Small Wind Turbines Factsheet · Factors that can increase the wind speed The tunnel effect is the...

Small Wind Turbines Factsheet

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Content Page

Introduction

Microrenewable technologies

Measuring your wind speed

Why you should measure your wind speed

Case Study: Installing FuturEnergy turbine

Wind turbine planning permissions

Getting planning permission

Wind turbine building course

DIY wind turbines

Small wind turbines impact on birds

Wind turbines: Noise and vibration

Selling your electricity to the grid

ROCs

Future information and contact details

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Introduction

Green energy factsheets Here we have heaped together a ton of information on saving energy in your

home, generating green energy, and a whole load of supporting facts on stuff

like the grants available to help you get started.

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Micro renewable technologies

So you've done everything you can to save energy? What next? In this booklet we take a

look at wind turbines, explaining how they work and what factors you should consider

before getting started on generating your own green energy.

Wind turbines These are either mounted on a pole in your garden, or in some cases fixed to your roof. A lot of

different makes are now on the market, but which is best for you? And what about planning

permission and grants?

In this booklet you can...

• Read about the options available for measuring your wind speed prior to investing in a

turbine.

• Find out why we recommend you should measure your wind speed with an anemometer.

• Read a case study on installing the FuturEnergy turbine.

• Find out more information regarding planning permission for wind turbines.

• Find out about a build your own wind turbine course, as well as some info on DIY wind

turbines.

We also take a look the tough questions...

• What affect does a wind turbine have on local bird populations? Read on to find out the

facts for small wind turbines, the manufacturer’s response, and the RSPB's opinion on the

matter.

• Doesn’t everyone complain about the noise and vibration created by turbines? Later we take

a look at how real is this problem.

Last but by no means least...

• Read about selling your electricity to the grid and ROCs

• To find out more information, you can contact us or visit our reviews section to find out

which turbine is right for you!

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Measuring your wind speed There are two methods you can use to measure your site's wind speed; one involves a detailed

site assessment, while the second is based on modelled data. We explain more below.

Measuring wind speed with an anemometer

The only way to know for sure what kind of power your turbine might produce before you invest in

one is take some direct wind speed measurements. Definitely worth doing. There are companies

around who can come and do a really professional site assessment, but for small machines, this

could end up costing as much as the turbine itself!

But you can do it yourself too with a gadget called an anemometer; a gauge for measuring the speed

and direction of wind. Ideally, you'll use it to gather data over several months and seasons to get an

accurate average wind speed. Decent anemometers are usually pretty pricey, so we've worked hard

to bring you a range of low cost anemometers that you can set up yourself.

The alternative: modelled wind speed data

Alternatively, there are also ways of roughly estimating your wind speed using modelled wind speed

data, but this needs to be taken with a pinch of salt.

One of the easiest ways to do access modelled data is by visiting the Segen website and typing in

your postcode to get back the average wind speed (in metres per second) for your house. There is

also a generalised wind speed map (at 50m above ground level) at www.windatlas.dk. The Carbon

Trust have also recently launched an online wind speed estimator.

The problems with modelled data

The figure you'll get from such modelled data will be the average for the square kilometre you live

in. But there's always a lot of variation within each square km, and the information takes no account

of the lower and more turbulent winds in urban areas. Have a think about where the turbine might

be installed, and what might affect the wind flows. Here's a handy list of things to account for (from

suggestions published by turbine manufacturers Proven Energy):

• Take account of nearby trees and buildings

• A site at the bottom of a valley or hollow will have a lower wind speed than the average, so

adjust the average wind speed down

• A site on top of a hill or knoll will have a higher wind speed than the average, so adjust the

average wind speed up

• The modelling does not include the effect of sea breezes, so for coastal sites add 0.5 - 1 m/s

to the wind speed

• For flat open countryside the model returns a more accurate result

• For complicated terrain the model is less accurate.

Why you should measureIf you are planning to install a wind turbine it is sensible to carry out a full site assessment and

measure the wind speed first, to find out how windy your potential turbine site really is. We can't

emphasise this enough, because if the wind speed isn't

- and with the best intentions in the world

energy bills (or climate change for that matter).

Winds are influenced by the ground surface of heights up t

likely be positioned below 20 metres this is a vital factor to consider in choosing your perfect site. So

not only do you need to assess the wind speed of your area but you need to think about local factors

to your site such as the roughness

buildings might affect the output. To

anemometer which measures the wind speed and direction at your exact l

Roughness

Roughness relates to the friction played out by uneven ground on the wind. In general a greater

level of roughness will slow down the wind speeds more. Smooth surfaces such as water, concrete

or tarmac will have little impact, whereas long grass, buildings

factors to consider when sitting

factors also increase turbulence which again reduces wind speeds.

