This thing looks like a giant mechanical kludge. If you put the brake (the paddles in water part) at the top of the tower, you have to pump water up the tower. If you put it at the bottom of the tower, you need a top gearbox with a right-angle bevel drive, a bearing ring supporting the gearbox so it can face the wind, long shafting, and bearings.
Some early power turbines were built that way, but nobody does that any more.
Vertical axis turbines like the Savonius turbine and Darrieus rotor can be used, but they're not very efficient, so you need a big one. They also are hard to shut down in an overspeed condition; they can't change direction, change blade pitch, or tilt upward, so you need a strong emergency brake system. Which is why they're rarely seen any more.
All this outdoor hot water plumbing needs to be well insulated, or you lose most of the heat. So a field of wind turbines, or one unit some distance from where the heat is wanted, is a problem. Moving energy around over wires is so much simpler.
Driving a heat pump mechanically might work better, but that's because heat pumps are far more efficient than heaters. (Moving heat is much cheaper than making it. See ). An electric windmill driving a heat pump is probably less hassle.
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!
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.
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 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.
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)
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.
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.
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.
FYI, solar radiation is more like 1050 W/m^2 on earth's surface, of which about 40% is in the visible spectrum.
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.
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 . So, if you go that route, a pump near ground level will more-or-less be required.
Dunno how to stop it at strong winds though.
- As noted in the article, wind can be highly variable in most areas. Optimizing a wind turbine for the average low speed (like here in the US Midwest) means that at super high speed winds can damage your turbine and it may need to be shut off. If you optimize for the high speeds you can get a ton of energy at those speeds but your turbine will mostly be still. Regions with a nice steady wind profile work better for power generation.
- Wind turbines with variable pitch blades do exist but add cost and mechanical complexity.
- Turbines often are installed at remote locations and maintence is difficult. One crazy story is a friend of a coworker was a tech for the giant wind turbines and fell INTO those giant fiberglass blades and almost died wedged in there before he could be rescued!
- "Urban" wind turbines was an idea here in Cleveland a few years ago, but wind turbines generate a lot of vibration which isn't good for buildings. Plus the turbines don't always spin all the time which is bad PR!
All this said I think wind power can be a part of a good energy portfolio but like with anything in engineering it boils down to a big "but if.."!!
This problem is solved centuries ago. Just cover only part of the blade with cloth.
I was about to suggest the idea of using gears like from a vehicle's transmission (i.e. first gear is easy to turn, will shift to larger when certain condition achieved), but it sounds like these ideas have been hashed out already.
Put it into a high gear in a high wind, it may not rotate fast and fly off due to angular momentum, but it might just snap off.
The surprising result of this is that the brake force needed to keep the turbine stopped is much smaller than the one needed to stop it, despite the relatively low mass of the blades.
If you're local "average wind speed" is 5m/s (~12mph, a "Gentle Breeze" and #3 on the Beaufort scale), and you size your wind turbine to generate useful power (say, 1000W, for example) at that speed, you have two consequences due to that speed-cubed term.
1) When there's only light wind - say half your design average speed, you're only gonna get 1/8th of your 1000W target, so only 125W which isn't very useful if you've got a 1000W requirement.
2) The _bigger_ problem is when the wind blows faster than average. If you get twice average speeds, your turbine is going to generate 8kW which you'll need to safely deal with. But twice isn't your problem - in the real world it's not uncommon for 3 or 4 times average windspeed (what we'd normally just call "a windy day" and 7 or 8 on the Beaufort scale), at which stage you're going to need to safely dump 64kW of power - if your turbine hasn't been braked/parks appropriately (or torn itself to pieces.) If you're still spinning in hurricane conditions, you've got another doubling of windspeed, and another eightfold increase in power, so now your "1000W generator" is unleashing half a megawatt into your wiring and control electronics (or the plasma in the smoke where your wiring used to be...)
Beaufort scale with speeds and descriptions:
Some real world windspeed measurements showing upper end outliers of 8 times average speed:
wind speed hours/year
The other problem is adding the mechanical complexity all up in the nacelle of the wind turbine, where it is hard to service and maintain.
