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#146100 - 10/14/06 07:24 PM domestic solar/wind installation
aussie240 Offline

Registered: 07/06/05
Posts: 221
Loc: Blue Mountains, NSW, Australia
About a year ago I decided to finally set up a 12v solar and wind powered home lighting plant. Apart from the degree of self sufficiency it could provide, there was also the issue of sometimes frequent power failures. This is one of those projects I'd been wanting to do for years, but now it is at last operational though not completely finished. So, now I'll explain the design:

Here is were most of the power comes from; an array of three 40W panels. I have another two 60W panels but haven't got around to welding up the frame for them yet, and as it happens I haven't really needed to.
Next is the wind generator:

It's an Air X Marine that supposedly can put out 400W. This has only been in operation for just over a month now and is only a temporary set up as I'm learning about its performance, and the best location for it. It turns out performance isn't what I expected. First thing is it needs proper wind to start generating. Just a breeze won't do. With all the surrounding objects, the wind is turbulent when it does blow so actual useful output is very intermittent. There is no way the wind generator could keep the batteries charged on its own.
Here's the first switchboard where the solar panels and batteries connect:

The solar panels are fed into a homemade regulator that simply disconnects the panels when the batteries reach about 14V. Also on this panel is a homemade 300W auto start inverter that feeds a GPO in the house for use during power failures. The two circuit breakers feed the light and power circuits in the garage. Both are fed with 4mm TPS. The AVO meter is temporary for the wind generator until I make up a proper meter for it.
The batteries are old and dying. I've had them for a long time and they were already second hand then. There's four 6V 90A lead acid batteries making up a 12V 180Ah bank.
From the garage where the batteries are, to the house is a 8m run of paralleled 16mm cable.
Under the house is this switchboard:

Coming up from the bottom you can see the 16mm supply. At the left is the 240V feed from the 300W inverter. To the right is the two 15A breakers for the house light and power. The light circuit has a 4mm feed up into the roof where it's distributed ring main style to the lights:

These are 12V 50W bulbs in porcelain pull chain switch sockets.
At the top of the under house switch board you can see the power feed with 16mm wire; and you can also see the start and end of the ring main. Tap offs to the wall sockets are done thus:

It wouldn't comply if it was 240V, but with ELV more things are permissable. 2.5mm TPS is simply spliced into the 16mm feed. I felt that soldered connections would have less voltage drop than screwed ones, and besides it's cheaper. And, finally here's an outlet:

There's a pair of 402/32 sockets on a period looking repro mounting block. To the right is an existing 240V GPO...actually the original one for the house.

[This message has been edited by aussie240 (edited 10-14-2006).]

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#146101 - 10/15/06 07:44 AM Re: domestic solar/wind installation

Registered: 12/08/05
Posts: 862
Loc: Titirangi, Akld, New Zealand
Cool !!

Great to share your set up with us, a lot of experiments are needed to get maximum advantage of the wind and how to get best yield from the alternator even during periods of light wind.
Sometimes by reducing the exitation to the alternator to a lower level may still provide some charging current although at a lot lower amperage, but perhaps enough to top up the batteries.

There should be enough sunshine in Australia to cover the windless days.
The product of rotation, excitation and flux produces electricty.

#146102 - 10/17/06 06:10 PM Re: domestic solar/wind installation
aussie240 Offline

Registered: 07/06/05
Posts: 221
Loc: Blue Mountains, NSW, Australia
There's certainly enough sunshine where I live not to require the wind generator. I just happened to already have it before I built the system up. Certainly, for my area, the money would be better put into more solar panels if I was to do it all again.
I will say on the subject of cloudy days and solar panels, the charge current is dramatically reduced; say to about 20% of what is in full sunlight. So a rough rule of thumb for places where cloudy days are the norm, you'd need five times as many panels.
As it usually happens, power failures here tend to occur on windy nights, so there's no regrets installing the Air X. I have to say that it's performance has improved somewhat since I installed it. The manufacturers claim the bearing needs to wear in and that it my appear sluggish at first. Looks like they're right.
There's a lot of info on the Air X on the internet if anyone's interested, but briefly it uses a permanent magnet alternator. Regulation is acheived by simply shorting out the alternator when the battery reached 14.1V. The same technique is used to stall the generator in excessive wind speed.
When this happens the turbine slows down to a few RPM. Given my batteries have a high internal resistance it's possible the generator is shutting down prematurely. This theory is supported by the fact that it the blades rotate more often when I'm drawing current.
Next step is to replace the batteries and see how it goes before I go setting anything in concrete, literally.
At present I've just got the mast G clamped to the back of the house for testing and a plie of bricks to stabilise the bottom of it.
It could well be that other heights and locations within my backyard are better and this is what I have to find out.
Fortunately, there isn't much of a noise issue. At full revs, it sounds like a line trimmer with no motor. Much of that is masked by the wind blowing through the trees anyway.


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