Roughness is defined by class; smooth su

are 0.5, while landscapes with many trees and buildings have a high roughness class of 3 to 4. To

calculate the projected wind speeds at different heights above the ground, roughness length, or the

height above ground level where the wind speed is theoretically zero, is used.

Wind shear

Wind shear shows the relationship between wind speed and height above ground.

shows that wind speed is slower nearer the ground

influence lowers, the speed increases logarithmically.

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Why you should measure your wind speed If you are planning to install a wind turbine it is sensible to carry out a full site assessment and


emphasise this enough, because if the wind speed isn't good enough you'll be wasting your money

and with the best intentions in the world - a turbine that doesn't turn is hardly going to help your

energy bills (or climate change for that matter).

Winds are influenced by the ground surface of heights up to 100 metres. As most wind turbines are



roughness of the surrounding terrain and obstacles such as trees and

output. To fully take such factors into account you really need to use an

anemometer which measures the wind speed and direction at your exact location.



or tarmac will have little impact, whereas long grass, buildings, hedges and trees are all important

your turbine as they can greatly reduce the speed of the wind.

turbulence which again reduces wind speeds.

Roughness is defined by class; smooth surfaces have a low roughness class such as concrete runways



ove ground level where the wind speed is theoretically zero, is used.

Wind shear shows the relationship between wind speed and height above ground.

speed is slower nearer the ground. As the height increases and

influence lowers, the speed increases logarithmically.

If you are planning to install a wind turbine it is sensible to carry out a full site assessment and


good enough you'll be wasting your money

a turbine that doesn't turn is hardly going to help your

o 100 metres. As most wind turbines are



of the surrounding terrain and obstacles such as trees and

fully take such factors into account you really need to use an

ocation.



, hedges and trees are all important

your turbine as they can greatly reduce the speed of the wind. These

class such as concrete runways



Wind shear shows the relationship between wind speed and height above ground. The graph below

the surface friction

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The natural logarithmic function this graph is based on is:

V = Vref ln (Z / Z o ) / ln (Z ref / Z o)

Where V is the wind speed at a certain height Z, V ref, is the known speed at height Z ref, and Z o is the

roughness length.

Obstacles

It is very important to look for potential obstacles to your wind turbine such as buildings and trees -

the speed is reduced as the wind swirls around the obstacle, creating turbulence.

The porosity of the obstacle must also be considered, for instance trees in winter are fairly open and

will still let some wind through, however buildings are solid and so will completely block the wind

creating wind shade behind the obstacle. Porosity is defined as the open area divided by the total

area of the object facing the wind

Wind shade causes a loss of energy due to a slow down effect. This is more pronounced closer to the

object and near the bottom, and increases with height and size of the object. Any obstacles should

be taken into account if they are within 1km of the potential turbine site. E.g. a building 20 metres

tall will cast a shadow that encompasses a full size turbine with a hub height of 50 metres, 300

metres away. So the further away you place your turbine from any obstacle the lower the impact on

the wind speed.

Prevailing wind direction

Winds for a specific site will generally from come from one direction for the majority of the time.

This is called the prevailing wind. General rule for prevailing wind speed directions are:

Latitude 90-60oN 60-30

oN 30-0

oN 0-30

oS 30-60

oS 60-90

oS

Direction NE SW NE SE NW SE

Other local factors

Sea breezes are caused by the land mass heating more quickly than the sun, as the warm air rises it

flows out to sea, creating an area of low pressure on land which draws in the cooler sea air. This will

potentially alter the prevailing wind direction. During the night as land temperatures decrease the

effect is reversed, although these land breezes are much weaker.

Factors that can increase the wind speed

The tunnel effect is the increase in wind speed between two buildings or hills due to the increase in

air pressure as the air is compressed between the obstacles to the wind. So if you can site your

turbine in one of these natural or man-made tunnels it is likely you will see a significant increase in

the wind speed and so wind energy produced.

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The hill effect also increases wind speeds. If you're lucky enough to have access to the top of a hill

this will most likely be the best place to site your turbine, other factors considered. The wind

becomes compressed on the windy side of the hill (facing the prevailing wind direction) as it reaches

the top it is able to expand and flow into the low pressure area on the lee of the hill. But! If the hill is

too steep or has an uneven surface it will experience turbulence negating the benefits of sitting the

turbine there.

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FuturEnergy turbine installation on boat

Our new friend Ben is not your average run-of-the-mill architect. In 2005 he decided to buy a boat

to live in. He tells us that his original plan had been to get a Dutch barge - a sensible choice for a

houseboat. That was the plan anyway...

Later that year Ben chugged up the London's Thames with, er, a 28-

metre, decommissioned Polish icebreaker, with plans to convert it into a

Mecca of stylish alternative living.

