Stinchcombe turbines: Q and A

Last week Stroud Life covered views regarding the wind turbine proposals near Stinchcombe - the so-called Berkeley Vale Wind Farm - see my previous comments here (with links to Green party news release that was also covered by the paper).

Stroud Life's Q and A were so good I've copied them below....if the scheme goes ahead it will power the equivalent of nearly 25% of the Districts housing.

Stinchcombe turbines: Q and A
Wednesday, September 16, 2009

Why is Stinchcombe an ideal site for turbines?

Because wind turbines can be built here, we believe, with minimal impact. It’s one of the very best places in the district. It’s not in the AONB, it’s windy and it’s far enough away from homes that we can be sure turbines here will be good neighbours.

How big is the site?

The site area is 145 hectares (359 acres) of which a tiny proportion would be taken up by the turbines – they typically occupy less than 1% of the land they sit within. The rest of the site can continue to be used for farming – animals can graze and crops grown right up to the base of the turbines.

How many turbines would go there?

We currently think this is a good site for eight turbines. This is subject to consultation though and may change as we learn more about the site.

How do turbines work?

The wind turns the blades which turn a generator which makes electricity. This electricity travels down the tower to a substation where it’s made into grid quality electricity. We then feed this into the local grid. The turbines we use are fully automatic. They keep themselves facing the wind as it changes direction and feather their blades to make optimum use of the wind. If they develop a fault they send us a message but they generally need no more than two days maintenance a year. They really are amazing machines.

What are they made from?

The tower is steel and the blades are glass fibre.

How are they built?

An underground foundation supports the turbine. The actual construction takes a matter of days. Tower sections are lifted into place by a crane which is then used to lift and fit the generator and three blades.

How tall are they?

The turbines we’d like to build on this site have a tower height of nearly 80m with the blades reaching up to a maximum height of 120m, the same dimensions as the three turbines at Avonmouth Docks.

How long is each of the blades?

About 40m.

Why are there only three blades?

Two’s not enough and four’s too many! Three blades is the optimum design for making electricity.

How much noise do they make?

Modern wind turbines are very quiet.The ones we propose to use are the quietest available. Standing several hundred meters away you’d be hard pushed to hear them. Anyone concerned about noise should go and visit our turbine at Lynch Knoll, just outside Stroud. We built this turbine 13 years ago now. It’s been working day in day out, disproving many of the myths that exist around wind power.

Why are turbines white?

They’re actually a light matt grey. It’s a colour that the industry arrived at because it’s the most neutral in a wide range of weather conditions.

How strong does the wind have to be to generate power?

Our turbines start producing electricity at wind speeds as low as 5 mph and up to over 60mph, that’s gale force. Data from the nearby Met Office at Avonmouth shows that in 17 years just 10 hours have been recorded with a wind speed exceeding 63mph.

How much power will each of them produce?

The eight turbines combined are predicted to generate nearly 40 million million Units (kwh’s) of electricity each year, equal to the power consumption of nearly 12,000 homes, that’s about 25% of the homes in the Stroud District.

Is there any threat to the environment or wildlife?

We don’t believe there’ll be any adverse affects. We’ve spent a lot of time studying the site and considering the potential impact turbines here could have. We’ll shortly be producing an environmental report which will set out all of the information we’ve found. Before we submit an application we have to be sure our turbines will make good neighbours. If we can’t be sure, we won’t proceed with an application. We run fifteen wind parks the length and breadth of the country, none of which have caused any major problems for our neighbours.

Do you need planning permission?

Yes.

At what stage is the planning application?

There is no planning application as yet. We’re currently in discussions with the Council and other consultees to define the issues we should be looking at.

How can people comment on the plans?

Anyone can comment or put questions to Ecotricity at berkeley-vale@ecotricity.co.uk, by phone at 01453 756111. Once we have submitted a planning application, you can register your support or objection, and any comments you have, with the planning department at Stroud District Council.

If the scheme gets planning permission, how long would it take to build the turbines and start harnessing the wind?

We'd hope to have the turbines up and running within twelve months of getting permission. And then each year for the next 30 years they’ll feed green energy directly into the local grid, enough to power nearly 25% of the homes in Stroud District. All from a local renewable source saving over 16,000 tonnes of CO2 from being emitted each year - in it's lifetime that’s nearly 500,000 tonnes of CO2. A very worthwhile contribution to the fight against climate change.