Wind Farms

[DGR]

Has anyone looked at the Crown Estates Website and seen how many windfarms are being built? (Link at the bottom) I'm all for renewable energy, but that DTI exclusion zone looks a bit drastic.

Anyone know what that actually means?

Dylan...

P.S. I notice that there aren't any on the South Coast......!!

Crown Estates Website

[DGR]

The link won't work properly. If you go to the home page, there is a banner which says

"New Sites for Proposed Windfarms Announced"

Click on it and it takes you to a page where you can look at maps of the North West, Wash, and Thames areas to see where they will go.

D...

[DJL]

Originally posted by DGR
P.S. I notice that there aren't any on the South Coast......!!

I believe they are planning to build a wind farm off Portland. The sailing club bidding for the olymics was complaining about the idea.

[Mark Halliday]

Originally posted by DGR

P.S. I notice that there aren't any on the South Coast......!!

Lunchtime news today had a piece on proposed wind farm on sea wall at Portland Harbour.

Would totaly screw up one of the best international sailing sites in the UK.

[tue]

They are indeed planning on building some in Portland. The exclusion zones cover some of the most popular dive sites there.

[DGR]

But what do the Exclusion zones actually mean? The 'DTI Exclusion Zone' appears to go from the Coast to the 12 mile (km?) limit. I can't be an exclusion for shipping - 'cos Liverpool, Fleetwood and Preston docks would have to shut down - but I can't find what it DOES mean.

Anyone know?

Otherwise I'm going to be stuck up the River Ribble, albeit with a paddle AND an engine!!

Dylan...

[Garygee]

Hi folks

Dylan

Where is the exclusion zone ?.

The map I am looking at http://www.crownestate.co.uk/estates...s/a4plannw.pdf
apears not to show any.

The only thing at 12 miles us the UK waters limit.

Am I looking in wrong place ?.

Regards Gary

[DGR]

That's really weird.

When I looked earlier, there was a big fat grey striped area from the NW coast out to the shore-most edge of the red marked wind farms. It ran all the way from Morecambe Bay down past Fleetwood (the straight line you can see going through Morecambe Bay was one edge of it) and along the coast.

Maybe I was hallucinating - but if there is no exclusion zone, why have it on the key to the map? It's gone off the other maps too - maybe it's something to do with the PC at work I was using. Oh well.

Or, it could just be the power of RIBnet............

[Louise]

It was still there when I looked a minute ago - clicked on the link to the UK map.

Very interesting site, BTW - thanks.

[Andy]

Its a bugger as Portland Harbour Authority seems determined to wipe out diving in the harbour. They have banned diving on the Hood, and if this goes ahead all the dive sites inside the harbour will also be out of action as they are too close to the site of the turbines (or whatever they are called).

Its a shame as diving has provided locals with a sustained income over the past years.

There was a big action via MPs over this last year and it seemed to go away, but its not back on the agenda.

Shame

[nik]

Its a bugger as Portland Harbour Authority seems determined to wipe out diving in the harbour.

They had a pretty good go at trying to banish windsurfing in the harbour as well.
Nick

[DGR]

I did my degree project on Wind Turbine blades - hence the interest and why I was looking on the Crown Estates web site in the first place - but (way back) then they all talked about siting them 'far away from land' to reduce the 'environmental' impact (on us humans I assume).

That looks like what they are trying to do in the North West - at least they're a few klicks offshore. I wonder if the planning for building them takes into account previous usage and stuff like that?

It does seem a bit odd that they want to do it in Portland Harbour, and on top of known, good, dive sites. There is a lot of sea-bed between the low-water and the 12 km line - I'm sure they could find a bit no-one was THAT bothered about if they tried.

[nik]

Hello DGR,
can you tell me this? Most windfarm turbines I have seen have 3 blades, if more blades were added to the turbine, would it not generate more power?
Nick.

[DGR]

The turbines are designed to produce a specific amount of power (i.e. 1MW etc) within a specific windspeed range, and then the blades are designed to produce the required amount of effort to drive the turbine.

You tend to see 2 and 3 bladed designs, but a 2 bladed design needs longer blades to generate the same power as a 3 bladed one - from (very hazy) memory, a 1MW (big) turbine had a similar wingspan to a Boeing 747 if you use a 2 bladed design. A 3 blade design means significantly shorter blades, and therefore a much shorter (and cheaper) tower for the same power generation and ground clearance.

From there I think you get diminishing returns on extra blades - the additional costs of the blades, the extra control mechanism and the interference effects of the blades negates any of the benefits (slightly shorter span and slighty shorter towers). The biggest benefit seems to come from 3 blades - so that's what most are.

I also seem to remember that 3 bladed turbines are quieter than 2 bladed ones as well - the tip speeds are lower so they don't "whoomp" as much as they go round.

It's a long time since I did any of this - and a lot may have changed since I looked at it - not least of which is probably my memory!!

Dylan...

[nik]

Thanks Dylan,
This has puzzled me for a while. I can remember in westrns, seeing wind driven water pumps for wells which had loads of blades. But that could be down to limited quality of materiels and limited technology.
Nick.

[DGR]

Yes - I guess all those wind turbines in the movies did was just pump up water from a well, so just as long as it was powerful enough to go round and drive the pump then it was OK. Modern wind turbines are trying to extract as much energy out of the moving air as they can - so use technology/modern materials to do that.

Dylan...