Thread: Discuss - Going off grid

Originally Posted by Malibu

Bob, have you thought about a wind turbine?

I have a bank of 16 PV panels on the roof at the moment and for the most part, they're OK and generate up to 20+kw per day in summer. During winter, it can be down to 1 or 2 kw per day, depending on the local weather of course.
Being in Melbourne, my weather situation is different to yours, but no matter where you live, the panels don't work at night (naturally enough! )

My system has dropped my electricity costs from around $600 to $800 for the summer period, to my last bill of $180, which I'm pretty happy about - but that's with a FIT of $0.66/Kwh, which I doubt will ever come around again.
In the mathematically broader view of things, I get about 6 hours of power generation per day from my solar system (3kw panels and a 4kw inverter)
The good lady Boss and I have just bought a block of land and will build & move in the next couple of years. The current stage we're at is tossing plans around, but I'm also thinking of the house energy ratings, etc for future building permits and the like... One of the things I need to think about is PV panels, but being a bush block, I'm going to have trouble with shade, orientation and so forth, so I don't think PV's are the way to go in my situation.

I'm now looking at a wind turbine, which, as far as my early research reveals, is basically the same 'type' of installation as PV's (ie: a generator and an inverter)
The real advantage is that the wind blows most of the time, so, cloudy days, night time, stormy weather and shady areas will still produce your power.
By my initial maths, I would only need a 1.5kw turbine with the wind blowing 12 hours a day for a similar output power to my current PV system. Of course, if it blows 24 hours I would double that figure.
That's gotta be good in the long run!

It would probably be ideal for an off grid system too. Charge the batteries overnight and use the stored power the following day... Of course, the batteries will still be charging during the day too, depending on how much juice was left from what you're using at the time.
As far as comparable costs, I think that turbines are a cheaper option and won't change their electrical parameters (much) over the years. The PV panels will lose efficiency as time goes on.

Just my rambling thoughts at the moment because I need to keep ideas running around my little brain for house designs, but I thought it might be helpful to your situation.

Sounds great in theory, but having had some experience make sure you check your local wind speeds and what wind speed you actually need to get the rated power out of one. Just coz it is spinning doesn't mean it is making much power. Also, depends on what obstacles you have around you. If you have any other structures, trees etc within about 100-150 metres you will get TURBULENCE unless you have it on a mighty high tower, and it will be as good as useless.

Originally Posted by Stustoys

Hey I'm wrong all the time.
Stuart

You would be married then....

I have been told that even if you get a decent inverter and panels you also have to look at the quality of the rails that mount them and maybe the quality of the installation ?

Is there somewhere I can find reliable information on suppliers/installers in Brisbane and NSW ?

One thing to think about if you want to go off grid is that storage does not just need to be for using power generated during the day overnight. A cloudy or overcast day can also seriously reduce the output from a system. We recently in Brisbane have had several periods of time where we got very little for a week or so. If you want to be truly off grid, you probably need to factor in enough storage to get you by for at least a week with little generation at all.

Hi Peter
Yes, that is one of the points that make it seem to be a very costly exercise. What we need is a way to store power in a fashion that is retrievable as electricity and that doesn't cost much at all.

I have seen people living beside running water using water wheels for generation. That would be pretty cool because I imagine it would be a lot more reliable. One thing that I have seen proposed (not sure but it may even be possible now) is using an electric or hybrid car for storage - the idea being that you could have the car plugged in during the day and charge it using solar power, and it could then discharge into the house at night. Problem with this scheme is that it ignored the idea that you might just want some change in your car to be able to transport things, and the most likely time the car will be away from home is during the day.