That’s the rub, isn’t it? Unless you’re off the grid, out in some rural area, I don’t think this is practical. The reason that we build electric grids in the first place is to distribute energy to...
Providing enough storage to bridge a week without wind thus requires up to 7 tonnes of water, which corresponds to a volume of 7 cubic meters plus insulation. However, energy losses (self-discharge) should also be taken into account, and this explains why the Danish heat generating windmills usually had a storage tank holding ten to twenty thousand liters of water.
That’s the rub, isn’t it? Unless you’re off the grid, out in some rural area, I don’t think this is practical. The reason that we build electric grids in the first place is to distribute energy to do any kind of work that is needed, on demand, even if it introduces inefficiencies. If you have the space, own your own land, have the resources to build one of these systems along with the proper radiators in your home, and live in a climate that makes sense, this is probably a good way to eke out efficiency. If you don’t (which is probably most humans—that’s a lot of conditions), then this isn’t practical.
A week with no wind is a long time. Even my relatively small suburban house could easily fit a 500L water tank and insulation (in fact, it has an unused one in the loft space already). More to the...
A week with no wind is a long time. Even my relatively small suburban house could easily fit a 500L water tank and insulation (in fact, it has an unused one in the loft space already). More to the point, who says you have to become entirely self-sufficient? If you get 75% of your heating from the wind, that's still a significant reduction in the amount of energy you need from other sources. The space for the windmill is slightly more of an issue. Not sure I'd get planning permission for one of those..
If you look at solar, very few people have off-grid solar systems. Most houses with PVCs on the roof use them to reduce their energy requirements, not replace them.
District heating is a thing too (it predates electricity by a few thousand years!). It's not uncommon for hot water to be piped to homes where a source of easily available hot water exists - such as certain types of power station which have excess heat to dump. One windmill to heat a village isn't unthinkable - we already do that with electricity in some places, just a few miles from where I live there's a village who bought a electricity windmill and now people there have very cheap electricity bills. Would be slightly more work to install a heat version but still worth doing.
I think, generally, it is uncommon. Most homes are fed cold water from public utilities and then the water is heated in a water heater within the home.
It's not uncommon for hot water to be piped to homes
I think, generally, it is uncommon. Most homes are fed cold water from public utilities and then the water is heated in a water heater within the home.
I think you have a warped view of what situation most people live in. Installing large water tanks and windmills in cities is infeasible. How do I pump hot water to the 10th floor of an apartment...
I think you have a warped view of what situation most people live in. Installing large water tanks and windmills in cities is infeasible. How do I pump hot water to the 10th floor of an apartment building? You now need to spend more energy to move the hot water around, and if you use the wind, now you need to make the modern kind of wind mill that generates electricity, not just heat and we’re back to the inefficiencies. I stand by my statement that the only practical use for this is in very rural areas. It’s not surprising to me that this was popular with Danish farmers, but its never going to catch on in any urban area (not to mention, if you don’t own the land or building where you live, you probably don’t have the authority to install these systems anyway, and it’s not clear to me you can install such a system retroactively without tearing the whole building apart).
Edit: I take it back that installing large water tanks is infeasible. The windmill systems I still stand by.
"Most people" don't live in tall apartment buildings. Lots of people do, sure, but most people live in lower buildings or suburbs. For example, 1/4 of a million people live in my city and there...
"Most people" don't live in tall apartment buildings. Lots of people do, sure, but most people live in lower buildings or suburbs. For example, 1/4 of a million people live in my city and there are no more than six or seven high rise residential buildings here. Also bear in mind that pumping water up a few tens of metres is relatively cheap, energetically speaking, compared to heating that water from ambient to heating temperature (it already happens with cold water, so people can have taps in their flats). Yes, electrical cables have a lower cost to gain height but moving water just isn't that big of a problem. Having a big tank on the roof of an apartment building is reasonably possible. If that tank hooks in to everyone's heating and hot water systems you don't actually need it to be too big, because all the water in the system still counts as thermal ballast.
