Beginner’s guide to wind turbines

Wind turbines are topping the must-have list for the eco-conscious. But are they just a green fad for extremists, or will they soon be as common as satellite dishes?…

wind5As the price of oil reaches record heights, a recent survey by the Energy Saving Trust has revealed that 65 per cent of us worry more about energy bills than personal health and well-beingWe all know about solar panels being used by green householders to cut their fuel consumption, but a growing interest in domestic wind turbines has recently been sparked by some very high-profile eco one-upmanship. 

Of course, it could be for reasons of vote winning, rather than bill cutting, that Tory leader David Cameron and energy minister Malcolm Wicks are putting wind turbines on their houses, but that doesn’t make it a bad idea.

The Answer My Friend&

Pic: Eclectic Energy
wind4Wind turbines have three major merits. Firstly, the green credentials – a typical domestic turbine can save 2.8 tonnes of CO2 per year and around 56 tonnes over its lifetime – more than enough to fill a hot air balloon.Secondly, the financial incentive – investing in a wind turbine, or any other microgeneration technology, reduces the cost of your fuel bills. You may even be able to sell some of the energy you generate back to the grid.

Thirdly, independence – in the event of a power failure, households with their own energy supplies could be largely unaffected, though they will, of course, be besieged by neighbours requesting tea.

While there are an estimated 75,000 solar water-heating systems in the UK, and 1,300 solar voltaic systems producing electricity, year-round sun is obviously not what we are known for in Britain.

We do, however, have 40 per cent of Europe’s total wind energy. But crazily, it’s still largely untapped and only 0.5 per cent of our electricity requirements are currently generated by wind power.

Up On The Roof

Pic:

Proven Energy
windSo where do you put your turbine? Wind speed increases with height, so the ideal location is a smooth-topped hill, away from anything that will obstruct the flow of the wind, such as large trees or buildings.Fine if you live on a farm in Cumbria, but, for the rest of us who live in towns and cities, domestic wind turbines are being developed to go on top of any building.

In addition small-scale building-integrated wind turbines are currently in development that will fit discretely within the roof stucture of newly built homes within the next few years.

Mari Martiskainen, from the British Wind Energy Association says, “about 700 turbines have been installed in the UK, but a small minority of these are for householders. They are mainly on small businesses, schools, commercial centres and farms.”

So, are they noisy? “No. It’s a myth,” says Mari. “Noise is generally not thought of as an issue. The 1.5kw turbines produce less than 3.5 DBA.”

Mari believes that the reason why the market for domestic turbines is small is the cost – £2,000-3,000. However, Scottish and Southern Energy, and British Gas are trialing a sell-and-install service, so it could get cheaper soon.

Peckham Pioneer

Donnachadh McCarthy

3 Acorns
wind6The change won’t come soon enough for Peckham wind turbine pioneer Donnachadh McCarthy. In October 2005 he had London’s first wind turbine installed on his home.McCarthy is also known as the first London homeowner to have sold power, produced from the solar panels on his roof, back to London Electricity. So why did he need a wind turbine?

“In the summer it’s great and I export four to five times the amount I import. But in the winter I produce only 10 per cent of my own consumption. With the turbine I can address the production at night and in the winter.”

But being a ground-breaker is never easy, and it looked like McCarthy’s dream of 24-hour, year-round, environmentally-friendly power was doomed when planning permission was refused.

McCarthy had prepared and distributed an information pack explaining the turbine to all the neighbours who would be able to see it when it was positioned on the gable end wall of his terraced house.

“The feedback was fantastic,” says McCarthy. But then the council received an objection from a neighbour further away who was worried about her cat being killed by it.

McCarthy was told by the councillor he spoke to, “if I give you permission everyone will want one”. McCarthy replied, “good, then we’ll all be doing something to combat global warming.”

Cats Are Safe

Donnachadh McCarthy

3 Acorns
wind2But once McCarthy had reassured his worried neighbour that her cat would be unharmed, and, following a petition by the neighbours, permission was granted.Did he need any kind of structural survey before he put up the turbine? “Eclectic Energy,” he explains, “arranged for Hilti Intl to test the bolts after they were attached to the wall for forces equivalent to almost 4 times storm force.

“Thankfully as the wall had been rebuilt 10 years ago – they passed with flying colours.” The estimated commercial cost of such testing is £800- and it’s advisable to have this, or an equivalent structural survey, done before you erect a turbine on your roof.

There have, however, been problems. It took McCarthy three years to actually get his Stealthgen D400, made by Eclectic Energy, when he was let down by his first supplier.

And, due to some teething troubles with the very new technology, he is currently not producing the amount of electricity he had hoped for.

Off The Shelf?
So far we are a long way from turbines being sold at B&Q. And, although the number of planning applications is increasing, McCarthy believes that there are still only three or four domestic wind turbines on roofs in London.

In the recent budget the Chancellor announced an additional £50 million to develop microgeneration technologies under the new Low Carbon Buildings Programme.

Although this is itended to be spent by local authorities, schools, and other public bodies, it’s hoped that boosting mass production will lead to a reduction in the cost of domestic microgeneration technologies.

Although price is cited as a major disadvantage of wind turbines, McCarthy’s turbine cost only £1,000 and the inverter, which turns the electricity from DC to AC, cost him a further £1,000.

Grants are available of £1,000 per kW installed, up to a maximum of £5,000 subject to an overall 30 per cent limit of the installed cost.

The manufacturer of McCarthy’s turbine claims that, given average wind speeds at the site of around 12 mph, it could provide 15 – 20 per cent of a home’s annual electricity requirement.

So, as long as it’s windy enough, your turbine could pay for itself within a few years. You can work out average windspeeds for your postcode from the windspeed database on The British Wind Energy Association.

And, as the technology for microgeneration progresses, hopefully it won’t be long before a few more of us have the satisfaction of billing our utilities companies.

Installing a Small Wind Turbine – BWEA Top Tips

1. Get a reliable estimate of the wind speed at the proposed site. Turbine manufacturers should be able to help.

2.

Consult your local council as to whether you need planning permission.

3.

You should try to minimise the environmental impact of the turbine, and it will be helpful to inform your neighbours of your plans at an early stage.

4.

With a roof installation, it is very advisable to get the structure tested for stability – the turbine company should be able to help with this.

5.

With a tower installation, mount the turbine on as high a tower as possible and well clear of obstructions, but do not go to extremes. Foundations for the tower may be needed depending on the size and tower type. It is also important to ensure that the wind turbine can be easily lowered for inspection and maintenance.

6.

Try to have a clear, smooth fetch to the prevailing wind, e.g. over open water, smooth ground or on a smooth hill.

7.

Use cable of adequate current carrying capacity (check with the turbine supplier. This is particularly important for low voltage machines). Cable costs can be substantial.

8.

For larger machines you may have to pay rates. This can make a big difference to the economics of the installation, again you should find this out by consulting your local council.

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