Ben asked us to help him fit a wind turbine to his mast to run his lighting, a

water pump, and other 12v devices via a bank of batteries. We thought

this was a great opportunity to test out one of the turbines, and monitor it

closely over the coming months.

Our research tells us that FuturEnergy's 12v turbine is the one for the job, as this DIY turbine will kick

out a lot more power for your pound than its rivals. His mast is a large steel C-section, so it'll be

strong enough to take the strain.

Measuring the wind speed

The first task was to measure the wind speed at the top of the mast. Many sites in London are

unsuitable for small wind turbines - there are just too many interruptions to the wind flow like other

buildings and trees. Luckily, Ben's spot on the Thames is fairly open, and his mast is tall, so it will

hopefully be a reasonable site for the turbine. Toby shinned up the mast and fitted one of our

anemometers to record the wind speed. We got an average of 4.1 metres per second over the time

we recorded. Ideally you'd measure over several months and seasons before buying the turbine, but

we're testing it out so we'll leave the anemometer up there alongside it so we can check out the

published outputs.

Mounting the turbine hub

A couple of weeks later, our boxed FuturEnergy turbine arrives, in lots of bits. The FuturEnergy range

is designed to fit neatly onto a standard scaffold pole, so we attach a pretty-much-vertical pole

alongside the not-entirely-vertical mast, and paint it white to match. This isn't as easy as it sounds,

but by the end of the first day we are pleased with our work - and finish by threading the power

cable down through the pole, and fitting the heavy generator part of the turbine onto the top

(pictured right).

Assembling the turbine blades

Our next day starts with putting together the five plastic turbine

blades. Each one slots snugly between the two halves of a cast

metal hub which then clamps them together.

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Each blade is set to an exact angle, and we test the blades are equally balanced by hanging the

assembly up on a special string from the roof of one of the boat's cabins.

Fitting the blades and hoisting the turbine up

We're happy that the blades seem well balanced and are firmly seated in

the metal housing. So Toby climbs the mast again and Seb winches up the

blade assembly to him for bolting directly on to the front of the generator

hub. It's a bit windier than we'd like during this precarious step, but it all

goes smoothly and, with the blades in place, we fit the white enamelled

nose cone to finish it off nicely. Although we can hardly wait to see the

turbine whizzing around, we have to secure the blades at this point with a

bungee cord to stop them turning until we're ready. Next we gradually

inch up the completed turbine and its pole high enough alongside the

boat's mast so the blades are clear of all obstructions.

Charge controlling

So we've got the turbine itself ready to go, with a positive and a negative cable running down the

mast. So far so good. These cables will be connected to batteries in the boat's engine room, but first

we need to fit a charge controller. This clever box of tricks monitors the batteries and makes sure

they don't get overcharged or damaged. The Xantrex C60 charge controller is designed to do just

that, and comes with an optional screen to display the battery voltage, and current (amps) is being

generated so you can see it is working.

Dump load

If the batteries get fully charged, the energy that is being generated by our turbine needs

somewhere else to go. So the usual thing to do is connect a 'resistive load' (or 'dump load') to the

charge controller to act as an overflow to suck up the excess power. We toyed with the idea of using

an old kettle heating element, but in the end opted for a specially-made dump load box supplied by

FuturEnergy.

Connecting the batteries

Ben had previously strung together a load of old 12V car batteries in his boat's engine room, but we

knew these weren't going to be good enough. To work properly, renewable energy kit needs 'deep

cycle' batteries, that hold much more charge and don't gradually go flat like car batteries do. We

found some suitable batteries on offer that in a former life had been used as backup power for a

mobile phone transmitter. It was a long wait for them to arrive, so in the meantime we had to make

do with the old car batteries - which rapidly demonstrated how unsuitable they were for the job, as

they hardly held any charge. Finally, the new batteries arrived at the boat and we headed down to

hook them up with the help of Dave Letham, a friendly local DC-charging expert who popped down

to help the set up.

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All done!

It took a bit longer than we thought, because of the trouble with

getting the batteries, but we now have a FuturEnergy turbine up

and running on Ben's boat, which so far has admirably supplied the

crew of 5 with enough power to run their lights, 12V water pump,

and hi-fi. We think they will be able to draw a lot more load than

this too - and our tests will be ongoing over the next six months as

we'll be monitoring the output performance of the turbine at

different wind speeds.

If you want to see the turbine in action, it is clearly visible from the

riverside walk adjacent to Brentford High Street near Kew Bridge.

Ben's boat, The Liss, is pretty much the last boat moored along the bank as you walk away from Kew

Bridge.

A bit more on noise abatement

Being a steel-hulled boat, in high winds the turbine can cause quite a lot of noise to be transmitted

down through the steel mast and then amplified around the boat. Over winter, with stronger winds

more common, this became an issue for the people living aboard the boat - it was stopping them

from sleeping.