The best way to apply it to urban areas is to have larger plants which distribute hot water. District heating works just fine in urban areas, plenty of places already do it, although they don't tend to use windmills as the initial heat source, but that's a non-problem. Moscow springs to mind as one of the more famous centrally heated places. But even America has some installations.
Installation should be relatively trivial in any house with water based central heating. You just pump the incoming hot water into the header tank for that system and you're done. The existing heating system picks up the slack as needed. This part is an entirely solved problem already - my parents house dumps excess solar energy into their hot water and heating system, for example.
In my house you'd need to install a new header tank but there's plenty of room for that in the loft space. For a district system you'd just need to run a pipe into the house. Quite a lot of digging to do a whole city but it's not too challenging in terms of engineering. I'm sure there are some buildings which you'd need significant work on but almost all residential buildings have some pipe-based infrastructure already installed so you can probably work around that. The central heating in my house was installed about forty years after the building was put together, so it's definitely possible in some cases, if not all.
This is an interesting assertion. I don’t think I can refute it outright, but it doesn't align with my mental model of the world. I did a little bit of research, but if anyone else has some...
"Most people" don't live in tall apartment buildings.
This is an interesting assertion. I don’t think I can refute it outright, but it doesn't align with my mental model of the world. I did a little bit of research, but if anyone else has some authoritative studies on this subject, I'd be very curious.
Here are some interesting, relevant, but not definitive findings in a quick Google Scholar search with the query: "floor of residence housing high-rise building".
In recent years high rise housing has become a common phenomenon with the mode being buildings of eight storeys and 32 apartments, and the maximum size---20 storeys, and up to 120 apartments.
Over a period of 40–50 years, high-rise public housing has become not just the lifestyle of the majority of the population, but also the dominant building form.
As with Hong Kong, the height of Singapore’s apartment housing is set to rise. New housing, especially private, has launched ever-taller heights in Singapore’s downtown: 50- and 70-storeys (The Straits Times, 11 February 2003, 29 May 2003, 1 October 2004).
Singapore and Hong Kong are not unique in tall(er) housing development. In the past 10 years, high-rise has re-emerged as a residen- tial option in the 21st-century urban regener- ation agenda. Since the 1990s, the arrival of new construction technologies combined with a growing urban population have encouraged many large Chinese cities (for example, Shanghai and Beijing) to engage in high-density site planning by building high- rise apartment buildings (The Straits Times, 31 May 2003). Elsewhere, with rapid urbanis- ation (about half of the world’s population lives in urban areas), many other cities are revisiting and building high-rise (some being built by the private sector in prime inner-city locations) to house the growing population. In Europe, Manchester and London—for example, have started to build 47 to 50- storey tower blocks as the latest answer to the country’s housing shortage even as many of the earlier (1960s) high-rise public housing blocks are being demolished (Abel, 2003). In a similar vein, there has been a return to high-rise in Australia, in particular Melbourne, in the past 10 years following a period of abandonment since the 1970s (Costello, 2005).
In 2001, the number of apartment houses in the country reached 5.5 million or 47.8% of all the houses in Korea. HMUH complexes began to appear in the second half of the 1990s, where apartment complexes with more than 30 stories totaled 32 in the Seoul metropolitan area, and those with over 25 stories reached 47. 1 This harbingered the trend of HMUH buildings becoming the new standard housing type in South Korea.
The numbers of high-rise mixed-use residential buildings have recently rapidly increased all over the world ...
This book has a chapter that looks interesting, but Google Books has removed some of the relevant figures.
In any case, I'm not sure if the true majority of humans occupy living spaces in high-rise buildings as I can't find any hard evidence to back this up in either direction. That's actually disappointing, as this seems to be a demographic statistic that ought to be well studied. Even if it's not a majority of the population, let's at least agree that a significant number of humans live in compact cities, as evidenced by the trend of urban development since the 1960s in the developed world, and that a significant number of humans live in high rise buildings.
