Top Myths About Wind Energy

Many people make many claims about wind turbines and the effects that they allegedly have. We’ve collated our favourites and given the answers.

Windfarm near Kilmuckridge, Co. Wexford.

Windfarm near Kilmuckridge, Co. Wexford.

  1. Myth: Tens of thousands of wind turbines will be cluttering the British countryside Fact: Government legislation requires that by 2010, 10% of electricity supply must come from renewable sources. Wind power is currently the most cost effective renewable energy technology in a position to help do that. Around 3,500 additional modern wind turbines are all that would be needed to deliver 8% of the UK’s electricity by 2010, roughly 2,000 onshore and 1,500 offshore.
  2. Myth: Wind farms won’t help climate change Fact: Wind power is a clean, renewable source of energy which produces no greenhouse gas emissions or waste products. The UK currently emits 560 million tonnes of carbon dioxide (CO2), the key greenhouse gas culprit, every year and the Government target is to cut this by 60% by 20501. Power stations are the largest contributor to carbon emissions, producing 170 million tonnes of CO2 each year2. We need to switch to forms of energy that do not produce CO2. Just one modern wind turbine will save over 4,000 tonnes of CO2 emissions annually3.
  3. Myth: Building a wind farm takes more energy than it ever makes Fact: The average wind farm will pay back the energy used in its manufacture within 3-5 months of operation4. This compares favourably with coal or nuclear power stations, which take about six months. A modern wind turbine is designed to operate for more than 20 years and at the end of its working life, the area can be restored at low financial and environmental costs. Wind energy is a form of development which is essentially reversible – in contrast to fossil fuel or nuclear power stations.
  4. Myth: Wind farms are inefficient and only work 30% of the time Fact: A modern wind turbine produces electricity 70-85% of the time, but it generates different outputs depending on the wind speed. Over the course of a year, it will typically generate about 30% of the theoretical maximum output. This is known as its load factor. The load factor of conventional power stations is on average 50%5 . A modern wind turbine will generate enough to meet the electricity demands of more than a thousand homes over the course of a year.
  5. Myth: Wind energy needs back-up to work Fact: All forms of power generation require back up and no energy technology can be relied upon 100%. The UK’s transmission system already operates with enough back-up to manage the instantaneous loss of a large power station. Variations in the output from wind farms are barely noticeable over and above the normal fluctuation in supply and demand, seen when the nation’s workforce goes home, or if lightning brings down a high-voltage transmission line. Therefore, at present there is no need for additional back-up because of wind energy. Even for wind power to provide 10% of our nation’s electricity needs, only a small amount of additional conventional back-up would be required, in the region of 300-500 megawatts (MW). This would add only 0.2 pence per kilowatt hour to the generation cost of wind energy and would not in any way threaten the security of our grid6. In fact, this is unlikely to become a significant issue until wind generates over 20% of total electricity supply.
  6. Myth: Installing wind farms will never shut down power stations Fact: The simple fact is that power plants in the UK are being shut down, either through European legislation on emissions or sheer old age. We need to act now to find replacement power sources: wind is an abundant resource, indigenous to the UK and therefore has a vital role to play in the new energy portfolio.
  7. Myth: Wind power is expensive Fact: The cost of generating electricity from wind has fallen dramatically over the past few years. Between 1990 and 2002, world wind energy capacity doubled every three years and with every doubling prices fell by 15%7. Wind energy is competitive with new coal and new nuclear capacity, even before any environmental costs of fossil fuel and nuclear generation8 are taken into account. The average cost of generating electricity from onshore wind is now around 3-4p per kilowatt hour, competitive with new coal (2.5-4.5p) and cheaper than new nuclear (4-7p)9. As gas prices increase and wind power costs fall – both of which are very likely – wind becomes even more competitive, so much so that some time after 2010 wind should challenge gas as the lowest cost power source. Furthermore, the wind is a free and widely available fuel source, therefore once the wind farm is in place, there are no fuel or waste related costs.