To address this we have subsequently made two improvements to the setup. The first is dampening

the turbine mount with some thin strips of rubber. This has removed the worst out of the noise. The

second improvement was fitting a stop-switch to the control equipment. This means that if the

turbine is causing sleepless nights, the people living aboard can safely isolate, brake and stop the

turbine, using a clever 3-stage switch designed by FuturEnergy turbine, using a clever 3-stage switch

designed by FuturEnergy.

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Wind turbine planning permission

Unlike most other forms of renewable micro generators, wind turbines still need planning

permission. This will need to be sought from your local planning authority. These are listed on

the Government's Planning Portal.

Contact them as soon as you can to find out their stance on domestic wind turbines. They may not

seem very keen but, according to the Planning Policy Statement 22, they are supposed to be

encouraging the use of renewable energy. You will probably be asked to show them plans and

drawings of the turbine with dimensions. They might then tell you that you don't need planning

permission (though there will still be building regulations to comply with).

Initial considerations

To maximise your chances of being granted planning permission, try thinking from the planner's

point of you. Consider the following:

• visual impact

• noise

• vibrations

• electrical interference with TV aerials

• safety

At least one LPA suggests that your turbine should not be in the front garden, invisible from the

highway and at least 2m from any boundary with a neighbour. They also suggest that a roof-

mounted version not protrude over the apex of the roof - this would likely render the turbine

sheltered and virtually useless!

Building regulations

Not only the planners need to get kept happy. Building regulations must also be adhered to if the

turbine is to be attached to your house. These ensure that the structure is safe and will not damage

the building. The important factors are size, weight and vibrations, plus the safety of the electrical

connections. For a free-standing turbine, it will only be the electrics that are of concern. In both

cases, a professional electrician will probably need to be used.

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Getting planning permission

In general, planning permission is required for wind turbines but is not usually needed to install

solar pv panels, solar hot water panels, geothermal heat pumps or biomass boilers. It is still

important that you check this with your Local Planning Authority (LPA). Things are changing for

wind turbines though! The English, Scottish and Welsh Governments are all considering making

wind turbines meeting certain criteria permitted developments. Here we try to keep you up-to-

date on the situation and guide you to where you can find out more for yourself.

Local authorities have the main responsibility, so for any specific planning questions it's best to

contact your local planning officer.

Current legislation

Planning Policy Statement 22 (PPS22) sets out a clear national policy framework on renewable

energy for planning authorities in England to ensure that the Government's renewable energy

targets are met.

Under PPS22, regional and LPAs should recognise the full range of renewable energy sources, their

differing characteristics, locational requirements and the potential for exploiting them subject to

appropriate environmental safeguards. Small scale developments can also be permitted within areas

such as National Parks, Areas of Outstanding Natural Beauty and Heritage Coasts provided that there

is no serious environmental detriment to the area concerned. PPS22 introduces a new policy area

for small systems by encouraging LPAs to require that new developments should supply a

percentage of their energy needs from onsite renewable energy sources.

Scottish Natural Heritage (SNH) has specific guidance on location of wind farms in Scotland, which is

contained in their policy statement Strategic Locational Guidance for onshore wind farms in respect

of the natural heritage to be read in conjunction with the National Planning Policy Guidelines on

renewable energy (NPPG6). Paragraph 7 deals specifically with smaller wind turbines and states that

the special rules required for wind farms do not apply to small scale wind turbines: "The guidance

only applies to the consideration of onshore wind farms, and it excludes small wind developments of

a domestic or small business scale, typically single turbines of under 50kW capacity, which may be

accommodated satisfactorily in most landscapes and in relation to which strategic guidance of this

sort is unnecessary."

In other words, your local authority is meant to be encouraging this type of thing.

Permitted development

In April 2008, the rules were relaxed regarding planning permission in England for some forms of

renewable generation. Permitted development rights were given for installation of solar thermal,

solar pv, heat pumps, micro CHP and biomass technology, meaning you will not need planning

permission to put them on your property. There are exceptions. The details, which are pretty brief,

are in the Town and Country Planning (General Permitted Development) (Amendment) (England)

Order 2008 .

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Wind turbines and air source heat pumps still require planning permission. There is a promise of

something to follow - standards for devices that will be granted permitted development status

probably - and the website we have been told to check for updates is the Microgeneration

Certification website. Small wind energy installations require planning permission and local

consultation with relevant stakeholders, such as neighbours. Deciding factors include environmental

considerations, access to the site, noise and visual effect. Overall, national planning policies support

the development of small scale wind energy, as noted below. We also offer some more technology-

specific advice on getting planning permission for your wind turbine.

In Scotland, planning permission is still required for all microgeneration systems. This could be

changing, with an Order having been laid in the Scottish Parliament on 6th

February 2009.