Also bear in mind that pumping water up a few tens of metres is relatively cheap, energetically speaking, compared to heating that water from ambient to heating temperature (it already happens with cold water, so people can have taps in their flats).
Right, but this work is typically performed by pumps connected to the electric grid. Take NY City for example. So, the water tanks are already there, but I really don’t think you’re going to get traction to build the windmills and radiators to use it for heat.
Installation should be relatively trivial in any house with water based central heating.
Well, then, the question becomes, how many buildings use water based central heating? I haven’t ever lived in such a building myself.
I would like to see more information should anyone have it because my claim was based purely on my personal experience. Most places I've been aren't full of high rise residential buildings. But...
I would like to see more information should anyone have it because my claim was based purely on my personal experience. Most places I've been aren't full of high rise residential buildings. But you are right, plenty of people do live in tall buildings. Except I don't think that's particularly relevant to the discussion at hand because pumps are a thing and it's not like a heating system needs to be high pressure.
this work is typically performed by pumps connected to the electric grid
Is there a reason that the pumps can't be connected to the electric grid? The point I was making was that it's not unfeasible to pump water up a bit. I didn't think it would be free! :)
I think we have to be prepared to think a little outside the box when it comes to restructuring our infrastructure to be sustainable. There is no engineering reason we can't heat our homes and offices with wind, be those homes rural, suburban or high-rise. In the final analysis it might not be the most cost-effective way to become sustainable, but it should definitely remain an option on the table for consideration.
No, but from the original article, the whole benefit of this system seemed to stem from the fact that you didn’t need to be on the grid. I was just taking a holistic view.
Is there a reason that the pumps can't be connected to the electric grid?
No, but from the original article, the whole benefit of this system seemed to stem from the fact that you didn’t need to be on the grid. I was just taking a holistic view.
I'd say almost every home in the UK uses water based heating. Every place I've lived for the last 40+ years does. As has every office building I've worked in, as far as I can remember. I seem to...
Well, then, the question becomes, how many buildings use water based central heating? I haven’t ever lived in such a building myself.
I'd say almost every home in the UK uses water based heating. Every place I've lived for the last 40+ years does. As has every office building I've worked in, as far as I can remember. I seem to recall it being the same in houses I've visited on the mainland EU too (I once had to carry a radiator up several flights of stairs in France, before plumbing it in).
How else do you heat a house? I'm not being facetious, that's an honest question. Obviously fires/stoves are an option but that's what people had before central heating was a thing, so some older houses might still use those. Certainly nothing in a modern city would.
Air. I live in the U.S. (in the northeast), and the majority of buildings I’ve lived and worked in used air vents part of an HVAC system, or baseboard radiant heaters (basically just a bunch of...
How else do you heat a house?
Air. I live in the U.S. (in the northeast), and the majority of buildings I’ve lived and worked in used air vents part of an HVAC system, or baseboard radiant heaters (basically just a bunch of metal fins attached to a heating element).
Edit: I have seen water radiators in the U.S., but mainly in older buildings, and it’s not common any more. I’ve also seen a lot of buildings that used to use water radiators, but no longer do. My elementary school building was very old (even when I attended school there 25 years ago) and used water radiators, but that building was turned into offices and the old heating system was replaced with HVAC.
Well, looks like you really do learn something new every day. I knew US had AC for making cold but I didn't know they used it for heating too. How do you heat the air? Hey I guess in theory you...
Well, looks like you really do learn something new every day. I knew US had AC for making cold but I didn't know they used it for heating too. How do you heat the air?
Hey I guess in theory you could heat it with... a windmill!
So, electricity. In the UK electrical heating is usually prohibitively expensive. I wouldn't be able to have the heat on very often if it cost me six times as much as it currently does! (gas = 1/6...
So, electricity. In the UK electrical heating is usually prohibitively expensive. I wouldn't be able to have the heat on very often if it cost me six times as much as it currently does! (gas = 1/6 electricity £/kWh here)
Anyway, drifting a little off topic here. In summary I'd say windmills to heat water (and then buildings) might be feasible as part of a blended system in some environments, although perhaps not so much the US where existing infrastructure may make it tricky to install.
