Solar Lighting

Casa2 · May 30, 2007 10:58 pm

Yak Chat,

Your wind generators that produce 9/17 kWhr per day are great. They would provide the entire average energy need for a household.

How big are they? And ho high up do they need to be mounted?

As an aside, later down the track, I'd like to add a "tunnel" alone a 14 m roof section with a wind generator in it. The blades would have to be about 1.5 m diameter, but there would be a good pressure differential to drive them. This is way down the track and just a thought for now. Happy if I can get 4 kWhr per day out of it.

Cheers,
Casa

Yak_Chat · May 31, 2007 10:02 am

Hi Casa, Generators are 1.5 and 2m diameter respectivly.

Height needs to be where it can catch the breeze and most docs state 10 metres is ideal, but I live on the side of hill that got close to 90km winds on Tuesday and I'm close tot he sea, and most nights I get a breeze that at tiems will shake the house, so I reckon I can get away with mounting it lower than 10 metres.

See the BOM data and you wil see where they measure the breeeze. at 3 metres you get ground effect which is not ideal in suburban environment.

Re the tunnell, that'd be pretty directional - Do you think that will work - ie are your breezes constant in direction?

Check the WIND ROSE for your area on the BOM site, and you'll see what your prevalining breeze is am and pm for each month. They are in that climate area once you click the wind stats for a month in a graph.

Steve

DeKa · May 31, 2007 1:24 pm

NeilD

devank

They come on as it gets dark and fade away after about 5 hours. By the next night they are charged again.

And this is the problem with solar lights - they aren't on when you might need them (at this time of year they'll probably be off by 9.30 or 10pm.

I still recommend 12v or 24v low voltage lighting (as long as it's done correctly with a heavy duty trunk cable) as the most effective way of running a lighting system up a driveway our other outdoor situations.

Casa2 · May 31, 2007 7:06 pm

Yak Chat,

Thanks for the reply. 1.5 m diameter is nice and compact.

I've got many low energy heating and cooling aspects pretty well worked out as they will be on the house when it is build. This includes an array of solar panels on a 2.4 m x 8.5 m roof. Should be able to get 2 to 3 kW peak, which should just about make us electric energy neutral.

I'm trying to allow in the construction for a possible wind generator. As mentioned, rather than using a pole, blades and generator would be housed in the roof. A 14 m long tunnel would funnel any wind energy in past the generator.

Keeping in mind it's early days and all I'm doing is making sure the roof space can accommodate the possible future concept I have some ideas. Firstly, it doesn't matter if the wind is driving at an angle to the tunnel, all that would mean is that it's effective length would be reduced - by the sine of the wind's direction would be my first order approximation. Therefore if the wind was at 45 degrees to the axis of the tunnel, the effective length would be about 10 m. Still a good length.

I can let you know how my low energy heating and cooling goes in about 2 years, but the wind-turbine-in-roof-tunnel will have to wait for several years beyond this. But I like the idea!

Cheers,
Casa