Backyard Aquaponics
A place to discuss aquaponics

I was thinking about connecting a small wind turbine on my shed roof to put some free power into my aquaponics system.

I have a little 2 stroke generator that puts out 12v DC and 240v AC, and was wondering if it ran a car alternator inside, or if it was a generator. (I think that's what I mean) as I understand it, an alternator isn't suitable for wind power because of the high revs it needs before it makes a magnetic field, but a generator is more suitable for low revs power generation.

I was thinking about just pulling the petrol engine bits off and also removing any 240v bits to make it a bit safer for me to play with, and seeing if there is some nice shaft in there that I can directly connect a turbine to.

Has anyone pulled one apart?

Mine is labelled "G-Force", and from memory output 300w but it doesn't appear to be a real brand. I think it came from bunnings a few years ago. It weighs around 15-20kg, in case that's any way to judge what's inside.

I figure they all work pretty much the same, and I'm guessing it either makes 240v then runs a transformer to 12v or starts with 12v and has a built in rectifier to make 240v. If it starts with 12v, it should be easy to rip out all the petrol bits, and the 240v bit.

Vague notions/derisive laughter all welcome.

Dont waste your time or money. You are much better off putting your effort into mounting a solar panel or 2 in a sunny spot, you will get much more energy from them than you will from wind, unless you live in a particularly windy area. I mean unpleasantly windy to be outside in for a fair proportion of the time, not just a bit breezy every now and then.

The amount of energy in the wind is proprtional to the cube of the wind speed, meaning there is bugger all to be had at wind speeds below 15 or 20km/hr. Also, you need a tower that is well above any nearby trees, buildings etc, as turbulence kills WTGs [1]- mechanically and energy wise. There are good reasons the large commercial WTGs are on such high towers- less turbulence, and the wind speed is generally higher the further above ground you go.

Alternators can be built for any speed- car alternators are just one variety that is designed to operate at many thousands of rpm, because it is powered by a motor doing high speeds. Small permanent magnet alternators, such as found in the cheap Chinese WTG imports, operate at a few hundred rpm.

[1] Wind Turbine Generator - generator as in generates electricity, with an alternator

Here you go Bull. I have posted it a few times http://www.windstuffnow.com/main/vawt.htm even tells you how to build the generator.

Keep your cheap generator as a back up, they are a pain in the ass to fix or modify.

I do have a belt driven DC generator in the garage somewhere (used I think to power dodgem cars) never really found a use for it (voltage increases as rpm's increase), but you never know.

Gunagulla is correct if you are using a 3 blade turbine.
i would use a "turby" style turbine which is designed for highrise buidings, but should do ok at the edge of your garage roof.
I can certainly see what gun is saying, but not everything can be solar panels, there must be generation when there is no sun if you want any sort of versitility.

VAWTS are much less efficient than HAWTs, so you will need one of significant size if you want to produce a decent amount of electricity. PV panels still produce a bit of power in cloudy weather, and will produce more electricity per dollar spent than any WTG by a significant margin in almost every location. For an off-grid system, if you want power when there is no sun, use better/larger capacity batteries.

Yes and no.

It gets down to sophistication, and the ease of build; personalty I think a VAWT is better in some applications.
You have to look at what you want to do with the end result.

Gunagulla is right. Wind power is not (yet) very efficient and hardly worth the trouble. I had a combi wind/water generator on my sailing boat for some years. Made a lot of noise through vibrations and only gave some interesting output at wind forces of 5 Beaufort and above. At speeds above 7 bft it turned from the wind for safety.

Solar panels in combination with a sufficient battery bank is the most viable option for renewable energy at the moment. Just got 42 panels of 320 Wp, going to generate about 60 Kw daily. The Sunny Boy and Sunny Island are on their way here and for batteries I chose Trojan 2V 1110 Ah (24 pcs) giving 48V. It's quiet, reliable and with a 3 to 4 days buffer, enough. For backup we have a 7.5Kw diesel generator.

yes that system by itself is all well and good for someone in the tropics, but down south where winters can get cold and cloud covered for a week or more at a time, cheap homemade wind supplimentation is very, very handy even at low outputs, if made properly can still be quiet and a few stuck on an appropriate roof can help a fair bit.

All that stuff's true, but ... but...

Wind turbines are more fun than solar

PV solar can move too, although maybe not quite so fast as a WTG

http://www.gunagulla.com/organic/images ... 09-6MB.wmv

Nice.

Someone posted a video of a tiny solar tracker with a postage stamp sized solar panel that did all it's tracking with just a couple of capacitors. That moved about the same speed, but in real time.

I need to find that post, and see if there was a circuit diagram that came with it.

Perhaps I'll ditch this generator idea and get back to making my solar stuff work.

I see junk, and I get distracted. Sometimes I walk out of the shed with a dozen different bits of junk that I need to keep close so I'll know where they are when I get around to the project that needs them.

So basically, I move the contents of the shed, arm-full at a time into the house, until the house is full and I start doing stuff in the shed again because there is more space. Then put everything back into the shed again, and repeat.

If you're going back to solar I have just ordered one of these to control my to be back up system http://www.ebay.com.au/itm/310696290937 ... 1438.l2649

I will let you know how it goes on 2 x 170w 36v panels paralleled.

That looks pretty good. I'm very keen to know how it turns out.

I like an ebay listing that just drops a copy of the docs at the bottom of their ad.

That listing says MPPT and PWM. I thought it was one or the other.

Anyway...

I hope you have more fun than me. Mine is still unresolved. Ebay seems to have decided to wait me out after refunding part of my money..

Good luck.

And it has a USB power outlet.

That might come in handy for my epic boating adventure.

I didn't read the specs for it, but for the cost I wouldn't expect too much reliability, or even true MPPT. I'll be interested to see how it performs though.

MPPT chargers use MPPT during the bulk stage and switch to PWM when regulating to a voltage during the Absorb stage charging and then into Float when the battery reaches full charge, when MPPT isnt required to maintain the voltage set point. MPPT can still be employed in Absorb and Float though, if required.