov.uk
The Sustainable Development Commission: www.sd-commission.org.uk
Julie's Bicycle: www.juliesbicycle.com
Renewable UK: www.renewableuk.com