  8. Myth: The UK should invest in other renewable energy technologies and energy efficiency instead of wind power Fact: Wind energy’s role in combating climate change is not a matter of either/or. The UK will need a mix of new and existing renewable energy technologies and energy efficiency measures, and as quickly as possible. Significant amounts of investment have been allocated for wave and tidal energy development, and these technologies, along with solar and biomass energy, will have an important role in the UK’s future energy mix. However, wind energy is the most cost effective renewable energy technology available to generate clean electricity and help combat climate change right now. Furthermore, developing a strong wind industry will facilitate other renewable technologies which have not reached commercialisation yet, accumulating valuable experience in dealing with issues such as grid connection, supply chain and finance.
  9. Myth: Wind farms should all be put out at sea Fact: We will need a mix of both onshore and offshore wind energy to meet the UK’s challenging targets on climate change. At present, onshore wind is more economical than development offshore. However, more offshore wind farms are now under construction, with the first of the large-scale projects operational at the end of 2003, and prices will fall as the industry gains more experience. Furthermore, offshore wind farms take longer to develop, as the sea is inherently a more hostile environment. To expect offshore to be the only form of wind generation allowed would therefore be to condemn us to missing our renewable energy targets and commitment to tackle climate change.
  10. Myth: Wind farms are ugly and unpopular Fact: Beauty is in the eye of the beholder, and whether you think a wind turbine is attractive or not will always be your personal opinion. However, studies regularly show that most people find turbines an interesting feature of the landscape10. On average 80% of the public support wind energy, less than 10% are against it, with the remainder undecided. Surveys conducted since the early 1990’s across the country near existing wind farms have consistently found that most people are in favour of wind energy , with support increasing among those living closer to the wind farms.
  11. Myth: Wind farms negatively affect tourism Fact: There is no evidence to suggest this. The UK’s first commercial wind farm at Delabole received 350,000 visitors in its first ten years of operation, while 10,000 visitors a year come to take the turbine tour at the EcoTech Centre in Swaffham, Norfolk. A MORI poll in Scotland showed that 80% of tourists would be interested in visiting a wind farm. Wind farm developers are often asked to provide visitor centres, viewing platforms and rights of way to their sites.
  12. Myth: Wind farms harm property prices Fact: There is currently no evidence in the UK showing that wind farms impact house prices. However, there is evidence following a comprehensive study by the Scottish Executive that those living nearest to wind farms are their strongest advocates12.
  13. Myth: Wind farms kill birds Fact: The RSPB stated in its 2004 information leaflet Wind farms and birds13, that “in the UK, we have not so far witnessed any major adverse effects on birds associated with wind farms“. Wind farms are always subject to an Environmental Impact Assessment and BWEA members follow the industry’s Best Practice Guidelines and work closely with organisations such as English Nature and the RSPB to ensure that wind farm design and layout does not interfere with sensitive species or wildlife designated sites. Moreover, a recent report published in the journal Nature confirmed that the greatest threat to bird populations in the UK is climate change14.
  14. Myth: Wind farms are dangerous to humans Fact: Wind energy is a benign technology with no associated emissions, harmful pollutants or waste products. In over 25 years and with more than 68,000 machines installed around the world15, no member of the public has ever been harmed by the normal operation of wind turbines. In response to recent unscientific accusations that wind turbines emit infrasound and cause associated health problems, Dr Geoff Leventhall, Consultant in Noise Vibration and Acoustics and author of the Defra Report on Low Frequency Noise and its Effects16, says: “I can state quite categorically that there is no significant infrasound from current designs of wind turbines. To say that there is an infrasound problem is one of the hares which objectors to wind farms like to run. There will not be any effects from infrasound from the turbines.”
  15. Myth: Wind farms are noisy Fact: The evolution of wind farm technology over the past decade has rendered mechanical noise from turbines almost undetectable with the main sound being the aerodynamic swoosh of the blades passing the tower. There are strict guidelines on wind turbines and noise emissions to ensure the protection of residential amenity. These are contained in the scientifically informed ETSU Working Group guidelines 199617 and must be followed by wind farm developers, as referenced in national planning policy for renewables18. The best advice for any doubter is to go and hear for yourself!