Lolwut? Everybody who has rubbed their hands together in winter knows that a windmill can provide heat directly. The problem (as in literally all forms of renewable energy) lies in the storage of...
Almost nobody knows that a windmill can produce heat directly
Lolwut?
Everybody who has rubbed their hands together in winter knows that a windmill can provide heat directly. The problem (as in literally all forms of renewable energy) lies in the storage of that energy. Where are you going to stick the heat until you need it? The massive water storage systems talked about in the article pale in comparison to poor quality LiPo battery storage options, and if you want to talk efficiency let's talk about the fact heat... dissipates?
I also love
This is a solar-powered website, which means it sometimes goes offline
A friend of mine is currently looking to install a system like this - they don't have to be massive water storage systems, they can be standard water tanks like you'd get in a lot of homes. A...
A friend of mine is currently looking to install a system like this - they don't have to be massive water storage systems, they can be standard water tanks like you'd get in a lot of homes. A well-insulated water tank can hold heat for a very long time - certainly longer than you'd likely need it to (anyone who has used a vacuum flask knows that). The article claims 100L (edit, dropped a 0, updated numbers below) 1000L of water can store 90kWH of heat - to match that you need a lot of relatively expensive and chemically a bit unpleasant batteries or a simple 1m3 steel water tank which costs about £2000 (or far, far less for plastic+lots of insulation). You can't get a huge amount of batteries even for £2000 and water tanks don't lose capacity as you use them, you probably only install those things once a lifetime.
If you have that tank hooked up to your central heating system, as my friend is looking to do, you gain even more thermal ballast while the heating is on (where he lives that's 6-7 months of the year). A heat exchanger in the tank can tap off heat into a second tank which is used for washing/cleaning water. Given many parts are off the shelf it's a very cheap way to harness wind energy to heat your home compared to complex and expensive electrical systems, although realistically if you were going all the way off-grid you'd likely end up with a combination system probably using PVCs for electricity and wind for heat, maybe even crossing over as required.
Also, got too much hot water in the summer because your heating is off? HOT TUB.
You dropped a 0, the article says 1000L of water stores 90KWh of heat -- enough for 1-2 days. Don't underestimate the size of the tanks needed to store all this heat. At the upper bound that's 20...
You dropped a 0, the article says 1000L of water stores 90KWh of heat -- enough for 1-2 days. Don't underestimate the size of the tanks needed to store all this heat.
(...) this explains why the Danish heat generating windmills usually had a storage tank holding ten to twenty thousand liters of water.
At the upper bound that's 20 cubic meters of water storage, or a 2*2*5 meter box.
Whoops, my bad, thanks for catching that. 1000L is 1x1x1 metres. It's still not an unfeasibly large tank. If I felt like braving the forest of dust and spiders that is my attic I'd measure the...
Whoops, my bad, thanks for catching that. 1000L is 1x1x1 metres. It's still not an unfeasibly large tank. If I felt like braving the forest of dust and spiders that is my attic I'd measure the size of (unused) tank up there but from memory it's probably in that kind of ballpark.
The size of the tank is an issue for direct solar themal collection too. I'm surprised that nobody's made a latent heat storage device for these applications yet... For example, the latent heat of...
I think you overestimate the intelligence of the layman. There are people out there that don't even know that windmills produce electricity. Low Tech Magazine is something you kind of have to get...
I think you overestimate the intelligence of the layman. There are people out there that don't even know that windmills produce electricity.
Low Tech Magazine is something you kind of have to get used to reading. It's got an ethos of sustainability that is held to a much higher standard than anything else I've ever seen. One of the ideas the author has suggested in the past is to store energy by moving water into a raised storage tank and releasing it with the force of gravity. Why? Because it's more sustainable than Lithium.
