> For now, the concrete supercapacitor can store a little under 300 watt-hours per cubic metre – enough to power a 10-watt LED lightbulb for 30 hours.
> The power output "may seem low compared to conventional batteries, [but] a foundation with 30-40 cubic metres (1,060-1,410 cubic feet) of concrete could be sufficient to meet the daily energy needs of a residential house", says Stefaniuk.
This made me suspicious, because it sounded too low. But it turns out it's true ... for an average British home that's heavily dependent on gas.
40 m^3 * 300 watt-hours/m^3 = 12 kwh. I.e. 500 watts for a whole day.
Apparently the average American residential electricity use is 10,791 kwh/year, which is ~1,231 watts, whereas the average British home is only 2,700 kwh/year which is ~308 watts. I had no idea that the difference was so large.
I'm saying this with no data, but could it be because energy is just cheaper in the States? I have been using considerably less electricity since moving to NYC, since the price-per-KWh is about double what my costs were when I lived in Texas.
Also, I'd be curious how much of this could be due to electric car usage increasing?
This of course is anecdata, but I think a large percentage of it might come down to the fact that UK houses don't seem to run AC nearly as much. I spent two weeks in York a few years ago, during an extremely hot summer, and I was missing my AC very very much.
* UK requires appliances to be eco friendly - that means for most appliances they only take a quarter of the energy to do the same job. Dishwasher/washing machine/etc.
* UK housing has really high insulation requirements for new builds. Your body heat will keep it warm most of the year. They are starting to require retrofits for old buildings too.
* Widespread use of LED lighting and expensive electricity
* Smaller houses - less rooms etc.
* Tumble driers aren't widespread (big energy user).
* Electric water heating is rare (most houses use gas or oil).
* Air conditioning isn't widespread, despite the climate kinda needing it in the middle of summer.
UK climate "needs" AC for 1-2 months, one summer in three.
And a fair chunk of that is the summer holiday season, when a lot of people won't be home anyway.
It is possible to mis-design houses and apartments to need it more than that (extreme sun traps essentially); schools/offices and public transport are a different case because of the number of human bodies in a small space.
But our homes need A/C so rarely that it's not worth it, same as most people don't have winter tyres or snow chains, or even know how to fit them. Materially significant amounts of snow for a few days one winter in three, unless you live in Scotland or the Pennines.
Having living spaces too hot has a substantial effect on productivity. Bad sleep, lethargy, etc.
As a government, it's probably a good move to encourage installation of AC in your citizens homes even if it only gets used a couple of days a year simply for the productivity benefits.
Unfortunately, current UK policies on Heat Pumps specifically discourage installation of AC (you become ineligible for various grants if your heat pump system has a valve to allow use as an AC system).
Houses rarely need AC - we usually only get a few hot days in a row, with time for houses to cool down in between hot periods. It is also usually possible to get airflow through a house, and cool things down enough.
Different story for badly built apartments, though. We used to live in a 1950s apartment, top floor with a flat roof. It reached 38C inside, when outside was 36C, and then wouldn't cool down at all during the night. It was unbearable, and we moved out!
Yep, definitely possible to design and build unpleasant sun traps! But also mostly possible (even for curtain-wall apartments) to avoid it with good design.
Not much help if you buy an existing place whose builders didn't take hot summers into account though!
These days its practically every summer tbh :P The last two have been super bad for me, as my apartment is south facing and doesn't have any AC. I'm not looking forward to this summer at all haha
> UK housing has really high insulation requirements for new builds. Your body heat will keep it warm most of the year. They are starting to require retrofits for old buildings too.
UK housing is mostly quite old - an average age of 50 years or so. Modern insulation requirements only became law in the last 20 years. Most houses aren't particularly well insulated - and most houses haven't had much retrofit work done. The UK is really far behind most of Northern Europe in this regard.
I think the rest of your reasons are valid. Average floor area is probably half that of a US house. Domestic air conditioning is almost unheard of. Almost everyone heats with natural gas.
