More Interesting Things About Friction And Mechanical Heating - It's All So Interesting! 

What about a watercooled aircompressor. Then you get compressed air for the workshop, and heating of the water.

If your metal plates gain weight from the friction, you can exchange them with somebody else whose plates lose weight from friction. Keep trading them back and forth and you'll solve each other's problems!

"Lots! Lots, and that's metric lots as well as imperial lots!" is going straight to my vocabulary

Once the water is heated, the next question is how to keep it insulated

Hey Tim, may have been said but the favorite for energy storage is a sand battery. How about stirring the sand to heat it, like a huge rock tumbler, low speed high torque can be used by large diameter tumbler and small diameter for high speed low torque. The paddle could be made variable diameter or pick up more if available energy rises. Cheers

You do not need rotational speed, you actually need linear speed to make the hydrodynamic friction work. So, instead of increasing the RPM, you can increase the diameter of the rotating element, thus reducing the losses from gearing.

Completely get why you want to use the plates like this (some wheeled diggers basically use this for brakes - it works well! but it might be worth alternating materials so you don't get cold Welding / galling (not sure what's an easy/ cheap second layer, wood might be too low friction when wet and concrete might wear the steel to quick? - oil could be used instead of water too for higher friction materials ). Another cheapish option for magnetic heating is just submerging an old pm motor in oil, and shorting its windings (through a few metres of thick wire which is also under oil). The windings are normal good to at least 180c (a longer shorting wire can increase its resistance and lower running temp if to hot - or a big resistor bank could be used ). Ac works better for this as brushes wear and knacker bearings if in oil, the brushes might not cope with the current too - but dc would still work for a while though!

If you're worried about mechanical losses in the gearing, one way to mitigate that is to put the gears themselves in the fluid. Then the "waste" friction of the gears isn't waste at all!

I think friction heating is a bad idea. Personally I'd calculate the max energy from the wind using an appropriate equation, then size the othe components to suit. I'd either use an old torque converter or a dynomometer and a heat exchanger from an old combi boiler. They're ready made and available at scrap prices. Vibration and throw will destroy your primary side container and a single plate exchanger system will not transfer any useful energy.

Car air conditioner is much simpler. With a small compressor that is belt driven. The hot side radiator could place in water to heat or a fan to blow heat. Of course the cold side radiator will give cooling for summer.

+1 for heat pump.

5:35

Some old automotive AC systems used compressors that were powered directly by the engine belt via a pulley, I think such a thing could be a good candidate for running a heat pump if you can get your hands on one, I've also heard (though correct me if I'm wrong) that some hobbyists have built heat pumps / refrigeration systems using propane as a refrigerant.

Thinking of friction - what about car or even truck (lorry) brakes? They´re made to turn kinetic energy into heat and release it into the air (or in your case water) around. You could stack brake discs and pads inside a pot and control the friction with a spring pressing on the whole stack. The more rpm the windmill turns, the more pressure on the spring so alongside to the heat you get kind of a governor for the rpm of the mill.

Get well soon!

Heat pumps are a miracle, technology connections has explained it again and again a bajillion times better than I ever could!

Thanks Tim. I'm enjoying this latest rabbit hole

I love when you have a big project going. And I love when you nicely prove how smart you are! You are a gentleman!

Tim doesn't think outside the box, he asks what box?

As an electronics engineer, I would obviously default to a generator, but I really respect the mechanical approach. I honestly would have never of thought of it as an option. But I like it, alot. and the vibe im getting is your doing this for the fun of the project, not profit or anything like that. I think your on a pretty good path, you could do alot with 1kw of constant heat. Hope your feeling better soon Mate