In any case, they do mention that storing the energy is not very efficient:
However, using the stored heat for electricity production is considerably more costly and less sustainable compared ro using heat generating windmills for direct heat production. Converting the stored heat into electricity is at most 30% efficient, meaning that two thirds of the wind energy is lost due to needless energy conversions — and the same is true when solar thermal is used for power production.
The Eddy current version is a pretty smart idea. I think it's possible even to make a hybrid system of Eddy current heater and power generator, where energy can be diverted in electrical form for...
The Eddy current version is a pretty smart idea. I think it's possible even to make a hybrid system of Eddy current heater and power generator, where energy can be diverted in electrical form for various use and this way we have a 2 in 1 wind turbine, for efficient heating and less efficient but more versatile electric power.
That’s the rub, isn’t it? Unless you’re off the grid, out in some rural area, I don’t think this is practical. The reason that we build electric grids in the first place is to distribute energy to do any kind of work that is needed, on demand, even if it introduces inefficiencies. If you have the space, own your own land, have the resources to build one of these systems along with the proper radiators in your home, and live in a climate that makes sense, this is probably a good way to eke out efficiency. If you don’t (which is probably most humans—that’s a lot of conditions), then this isn’t practical.
A week with no wind is a long time. Even my relatively small suburban house could easily fit a 500L water tank and insulation (in fact, it has an unused one in the loft space already). More to the point, who says you have to become entirely self-sufficient? If you get 75% of your heating from the wind, that's still a significant reduction in the amount of energy you need from other sources. The space for the windmill is slightly more of an issue. Not sure I'd get planning permission for one of those..
If you look at solar, very few people have off-grid solar systems. Most houses with PVCs on the roof use them to reduce their energy requirements, not replace them.
District heating is a thing too (it predates electricity by a few thousand years!). It's not uncommon for hot water to be piped to homes where a source of easily available hot water exists - such as certain types of power station which have excess heat to dump. One windmill to heat a village isn't unthinkable - we already do that with electricity in some places, just a few miles from where I live there's a village who bought a electricity windmill and now people there have very cheap electricity bills. Would be slightly more work to install a heat version but still worth doing.
I think, generally, it is uncommon. Most homes are fed cold water from public utilities and then the water is heated in a water heater within the home.
I think you have a warped view of what situation most people live in. Installing large water tanks and windmills in cities is infeasible. How do I pump hot water to the 10th floor of an apartment building? You now need to spend more energy to move the hot water around, and if you use the wind, now you need to make the modern kind of wind mill that generates electricity, not just heat and we’re back to the inefficiencies. I stand by my statement that the only practical use for this is in very rural areas. It’s not surprising to me that this was popular with Danish farmers, but its never going to catch on in any urban area (not to mention, if you don’t own the land or building where you live, you probably don’t have the authority to install these systems anyway, and it’s not clear to me you can install such a system retroactively without tearing the whole building apart).
Edit: I take it back that installing large water tanks is infeasible. The windmill systems I still stand by.
"Most people" don't live in tall apartment buildings. Lots of people do, sure, but most people live in lower buildings or suburbs. For example, 1/4 of a million people live in my city and there are no more than six or seven high rise residential buildings here. Also bear in mind that pumping water up a few tens of metres is relatively cheap, energetically speaking, compared to heating that water from ambient to heating temperature (it already happens with cold water, so people can have taps in their flats). Yes, electrical cables have a lower cost to gain height but moving water just isn't that big of a problem. Having a big tank on the roof of an apartment building is reasonably possible. If that tank hooks in to everyone's heating and hot water systems you don't actually need it to be too big, because all the water in the system still counts as thermal ballast.
The best way to apply it to urban areas is to have larger plants which distribute hot water. District heating works just fine in urban areas, plenty of places already do it, although they don't tend to use windmills as the initial heat source, but that's a non-problem. Moscow springs to mind as one of the more famous centrally heated places. But even America has some installations.
