All solar, no wind?

sevenhills

We see really big wind turbines, and solar panels on roof tops, but not many small wind turbines for domestic use.
Why is that? What are the output differences?
I would love one fastened to the end of my outhouse.

Exiled_Tyke

Martyn can provide a better answer than me but in short: size and height of wind turbines makes a massive difference. Wind turbines are just not viable on the tops of homes, in addition to the above there's too much turbulence at 2-3 storey heights. And to get any decent output the vibrations on a home would be too great.

Martyn1981

From what I've learned on the renewables forums ET has nailed it, they just don't perform very well unless you can get them high enough, and also far enough away from downwind obstacles that cause turbulence, such as trees, houses etc. otherwise they'll spend all their time 'hunting' (trying to turn into the wind) rather than sitting there generating. Vibration hadn't really crossed my mind until again reading comments from off-gridders that you really wouldn't want one attached to the structure you live in.

Ideally you need the turbine mounted about 10m high and up to 200m from obstacles in the direction the wind normally comes from.

It's a shame because even a small turbine (200-300W) would be an amazing compliment to PV, especially if batts are involved too.

The odd thing about PV is that there aren't really any economies of scale, a panel on a house is basically the same as a panel in a field, they are standardised for mass production, shipping and handling. There are of course economies of volume (cheaper to buy 16,000 than just 16) but not real economies of scale.

But wind is the master of economies of scale, not only is one 1MW turbine cheaper and better than 1,000 1kW turbines, but it sits higher, and higher is better with wind. That's why the off-shore monsters might even threaten on-shore wind in price, as they can harvest much higher and more constant/consistent winds.

On a personal level you can always try to take part via a community wind scheme, or as I have done, invest in wind (and other RE) via something like Abundance. It won't reduce your leccy consumption, but at least you'll know it's being offset elsewhere.

Every few months somebody designs another clever VAWT (vertical axis wind turbine, as opposed to the normal horizontal axis (HAWT) style) that will work fine in all wind and weather etc etc, but nothing ever seems to come of them.