[HN Gopher] World's first large-scale 'sand battery' goes online...
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World's first large-scale 'sand battery' goes online in Finland
Author : bobse
Score : 46 points
Date : 2022-07-06 21:03 UTC (1 hours ago)
(HTM) web link (www.energy-storage.news)
(TXT) w3m dump (www.energy-storage.news)
| dghlsakjg wrote:
| From this article it seems like they are using the sand to store
| heat that would otherwise go to waste due to temps too low to
| otherwise turn it into other forms of energy.
|
| At least that's what it seems like. They aren't very specific,
| but it explains why they aren't using something more akin to
| pumped water energy storage.
| pavon wrote:
| As an American it completely breaks my expectations that district
| heating not only works can be more efficient that decentralized
| heating. The amount of heat lost just moving water from the water
| heater on one side of the house to the shower on the other is
| ridiculously high in houses here. The idea that you can insulate
| well enough to efficiently move heat across a city is amazing to
| me.
| [deleted]
| Swizec wrote:
| My hometown has a power plant in city center. During winter it
| uses the entire downtown area as a heat sink. It's great. Power
| plant gets cooling for its hot water, city residents get cheap
| heating for their homes.
|
| Best part is you don't even care about heat loss because you're
| trying to get rid of all that heat anyway.
|
| This scheme has been inplace since the 60's.
| https://en.wikipedia.org/wiki/Ljubljana_Power_Station
|
| District Heating is quite popular in much of the world. USA
| built the first such system back in 1853.
| https://en.wikipedia.org/wiki/District_heating
| teruakohatu wrote:
| Given how much health problems are caused by coal power
| plants, not sure it is that great to live near one.
|
| But if you have to have coal, it makes good sense to harvest
| the energy rather than wastefully pumping the steam into
| cooling towers.
| Swizec wrote:
| I mean it's already there and has been for 60 years. I'm
| sure its polution pales in comparison to the 1,200,000 cars
| registered in the area.
|
| Back when the coal power plant was built it was pretty
| normal to live near coal burning things.
| gamegoblin wrote:
| Many American universities use district heating for the whole
| campus.
|
| Also, as made famous by the many steam vents in NYC movie
| shots:
| https://en.wikipedia.org/wiki/New_York_City_steam_system.
|
| More info:
| https://en.wikipedia.org/wiki/District_heating#United_States
| konschubert wrote:
| As a German living in a city with mandatory district heating...
| the end result is to be that people seem pay more for heating
| than they would with a decentralised system.
|
| I think that's mostly due to the high upkeep costs of the
| system, though, the transmission loss is quite manageable, I
| think. Of course there are arguments to be made that when
| accounting for the cost of installing a heating system, and the
| space it takes, the premium paid for district heating is not
| that high.
|
| But still... if district heating is so smart, why ain't it
| cheaper?
|
| What's nice about it, and maybe hard to quantify, is how this
| limits air pollution in the city. However, people are still
| allowed wood burning ovens... which they are now all turning to
| since the district heat is getting really, really expensive..
| socialdemocrat wrote:
| Here in Norway we generally pay LESS when we have district
| heating.
| teruakohatu wrote:
| > What's nice about it, and maybe hard to quantify, is how
| this limits air pollution in the city.
|
| It should be simple to quantify. If gas is used for heating I
| can't think there would be any improvement.
|
| Local heating with a heatpump would be an improvement if the
| power supply mix is greener than gas only, maybe worse if the
| power is all coal.
| Symbiote wrote:
| I find district heating in Copenhagen to be good value, and
| it seems to be a good deal greeted.
|
| https://celsiuscity.eu/district-heating-prices-highly-
| compet...
| vkou wrote:
| > The idea that you can insulate well enough to efficiently
| move heat across a city is amazing to me.
|
| It only works well when heating is 'free' - such as when you're
| using waste heat from a nuclear power plant, or from
| overproducing solar/wind plants.
| dubswithus wrote:
| I have a hot water recirculator installed and love it. It's
| even faster than on demand.
|
| Faster hot water incentivizes hand washing. Just think about
| how many more people would wash their hands at the airport if
| they didn't have to wait 2 minutes (or forever) to get hot
| water.
| Nick87633 wrote:
| I wash my hands with the cool water that initially comes out?
| ortusdux wrote:
| I'm looking at going this route before I finish the basement.
| The master shower is the furthest point from the heater, and
| it takes a solid 2-3 gallons to get hot water in the morning.
| The math didn't make sense until I put in a heat-pump water
| heater. Now I average $170/year to heat my water, and the
| recirc should only add ~$30/year. My pipes are well
| insulated, but I'm in a colder climate so loosing heat into
| the walls just lowers my heating bill.
| bluSCALE4 wrote:
| I installed a recirculating pump and had it on the timer.
| But then for some reason, I switched it to always on and
| it's so much nicer. Hot water is always hot.