Installation should be relatively trivial in any house with water based central heating. You just pump the incoming hot water into the header tank for that system and you're done. The existing heating system picks up the slack as needed. This part is an entirely solved problem already - my parents house dumps excess solar energy into their hot water and heating system, for example.
In my house you'd need to install a new header tank but there's plenty of room for that in the loft space. For a district system you'd just need to run a pipe into the house. Quite a lot of digging to do a whole city but it's not too challenging in terms of engineering. I'm sure there are some buildings which you'd need significant work on but almost all residential buildings have some pipe-based infrastructure already installed so you can probably work around that. The central heating in my house was installed about forty years after the building was put together, so it's definitely possible in some cases, if not all.
This is an interesting assertion. I don’t think I can refute it outright, but it doesn't align with my mental model of the world. I did a little bit of research, but if anyone else has some authoritative studies on this subject, I'd be very curious.
Here are some interesting, relevant, but not definitive findings in a quick Google Scholar search with the query: "floor of residence housing high-rise building".
This 1984 study of high-rise housing in Israel claims:
From a 2016 study of Singapore:
From a 2011 study of South Korea:
This book has a chapter that looks interesting, but Google Books has removed some of the relevant figures.
In any case, I'm not sure if the true majority of humans occupy living spaces in high-rise buildings as I can't find any hard evidence to back this up in either direction. That's actually disappointing, as this seems to be a demographic statistic that ought to be well studied. Even if it's not a majority of the population, let's at least agree that a significant number of humans live in compact cities, as evidenced by the trend of urban development since the 1960s in the developed world, and that a significant number of humans live in high rise buildings.
Right, but this work is typically performed by pumps connected to the electric grid. Take NY City for example. So, the water tanks are already there, but I really don’t think you’re going to get traction to build the windmills and radiators to use it for heat.
Well, then, the question becomes, how many buildings use water based central heating? I haven’t ever lived in such a building myself.
I would like to see more information should anyone have it because my claim was based purely on my personal experience. Most places I've been aren't full of high rise residential buildings. But you are right, plenty of people do live in tall buildings. Except I don't think that's particularly relevant to the discussion at hand because pumps are a thing and it's not like a heating system needs to be high pressure.
Is there a reason that the pumps can't be connected to the electric grid? The point I was making was that it's not unfeasible to pump water up a bit. I didn't think it would be free! :)
I think we have to be prepared to think a little outside the box when it comes to restructuring our infrastructure to be sustainable. There is no engineering reason we can't heat our homes and offices with wind, be those homes rural, suburban or high-rise. In the final analysis it might not be the most cost-effective way to become sustainable, but it should definitely remain an option on the table for consideration.
No, but from the original article, the whole benefit of this system seemed to stem from the fact that you didn’t need to be on the grid. I was just taking a holistic view.
I'd say almost every home in the UK uses water based heating. Every place I've lived for the last 40+ years does. As has every office building I've worked in, as far as I can remember. I seem to recall it being the same in houses I've visited on the mainland EU too (I once had to carry a radiator up several flights of stairs in France, before plumbing it in).
How else do you heat a house? I'm not being facetious, that's an honest question. Obviously fires/stoves are an option but that's what people had before central heating was a thing, so some older houses might still use those. Certainly nothing in a modern city would.
Air. I live in the U.S. (in the northeast), and the majority of buildings I’ve lived and worked in used air vents part of an HVAC system, or baseboard radiant heaters (basically just a bunch of metal fins attached to a heating element).
Edit: I have seen water radiators in the U.S., but mainly in older buildings, and it’s not common any more. I’ve also seen a lot of buildings that used to use water radiators, but no longer do. My elementary school building was very old (even when I attended school there 25 years ago) and used water radiators, but that building was turned into offices and the old heating system was replaced with HVAC.
Well, looks like you really do learn something new every day. I knew US had AC for making cold but I didn't know they used it for heating too. How do you heat the air?
Hey I guess in theory you could heat it with... a windmill!
By passing the air over a heating element. Here’s a selection of the typical kind of baseboard heaters you see in the U.S.
