[diarmaid]

Hi folks,

Building my own wind turbine has been on my list of 'to do' things for a longggg time now. And it probably will remain on the list for a long time!

But, Im wondering has anyone here built or bought their own turbine, and I thought that if I could drum up some interest I might get some useful info for when I eventually get around to doing one myself. I figure in my own case I'll stay off the grid, and use a battery system, since in Ireland at the moment there's no payment scheme for producing excess, and no tax breaks.

I can run wires from the battery system into my workshop (Which isn't built yet..next year) and into the new house (Which isn't bought yet...next year) . And I'll have seperate plug sockets powered from my batteries. I figure I'll always plug the tools and some household appliances into the battery powered wall sockets until they run down, then plug into the regular sockets. Cnc machinery and computers obviously will nearly always be connected to the regular mains in case the batteries drain. I figure I'll use 20 12V lead acid batteries to generate 220V then step down to the workshop for 110V and run direct to the house (After DC/AC conversion) for the household 220V.

There's lots of info on the net but I have a few electronics questions.

1) Is it possible to get a 110VDC to 220VAC inverter capable of handling a max load of about 4KW? I haven't seen any on the net but I think it might be cheaper to just buy 10 (Instead of 20) lead acid batteries for 110V and step up for the house since the extra 10 btys are a lot of extra expense. A lot of off the shelf systems I have seen seem to output 24V using two lead acid btys. I can't see how 24V is useful for anything? I have a 24V DC to 240V AC inverter I got for a previous project (About €90 I think), but nothing like the wattage capacity needed for this.

2) I understand that I need some sort of battery voltage regulator so that when the batteries are fully charged any power coming from the turbine can be diverted, so as to avoid causing excess hydrogen from the bty's, and possibly an explosion . How does this work and where is the turbine power diverted to (Ground possibly...)?

3) If I could get a 24VDC to 220VAC inverter would that be a good way to go with only 2 bty's, or is there any reason I should have 10 bty's giving 120VDC and use an inverter to get 220VAC? (More reserve capacity for those days with no wind possibly...)

Thats it for now.
Thanks all.

[Al_The_Man]

They have recently installed some windfarms close to where I am and the govt have published some details on individual stations, I haven't read it but you may get something from it, The full size windfarm units are HUGE.
http://www.smallwindenergy.ca/en/SmallWind.html
Al.

[diarmaid]

Thanks Al. The more info the merrier. Im sure someone out of the zone's 40,000 members have had experience with this type of thing before. With all those workshops, the savings from having your own electricity generation are huge! Do you have any suggestions on questions 2 & 3 above?

[ViperTX]

Also check MrBean's posting here.....he has a thread about doing a wind device..

[diarmaid]

Thanks Viper. But I can't find any of his posts. Do you have a link?

[HayTay]

Thanks Viper. But I can't find any of his posts. Do you have a link?

Here ya go diarmaid,

CNC made wind turbine by MrBean

[rippersoft]

I have been building savinous type vertical axis wind turbines (VAWT) and find it to be very interesting to see how the wind and the rotor react. This kind of hobby does take some engineering to get some good results.

There are many sites with info on how to design and build. Some of the parts can be cut with CNC, some have to be done by hand.

I am working on my third design and hope to have this one turning a generator.

Rippersoftware

[Geof]

Here you are a source of information right next door.

http://www.bwea.com/index.html

[epineh]

Thanks Al. The more info the merrier. Im sure someone out of the zone's 40,000 members have had experience with this type of thing before. With all those workshops, the savings from having your own electricity generation are huge! Do you have any suggestions on questions 2 & 3 above?

Re. Question 2, once the batteries are charged, the charger won't (or at least shouldn't) draw any more power, the old comparison between electricity and water is a good one, think of it as turning off a tap, sure the water stops flowing and will still come back if you need it by turning back on the tap. If there is no current drawn by your battery charger, the turbine simply doesn't generate any current, it will have potential (voltage) but no current, it doesn't go anywhere it just isn't used. You could feed back into the grid but that is a whole other bag of fun.

Question 3, the lower your primary voltage on an inverter (stepping up in voltage) will mean a higher current draw. If you have a battery voltage similiar to what you are "creating" with you inverter, the batteries will "see" a similiar current. Halve the battery voltage you double the battery current for the same secondary current and so on. There are other factors involved but this is generally the concept.

