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Hi,

I've heard that it's a futile exercise to try to generate electricity from wind power in London because the wind is so gusty. Does anyone have any experience with wind power in London? Is it possible to get a decent amount of power from a roof-mounted wind turbine in south London?

I have considered using photovoltaic solar cells but they seem to be WAY over my budget.

Thanks,
Jack

The BBC Magazine ran something on this the other day

dan_aka_jack wrote:I've heard that it's a futile exercise to try to generate electricity from wind power in London because the wind is so gusty. Does anyone have any experience with wind power in London?

None at all, but microgeneration is in the news quite a lot lately - have a look for some links in my other posts in this section.

I have heard people say that roof-top windmills are less effective than ones placed out in the open on a high mast - but we have to work with what we've got. It probably depends upon the buildings around you, too. I guess you could experiment by hoisting a flag up to where you would have a windmill, and monitoring just how much the wind affects it over a period of time and in different conditions.

Time may come before long when even gusty wind is more cost effective than mains electricity.

Yes, it's a very good idea to run a test before shelling out the cash for a full system - thanks. I expect I could buy/make a little electronic wind-monitoring kit for just a few quid... getting up on the roof to mount my testing device wont be so trivial though.

Does anyone know of any sites which might tell me how to build a DIY solar water heater?

try these: http://www.fuellesspower.com/solar_cell2.htm

http://www.bigginhill.co.uk/solar.htm

http://www.mansolar.com/make.htm

http://facstaffwebs.umes.edu/eyilmaz/solase04.pdf

unless you have a vast garden, I really do think wind power really isn't a viable option in a city. Roof mounted ones are a con - they'll damage the building, transmit vibration, and basically "won't do what it says on the tin", because roof level is possibly the worst place to put it! (a bit like putting a solar panel in heavy shade).
PV panels are still ludicrously expensive, so probably your best bet is solar water heating - there's bags of plans available on the net to build simple home-made collectors using old radiators - they aren't terrifically efficient, but they do work in summer! 8)

Hi there,

Buying a wind turbine may cost you more than just buying green electricity from a supplier, for two reasons:

1) Your wind turbine is smaller than the ~2MW ones deployed in farms, and loses on economy of scale;
2) Your London house may not compare well for wind speeds with Scotland and Wales and all the other places wind turbines love.

If you want green electricity you can get it from electricity companies, who ensure that they generate enough green electricity to suppy you with it. Options & costs of green electricity for London residents are shown here: http://www.greenelectricity.org/regions/london.html

In the end it comes down to economics, could the money you've set aside for the turbine get more kWh's through a green electricity tariff or through a buying a turbine? Proven Energy have a case study for their 6 kW wind turbine at Wandsworth Town BP Garage showing costs and electricity generated each year (estimated). You can see that info here: http://www.provenenergy.co.uk/images/st ... sworth.pdf

From my rough calculations it's a pretty close call, but I reckon that the hassle and risk of getting a wind turbine on the small scale may not justify the money spent. My hunch is that most people who get a wind turbine are doing it to give the 'impression' they are green. If you're serious about getting the most green electricity for your money, buying a green electricity tariff is probably the better bet.

But don't take my word for it, check the economics for yourself!



P.S. This is my first post here, so hi everyone, this looks like a great forum! I'm a mechanical engineer and work in renewable energy so enjoy this kind of stuff :)

are the number of companies telling downright porkies trying to sell a gullible and largely ignorant public such jokes as what I've seen referred to as the "Swindlesave" roof-mounted turbines!
They can't possibly "do what they say on the tin", and are increasingly being sold as a "lifestyle statement"
A bit of simple wind generation is anything BUT simple, and is very open to "smoke and mirrors" - take for instance "power curves" - what is important is how much power your wind genny captures from the wind in your particular site over a period - peak power output is largely irrelevant, but that is what they "trade" on (usually using little used things like metres/second - what wrong with mph or knots - if its good enough for blasted speed cameras!)
I was reading a tale of two turbines yesterday - one a 2kw heavy duty job from probably the most respected manufacturer in England, the other, a Navitron chinese turbine rated at 500 watts - time after time, the 500w "cheapie" outperformed the 2KW, in all sorts of conditions.........(the power kicks in a lot earlier on the Navitron), so in AVERAGE conditions size isn't everything......... 8)

BraveWorrier wrote:P.S. This is my first post here, so hi everyone, this looks like a great forum! I'm a mechanical engineer and work in renewable energy so enjoy this kind of stuff :)

Hi, Brave Worrier, welcome to the site!

I'd love to have a small turbine - I think where I live it would be quite sensible (Scotland, up in the hills..). Economics are, of course, the problem. Even if the initial cost will be recuperated in a few years' time - any idea what maintenance costs have to be expected?

usually they're tough as old boots, and should need minimal maintenance - usually recommended to grease the bearings, clean the slip rings if you have any, and check the blades too, once a year! 8)
Sounds like the wilds of Scotland would be a perfect place for a "home" wind turbine.
If it helps cost the exercise, I've been doing some sums - it is generally estimated that the AVERAGE family electricity consumption can be met with a well-sited 2- 2.5kw turbine - you can buy one for around £1600 - then you've got the choice of adding a G83 approved inverter if you want to do "grid tie"
(ludicrously expensive at around £1500), or a thumping great battery bank (anything from £900 upwards)............add to that £80 for the "sell to the grid meter", and probably about £500 for all the oddments and footings etc. - for heavy use a 5kw at £4,690 will need a £3,000 inverter or a larger battery bank. (rough rule of thumb, about £5000 for a complete 2kw system installed, double that for the 5kw). 8)

if that's too expensive, I'm looking at putting together a really cheap system for myself - I've decided to use my garage for storage and office space in the short term, and it could do with light and power sufficient to drive a laptop, radio etc, and perhaps have a bit left over for heating - the major items are a 200w genny, mast, rectifier/controller unit and inverter package at £300 - add to that four 110 amp 12v batteries @ £45 - £180 - dump load controller - £105 - and dump load (small heating element £20) - add to that some footings materials and a weekend or so of straightforward diy - about £600 - £650... 8)
OR if you have diy skills, visit Hugh Pigott's site http://www.scoraigwind.com/ and learn how to make your own (it isn't rocket science), he teaches people how to make his simple design of very powerful turbines the world over - I take my hat off to the bloke

Wow - loads of replies since my last visit! Thanks loads for all your help.

Thanks,
Jack

ina wrote:any idea what maintenance costs have to be expected?

On the optimistic side I would estimate 2% of the cost of the turbine installation per year. For example, if you spend £15,000 on the turbine and other equipment, then budget £300/year. On the normal to pessimistic side, budget for 4%.

These are just rough guesses, but should be good enough for a first stab at the economics!

Thanks for all those numbers! I wouldn't need a terribly big one - one person, don't use much (but all heating is electric - nothing I can do about it as it's not my house). Which brings me to the next idea I had - how difficult would it be to dismantle a small turbine and move it to another location? (I live in a tied cottage and will have to move out eventually... If I'm lucky, at the end of my working life; if I'm not so lucky (or, alternatively, if I win the lottery or an aunt that I don't know about yet leaves me a lot of money in her will ), I might have to move out before the pay-back period is over...