Heating is a huge part of energy demand - around 25% of UK total energy goes into space heating - so if you're not doing that via electricity then average energy consumption per house will be much lower.
I'd agree with the article authors figures. I have a small family home in the UK and use about 2000 KWh a year electric only. I have gas heating and water.
Electricity cost is currently running at about 28p/KWh. I presume that's a lot more than the US. Electric heating is indeed rarer because gas is about 1/3 of the cost.
I'm thinking your points about air conditioning is likely the major difference combined with the average US home being larger so more space to air-con. Few UK homes have air conditioners (offices do) as it doesn't usually get hot enough. Although this has started to change in the last few years and I'm seeing them occasionally popping up now on neighbours houses. I wouldn't have needed one this year at all so far. Last year, maybe for one week. I was thinking about it but by the time you've looked into organising something the heat has gone and you forget about it until next year. There is a push to move to heat pump heating instead of gas and those units often can do air-con as a byproduct so that may be a driver for change.
Tumble driers are easily available and definitely widespread in the UK. The lack of tumbler driers is a bizarre myth I see again and again on lists of differences between the US and UK. I have no idea how the authors of these lists come to this conclusion. The only idea I have is maybe people from the US who come to the UK rent a furnished house and the landlord cheaps out and decides not to supply one. I do have one and it runs to about 2KWh a load maybe? I don't think that would explain the difference in any case.
> Tumble driers aren't widespread (big energy user).
My 20 year old drier uses about twice amount of kwh as my 7 year old dishwasher (on actual clean mode, not "eco: everything is still dirty and you should do it by hand mode"). I also use it far less, so on average they are about the same.
So does the UK. Everywhere I've lived in the UK had electric stoves; everywhere I've lived in the USA had gas stoves. I'd be interested to see stats if they exist.
Also in the USA you see gas-fired tumble dryers, which you never see in the UK, probably due to 240V all round.
A lot of that doesnt apply to old dwellings does it?
I recall in my great grandparents old terrace house, the kitchen was set behind the neighbors fireplace. The only rational place for the fridge stand effectively copped 50-80 degrees from the neighbors fire, just radiating from the brick. This lead to the fridge running constantly and having an extremely short lifespan (and sometimes not functioning at all)
That said because it was old everything was air dried.
The UK has a ton of old dwellings. Like, a three century old home isn't even a local landmark. It's just a house.
They have of course been retrofitted with electricity and plumbing and gas and modern insulation (usually), but exactly what you get depends on how recently it's been renovated. And "mid 20th century" is a very common answer.
I had a look at their home town on google maps, and it looked like 1/2 to 1/3 of the town was still made up of old terrace houses. I imagine it would be tricky to selectively demolish them.
Not really, the U.K. has some of the oldest housing stock in the world. For e.g. my house is pretty typical, built in 1912, it has a double skin wall of bricks but with no cavity. It has three original fireplaces which are all very draughty. I have timber sash windows, and though I recently got double glazing my neighbours on either side do not have it.
New builds require Roofs: 0.11 W/m²K. Walls: 0.18 W/m²K. Floors: 0.13 W/m²K. Assume 2024 houses are 7mx7mx5m high and terraced.
So you have 70m² of wall, 49m² of roof and floor. Total 24.6 W/K. So, with the average UK electricity consumption (300 watts), plus the body heat of 3 people (300 watts) you have 600 watts of heating, which should keep that building 25 deg C above the outdoor temperature.
The UK in winter normally averages about 5C, so you'd have an indoor temperature of 30C - plenty toasty.
Obviously many buildings don't meet the required standards, people aren't home all day, there are air leaks, etc. But, for most buildings, heating is still not required most of the time.
A free standing house at only 49 m^2? Is that typical in the UK? The US average size for single family homes was triple that back in the 1970’s. Today it’s more like 5 times that size.
Yes, it's small, but new houses are mostly very small because they try to be 'affordable'.
Most people with lots of money buy an older house which is bigger, sometimes knocking down and rebuilding the same house if you want to modernize (in many areas you have to rebuild something the same size, shape and appearance).