Power is given as P=VI where P is power, V is voltage, I is current, so you can see for the same power consumption, if you change the voltage you can calculate what the current will be.

I'm keeping things simple here, there are other factors that influence all of this in an AC system like load types - resistive, inductive and capacitive that will affect current draw by changing the load's power factor, which will affect the equation, but that is a whole other story.

One word of warning though, if you decide to link a heap of batteries together to reduce battery current, take EXTREME care in your connections and layout, I would suggest installing fuses on the battery "string" output, and a couple of removable links in series with the batteries every 4 or so batteries to cut supply to work on or replace batteries. There is no other way of turning off a battery bank, and fault current conditions are just as nasty if not worse than grid powered cabling.

I have heard some real horror stories with DC supplies if you want to hear one, suffice to say they can bite so a little safety goes a long way.

Good luck if you go ahead with it, I would like to be self sufficient power wise myself but cannot work out a decent way (yet) to do so that doesn't involve the use of large batteries.

Russell.

[greybeard]

Hi Diarmaid.
I've also got the wind turbine project hovering on the to do list, and with the season cooling down, it's rising up the list fast !
Our take on using the power is not to go for batteries, but to use the current to heat soil directly with soil cable under the greenhouse. This means I don't have to worry too much about varying voltage/current.
If my prototype setup works, the next step is to build a bigger one as a water heater for the house, either for space heating or pre heating the hot tank.
Then on to making the solar powered unit in the spring....................

John

[rippersoft]

Here is a list of sites that cover a broad range of the subject:

Chargers
http://www.cirkits.com/scc3/
http://www.interlog.com/~dgv/solar_prods.html
http://www.fieldlines.com/story/2004/9/20/0406/27488
http://www.nwpwr.com/products/Charge...tracecontr.htm
http://www.hydrogenappliances.com/batteryregulator.html
http://www.thebackshed.com/Windmill/charger1.asp

Inverters
http://www.dcacpowerinverters.com/24...inverters.html
http://www.dcacpowerinverters.com/12...inverters.html
http://www.technology.niagarac.on.ca...mcsele/i2k.htm
http://www.edn.com/article/CA46937.h...sc=designideas
http://www.edn.com/article/CA46937.h...esignideas#ref
http://www.aaroncake.net/circuits/inverter.htm
http://theepicenter.com/tow02077.html
http://members.shaw.ca/roma/thirteen.html
http://sound.westhost.com/project22.htm
http://www.harborfreight.com/cpi/cta...emnumber=92464

Parts, etc.
http://www.1stconnect.com/anozira/Si...alternator.htm
http://www.batteryspace.com/index.as...OD&ProdID=1634
http://www.magnetsrc.com/neo_magnet_NdFeB_magnet.htm
http://www.zena.net/
http://www.rare-earth-magnets.com/
http://www.survivalunlimited.com/win...tionroller.htm
http://www.sma-america.com/index.aspx
http://www.magnet4less.com/
http://www.magnet4less.com/NB004.html
http://www.tlgwindpower.com/
http://www.watchtv.net/~rburmeister/products.html
http://www.scoraigwind.com/books/marty.htm
http://www.northerntool.com/webapp/w...6024_200256024
http://www.aagelectronica.com/aag/in...tml&lang=en-us
http://www.hydrogenappliances.com/

Lightning protection
http://store.solar-electric.com/deldcphotsur.html
http://store.altenergystore.com/Fuse...Arrestor/p473/
http://www.nwpwr.com/products/electr...protection.htm
http://www.solarray.com/TechGuides/L...otection_T.php
http://www.wind-sun.com/Systems/Ligh...Protection.htm

