[HN Gopher] Researchers make a supercapacitor from water, cement...
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Researchers make a supercapacitor from water, cement, and carbon
black
Author : ranit
Score : 96 points
Date : 2024-06-11 10:55 UTC (1 days ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| jakelsaunders94 wrote:
| 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?
| rini17 wrote:
| 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.
| amarant wrote:
| 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)
| teraflop wrote:
| 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.
| killingtime74 wrote:
| 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
| kwhitefoot wrote:
| It's only half the energy associated with raising the
| temperature of the same mass of concrete by one kelvin.
| kallistisoft wrote:
| I'm happy this invention is still in the news cycle after the
| initial announcement 10 months ago...
|
| [0] https://news.ycombinator.com/item?id=36958531
|
| [1] https://news.ycombinator.com/item?id=36993411
|
| [2] https://news.ycombinator.com/item?id=36951089
|
| 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!!
| westurner wrote:
| - "Low-cost additive turns concrete slabs into super-fast
| energy storage" (2023)
| https://news.ycombinator.com/item?id=36964735
| imtringued wrote:
| 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.
| contingencies wrote:
| 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.
| abdullahkhalids wrote:
| > 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.
|
| Paper, if anyone interested:
| https://www.pnas.org/doi/full/10.1073/pnas.2304318120?doi=10...
| kwhitefoot wrote:
| 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.
|
| See https://www.ukseptictanks.co.uk/size-septic-tanks
| idiotsecant wrote:
| 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.
| abeppu wrote:
| > 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.
|
| https://www.eia.gov/tools/faqs/faq.php?id=97&t=3
|
| https://www.britishgas.co.uk/energy/guides/average-bill.html
| tombert wrote:
| 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.
| dgacmu wrote:
| Some quick checking:
|
| Average (well, median) US house size: 2000 ft^2
|
| Average UK house size: 68 m^2 = 740 ft^2
|
| That makes for a very, very different HVAC bill.
|
| Numbers vary a lot by source but the relationship (2x+ larger
| in the US) holds. For example:
| https://www.zigguratrealestate.ph/post/how-big-is-a-house-
| av...
| tombert wrote:
| 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.
| oersted wrote:
| From my anecdotal experience, residential HVAC is fairly
| uncommon in EU. Lived in northern Spain and Netherlands for
| many years.
| idiotsecant wrote:
| 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.
| londons_explore wrote:
| In the UK, places without natural gas almost all use oil
| for heating instead.
|
| A small chunk of buildings built in the 60's use
| electricity because we thought that would be cheap in a
| post-nuclear world. We were wrong.
| londons_explore wrote:
| The big differences are: * 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.
| bitlevel wrote:
| Simplest explaination - air conditioning - which isn't much
| used in the UK.
| mathsmath wrote:
| 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.
| salty_biscuits wrote:
| 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.
| johngalt wrote:
| >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.
| kwhitefoot wrote:
| 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.
| ranit wrote:
| This is the research paper linked in the article.
|
| https://www.pnas.org/doi/10.1073/pnas.2304318120
| swores wrote:
| > " _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"?
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