Actually, given the recent interest in tethered blimps hosting high-altitude turbines, that's not as dumb an idea as it sounds. The prototypes shown so far generally use helium which is expensive and in limited supply.
Same with solar, in the dead of winter the sun is at quite a low angle in the sky, not even above the tree tops, and I doubt there's much to be gained either from photovoltaic solar or using it to directly heat water for the house.
According to the US Office of Energy Efficiency and Renewable Energy:
"Countries such as the United States, which lie in the middle latitudes, receive more solar energy in the summer not only because days are longer, but also because the sun is nearly overhead.
The sun's rays are far more slanted during the shorter days of the winter months. Cities such as Denver, Colorado, (near 40° latitude) receive nearly three times more solar energy in June than they do in December." 
Looking at these maps  for solar production in January and July, it seems like a lot of places drop by around 50% summer to winter. So it's a significant drop, but unless you're extremely far north, there's still energy to be harvested.
 January: https://www.nrel.gov/gis/images/map_pv_us_january_dec2008.jp...
 July: https://www.nrel.gov/gis/images/map_pv_us_july_dec2008.jpg
(For some scenarios this might even be a good solution without the heat pump, just run the water through a radiator. Is this something that people have tried?)
Now I don't know whether an equivalent pv system is cheaper in absolute terms than a thermal system, but from what I can work out, the marginal cost of adding extra pv to cover hot water is cheaper that adding a separate thermal system.
So yes they have different uses, pv generates electricity which can be used for a variety of things, thermal just generates heat. So if pv is cheaper or has a quicker payback, it seems like a no brainer to me.
Edit: Not sure what you mean by 'pay-off'. Solar thermal can be as simple as a black bucket sitting in the sun. It doesnt get much cheaper than that :D
It's counter-intuitive, but the reality is that PV has become much cheaper, while solar hot-water panels plus plumbing are expensive.
Plus you can use any surplus PV for multiple purposes.
A simple passive open-loop system is very cheap, and adequate for a hot water during warmer seasons (if you dont need hot water in the morning, i may add :D)
During colder seasons, you would need a closed loop system with a heat exchanger (often a heat pump, which you can power by PV) and insulated storage. Thats when it starts to get expensive, and the effective efficiency can be decreased if you are pumping more heat than you consume. This is an alternative to the air-source heat pump that your research probably used for comparison.
That said, I can totally see how PV could fulfill a hot water need right through the year, its just WAY more expensive than a low-tech solar thermal system (and likely less efficient in the summer).
Again, no harm in using both if you have the funds (and space) :D
Payoff as in if you buy a pv system it will pay for itself quicker than a thermal system. Electricity is more expensive and valuable than 'heat' (read gas substitute) so even if the pv system is more expensive, the savings are greater, which offsets the higher purchase price.
Hey if you want to shower under a black bucket, go for it :)
Could you name the particular brands and models of PVs you are using that produce 25% in the field? 15% under ideal conditions is more typical and your 25% is above current state of the art available for home installation. Also interested in your heat pumps above 3. Are these geothermal? If not, who makes them?
Normal set up is going to be 15% max on the PV and 3 on the heatpump, for 45% max, but more typically 25% as the PV is seldom set up to capture ideally.
"The COP for heat pumps range from 3.2 to 4.5 for air source heat pumps to 4.2 to 5.2 for ground source heat pumps"
The most efficient panels are at 22% right now, and that's with no overcast conditions or rain, sun directly overhead, and full tracking. The 22% are significantly more expensive. Most panels have around 15% efficiency, when new, under ideal seasonal, weather, tracking and lighting conditions. Quite a bit less when not.
I have a self built solar water heater and a house designed around passive solar. This handles heating and cooling sufficiently without grid inputs. My house stays at temperate conditions year round and my monthly energy bill, consisting of non-heating uses, is around $25/month on average.
