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helimutt
29th Jan 2009, 17:48
It's probably been asked a load of times already but I can't be ars*d to look. Anyone built a wind turbine for themselves and if so, how did you do it and did it work/does it still work?

Just bored and wanted another project for when I finish present one.
:ok:

Flight_Idle
29th Jan 2009, 21:47
I've done it in the past in the middle east, making them out of aluminium sheet, small multi bladed types. Just be careful of them throwing a blade in extra strong winds ect, there coud be legal issues if someone gets a blade embedded in their skull (A hazard in built up areas in particular)

Best go for big & simple in my opinion, two halves of an oil drum on a pole ect, it's safer.

Parapunter
29th Jan 2009, 21:51
I'm so glad neither of you Tom Goodes' are my neighbours:p

kluge
30th Jan 2009, 04:11
Here you go.
Everything you need to know about Savonius rotors:

Savonius wind turbine - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Savonius_wind_turbine)

You can play around with stacked rotors at different offsets on the y axis and there is also an optimum aspect ratio (which I've forgotten) for the diameter/rotor height. I think 3-4 about right for wind catching efficiency.

When used with a Darrieus wind turbine efficiency can be improved. One acts as a low speed gear for the other - kind of like an APU in an a/c.

Darrieus wind turbine - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Darrieus_wind_turbine)

The difficult bit is getting the optimum gearing right for the motor (hence you need to offset the axis of the motor and rotor, linked them with a rubber belt on pulleys and work out losses (and how to structurally encase the lot). Also you need to work out electrical cable sizes to minimize losses. Built one for my yacht once (a Savonius - diameter around 12 inches) using PVC pipe as a waterproof housing for the alternator. Worked ok before the housing leaked. Do some research on Forgen also. Turns out that a generator with a towed prop was more efficient in generating constant juice for topping up a battery bank- when at sea at 6 knots that is. Also when at anchor you don't want too windy a place hence defeating the objective of having one in the first place (at least for a yacht).

:8 :8 :8 :8 :8 :8 :8 :ok:

Captain Stable
30th Jan 2009, 09:08
Many, many years ago I helped build a Savonius wind turbine out of scaffolding, three truck wheel bearings, and a couple of oil drums plit down the middle. 'Twas attached to a pump to raise water from a well. Worked pretty well, too, after a little tweaking.

forget
30th Jan 2009, 09:16
You can get what you need from one of these. For how long, I don't know. :bored:

http://i21.photobucket.com/albums/b270/cumpas/EH3001.jpg

CargoMatatu
30th Jan 2009, 09:55
Forget

"Those" are too bl00dy expensive. Especially in the U of K! :ugh:

kluge
30th Jan 2009, 09:55
philistine

Avitor
30th Jan 2009, 10:02
The enlightened one stated she would like to lose a bit of weight, I gave her an old bike with a dynamo on it...might as well kill two birds with one stone!

Captain Stable
30th Jan 2009, 12:02
"Those" are too bl00dy expensive. Especially in the U of K!I certainly agree with the first part where I am right now, which is the United Kingdom. How does the price compare wherever the "U of K" is?

Dushan
30th Jan 2009, 13:19
Just bored and wanted another project for when I finish present one.


How about a giant conveyor belt instead?

OFSO
30th Jan 2009, 14:08
All together now, repeat after me:

IT IS NOT THE GENERATION OF POWER THAT'S THE PROBLEM, IT'S THE STORAGE !

Solve that one and we'll all be happy ever after.

R

G-CPTN
30th Jan 2009, 15:38
Gas.
Used to work in the 19th Century.

bnt
30th Jan 2009, 16:27
If such a turbine was to be used in a populated area, I'd also be concerned about the possibility that a garage-made turbine would be noisy. Not something the neighbours want to hear, eh?

As for energy storage being the problem... sure, I've been wondering about that too. You may have heard of stored energy schemes, in which water is pumped up to a mountain lake when power costs are low, then the flow is reversed to generate electricity during peak hours. I've been wondering about a domestic version of that, but it would have to be on a farm, not in a built-up area, because of the volume of water involved. You could use a conventional windmill pump to raise the water, storing the energy, but I can see problems getting the energy out of storage in a consistent manner.

