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> If you put the brake (the paddles in water part) at the top of the tower, you have to pump water up the tower.

You have a windmill, so you have a source of energy to do that. Much of the mechanical energy that goes into the pumping becomes gravitational potential energy, which will become heat when the water goes back down the tower. A lot of the rest will be lost as heat during pumping. Either way, it's ending up as heat, which is what you want.

Heaters are the only type of machine which are naturally efficient!

> Heaters are the only type of machine which are naturally efficient!

I had a big argument with my physics teacher about this back in highschool. He was so stuck on the "no machine is 100% efficient" dogma that he couldn't look past it to the definition of "efficiency" for a heater in a closed room.

And for that matter, heat pumps can be more than 100% "efficient", since they move more thermal energy than they consume.

https://dothemath.ucsd.edu/2012/06/heat-pumps-work-miracles/

They're not a conversion system so you don't measure them in terms efficiency, rather you use coefficient of performance, you can never have efficiencies above 100%.

In power terms it is above 100% efficient because the watts in is lower than the watts out.

No, the heat moved is greater than the watts in. The machine itself has considerable parasitic losses, and a simple electric baseboard heater is more “efficient”, using the strict definition of the term.

The difference is that most people don’t care about “efficiency”; they care about heat moved per watt. But it matters a great deal more when you try to use a heat pump in a really cold environment, as the heat-transfer ratio of the machine plummets (which is why, in the real world, heat pumps fall back to gas or electric in cold weather).

It also matters in a scenario where you’re comparing two different machines that are powered by something small and intermittent, like a windmill.

I'd assume that some tiny fraction of the energy is directly converted to radiation that escapes the room instead of kinetic energy. Some of the energy should be transferred to particles outside of the room directly by electromagnetic forces (they fall off to near zero quickly, but never fall off to zero). Etc.

Probably 99.many_9s efficient, but I don't think it could be 100%.

(We'll assume you're talking about a resistive heater, fire, or so on. Not a heat pump where you can play games with the meaning of 100% efficient)

Energy is conserved (under normal conditions) so everything is 100% efficient if you want to include waste heat.

However, "efficiency" is actually a value judgement. You probably want to heat something specific, so you're going to lose some fractional efficiency by accidentally heating something else. Resistance in the wires leading to your heater will accidentally heat the outside of your house.

It's also not a terribly useful definition of efficiency environmentally: if you multiply the efficiency of burning fuel to produce the electricity by the efficiency of your electric heater, you get a worse result than burning fuel in your home. And it's not a terribly useful definition as a consumer either, since that electrical heater is only producing about 50% the heat that a heat pump could do with that electricity.

"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.

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.

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.

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.

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.

> 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

Speaking of heat pumps, I installed one 2 months ago, and dropped my electricity bill for heating water from $85/mo to around $25/mo. This saved me around 69%!

Reference: https://russell.ballestrini.net/hybrid-hot-water-heater-save...

What’s your payback period?

It's in his article - 1 year due to rebates, 2 years without.

The house we bought a year ago has an electric water heater, and it's a wishlist item of mine to upgrade it to a heat pump. Our electric bill is way higher here than where we lived previously, and the only thing significantly different is that we have electric hot water here. My in-laws have one and it seems to work pretty well. Plus you get a bit of A/C out of it in the summer.

Nice, here in Sweden there are even more efficient systems that recovers the heat from your house ventilation system and uses it to heat water for heating and bathing.

Maybe, but two things to consider.

The drag force in the fluid brake is proportional to the velocity squared. So you get harder and harder braking. (The air blades still need to not blow off though.)

Insulation requirements decrease with the size of the reservoir. (Since volume increases faster than area.) Besides, the reservoir could be placed inside the house as well.

Totally agree with regards to it being a kludge; power electronics have come such a long way since the '70s...

For the mechanical+pump permutation, the plumbing needs to provide a way to prime the pump, and the pump cannot be more than 20-something feet up without the whole system being pressurised [1]. So, if you go that route, a pump near ground level will more-or-less be required.

[1] http://processengineering.co.uk/article/2019233/maximum-suct...

Afaik the savonius turbine is known to be good for torque, bad for speed. And because it's vertical, you don't need a sjaft or gear box at the top.

Dunno how to stop it at strong winds though.

Those very water brakes seem ideal to prevent runaway turbine blades. Their braking power goes up very quickly as a function of impeller speed (ever use a rowing machine?).