Although this confuses the definition of joule with calorie, Joule's experiment was brilliant and laid the groundwork for the laws of thermodynamics:
A weight was suspended from a rope and allowed to fall. The falling weight was mechanically coupled to a paddle in a pool of water. As the weight fell slowly, it turned the paddle. Given that the mass of the weight and the water were known, the work performed by the falling weight and the heat absorbed by the water could be quantitated.
Here's a kitchen test of the principle where a household blender is used to boil water:
I suspect some heat transfer from the motor through the blades, but it's very surprising the water boils. He could have run a calculation, based on the power output of the blender, to see if the temperature increase was reasonable.
It's a beautiful device, worth googling around for the various photos that are online. I would embed a few choice images that I found but of course HN doesn't allow that. rolling eyes emoji
There's also an old Open University programme which reconstructed his experiment (conducted on his honeymoon, allegedly). It doesn't appear to be on YouTube.
I believe he meant 1 calorie, in Joules would be 4.184.
Also, DC is less efficient as the losses at your generator is heat that isn't captured. Generators are typically 80-90% efficient. This is pedantic though and doesn't matter (if this was the only concern DC is wroth the losses because you can divert it to lights or something else that is also useful)
Why would you use batteries? That’s silly, you’d simply heat water in both scenarios.
Water is heavy!
The easiest way to accomplish this is feed your lukewarm turbine water into the water heater intake. Every joule added to the input is a joule the gas heater doesn't have to deliver.
Unless you live in an area with very steady wind during the winter and a more or less equal need for heat all year around, the electrical solution is more practical even if it is less efficient.
I could imagine this for warm water with a different system used for heating or something like that.
Conveying the heat from a brake to a building: not so much.
A windmill with a generator inside it that is hooked to a wire that drives an electric heating element inside your house will be more efficient then a water break inside an insulated chamber that pushes hot water through tubes into your home.
There are interesting Phase Change Materials (PCM) out there that take advantage of a material's latent heat properties that get you a bit closer.
Typically you have an AC alternator (because DC generators have too high a loss in the brushes). How do you control the excitation voltage, you'd want high enough voltages to allow reasonable sized wiring but not enough to damage the insulation? How do you control the speed of the blades (under and overspeed) etc?
I can see how these things could be easily managed using direct water to heat. Simple spring loaded governors etc.
The difference is that a watermill would have a lot of extra heat lose from the very long prop shaft/belt drive to reach the top of the tower to the bottom, as well as heat that would bleed out of the chamber via the drive shaft, as well as heat lost in the tubing going both to and from the house.
Assuming the gearing and insulated piping carry high costs anyway, you could put that money instead into low gauge wire to lower resistance getting to the house heater element.
What kind of voltages are we talking about? I know that to get 12v from an alternator in a van to a leasure battery in the back with a modest voltage drop you need cables sized like welding cables. Is it possible to generate voltages nearer 240v directly from an alternator or do you need an invertor somewhere? How does the load on a heating element vary in low wind conditions? Presumably the voltage and / or frequency would be lower in that case.
With water you have the fact that it'll boil naturally regulating itself (so long as you let it escape). You could raise or lower the water level in the stirring chamber and possibly take advantage of convection to pump it back to a reservoir when it gets to a good temperature.
This is because the voltage is low, so the current has to be high for a given wattage (V x A). High current requires thick gauge wire.
> 240v directly from an alternator.
is it possible to generate voltages nearer 240v directly from an alternator or do you need an invertor somewhere
Yes, and since what comes from an alternator is AC, you don't need an inverter, but a simple transformer to step the voltage up or down. (However, you can't store AC, let alone high voltage AC.)
Motorists use inverters to get AC because the car's system is DC, as such. The car's alternator, however, "natively" puts out AC; this gets rectified to DC. (I think, alternators in fact put out three-phase AC.)
Car alternators are specially designed to output 12V; there is no such limitation in generators as such. In fact car alternators use voltage regulation to stay at around 12: when the system voltage rises above the target voltage (e.g. due to higher RPMs), the "field current" to the alternator is trimmed, which acts to reduce its output voltage.
I probably should have said AC-to-AC convertor rather than inverter.