Here's a "back of the envelope" example: imagine a huge tank on the ground, next to a well: the tank is 10m x 5m x 2m = 100m≥ of water = 100 metric tonnes or (100x10≥ kg) of water. (It had better be on solid ground!) The well is 10m deep, so say your windmill is raising those 100 tonnes by 10m (on average). The amount of potential energy you've stored is easy to calculate: e = mgh, where m = 100x10≥ kg, g is the gravitational acceleration constant, approx 10 m/s≤ *, and h = 10m.

e = 100x10≥ x 10 x 10 = 10,000,000 Joules = 10 MJ of potential energy in that tank, relative to the bottom of the well.

Now, to get it out... a pipe back down the well, with a generator in the pipe? It had better be a fat pipe, because you'd need a decent flow of water. Say you want to generate 1 kilowatt, to power a computer, TV, maybe a few lights, but no heaters: that's 1000 joules per second, so if you use that equation again, you find that you'll need to shift 10kg of water per second, or 10 litres per second, and that's ignoring any losses in the pipes or the generator.

At that (idealistic) rate, the water in that 100m≥ tank would last you a mere 10,000 seconds, or... 2ĺ hours of continuous 1kW power usage. To run a household, you're going to need a bigger tank - or a good wind all day. :hmm:

If you had a stream running nearby, that would be great, but that's getting away from the "storage" question. You can play with the variables: more height would be a good thing, assuming the windmill could generate that much "head" at a decent flow rate - or if you could take advantage of e.g. a stream. You could use something denser than water, which would let you have a smaller tank and pipes, but that won't get round the energy equation.


(* a typical value for g is 9.81 m/s≤, but the exact value is different in different places in the world.)

helimutt
30th Jan 2009, 17:18
I thought the idea was that if you generated enough power for your own needs and then some, this would go back into the grid, and you'd get maoney back?

If I erect a smallish (couple feet dia) turbine in my garden, do I just plug it into the mains socket or do I stick some wire into the consumer unit? All sounds a bit complicated to me, especially with this aspect ration thingy and also the problem of gearing to think about. No wonder B&Q were charging about 3k for theirs!


Oh well, just gonna stick to the good old U of K electrickery through the plug socket affair for now!

west lakes
30th Jan 2009, 17:38
If I erect a smallish (couple feet dia) turbine in my garden, do I just plug it into the mains socket or do I stick some wire into the consumer unit? All sounds a bit complicated to me, especially with this aspect ration thingy and also the problem of gearing to think about. No wonder B&Q were charging about 3k for theirs!

Some installations need an additional electricity meter to measure the power exported (leccy meters can't run backwards)

Lon More
30th Jan 2009, 18:02
That's the wind power thing sorted out then:)


Now, how can i build a nuclear power station at the bottom of the garden? (Bogger the fairies!!)

G-CPTN
30th Jan 2009, 18:12
Many years ago (30+) I bought a house next to a stream. I wanted to install an electricity generator using the water-flow. I visited this place:- Centre for Alternative Technology (http://www.cat.org.uk/information/aboutcatx.tmpl?init=4&subdir=information) - where my hopes were dashed (insufficient head).
I see that they are 'still going' - so they may be able to provide the information that you require.
The installation of a wind turbine usually requires permission from the local planning authority. It is also sensible to consider your neighbours, as a properly mounted turbine is likely to be very visible. Neighbours will generally be more supportive if they are consulted before an application goes in.

Can I put a wind turbine on my roof?
We would not recommend a rooftop or a building as a suitable mounting point. A turbine operating in high winds will create lots of force. This could produce resonance within the structure and may damage the building as well as being a nuisance.
Most houses are in relatively sheltered areas, and won't get winds anywhere near the UK average of 6 metres per second (m/s). On most rooftops, the average wind speed is more likely to be 3 or 4 m/s. As many turbines do not generate power at lower speeds than this, they�d sit idle much of the time.
Finally, a turbine mounted close to a roof will be operating in very turbulent winds. This means that when it is windy, the machine is likely to spend a lot of time turning round and round to find the wind, rather than actually generating any electricity. This will also wear the machine out very quickly.