SOURCE:  http://www.bwea.com/energy/myths.html

Evance R9000 Wind Turbine

An overview of the Evance R9000 5kW  wind turbine suitable for residential, farming and commercial installations.

Evance R9000 5kW Wind Turbine

Evance R9000 5kW Wind Turbine

Performance:

  • Class leading energy yield
  • Reactive Pitch technology continuously optimises aerofoil positioning
  • Generates from wind speed of 2.5m/s(5.6mph)
  • No cut out wind speed

Design Excellence:

  • Blends into the environment for low visual impact
  • Lower material use for high ecological performance
  • Aerodynamic and contemporary
  • Created from big wind technology and automotive expertise

Low Maintenance:

  • Autonomous operation up to 60m/s(134mph)
  • Direct drive – no gearbox
  • Patented ElectroBrake – automatic with no moving parts

Safety:

  • Reactive Pitch automatically limits maximum of 230rpm whilst generating maximum energy. No cut out speed or intervention needed.
  • Brake system tower top mounted – no dependence on external system
  • ElectroBrake provides secondary backup safety system

Quiet Operation:

  • System engineered for minimum noise generation
  • Advanced blade design for low noise aerodynamics and balance
  • Direct drive – no gearbox noise

Efficiency:

  • Proprietary Reactive Pitch technology ensures perfect positioning of the aerofoils to maximise yield
  • Patented axial flux generator sets new standard of 96% efficiency
  • Upwind architecture with tail vane ensures precise yaw control

Durability:

  • All parts manufactured in composite, stainless steel or coated to automotive standards
  • Blade erosion resistance tested to double military standards
  • Designed to IEC61400-2, the international standard for wind turbines
  • 5 year warranty underpinned by more than 2.5 million hours in the field

Reliability:

  • Reactive Pitch is a simple and durable mechanical system
  • ElectroBrake has no moving parts
  • Backed by manufacturer trained and certified service network
  • Integrated generator eliminates complexity
  • Existing installations average >99% up time

blog evance

Archimedean Screw Hydro Turbine – Fish friendly generation

Archimedean Screw – Fish-friendly generation

What site?
·  Fall (head) of 1m to 10m
·  Flow from 100 l/s to 10,000 l/s

Why an Archimedean Screw?
·  High level of efficiency maintained across a wide flow variation
·  Environment Agency approved
·  No need for expensive fine screening
·  Robust, simple machinery – low maintenance
·  Minimal construction work necessary
·  Dry running and debris in the water flow do not harm the machinery
·  No complex control system required
·  Design life: 25 – 40 years

Efficiency
·  Achieves an efficiency of up to 87%
·  ‘Water to wire’ efficiency of 77%
·  Highly efficient down to 20% of maximum flow

Steel Trough

Steel Trough

Fish friendly
Extensive fish passage tests have conclusively demonstrated that the large water chambers and slow rotation of the Archimedean Screw allow fish of all sizes, and debris safe passage through the turbine. As a result, the Environment Agency has agreed that no screening is required. Literally thousands of fish passages have been monitored and recorded using underwater cameras at the intake, inside the chamber of the Screw itself and at the outflow to assess the effect of the Screw on salmonids (including smolts and kelts), brown trout and eels. The trials looked at fish passage across a broad spectrum of sizes and turbine speeds, possibly the most impressive of which was the safe passage of a kelt measuring 98cm in length and weighing 7.6kg. In addition, behavioural and migrational patterns across the species have been shown to be entirely unaffected by the turbine. The implication of these findings is extremely positive for the economics of micro-hydro. Sites previously written off for hydro development owing to fish protection issues can be revisited, and the cost of installation for an Archimedean Screw turbine will be significantly reduced by the requirement for only minimal screening.

Fish friendly Archimedean Screw hydro turbine

Fish friendly Archimedean Screw hydro turbine

One year on -a customer testimonial
Mark Simpson, owner of the River Dart Country Park at Ashburton in Devon decided to install an Archimedean screw to replace an old Kaplan system which had been beset by problems in the past. “The screw suits this environment so well, particularly given the vagaries of the River Dart and the way that it copes with the debris and leaves which were a problem with the old Kaplan system.” The new system produces a maximum of 48kW, more than enough to run all the visitor facilities on site, Holme Park House (used as a conference centre and wedding venue) plus two visitor bungalows. “We have been running through the summer at pretty near full capacity (45-48kW). During the dry spell it did drop down to 35kW, purely because of the limited amount of water we could take out of the river and down the leat.” Mark is a great advocate of the Archimedean screw as a satisfied customer: “The power output is more than I budgeted for or envisaged in the planning stages and I’m delighted at how the whole scheme has come together”.