My problem with that is if your using a permanent magnet generator then the voltage generated is proportional to the speed and then how do you know how to size your wiring and your transformer? It's probably not that big a deal and the answer is probably somewhere along the lines of 'leaving plenty of room for error'.
In short though, I don't think it's quite as simple as just connect a generator and some wires to heat the water.
Electronics can get phenomenally complicated, but electricity itself can be pretty fantastically simple. There's no such thing as electrons leaking out of a poorly sealed wire onto your floor, for example, and you'll never accumulate sediment and corrosion inside your wires...
Electrons leaking out of a poorly sealed wire onto your floor is otherwise known as an arc fault. Sediment in your wires is the degradation of the electrical insulator by heat, radiation, chemical solvent, or biological factors such as rodents or insects, followed by moisture infiltration and oxidation in the current-carrying elements.
A junction of aluminum and copper wiring without dielectric protection may eventually burn down the building. That doesn't happen when your plumbing goes from copper to PVC, or PVC to PEX.
If you have a closed-loop circulating-water heating system, with the thermal energy produced by a windmill, its pipes are unlikely to freeze, unless the place gets really cold, without wind. The supply and return lines would probably be buried as deeply as is feasible, too.
But yes, hanging an outdoor-rated NM cable between windmill and building, and placing a resistive element inside it, would be cheaper, quieter, and more reliable, even accounting for squirrel mishaps. If you can spare the expense, mineral-insulated cable is a very durable, bio-resistant way to move power.
If we already have electric generation and conveyance in the picture, then the pump and tube system is additional.
Electric generation and conveyance is "low tech": we've had it for over a hundred years now. It has few moving parts.
Pipes can leak. The fluid needs to be drained and replaced. the system needs to be bled. Pumps break; seals wear out, and such.
You can use the windmill to also drive a pump that pumps the water through, say, 20 meters of well-insulated pipe and from there through your floor heating system.
Also, https://en.wikipedia.org/wiki/District_heating is at least somewhat competitive with other methods, so scaling up may be possible, too.
It sounds like air-to-water pumps may offer a new alternative, but it's still more expensive than gas in many scenarios.
However air to water heat pumps are also applicable in cold climates. If you're interested here is an example datasheet of an air to water heat pump (2018) (using Celsius here):
Mitsubishi PUHZ-SHW112YAA Guaranteed operating range (outdoor): Heating: -28 to +21
Domestic hot water: -28 to +35
On page 108 you can find the actual co-efficient of performance (COP) for different outside temperatures and inside water heating temperatures. As an example: at -10 and an water temperature for heating at 25 you still get a COP of 3+. That means that 100% electricity moves 300% of heat into your house.
Effective? A watt is a watt. A heater putting out 2000 watts of heating intensity is exactly as effective whether it runs on electricity, nuclear fusion, or burning dried unicorn poop.
Some electric heaters (like baseboard units) don't circulate air very well. They sometimes get installed under windows and basically just move hot air toward a cold window. If we take that to represent all manner of electric space heating, that is a strawman.
As another poster mentioned, it’s different in a place with unlimited hydropower like Quebec. Places like Boston or NY are about 3x more expensive for electricity... so gas is a no brainer and will be for a long time.
For example - Prague is (partly) heated by waste heat from Mělník power plant.
A Generator is 80-90% efficient in general, then you have battery charging losses (which I do not know), then battery discharge losses, finally, you have power transmission losses to get the electric around. All of the above losses are not captured. They are claiming that because everything is converted directly to heat near where it is used their total losses are less. (they assume insulation here)
The losses in their system are gears (some of which exist in most generator systems), and tank losses over time.
It is plausible they are right. However it all depends on local install factors which can be manipulated either way.
https://news.ycombinator.com/item?id=19263814 (this one)
I would have expected the anti-duplicate-submission mechanism to prevent one of these from being created, redirecting the later submitter to the already-existing story, given that these were both submitted around the same time.
Instead of connecting a windmill to an electric turbine, you can have it churn a pool of water where friction raises the temperature without the conversion loss.
Fascinating article. I had never considered this.
From what I understand, housing is one of the most-regulated sectors, and one which has also seen not much innovation (compare to computers or autos).
