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The article talks about this; it says the most efficient system is a mechanical heat pump (where the wind provides direct mechanical power to the compressor), b

The article talks about this; it says the most efficient system is a mechanical heat pump (where the wind provides direct mechanical power to the compressor), but only for local generation, since heat transfer is much less efficient than electricity transfer.

ams6110 8y ago
Yes, my thought was to use the windmill to run the heat pump, then buffer the heat as hot water in an insulated tank to heat the house. Not really practical unless you live in a place with fairly regular wind in the winter. Where I live, winter air tends to be fairly still with occasional exceptions and I could be wrong but I doubt it would be a great way to heat the house. 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.
- harpastum 8y ago
  Electricity production in winter can definitely be lower, but it depends on latitude. As you might guess, near the equator there's almost no difference in season. 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." [1] Looking at these maps [2][3] 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. [1] https://www.energy.gov/eere/solar/articles/solar-radiation-basics https://www.energy.gov/eere/solar/articles/solar-radiation-b... [2] January: https://www.nrel.gov/gis/images/map_pv_us_january_dec2008.jpg https://www.nrel.gov/gis/images/map_pv_us_january_dec2008.jp... [3] July: https://www.nrel.gov/gis/images/map_pv_us_july_dec2008.jpg https://www.nrel.gov/gis/images/map_pv_us_july_dec2008.jpg
- taneq 8y ago
  You could go all-out with an angled thermal collector panel (double-glazed or possibly vacuum insulated like some fancy solar hot water systems) which heats water to be piped back inside into a storage tank, then pump the heat from the storage tank into the air when required. (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?)
usrusr 8y ago
If for some reason (I don't know, heating a blimp perhaps?) you were restricted to an air-sucking heat pump you could go wild and route the intake (or some fraction of it) of the heat pump through the generator and motor: this should recapture all the losses. A worthless optimization since the waste avoided would be free (just build a slightly larger turbine), but technology for low intensity heat is uniquely simple, but why not use three opportunity to make it amazing ("conversion losses? Yeah, they are taken care of")
- taneq 8y ago
  > (I don't know, heating a blimp perhaps?) 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.

ams6110 8y ago

Yes, my thought was to use the windmill to run the heat pump, then buffer the heat as hot water in an insulated tank to heat the house. Not really practical unless you live in a place with fairly regular wind in the winter. Where I live, winter air tends to be fairly still with occasional exceptions and I could be wrong but I doubt it would be a great way to heat the house. 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.

harpastum 8y ago
Electricity production in winter can definitely be lower, but it depends on latitude. As you might guess, near the equator there's almost no difference in season. 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." [1] Looking at these maps [2][3] 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. [1] https://www.energy.gov/eere/solar/articles/solar-radiation-basics https://www.energy.gov/eere/solar/articles/solar-radiation-b... [2] January: https://www.nrel.gov/gis/images/map_pv_us_january_dec2008.jpg https://www.nrel.gov/gis/images/map_pv_us_january_dec2008.jp... [3] July: https://www.nrel.gov/gis/images/map_pv_us_july_dec2008.jpg https://www.nrel.gov/gis/images/map_pv_us_july_dec2008.jpg
taneq 8y ago
You could go all-out with an angled thermal collector panel (double-glazed or possibly vacuum insulated like some fancy solar hot water systems) which heats water to be piped back inside into a storage tank, then pump the heat from the storage tank into the air when required. (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?)

usrusr 8y ago

If for some reason (I don't know, heating a blimp perhaps?) you were restricted to an air-sucking heat pump you could go wild and route the intake (or some fraction of it) of the heat pump through the generator and motor: this should recapture all the losses. A worthless optimization since the waste avoided would be free (just build a slightly larger turbine), but technology for low intensity heat is uniquely simple, but why not use three opportunity to make it amazing ("conversion losses? Yeah, they are taken care of")

taneq 8y ago
> (I don't know, heating a blimp perhaps?) 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.