A lot of heating in the UK is gas (so wouldn't drive electricity consumption) and a lot of homes in the UK do not have AC (recent news reports suggest it is under 5% of the homes have it)
Yeah, that does not surprise me. The apartment I stayed at in York was absolutely tiny. It was decent, and big enough for one person, and it was pretty cheap, so I'm not complaining really, but I've never seen an apartment that small in the US.
Also there was just no HVAC there to begin with, so I guess even less of an HVAC bill.
It's kind of mad that the US houses are an average of 2000 square feet, yet if you watch some of the "New York apartment tour" videos on YouTube they are often far smaller than even what you'd find in London. The kitchens are often absolutely pitiful little spaces, especially considering the multi-thousand-dollar rents.
If you’re in downtown or midtown they’re small. I lived in Washington Heights (north Manhattan) for a few years and my apartment was two bedrooms with a relatively big living area, and I was able to afford that with an academic’s salary. I don’t remember the exact square footage but my wife and I lived there and it didn’t feel cramped at all. I own a house in Brooklyn now and if you count the basement it’s about 1600sqft.
Though York is a fairly rural town, and houses/apartments that small in rural America, as far as I am aware, are basically unheard of.
There's lots of places in the US that don't have natural gas infrastructure and do all heating electrically. The UK has a much higher population density so services like natural gas are more widely available, I'd guess with no evidence to back that up.
In the US there are lots of places where electricity is fact quite cheap like that. For example, in my county heating with propane doesn't even come close to making sense, due to the excess of cheap hydro power.
Keep in mind that the UK is much smaller and has a colder climate in general. If you look at a state like Colorado, the energy usage is vastly different than Florida or Texas with lots of heat and humidity.
I would bet that the southern states skew the results quite a bit for the entire USA.
Here in Australia the coldest state (tas) uses more energy (8600) than anywhere else (e.g. qld 5500). They have basically 100% hydro power and use reverse cycle AC for heating. Not sure what else is going on there.
>If you look at a state like Colorado, the energy usage is vastly different than Florida or Texas with lots of heat and humidity.
Electricity usage yes. Energy usage no. Household energy usage is lower in the warmer states, and higher in colder states. I would expect that CO household energy consumption would be higher than FL or TX.
Yes whoops. I should have made that distinction. The parent comment was talking about electricity, and that’s what I meant.
I would argue that the USA as a whole generally has more climate variability than the UK in addition to larger housing to account for the overall energy usage as well.
> Apparently the average American residential electricity use is 10,791 kwh/year, which is ~1,231 watts, whereas the average British home is only 2,700 kwh/year which is ~308 watts. I had no idea that the difference was so large.
Well, American homes aren't built out of brick and concrete like European buildings are, instead they're made out of wood and cardboard which is barely insulating against heat (and doesn't hold up at all to major storms which is why you're seeing so much destruction after hurricanes), so they lose a lot of energy during winter and have to spend a lot of electricity on AC during the summer.
On top of that, their homes are (at least in suburbia) so much larger than European homes. Heat loss/influx is cubic-related to the footprint IIRC, so it makes for much more energy demand as well.
> Apparently the average American residential electricity use is 10,791 kwh/year, which is ~1,231 watts, whereas the average British home is only 2,700 kwh/year which is ~308 watts. I had no idea that the difference was so large.
They main reason is that US has a higher percentage of all-electric homes. The average medium sized UK home uses 2700 kWh/year of electricity and 11500 kWh/year of gas. See that table in your second link.
What you want to compare is average household energy use excluding transportation. For the UK the numbers in your link give 9400 kWh/year for 1-2 people in a flat or 1-bedroom house, 14200 kWh/year for 2-3 people in a 3-bedroom house, and 21100 kWh/year for 4-5 people in a 5-bedroom house.
I'll leave it to someone else to find out how those are distributed to work out the average for the UK as a whole.