Were I a Bill Gates, I'd sponsor housing projects where innovators could be rewarded based on sustainability and cost. I guess, in order for anyone to live in them, I'd also have to sponsor some politicians to get government to then allow it.
From an efficient resource allocation (in other words, economic) perspective, there appears to be almost noone solving sustainibility problems. What I mean is, sustainability per dollar spent should be at the forefront of our minds, and I'd be very surprised this kind of tech did not find a place in the market if that were allowed to prevail.
It should be the opposite. The government should work to resolve market failures.
This is one of those issues which is not left vs right, but rich vs poor... That just gets completely ignored, whether by accident or design...
EDIT: The overall wind turbine isn't that efficient, that's the efficiency of the conversion of the mechanical rotation to electric power. There's a good deal of loss between the wind itself and rotation to vortices and whatnot.
The other important feature of this is that anyone can build a Savonius (or other) turbine and impeller at home, meaning that there is no lower floor on cost, meaning it's one of the only scalable uses of wind power that I've seen.
Free energy in the form of heat is all around us (orders of magnitude more than humanity uses currently, even considering a 20% electricity conversion efficiency). I'm in mourning that there is still no off-the-shelf supplier of Stirling engines for the world. Which is probably by design, considering how detrimental something like that would be to oil stocks hahah.
1) It takes a rather large system and stiff breeze, "a rotor diameter of 5 meters and a height of 9 meters – produced 3.5 kilowatt of heat at a wind speed of 11 m/s", ~25mph wind, to produce a modest heating output. that is the equivalent of two small 1750 watt heaters, which would barely heat a decent size room in cold weather.
2) The system is completely dedicated to heat production, and will be a waste of space over half the year. In the summer, most of the wind will be of essentially no use except for warm tap water. In contrast, you can use electrical generation any time.
The best system I've seen of this was at a remote boarding school in Florida. On the roof, they had black serpentine pipes in flat black boxes with glass lids, so mini-greenhouses. In the utility area, they had large insulated water storage tanks. They could get the water to 180F, and had to warn people to be careful when using the tap or taking showers. Pretty impressive, and this was decades ago.
I assume turbines already generate heat, and they also require brakes for when wind speed gets too high. Best case you could be generating maximum electricity and using the brake to generate useful heat. I guess this would aid dispatchability of the electricity, certainly with regards to limiting output as well.
Thinking about it some more, you should also be able to get kinetic energy out (or electricity) and water, by running a turbine on the compressed air and collecting moisture from the cooled air.
Essentially one of these: https://en.wikipedia.org/wiki/Heat_pump_and_refrigeration_cy... - they're not technically as efficient as a phase change, but if it's simpler and there are fewer moving parts, it might be a win.
Big downside is that heating with water brake is somewhat impractical and unexplored territory.
However big plus of this approach is that you can make water brake with middle-age technology.
This doesn't make any sense to me though. Can someone with a better understanding of physics than me explain to me why this would be the case? I would imagine electricity to be just about the most efficient way to transfer energy. And furthermore, as I understand it, lost energy tends to become heat!
On the other end of the spectrum, you have "low grade waste heat", take for instance the heat from running a computer. Almost all the (useful) energy input as electricity gets turned into hot air coming out. You can use that to heat your room, but nothing else.
So because electricity is so useful and high grade energy, we prefer not to use it "just" for resistive heating. Running heat pumps is an example of a much better use (you can get 4-5 times as much heat out).
The second law of thermodynamics says that the amount of energy won't change, it can only change form, right? (Correct me if I'm wrong, I'm not sure). So the electricity should either remain electricity or turn into heat?
I get that it might not happen at the place where we want it to. For instance, we don't want to be heating up the ground between the power plant and my house where the cable runs. And I also get that turning heat into electricity (as it happens at the power plant) might not be efficient. But I still feel that it should perform better than running a pipe with hot water which seems more likely to leak heat into the ground along the way.
> ..but why?
Because you are literally pumping heat from outdoors to indoors. You are reducing the energy of the outdoor air and increasing the energy of the indoor air.