| zdragnar wrote:
| American here.
|
| Most household water pipes really aren't insulated, or aren't
| insulated well enough. Plus, moving water under the frostline
| means that the ground it's moving through might be upwards of
| 55 degrees F.
|
| My house came with an outdoor wood boiler (it's more a rural
| cabin than a house, really). It moves 180*F water from the
| boiler 50 feet underground into the house, where it runs
| through an air exchanger in the central air system and pipes it
| back out to be reheated.
|
| Newer models of these things can get upwards of 98-99% burn
| efficiency, and ~85% heat transfer efficiency- as good as or
| better than you can get with standard efficiency furnaces.
| Animats wrote:
| That's useful. It's storing low-grade heat, which is fine for
| home heating but not useful for electricity generation.
| aaaaaaaaaaab wrote:
| Why sand?
|
| - water has 5x the specific heat capacity of sand
|
| - water can be pumped around easily
|
| - water can be used directly for district heating
| woodruffw wrote:
| Sand is non-corrosive and doesn't expand significantly at 500C
| (it takes temperatures ~3x that to get it to melt). That
| doesn't answer the "why" completely, but those are probably
| some of the factors.
|
| Edit: the article doesn't explain how the "battery" works, but
| my intuition is that the sand doesn't move. It's likely merely
| heated and then passively heats whatever actual transportation
| medium is used (likely water).
| vkou wrote:
| Presumably, because sand can be heated to above 100C.
|
| Given Newton's law of cooling, it's not entirely clear to me
| _why_ you want your thermal battery to be heated to above
| 100C... But I 'm not an engineer - I only play one on TV.
| droopyEyelids wrote:
| My guesses: - Water would either require a tremendous sized
| reservoir, or infrastructure capable of withstanding the
| pressure of superheated steam - superheated steam, and even
| water to an extent, has corrosive chemistry. Sand is basically
| inert.
|
| Those are just guesses though. I'd love an engineer who works
| on this to break down the real reasons.
| FastMonkey wrote:
| What's the round trip efficiency of something like this, and
| what's the rate of loss to the environment? There's been a couple
| of these posted in the last few days and I have no feel for these
| numbers.
| jpollock wrote:
| Data from Drake's Landing in Aberta has a COP of 30 (30kw of
| heat per kw of electricity)? The heat stored is waste heat -
| otherwise lost to the atmosphere, so storing it until use is
| should be compared to typical heat pump COP of 2-4.
|
| https://www.dlsc.ca/
|
| https://en.wikipedia.org/wiki/Drake_Landing_Solar_Community
| TheSpiceIsLife wrote:
| The key here is: this isn't a _battery_.
|
| It's electricity powered thermal storage for municipal heating.
|
| Which, in my opinion, is a smart idea. Why bother converting
| the heat back to electric to end up being used to generate heat
| in homes.
|
| You could use this as a heat sink at the home attached to a
| high efficiency heat pump for 6:1 thermal efficiency.
|
| We could do with municipal heating here in Tasmania
| vkou wrote:
| The RTE of turning electricity into heat (or hot water into hot
| sand into hot water) is pretty good, most of your problem will
| be environmental losses between the heating station and the
| end-users.
|
| It's not going to be as good as a heat pump, but they don't
| work very well in very cold climates, and storing _electricity_
| (or energy that you turn back into electricity) is expensive
| /lossy/difficult.
| loufe wrote:
| This was the question I came to pose... This is such an
| exciting field but when the CORE most important variable is
| missing, I tend to assume the worst - in this case being that
| the value is atrociously low.
| jpollock wrote:
| Alberta has a neighborhood that stores heat in the summer for
| winter use:
|
| https://en.wikipedia.org/wiki/Drake_Landing_Solar_Community
| htk wrote:
| The whole thing seems so inefficient but I am not an expert.
|
| Can anyone here expand on this?
| gebruikersnaam wrote:
| They are using waste heat that otherwise would just disappear.
| 50% efficient is still better than 100% not used.
| UberFly wrote:
| There are lots of websites online that explain it more like:
|
| https://www.bbc.com/news/science-environment-61996520
| rightbyte wrote:
| You can sink solar power into it in the summer and use the heat
| in the winter.
|
| With intermittent power like solar and wind you probably want
| to be able to sink it somewhere useful.
| ars wrote:
| It has 80 hours of storage - that's not enough summer/winter
| shifting. At most it's day/night.
| pyrolistical wrote:
| Strange they heat the sand instead of moving it around like a
| pumped battery
| mikewarot wrote:
| Moving sand (an abrasive grit) around is challenging at room
| temperate, doing it at 1000degF (500-600degC) seems impossible.
| It makes far more sense not to subject things to that kind of
| abrasion, and just flow air or water/steam through it.
| nonrandomstring wrote:
| A thermal battery is useful in concert with a heat pump.
| koreanguy wrote:
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(page generated 2022-07-06 23:00 UTC)