[lowtechmagazine]

"The article doesn't show a single non-demo installation".

It does. The Calorius windmill was commercially produced for about a decade, 40 of them were sold. Seventeen of these windmills were still operating in 2012.

It's all in the article. Also your points about the savonius are addressed.

[D_Alex]

Your article is interesting, but it makes a number of incorrect or misleading claims, the chief one being that heating via electricity produced by wind or PV is inefficient.

On the contrary, it is cheap, uncomplicated and very efficient in the modern context - by using the electric power to run a reverse cycle AC unit (in most cases, existing) you will get around 10 times the heat that a water brake system might deliver, with lower cost and much higher reliability.

[lowtechmagazine]

My article shows that heating without electricity is cheaper and more efficient than heating with electricity. It also has references to back up these claims. What you write is simply untrue.

[BlackFly]

The math kind of backs it up the efficiency of solar power backed electrical heating over wind.

Sunlight has a power of ~2kw/m^2 in visible spectrum (solar panels cannot capture all of this). At a strong breeze (10m/s) wind has a power of ~1kw/m^2 (windmills cannot capture all of this). So the mechanical heat generation would have to be more than twice as efficient to electrical generation to be worthwhile. But the "complications" mentioned are really what kill wind.

You want to capture sunlight: solar panels on the roof. No real obstruction.

You want to capture wind: massive windmills on your roof, need to disable the fan blade if the wind exceeds a certain value. Moving parts wear out.

I am not going to install a 2m radius windmill on my roof. Two 1m radius windmills have 1/2 of the area and are still an eye sore. Four 1/2m radius windmills, 1/4 of the area of the 2m radius blade.

[awaaz]

> Sunlight has a power of ~2kw/m^2 in visible spectrum

FYI, solar radiation is more like 1050 W/m^2 on earth's surface, of which about 40% is in the visible spectrum.

https://en.wikipedia.org/wiki/Sunlight

[jacobush]

10 times compared to what? Installation cost? I can't make your post to make sense. Also, if it were generally true, why would solar heat systems be so popular? I am thinking of vacuum tubes, the kind of installation which looks pretty much like a PV roof but it's only heat and water.