For other countries in the United Kingdom, you will need to check with your LPA. It is always good

to check with your LPA the current situation where you live before proceeding.

Case studies

David Cameron MP got the go-ahead from Kensington and Chelsea Borough Council for his domestic

wind turbine in July 2006. However the planning committee did impose a size limit on the turbine

and insisted on grey colouring to make it less obtrusive. They also told him that he must renew the

planning permission after three years. Planning rules are more sensitive in Mr Cameron’s locality,

because his property is located in a conservation area. The permission was granted despite some

opposition from neighbours. The turbine, however, was taken down again within a few days as it

had been fitted to the wall of the house, not the chimney stack as had been a requisite of the

planning permission.

For more information on planning please visit:

• Planning Policy Statement 22 (PPS22): Renewable Energy

o www.odpm.gov.uk/index.asp?id=1143909

• National Planning Policy Guideline NPPG6: Renewable Energy Developments (NPPG6)

o www.scotland.gov.uk/library3/planning/nppg/nppg6-00.asp

• PAN 45 (revised 2002): Renewable Energy Technologies

o www.scotland.gov.uk/library/pan/pan45-00.asp

• Contact your Local Authority for more information on planning in your local area

o www.direct.gov.uk/Dl1/Directories/LocalCouncils/fs/en

• Also visit the BWEA's section on planning.

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Wind turbine building course

If you're a practical type, who would rather build a wind turbine than buy one, this is for you! In

partnership with an experienced team of turbine builders and engineers, we can now offer

residential turbine-building courses starting at £200 for a weekend. They are usually held in rural

Lincolnshire, but also at other locations around the country from time to time (please ask for

latest details).

About the turbine

The course is based around a turbine design developed by Hugh Piggott of

Scoraig Wind - a powerful machine with a 2.4 metre blade diameter.

The blades are hand-carved from wood (usually Ash). The alternator is

built from scratch using permanent magnets and hand-wound copper

coils. 10 coils are then cast in resin to form a 'stator'. The permanent

magnets, 24 in total, are set on two discs either side, in front and behind

the stator. The rotor and alternator are attached to a welded steel

mounting which sits on top of the tower (if you didn't quite follow that,

don't worry - all will become clear on the course!).

Course format

Everyone attending the course will get direct and significant hands-on

experience carving turbine blades, wiring copper coils, soldering the

stators, constructing the magnetic plates and welding the metal frame.

By the end of the weekend you will have gained a good working

knowledge of how to make a 'Hugh Piggott' turbine.

Lectures during the weekend include in-depth knowledge of wind power and aerodynamic theory

and include hand-outs to take away with you.

On the Sunday you will erect a working wind turbine (ideally the one that has been built that

weekend) and look at ways to monitor its performance.

Price & timing

The £250 fee includes two nights camping and food for the weekend.

Discounts may be available for certain groups. For those not wanting to

camp there are some other alternatives both on and off site.

Each weekend course begins at 7pm on the Friday evening (although we

recommend you arrive around 5pm to set up tents and have dinner).

Activities run from 9am - 9pm on the Saturday and 9am to 4pm on the

Sunday.

Visit www.scoraigwind.com for more information and to book your place.

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DIY wind turbines

If you consider yourself pretty handy, there are various build-your-own plans available, or turbine-

building courses you can attend. Depending on your skills and the components you use, your

finished turbine may or may not be as efficient as a manufactured one, but could be a lot of fun to

make, and probably a good deal cheaper.

Hugh Piggot, of Scoraig Wind Electric in Ross shire, Scotland, is something of a guru

in the DIY turbines area, having been making and refining his own machines for

over 25 years.

He's written a 64 page step-by-step booklet called "How to build a wind turbine -

the axial flux plans", which you can order directly from his website for £11

including postage. There are full lists of materials, suppliers and tools for the job.

This involves carving blades and welding a frame, so it does sound like you need to

be fairly practically minded.

Hugh also runs workshop courses on building wind turbines at various locations

including the Centre for Alternative Technology in Wales.

Experimenting with smaller generators

Also worth a look is Ben Jandrell's pages on low cost DIY generators at www.gotwind.org . He's

focussing on DIY turbines from scrap parts for under £100. These aren't likely to ever power your

home, you'd be amazed at what you can do with a few old bicycle dynohub generators. There are

also some handy tips on finding and using old motors to generate a bit of energy here.

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Small wind turbines impact on birds

We've heard from several people who are worried about the impact of small wind turbines on

garden birds and other nearby wildlife. It's pretty hard to get a definitive answer on this, because

most of the research so far relates to very large wind farms, which are pretty different from home

turbines.

Below is some correspondence sent to us by one of our website visitors, Paul, who has been looking

into this issue.