The rest
http://www.dplusv.com/Photo-03.html
http://users.erols.com/mshaver/bikegen.htm
http://www.fuellessflight.com/windturbine.htm
http://www.windstuffnow.com/main/darrieus_type.htm
http://www.los-gatos.ca.us/davidbu/pedgen.html
http://www.thebackshed.com/Windmill/.../MattLyons.asp
http://www.thebackshed.com/Windmill/AssemblyA.asp
http://www.thebackshed.com/Windmill/default.asp
http://www.fraw.org.uk/cltc/tech2/turbine_erect.html
http://www.ette.no/index.html
http://www.greenwindmill.com/
http://www.homepower.com/
http://www.raphnet.net/divers/anemom...mometer_en.php
http://www.scoraigwind.com/books/index.htm
http://www.otherpower.com/anemometer.html
http://www.nrel.gov/homer/
http://www.tewari.org/
http://www.aerodesign.de/peter/2001/...index_eng.html
http://www.ata.org.au/articles/70byosav.htm
http://www.angelfire.com/ak5/energy21/microsavonius.htm
http://www.homemade-wind-turbines.co.uk/
http://forcefieldmagnets.com/catalog/
http://www.randysworkshop.com/
http://www.watchtv.net/~rburmeister/ametek.html
http://www.re-energy.ca/t-i_windbuild-1.shtml
http://www.southcom.com.au/~windmill/
http://www.aerodesign.de/peter/2001/...1_2001_eng.htm
http://www.naturalhealthwizards.com/windpower/
http://depalma.pair.com/index.html
http://www.msinter.net/tradingcave/w...ckingdiode.htm
http://www.aerodesign.de/peter/2001/...4-2000_eng.htm
http://www.totse.com/en/fringe/tesla/index.html
http://www.soe-townsville.org/strandwindproject/
http://www.morningstarcorp.com/produ...ar/index.shtml
http://club.cycom.co.uk/vertAxis.html
http://www.njqrp.org/digitalhomebrewing/pic-wx/
http://www.blueenergy.org/MultiMedia...acturing1.html
http://www.mag-wind.com/index.php
http://www.solwind.co.nz/vertical.html
http://www.infidigm.net/projects/windmeter/
http://www.windside.com/products.html
http://ivan.benkovic.szm.sk/wtfromfan.htm
http://www.web-ee.com/Schematics/Wir...essWeather.htm

Good hunting.

RipperSoftware

[diarmaid]

Thanks for all the replies and interest folks.
I have visited that other cnczone thread and read it all. Quite interesting but no links for the various material sources and Terry's site is gone. I think I'd prefer to buy a 48V Permanent Magnet Generator off the shelf than build my own. Maybe build my own at a leter date as a project, but the electronics is my most difficult part.

Under soil heating for a greenhouse, never heard of that before! Sounds interesting. How is 'soil cable' different to normal cable. Never heard of it either?

Thanks for answering my questions epineh, I hadn't thought about having disconnects in series but definately a must do with any system above 12V. Are there any specific reasons why you don't want to go with bty's apart from what you have already alluded to? Although I dont really have a choice, its always good to know the 'cons' of a system aswell.

Thanks for that list ripper, its gonna take me a while to get through it all! I would be hoping to build about a 3 or 4 KW per year system. Not sure how viable this is, but since avg Irish household use is 5 to 7 KW useage, and I want to have a full time business running from my workshop, it'd make a huge dent in the electricity bill. Irish electricity prices have gone up over 90% in the past 5 yrs, in an misguided attempt to entice private competition into the market but thats a different thread!

That first inverter link was just what I was looking for, 24VDC to 110VAC 7000W peak! Already further along. But then I have to step up again to 220V for the house.....Although even if I could provide power to the workshop it'd make a huge differance. I saw a post before on the zone where someone had bought a plasma cutter and was asking if it was normal for his electricity meter to be spinning rapidly when using it!!

[diarmaid]

I don't understand why I would need a 'charger', or am I mixing it up with a 'charge controller'. Can the Permanent Magnet Generator (PMG) outputs from the turbine be connected directly to the bty terminals for charging?

[greybeard]

Soil heating cable - same principle as resistive heating - think electric blankets. Here's some on ebay - item 140052875190.
John

[Geof]

......I would be hoping to build about a 3 or 4 KW per year system. Not sure how viable this is, but since avg Irish household use is 5 to 7 KW useage, and I want to have a full time business running from my workshop, it'd make a huge dent in the electricity bill...

The excerpt below was stolen from here:

http://www.bwea.com/you/byo.html

Wind energy on a large scale is now competitive with other sources of electricity on the national grid. However, small domestic-sized wind turbines have not yet reached this point. The wind is free, but small wind turbines are expensive in relation to what they produce, and cannot realistically compete with mains electricity. Building your own machine saves some of the cost, but please do not underestimate the difficulty of the task. If it were easy to save money by using small wind turbines, then they would be a major feature of the landscape by now.