So, electricity. In the UK electrical heating is usually prohibitively expensive. I wouldn't be able to have the heat on very often if it cost me six times as much as it currently does! (gas = 1/6 electricity £/kWh here)
Anyway, drifting a little off topic here. In summary I'd say windmills to heat water (and then buildings) might be feasible as part of a blended system in some environments, although perhaps not so much the US where existing infrastructure may make it tricky to install.
IIRC central heating systems commonly found in buildings and houses are typically gas-powered, which is cheaper. But I am no expert.
Oh, yes, having a gas-powered furnace as a heat source is more common than electric heaters.
Lolwut?
Everybody who has rubbed their hands together in winter knows that a windmill can provide heat directly. The problem (as in literally all forms of renewable energy) lies in the storage of that energy. Where are you going to stick the heat until you need it? The massive water storage systems talked about in the article pale in comparison to poor quality LiPo battery storage options, and if you want to talk efficiency let's talk about the fact heat... dissipates?
I also love
A friend of mine is currently looking to install a system like this - they don't have to be massive water storage systems, they can be standard water tanks like you'd get in a lot of homes. A well-insulated water tank can hold heat for a very long time - certainly longer than you'd likely need it to (anyone who has used a vacuum flask knows that). The article claims
100L(edit, dropped a 0, updated numbers below) 1000L of water can store 90kWH of heat - to match that you need a lot of relatively expensive and chemically a bit unpleasant batteries or a simple 1m3 steel water tank which costs about £2000 (or far, far less for plastic+lots of insulation). You can't get a huge amount of batteries even for £2000 and water tanks don't lose capacity as you use them, you probably only install those things once a lifetime.If you have that tank hooked up to your central heating system, as my friend is looking to do, you gain even more thermal ballast while the heating is on (where he lives that's 6-7 months of the year). A heat exchanger in the tank can tap off heat into a second tank which is used for washing/cleaning water. Given many parts are off the shelf it's a very cheap way to harness wind energy to heat your home compared to complex and expensive electrical systems, although realistically if you were going all the way off-grid you'd likely end up with a combination system probably using PVCs for electricity and wind for heat, maybe even crossing over as required.
Also, got too much hot water in the summer because your heating is off? HOT TUB.
You dropped a 0, the article says 1000L of water stores 90KWh of heat -- enough for 1-2 days. Don't underestimate the size of the tanks needed to store all this heat.
At the upper bound that's 20 cubic meters of water storage, or a 2*2*5 meter box.
Whoops, my bad, thanks for catching that. 1000L is 1x1x1 metres. It's still not an unfeasibly large tank. If I felt like braving the forest of dust and spiders that is my attic I'd measure the size of (unused) tank up there but from memory it's probably in that kind of ballpark.
Yeah I don't think it makes systems like this unfeasible, especially if the tank design and size is considered when designing the house to begin with.
The size of the tank is an issue for direct solar themal collection too. I'm surprised that nobody's made a latent heat storage device for these applications yet... For example, the latent heat of fusion of simple paraffin wax is ~175 Kj/kg, compared to the specific heat of water of about 4 kj/kg. Obtaining efficient heat transfer in and out of a melting/solidifying substance is obviously harder, but these are the same principals that are used on a large scale for those giant molten salts tanks at CSP plants.
I think you overestimate the intelligence of the layman. There are people out there that don't even know that windmills produce electricity.
Low Tech Magazine is something you kind of have to get used to reading. It's got an ethos of sustainability that is held to a much higher standard than anything else I've ever seen. One of the ideas the author has suggested in the past is to store energy by moving water into a raised storage tank and releasing it with the force of gravity. Why? Because it's more sustainable than Lithium.
In any case, they do mention that storing the energy is not very efficient:
The Eddy current version is a pretty smart idea. I think it's possible even to make a hybrid system of Eddy current heater and power generator, where energy can be diverted in electrical form for various use and this way we have a 2 in 1 wind turbine, for efficient heating and less efficient but more versatile electric power.