Paul: "I've become rather fond of the individual birds that visit our garden and I would hate to

accidentally kill any of them even if the overall conservation impact was small. I also wonder if it

would be so small if these turbines really fall in price and they are installed all over the place. I would

love to have definitive reassurance that birds see and avoid them before I buy one and start finding

chopped up sparrows on the lawn!"

"I sought reassurance from the company [Windsave] that their product would not injure the birds

and bats that visit our garden:"

Paul's email to Windsave:

I am interested in installing one of your turbines atop my three storey townhouse in Twickenham,

West London. One thing that concerns me is that we have a lot of birdlife in the area including

swifts, parakeets, blackbirds, sparrows, doves, crows etc. We also have bats. They all tend to fly over

the roof at just the height I would expect the turbine to be installed. Can you give some assurance

about the likelihood of birds being injured or is there an optional protective cage similar to the type

that is used on electric domestic cooling fans?

Windsave's reply:

Windsave replied an attached a document with the following collection of quotes:

BIRDS, BATS AND WIND TURBINES

At Black Law wind farm a close working relationship with RSPB Scotland helped enormously in

achieving significant benefits for a range of species including black grouse, curlew, lapwing, snipe,

otter and water vole. Black Law wind farm demonstrates that wind farms can deliver significant

biodiversity gains for a range of threatened habitats and species throughout the wider

countryside.

Alan Mortimer Head of Renewables Policy, Scottish Power

Compared with past assaults, such as pesticides, loss of hedgerows, illegal persecution of birds of

prey and intensive agriculture, wind farms should be low down the scale of threats.

Mark Avery, Director of Conservation, RSPB

We are not saying we should stop building wind farms. Birds would suffer much more from climate

change if we don’ t.

Andy Pullin, Centre for Evidence-Based Conservation Birmingham University

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There is no evidence to suggest that wind farms in the UK present a significant source of mortality to

bat populations.

In addition, if we were asked to defend ourselves against past problems with bird deaths, we can say

that we are aware of The Tarifa wind farm complex in Spain and Altamont Pass in California which

are two commonly quoted examples where developers failed to consider the impact on large birds

of prey, leading to hundreds of deaths. Similar mistakes have been made more recently at Navarra in

Spain. There is no evidence that these mistakes have been repeated at UK sites, due in part to

success in avoiding more sensitive sites.

Sustainable Development Commission publication, June 2005.

Birds Avoid Turbines According to Danish Research, geese and ducks learn to avoid the blades of

offshore wind farms. The research was carried out by the National Environmental Research Institute

in Grenavej, Denmark, using radar to monitor bird migration patterns over Nysted offshore wind

farm in the Baltic Sea. The research found that the percentage of birds entering the area decreased

significantly from pre-construction to initial operation, and a larger proportion of birds flew close to

the wind farms at night. Overall the study found that less than 1% of the birds migrated close

enough to the turbines to be at risk of collision.

More at: www.pubs.royalsoc.ac.uk/biologyletters.shtml

Paul's response:

Paul told them he thought this stuff was all a bit misleading and irrelevant as it relates to the impacts

of big wind farms, not small home installations.

Their response:

I do apologise that you feel that we have mislead you in anyway. That was not the intention of the

document I had sent you. As micro wind turbines are new to the market we can only go on the large

wind turbines and what affect they have had on wildlife. We have over 50 to 60 installation test sites

throughout the UK and have had no reports of any wildlife casualties at this stage. The document I

had sent you was to merely inform you of how wildlife adapts to various surroundings and new

additions to the landscape"

So he contacted the RSPB to ask their opinion.

RSPB response:

Dear Mr Campbell,

You are quite right that the quotes relating to offshore windfarms and other, industrial onshore

windfarms bear little relevance to a domestic wind energy appliance, and indeed some of the

quotes, for example: from Black law, have been taken out of context, as it was the habitat

improvements initiated by the developer at this site which were beneficial (although the RSPB would

say that the operational windfarm itself would also have indirect positive impacts through it helping

reduce CO2 production and so climate change - but that is not what the quote is alluding to).

I will discuss this with our policy team to ascertain whether any further action is needed - thank you

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for bringing it to our attention. In relation to domestic wind turbines generically, there really is no

scientific data that we are aware of as to the interactions between these appliances and birds.

However, they are small scale and this would suggest that they are less likely to be a problem in

terms of bird collision. Birds tend to be very good at avoiding structures during normal flying

conditions when they can see them - particularly small manoeuvrable birds like those listed in your

enquiry.

Of course, it is not impossible that a bird or bat could strike the blades. However, I believe this would

be likely to be a rare event. When industrial turbines have been a problem for birds in terms of

collision in the past, usually it is with a large array of turbines, sited next to areas used by highly

sensitive birds, or on migration routes of the same. Large raptors and wildfowl seem to be the

groups most at risk of collision. Although I wouldn't want to extrapolate directly from industrial to

domestic-sized appliances, as 2.5MW machines have the potential to have a much larger impact on

bird populations, and usually do not, it would suggest that the small domestic appliances should

have minimal impacts.