Is my site windy enough?
Most people think they live in a windy place, but in fact most residential locations are not suitable for windpower. Trees and buildings break the force of the wind, and create turbulent gusts which can be very destructive. Open hilltop sites or coastal situations with unobstructed views may be suitable for siting a wind turbine. A very tall tower is helpful, but these are frowned on in the UK. Do not forget the effect your wind turbine may have on neighbours, who may not share your enthusiasm!

What size of wind turbine do I need?
Wind turbines work with thin air, so they need to be large in relation to the power they produce. To power a modern home on a good site, the blades would need to span about 5 metres from tip to tip. This is known as the rotor diameter. With careful conservation of energy a smaller machine may suffice. A rotor diameter of 2 metres might yield about 500 kWh of electricity per year, compared with an average annual household consumption of roughly 4,500 kWh.

What sort of generator should I use?
Most small wind turbines are used for charging batteries, to provide a reliable stand-alone power source where grid power is not available. The obvious choice of generator for self-build is the car alternator. However this has major drawbacks. It must be driven at a high shaft speed (over 2000 rpm) to give full output, so you will need to gear it up or modify it in some way to drive it with rotor blades, which typically only manage a few hundred rpm. This reduces the efficiency. In low windspeeds there is very little power available in the wind, and you need a highly efficient generator to capture it. Most, if not all of the power in light winds will be used up energising the magnetic field in the alternator, so the results are disappointing. Nearly all small commercial wind turbines use purpose-built permanent magnet generators for this reason. The DIY enthusiast can make one too, but this is not simple to do. Or you can reuse a permanent magnet motor as a generator. The generator is the key to success or failure of the project, and by far the hardest part to get right.

[diarmaid]

Thanks Geof. I read that before. Im going to be out in the middle of nowhere, so once theres enough wind Im hoping to put up one with a rotor diameter of about 3 to 4 metres, and a height of about 15 to 25 metres. I'll either do it on the quiet if there are no nearby neighbours, and apply for retention if the s#$t hits the fan (So to speak! ), or otherwise apply for planning permission at the start. Failing that I'll go with a smaller one and less power generation, or maybe two smaller ones to bump back up the overall power a bit, but thats plan B. As mentioned above I'll probably buy a PMG since it is such an essential part of the system. I figure income will be tight enough starting my business, so if I can get one of these up before I quit my current job it'd be a big help. Thanks for the input m8.

[rippersoft]

I don't understand why I would need a 'charger', or am I mixing it up with a 'charge controller'. Can the Permanent Magnet Generator (PMG) outputs from the turbine be connected directly to the bty terminals for charging?

These are charge controllers. I probably should have stated Charge Controller instead of Charger on the list. Sorry.

[ViperTX]

diarmaid.....well....think of it as a voltage regulator....similar to a car's...you need to sense the state of charge of the batteries...otherwise if they are lead-acid....you'll boil away the electrolyte.

So, your next obstacle is power conversion....getting the 48VDC to 120 VAC or using the 48 VDC to only power certain objects....you could use the 48VDC to spin a motor which in turn spins a AC generator....that is probably the easiest.

[diarmaid]

Thanks all. I figure I'd get a DC/AC inverter for the conversion. Costs a bit but at least it'd be simple. Plug in, plug out!
The PMG I thought I would buy is actually a PMA so I suppose I have to rectify it before going to the bty's, but that shouldn't' be a problem.
As I mentioned, this is a way off.

[jhowelb]

Back in the 80's I worked in a machine shop where we produced wind machines. Ours used line voltage fed into a three phase motor. When the wind drove the motor "over speed" the motor would then produce more power that it consumed. Quite simple, actually!
The problem, as it later came to light, wasn't in generating power! It was in slowing and stopping the machine in high wind conditions.
These contraptions would literally beat themselves to death!!! We used air brakes from semi trailer wheels and they would over heat and fail big time. Terrifying watch one come unstrung, so much power out of control!! Maybe if we had used disc brakes??!! I don't know!
My bottom line is to advise you that like a fast car needs to stop fast and positive, the same applies to a wind machine. Put MORE thought into shutdown than into production. Your life may depend on it!
John