What will it cost?
The smallest kind of wind turbines, costing a few hundred pounds, are not big enough for most homes - they are designed to charge up a 12 volt battery in a boat or caravan. These small machines are a little bigger than a satellite dish, measuring between half a metre and one metre across. To generate enough to make a decent contribution to household energy use, a much larger turbine is needed, with a rotor 2 or 3 metres across.
The prices quoted for some new turbines look very attractive - much less than models already on the market. However, the cheapest can only be mounted on a roof, and as mentioned before, this would be a very poor site. Low price installations also don't include equipment for selling electricity though the grid. For a decent installation, including a tower, current installation costs are in the region of £5,000 - £10,000. The Low Carbon Buildings scheme (see below) offers grants that will cover 20% to 30% of this cost.
More at:- CAT Information Service (http://www.cat.org.uk/information/catinfo.tmpl?command=search&db=catinfo.db&eqSKUdatarq=InfoSheet_DomesticWind)

OFSO
30th Jan 2009, 18:24
Lon More writes: Now, how can i build a nuclear power station at the bottom of the garden? (Bogger the fairies!!)

Actually it's not that difficult. All deep-space spacecraft, which are too far from our sun to use solar power, have small nuclear generators on board. Another engineer friend and myself worked out the details of a simple home device last year. The "only" problems we could see were:

(a) where do you dump the unwanted energy when you don't want it, as a simple one running at constant output would be non-throttleable. Cooling tower in the back yard anyone ?

(b) shielding (not insurmountable, but...)

(c) authorisation. In a society which doesn't allow the game of conkers on "health and safety" reasons, can you imagine your local council's response to a request to have a nuclear generator in your cellar ?

(d) eventual disposal at end-of-life. Oh right, in the wheelie bin, alternate Thursdays, no not THAT bin, the organic waste bin, 18" from the gate and not over 20Kg, or else....

But given enough space and no interfering local officals, the mechanics of the thing are simple enough. Buy the fuel from your local Russian ex-submariner, melt botles for encapsulating glass, lead shielding from the covers on wine bottle tops, and you are away....

R

jimgriff
30th Jan 2009, 20:41
Since April last year you no longer need planning permission to erect a wind turbine for personal use on your property!:ok:

BAMRA wake up
30th Jan 2009, 21:45
Only reason to build a small one is probably fun because the economic benefits are miniscule. Grid connection and sale of electricity is a serious business and will set you back thousands - not a diy project - though the rewards can be high if you're in a location with a reasonable mean annual wind speed. 6kW minimum rated machine required, more in a low wind location. Alternatively a smaller investment in draughtproofing, insulation and say an air source heat pump could make substantial savings on electricity bills.

rans6andrew
30th Jan 2009, 22:45
thirty something years ago I worked in a battery test laboratory. Some of the cells we tested were in the 1000 amp hour capacity range. We used some clever battery chargers to charge the cells, either singly or several in series, and the same units could be used for discharging the cells. The discharge energy was put back into the mains electricity supply to the lab. Little heat was generated by the units and they didn't cost an arm and a leg to buy. The units were a little big for a domestic situation but they worked very well. A quick look inside one showed that there was a small circuit board on the back of the front panel and a bridge of thyristors on a heatsink at the back of the case and .......well nothing else really.

I can't remember who made the charger/discharger units but I suspect that a trawl of the www might come up with a circuit diagram of something similar that could be knocked up for a few 10s of pounds.

Even if you don't actually put electricity into the grid you ought to be able to reduce the measured amount that you take from your electricity supplier.

Andrew.

charliegolf
30th Jan 2009, 23:39
There are other reasons for generating small amounts of leccy. I have gas central heating in a semi rural area, where power cuts are not uncommon.

Power off and i have no heating due to not having a pump.

It would be useful to trickle charge a battery fulltime, so that in the event of a cut, I could run the pump via an inverter. I have a stream nearby, and harbour thoughts of a simple water generator.

A retirement project perhaps?