Talking to our Conservation Officer responsible for London she says: The RSPB considers the biggest

risk to birds from wind turbines in London will come when turbines are located along the River

Thames or its tributaries. This is because the species most likely to collide with turbines are swans,

ducks, geese and waders, and large migratory birds using traditional migration routes. These routes

tend to follow the rivers and streams. Individual birds could collide with a domestic turbine in

Twickenham, which would be unfortunate, but would not have significant nature conservation

implications. I hope that this is of some help.

Regards,

Daniel Pullan, RSPB.

Our view:

Our view at the moment is that small wind turbines pose only a very very small, if any, threat to

garden birds and wildlife. According to information from the American Wind Energy Association, a

sliding glass door poses a greater threat to garden birds than a small domestic wind turbine.

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Wind turbines: Noise and vibration

People living near large proposed wind farms are often worried they will be a source of noise

disturbance, especially in high winds. But what about small wind turbines - are they noisy?

The straight answer is that no working turbine is going to be completely silent. There are actually

two sources of noise to think about. The obvious one is the swoosh of the blades going around. But

unless you are very close, or it's very windy, this is unlikely to be much of a problem.

The main source of noise - and vibration - is caused by the magnetic generator that produces the

power as the blades turn around. This isn't too noticeable at low wind speeds, but usually gets much

louder at the higher, more energy-producing wind speeds. As any acoustic engineer will tell you, this

noise/vibration will resonate through anything the turbine is attached to.

If the turbine is pole-mounted, as we recommend, then you shouldn't have too much trouble. The

steel pole will channel the vibrations straight into the ground, where the earth will dampen it - you

may not even notice it happening.

However, if the turbine is strapped to the side of your house, there is a good chance that some of

the low vibration frequencies will be transmitted through the wall. It could even keep you awake at

night.

Some improvements can be made by isolating the turbine from the structure, with specially-

designed (or improvised) rubber mountings. You might cut out 2/3rds of the noise/vibration this

way, but you're never going to completely get rid of the problem.

Our first turbine installation, a FuturEnergy turbine mounted on a steel-hulled boat, is an extreme

case. The turbine pole is bolted directly onto the steel mast, which in turn is firmly welded to the

solid steel hull of the boat. Not surprisingly, at high wind speeds, the noise is rather effectively

channelled down the mast, amplified somewhat along the way, and transmitted into the living

quarters of the boat. Although the boat residents initially found this noise a novelty, when the

winter came, with the higher wind speeds, they understandably got a bit fed up.

It'll never be silent on a windy day, but to ease the problem, we fitted insulating rubber around the

mounting, and a stop switch to give the boaties the option of safely stopping the turbine at night if it

disturbs their sleep.

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Selling your electricity to the grid

If you are generating electricity and connected to the grid, there are a few ways of reaping

financial rewards. Some electricity suppliers will buy that which you are not using and is spilling

onto the grid. Some will buy the ROCs (Renewable Obligation Certificates) the generating

renewable energy accrues. Here we present to you the steps to get money from your renewable

efforts and look at how much money you could make.

To get paid for renewable energy

• When your wind turbine or solar PV is fitted, it should have an Ofgem accredited generation

meter. This will tell you how much electricity your device has produced.

• To put energy onto the grid, you will need to have the appropriate agreement with your

Distributed Network Operator.

• To obtain ROCs, you will need a schematic diagram of the electrics of your renewable

generator.

• Usually, you will need to be a customer of the energy company that you are going to supply.

The options

• You receive payment for every unit that your generation meter says you generate. This is

regardless of how much of it you use. No export meter is required.

• You have an export meter fitted and you are paid only for the amount of electricity that goes

to the grid.

• You supply the energy company with you total generation reading. They assume that you

will use a percentage of this and pay you for the rest. No need for an additional export

meter.

• Your generated energy earns you ROCs. You appoint the energy company as your agent;

they obtain the ROCs for you then buy them from you. This might be included in the rate

they pay for the units of electricity you generate.

• If you want to sell your ROCs separately, you will want to consider whether the price you get

in worth the installation of the export meter and the hassle that this seems to involve. The

value of ROCs is based on the buy-out price set by Ofgem. For 1st

April 2008 – 31st March

2009, it is £35.76. One ROC is currently awarded for each 1MWh generated in an obligations

period (one year).

Potential buyers of your energy

There are a couple of big energy companies and a few green energy specialists who will be

interested in buying your electricity. Either, it fits with their eco-credentials, their marketing stance

or helps with their Renewables Obligations. On the next page are the companies that we found

together with their contact details and what they are currently offering.