For the US, in 2011 [1], annual usage was 108 MBTU for single family detached houses, 89 MBTU for single family attached houses, and 54 MBTU for multi-family housing. In kWh that's 31700 kWh, 26100 kWh, and 15800 kWh.
I'll leave it for someone else to find the distribution so those can be combined, and to find later data. Almost all searches for household energy US of US households just return electricity usage and the 2011 document was the only thing I found that gave what I was looking for.
While I'm fairly dubious about the proposed dual-purpose structural implementation of this material -- if this works at scale it would be a boon for low cost DIY local energy storage in the developing world and remote areas in other places.
The idea that someone with minimal education/training can construct a durable electrical storage solution using commonly available materials and techniques is an absolute game changer!!
The most relevant (practical) questions to me are, how does this capacitor behave long-term? How does it fare over a large number of charge/discharge cycles? I'd like to assume that, since it's not a battery, thus not based on chemical process for energy storage, it will retain its initial performance for a long time, but the question is - how long? A human generation (i.e. 25-30 years)? Or maybe longer, as for at least ten generations? That would directly affect the demand for long term investments in the construction sector. And if things may sound rosy from its storage capacity capability, if it will get used for combined structural and energy storage use, what long term impact on structural properties may render this dual use?
> larger versions, including one up to 45 cubic metres (1,590 cubic feet) in size that would be able store around 10kWh of energy needed to power to power a house for a day.
45 cubic meter is a cube with side 3.56 meter. That is not large at all. Especially, if it can be sunk into the ground. I assume septic tanks are also about the same size.
A septic tank is usually only a few thousand litre. In the UK a house with a maximum occupancy of six would have a septic tank capacity of about 3 000 litre, that is, 3 cubic metre. A cube of just under 1.5 m on a side.
That is quite an expensive battery if you're just sinking it into the ground as a cube, though. Concrete is pretty expensive and I'm sure carbon black makes concrete look cheap.
I imagine the benefit would be if you can use it to build your foundation and get energy storage for 'free' in which case that's quite a lot of foundation.
You are actually right [1]. Using the quoted figures of 30'x30'x4'' = 8 meter cube costing 7.5k USD, we get 41k USD. Which is crazy expensive even for foundation.
It's easily twice that by the time you dig a hole and get it delivered and poured. 180-200 per cubic yard (basically a cubic meter), formed and poured is a good deal.
I’m not sure if I’ve misread the article but it seemed unclear as to whether the concrete needed to remain soaked in potassium chloride? Surely keeping a whole foundation soaked indefinitely would be impractical?
Some electrolyte is certainly required for a supercapacitor. Hopefully battery research(solid electrolytes) carries over so that there will be no need for soaking concrete in corrosive solution.
I see these things as a waste of time and resources. We already have all sorts of ways of storing energy, from chemical to mechanical to biological, which are known to work. There are myriad open questions regarding the practicalities of incorporating a battery as the frame of your house, and given the "technological inertia" of the building sector and its regulations, it would take several decades before we even start experimenting with this in real houses. Meanwhile, the world burns and we increase our energy consumption. Again, a waste of time and resources.
When looking at the diagrams for an ideal wall [1], I am reminded of diagrams of capacitors from Physics classes. This got me to thinking that two conductive vapor barrier with a dialectic/insulator sandwiched between them, such as aerogel, would work well as a wall element, and a capacitor storage device for a house.
Normal capacitors have to have absurdly thin dielectrics to get any appreciable charge storage. An aluminium electrolytic capacitor (the can shaped ones) use just thickness of an aluminium oxide layer. Any sandwich thickness that would be practical for thermal insulation will have essentially zero capacitance.
And even if you could have a super thin, delicate layer in the walls, and the builders don't break it putting it in, why not just roll it up tightly and put it safely in a can along with any electrolyte it needs in the first place?
The key feature of supercapacitors is that they exploit 3D effects (or rather a 2D effect around very tiny features in a 3D volume) that allow them to use the volume of the material, combined with a very tiny effective charge separation.
I don't want to be a naysayer, but I do have to wonder, are there any risks associated with making the walls themselves store large quantities of energy?