The electric energy spent is used to drive a motor that is pumping a fluid round in a loop. The pump is placed where you go from outdoors to indoors. Opposite the pump in the loop, you have a pressure reduction valve, and together these give you a higher fluid pressure on the indoor side, say 40 bar vs 20 bar. The trick is that this pressure difference means that the low pressure fluid is also cold, so it can be heated by the outside air, and the high pressure fluid is warm, so it can release heat to then indoor air.
The thing about running hot water (e.g. district heating) is because you use heat that is literally free. E.g. if you have a waste incineration plant burning all the garbage, that's a lot of free heat. Or if you have a big data centre, lots of waste heat. Let's use it!
In systems like the OP post, the water acts as both energy storage and a convenient way to distribute heat. No DC/AC inverter, etc.
AFAIK the whole problem is that "waste" heat happens at the coal/gas plant where heat is converted into electricity in the first place, and (to a lesser extent?) in the transmission lines, not at your house where it'd be useful.
for example if the power plant is burning oil, and converting that to electricity, then you convert that electricity to heat you're going to get much less heat than just burning the oil yourself.
OTOH, the power plant probably has a rail connection or pipeline for oil, and the marginal energy cost of transporting an additional unit of oil to the power plant is probably quite low compared to the marginal energy cost of transporting the same additional unit of oil to your house.
Of course that isn't the full picture either. Electric can come from many sources (wind, PV), and scale means they can mix sources cheaper. (imagine a coal furnace, gas furnace, oil furnace, PV heat, and a windmill all at your house - it is obviously ridiculous, but large utilities have this)
You also don't have to burn for heat directly. Electric leaves open the option of a heat pump which can be >100% efficient when it isn't too cold.
Uh, I have a natural gas pipe coming directly into my home, along with nearly everyone in my state, and also region.
Electric heating is more efficient than natural gas, but electricity is more expensive per BTU, at least where I live.
I usually get about 125 gallons at a time. And since heating oil is just diesel with dye in it, we can just add deliver costs in gallons. Even assuming im the only delivery, I doubt it would take more than a gallon of gas to travel to my house. But to be safe lets say 5.
With the above assumption, the question is Could 130 gallons burned at a power plant generate more heat in my house via electricity. Than 125 gallons burned in my house directly.
I dont know enough to give an answer but my gut says no.
I wonder what the efficiency of using direct hydro / wind power to power an air compressor (say rejecting the excess heat to preheat the hot water supply) and releasing the compressed air for air conditioning.
But I've wondered if you could get a useful amount of cooling/greywater disposal/hot clean water supply by mounting a wind-powered vacuum pump on top of a tall (11m +) column of water so that the water in the column would boil at ambient temperature.
Just insulate the building properly and then you can use rooftop solar to cool it down on those days when it gets too hot - largely because the sun is shining.
Moving heat is generally easier than generating it.
I love that people are thinking about this, and I truly hope that it becomes standard, but it's not exactly reasonable for folks to expect such a level of efficiency without paying through the nose.
I think you're firmly into diminishing returns if you're insulating your house to be warmed purely by body heat through the depths of winter.
Plus what happens if you have a child? Do you remove insulation, run the AC through winter?
An argument against that is that the work energy counts against the operation of an AC unit, whereas it works for the operation of a heat pump. So you get a better CoP heating.
These mechanisms are good because they can be easily understood and whilst they will require patching and hacking and repair and are inefficient and can't do all things, if they can provide a stable heat source to remove the burden of burning things, which actually kills more women and children because of lack of oxygen, CO/CO2 poisoning, asthma and other effects, there is a huge positive upside.
But, as has been said since at least the 1920s what we really need is soviet power, plus electricity.
Generate electricity during peak hours (high price)
/ Generate storable heat during off-peak hours.
Or would it be better to generate e-power all the time if the turbine is capable of it?
Anyone else getting this? I'm just going to read it on archive.org but it seems weird. I'm coming from a Digital Ocean NYC IP
Note too that nobody has defined the actual size. Your idea of a small town could be larger than my idea of a large city. Local factors matter in this definition as well.