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01905 340 646

npower will assume that you will export 60% of your energy if it was generated by wind turbine and

50% if it was generated by PV. You provide them with the total you generated. They will pay you for

the amount they assume exported at a rate of 12p unit of PV and 10p per unit of wind energy. They

will not require you to relinquish your ROCs. You can appoint them as your agent, supply them will

the relevant information and they will pay for them at the buy-out price.

0800 051 1905

Edf do not have many details on their website of the prices they will pay you and suggest it is best to

call them for the current options. We found them to be buying your total generated electricity + the

ROCs at 5p/kWh if your generator is rated as 5kWp, 4.5p/kWh for larger installations. Alternatively,

for generators up to 10kWp, they will buy just the electricity you export at 7.6p/kWh. This will

require you to have an export meter but you will not have to relinquish your ROCs.

0845 555 7100

[email protected]

Electricity generated by wind turbine, PV or small hydro, by systems rated up to 10kW can be sold to

ecotricity. Starting from the beginning of February 2009, they will pay 12p/kWh for the total

generated electricity and the ROCs.

Using the reading from a total generation meter, Good Energy will 10p per unit for everything that

you produce + the ROCs. Quite excitingly for those with or considering thermal solar, Good Energy

are trying to find a way to reward you for your eco-efforts and, at the same time, off-set their new

gas offering. This is currently a test scheme. Using the size of your panels, orientation, angle and

position, they will estimate how much heat you should be generating and work out how much to pay

you. For more information, please e-mail [email protected].

22

0845 456 9550 or speak to Sharon on 01920 483046

Green Energy is an unusual energy company in that their customers become their shareholders.

They pay at two rates depending on the size of your generator:

• small scale (under 6kW) - a flat rate of 10p for every unit generated + ROCs, including the

units used on site. Only generation meter required.

• larger scale (6-30kW) - 8.5p for the units exported through an export meter and 4.5p per

unit generated for the ROCs minus a daily standing charge of 15p for export to the grid. You

could opt to obtain your ROCs and sell them to someone else.

Getting an OFGEM accredited export meter

The list of OFGEM accredited generation meters can be found here (PDF). Second hand OFGEM

accredited single phase meters can be found on Universal Meter Services for as little as £5 and new

ones for £25.

More info

There's a good list of the grid-exporting offers available over at Paul's Alternative Energy website and

West Wales Eco Centre, which we drew on in our research. The Times also published a useful article,

"Get paid for making your own electricity".

Distribution network operators

In order to be connected to the grid, you will need to have agreement with the people who run the

National Grid in your area. These are the distribution (or distributed) network operators.

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Renewables Obligation Certificates (ROCs)

Sounds complicated, but isn't really. ROCs were dreamt up as part of the

Renewables Obligation to reward people who produce renewable energy with

extra cash. All suppliers (eg npower or British Gas) must get a percentage of the

electricity they sell to you from renewable sources. In 2005/06 this was set at

5.5% and the idea is that is rises gradually to be 10% in 2010, and 15.4% in

2015/16.

How it actually works

Renewable energy generators (and this could include you with your mini-turbine) are awarded a

ROC for each MWh of renewable electricity they generate. At the end of each year, the energy

suppliers can either present enough certificates to cover the required percentage of their

renewable energy, or they can pay a ‘buyout’ price for any shortfall (£37.19 per MWh for 2009-10,

up from £35.76 in 2008-09). The proceeds from these payments are then divided up between the

renewable generators in proportion to the number of ROCs they originally cashed in. For example

in 2004/05, £13.66 was returned per ROC.

What is it intended to do?

Because renewable energy is currently quite expensive to generate, the Renewables Obligation is

designed to make it more economic to generate renewable energy, as by selling their ROCs,

renewable generators have an additional source of income.

So how much is a ROC worth?

One ROC is worth around £30 (although the price fluctuates), and you’ll get issued one ROC for

every 2MWh (which is the same as 1000 kWh or 1000 units of electricity) your system produces.

How do I sell my ROCs?

There is a fair bit of paperwork involved, so most households who export to the grid choose an

energy supplier, or another intermediary who deals with the admin on their behalf. Good Energy

and Ecotricity offer this service, as do many of the other energy companies. Paul at Alternative

Energy is going through the process of selling his ROCs, via Scottish and Southern, follow the link to

his pages to find out more.

More info:

More information on ROCs can be found on the BERR website and through OFGEM who regulate

the RO, in particular their guidance for microgenerators (under 50kW or less) contains more

detailed information on ROCs.

24

Further Information

If this all sounds very appealing and you think that wind energy is right for you... take a look at our

website where we compare nearly over 45 of the top wind turbines out there!

Finally, if you have any questions about the topics covered in this booklet, you will always find us at:

Email: www.bettergeneration.com

Address: 23 Jacob Street

London

SE1 2BG

Phone: 02077385800

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