CG

G-CPTN
30th Jan 2009, 23:49
Power off and i have no heating due to not having a pump.Something that I found out in the 1970s - no electrics, no ignition (due to 'safety' circuitry). :ugh:
It would be useful to trickle charge a battery fulltime, so that in the event of a cut, I could run the pump via an inverter.
Probably cheaper to buy a small (secondhand?) petrol generator.

ShyTorque
30th Jan 2009, 23:58
Probably cheaper to buy a small (secondhand?) petrol generator.

But if the power cut is widespread (like ours a few years ago) the filling stations can't pump petrol.... :p

Storage
What is the limit of the amount of petrol I can store for domestic use?
The Petroleum Spirit (Motor Vehicles etc.) Regulations 1929 and the Petroleum Spirit (Plastic Containers) Regulations 1982 limit the amount of petrol that can be kept in a domestic garage or within six metres of a building (e.g. most domestic driveways). The limit is a maximum of two suitable metal containers each of a maximum capacity of ten litres or two plastic containers (which have to be of an approved design) each of a maximum capacity of five litres. These limits also apply to any containers kept in a vehicle parked in the garage or on the driveway (but not to the internal fuel tank of the vehicle). Under no circumstances should the petrol containers be stored in the home itself.

TURIN
30th Jan 2009, 23:59
Now, how can i build a nuclear power station at the bottom of the garden?

It's been done.

A schoolboy in the states made a working reactor in his dad's shed.

He got the fuel from old clocks and watches. You know the glow-in-the-dark bits off the face. :eek:

Here it be...David Hahn (http://www.guardian.co.uk/life/opinion/story/0,12981,1261144,00.html)

CrimsonEclipse
31st Jan 2009, 00:12
Welcome to OTHERPOWER.COM (http://www.otherpower.com)

Lotsa info.

CE

CrimsonEclipse
31st Jan 2009, 00:14
Homebrew Wind Turbine Evolution (http://www.otherpower.com/learningcurve.html)

I like the evolution of this guy's projects.

(Don't know why my first post vanished)

CE

barit1
31st Jan 2009, 03:23
Probably cheaper to buy a small (secondhand?) petrol generator.

But if the power cut is widespread (like ours a few years ago) the filling stations can't pump petrol....

Some alternatives are:

If a natural gas furnace, then a natural gas-fueled engine/genny. (or propane for both...)

or if oil-fired furnace, a diesel (runs using the furnace fuel oil).

:ok:

arcniz
31st Jan 2009, 05:36
A schoolboy in the states made a working reactor in his dad's shed.


Nobody here who were a damn fool in youth, of course. Not hardly.

He seemed to have the main concept fairly solid, but was oblivious to the nuances - as is typical with some (99.875%) teenage males. Had had the rudimentary rad bits right but no clue about instrumentation and not much about shielding, so, era un huomo tostada.

Reason they wouldn't let him on the Nuclear Subs is probably that they surmise he already has had such a dose of radiation exposure that he will eventually be a notable statistic... with discernable evidence of rad sickness... and thus not desirable on the escutcheon of the GloSubCorps. Of course, also, he might live to be 120 years old as a byproduct.... bad for the retirement fund calculations. No way, Jose.

Lon More
31st Jan 2009, 11:19
Re David Hahn, who obviously hasn't learned his lesson, from Wiki:
On August 1, 2007, Hahn was arrested in Clinton Township, Michigan for larceny, in relation to a matter involving several smoke detectors, allegedly removed from the halls of his apartment building. In his mug shot, his face is covered with sores which investigators claim are possibly from exposure to radioactive materials. During a Circuit Court hearing, Hahn pleaded guilty to attempted larceny of a building. The courtís online docket said prosecutors recommended that he be sentenced to time served and enter an inpatient treatment facility. Under terms of the plea, the original charge of larceny of a building would be dismissed at sentencing, scheduled for Oct. 4. He was sentenced to 90 days in jail for attempted larceny. Court records state that his sentence will be delayed by six months while Hahn undergoes treatment for radiation exposure.

A television documentary, The Nuclear Boyscout, aired on Channel 4 in the United Kingdom in 2003. In it, Hahn reenacted some of his methods for the camera. Though slated to air on the Discovery Channel, the program has not yet been broadcast in the United States.