I'm thinking fire hazards or shorts associated with, say, hanging a framed picture on the wall (or anything else that would involve drilling in the concrete)
300 watt-hours per cubic meter is not large by any means. You can get 300wh portable batteries and they are the size of a loaf of bread, this is at least 1 magnitude bigger/less dense
I mean, one way to look at it is that the energy density of this concrete supercapacitor, when fully charged, is about 4 orders of magnitude smaller than the chemical energy density of wood.
So depending on the design, electrical shorts might be something to worry about, but I have a hard time worrying about it as a significant fire hazard when compared to all of the other flammable things you might find in a house.
Why not use this for a way more obvious application such as corrosion protection? You can then mix in the sacrificial anode as a powder instead of having discrete anodes.
At least in a nautical context, sacrificial anodes wear out every few years and have to be swapped out for new material. That will be impossible if the anode is embodied within the material. But yeah, it probably has applications somewhere.
That's a very poor article. It doesn't explain what the potassium chloride is for.
It's interesting but you can store a lot of thermal energy in concrete. The heat capacity is 1050 J/(kg.K). One cubic meter of concrete is about 2 400 kg and the heat capacity is roughly 1 x 10^3 J/(kg.K) so raising the temperature by just 1 degree C would store 2.4 x 10^6 J. That's 666 Wh.
Twice the energy storage for only one kelvin temperature rise with no technological breakthroughs needed. Granted it's not electricity but in temperate and colder climates a lot of the energy needed in a home is heat.
Still a very interesting idea and if it can be made to work cheaply enough even at the storage capacity they quote it would add a lot of flexibility to the energy system.
> "Supercapacitors are not perfect. Existing iterations discharge power quickly, and are not ideal for steady output, which would be needed to power a house throughout the day."
Could someone kindly explain to me how this works?
For example, if you had an empty lithium battery which can store X amount of power, and a fully charged supercapacitor which holds 10X, can you charge the lithium battery to full and leave 9X in the supercapacitor?
If no, why not and how do you (both safely and usefully) get energy out of a supercapacitor? Or if yes, could a relatively small battery between the SC and a house act as a buffer to stop it mattering that the SC discharges "too quickly and unsteadily"?
The issue with a super-capacitor is that it leaks. If you put X Joules in there and wait a while then you will only have X/2 Joules. Wait a little longer and you'll only have X/4.
So on the other hand, super-capacitors are great at charging and discharging rapidly with low loss. So if you want to fire a high powered laser for a few femtoseconds then they work great. You can't get power into and out of a battery that quickly because chemical reactions take time, so super-capacitors have their applications. It's just that holding power for more than a few minutes is probably not it.
There are some practical losses in efficiency from voltage conversions and such (a capcitor's voltage is proportional to the square root of it's stored energy, while a battery's voltage is a much flatter function of stored energy), but theoretically, yes you can do just that. The biggest issue is that capacitors typically have much lower energy densities than batteries.
You just have to put regulation in for supercapacitors that batteries don't need. Batteries have natural internal resistance, so they "meter" the power out, whereas capacitors are perfectly happy releasing all of their energy at once (also known as a bomb). If accounted for I don't see it as a big deal, but it is a potentially explosive risk.
> The power output "may seem low compared to conventional batteries, [but] a foundation with 30-40 cubic metres (1,060-1,410 cubic feet) of concrete could be sufficient to meet the daily energy needs of a residential house", says Stefaniuk.
This made me suspicious, because it sounded too low. But it turns out it's true ... for an average British home that's heavily dependent on gas.
40 m^3 * 300 watt-hours/m^3 = 12 kwh. I.e. 500 watts for a whole day.
Apparently the average American residential electricity use is 10,791 kwh/year, which is ~1,231 watts, whereas the average British home is only 2,700 kwh/year which is ~308 watts. I had no idea that the difference was so large.
https://www.eia.gov/tools/faqs/faq.php?id=97&t=3
https://www.britishgas.co.uk/energy/guides/average-bill.html