Good idea but why is it being measured in MW/MWh when it’s not an electrical battery? I know they can be converted but maybe it should be measured in actual thermal units like Btu?
Finnish City Inaugurates 1 MW/100 MWh Sand Battery
81–90 of 190 posts
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#82Finland is still 25% oil for electric generation [1] (and almost 40% fossil fuel). That means a lot of the electricity to heat the sand still comes from oil. It makes me wonder if this is more efficient than just using oil heating. Or some hybrid approach that uses oil to heat the sand. Of course there are other benefits: it's still a good way to level electric generation, which is important for e.g. nuclear plants a…
95% of Finnish electricity is clean: nuclear, wind, hydro, renewable biomass. Oil 0.3%, coal 1.5%, net import of electricity 3.8% (most of it clean also).
Older private homes still use oil for heating. All new use electric, heat pumps, or geothermal heat pumps.
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#83Earlier quoted context omitted.
The Wikipedia article says: "Rock, sand and concrete has a heat capacity about one third of water's. On the other hand, concrete can be heated to much higher temperatures (1200 °C) by for example electrical heating and therefore has a much higher overall volumetric capacity." and "Polar Night Energy installed a thermal battery in Finland that stores heat in a mass of sand. It was expected to reduce carbon emissions f…
The higher temperature output is a good point, you can't get 400C output for industrial processes from a 100C water based heat battery.
a Blast furnace needs closer to 2000° than 400°
in any case, how would you transport high temperatures to the industrial sites? water boils at 100° and few liquids boil above 400°. most liquids will be impractical due to cost or safety (combustibility, toxicity…).
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#84Earlier quoted context omitted.
I think with enough renewable in the grid, there will always be times when the costs are 0 or negative, so you can help stabilize the grid by consuming.
Are there downsides to "just" sending all of the extra energy to ground? I've often wondered why overpowering the grid has been talked about as this huge unsolvable problem. I understand it's wasteful, of course, but waste in a ecosystem of vast abundance seems like a feature, not a bug.
As I understand it, you need to limit the current flow to ground to not create a fault that burns out the whole setup. The most practical way to do that is with a bank of resistors. At that point, the resistors are doing the work and you're just using the ground as a return path, which isn't necessary.
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#85Earlier quoted context omitted.
I think with enough renewable in the grid, there will always be times when the costs are 0 or negative, so you can help stabilize the grid by consuming.
Are there downsides to "just" sending all of the extra energy to ground? I've often wondered why overpowering the grid has been talked about as this huge unsolvable problem. I understand it's wasteful, of course, but waste in a ecosystem of vast abundance seems like a feature, not a bug.
Solar and wind can be trivially turned down when not required. They are much, much better at it than traditional sources.
So easy that one of the actual problems we face is that by default grids will generally prefer to turn off the clean renewables and let the difficult to modulate fossil fuels run.
This is why negative prices are a good thing, financially incentivizing fossil producers to plan for flexibility and fining them when they fail to do so.
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#86Problem here is that if heating was done with electricity itself, it could have like 300% effective efficiency because of using heat pump, but a heat pump can't be used for 500C temperatures, it must be resistive heating. So even if no thermal loss occurs at all, we end up getting a lot, lot less heat than we could do otherwise. It's a lot better to use normal li-ion instead, surely 100 MWh means 500-ton battery and with longer life chemistries and thermal management, probably a 1000-ton one...
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#87Really like the idea, but my house alone has roughly 16 MWh/a heat consumption. Of which half gets consumed November through January. So this system could supply 12 houses? Shows the importance of proper insulation, which is still on our todo list.
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Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#88Good idea but why is it being measured in MW/MWh when it’s not an electrical battery? I know they can be converted but maybe it should be measured in actual thermal units like Btu?
Finland probably doesn't use US customary units like BTU (British Thermal Unit).
In fact even Britain doesn't often use such units - even gas boilers, heat pumps and some AC are specced in kW. You do see BTU (the /hr is often missing) sometimes on AC marketing. My theory is 18000 sounds big and impressive and 5.2kW sounds "meh". We definitely don't talk about "tons", and we buy gas in cubic metres or "units" (which is just kWh)
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#89Earlier quoted context omitted.
> And I understand that debunking low-effort accusations is asymmetric warfare Is the comment even that unfair? Asserting that it will never pay off because the presentation avoided mentioning anything about the payoff might be a little bit cynical, but not terribly so. It could be fairly presumed that if the project is a clear economic win, they would be proudly bragging about it; and the opposite presumption is als…
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All those subjects in the right context are things the left wing fights for. Reducing a complex subject and then saying because you do not agree with my interpretation you are against children, is not optimal. E.g. Climate Activists are a pretty diverse group you will find lots of people who have said the same thing. It is obvious this is a PR/Research stunt, but it might still pay off. This is not a straight forward discussion where all people in the right or left groups has to agree.
Re: Finnish City Inaugurates 1 MW/100 MWh Sand Battery
#90This is super cool but the ending is bizarre. > A comment on the YouTube video below complained, “Not a word about return on investment in the presentation. That means it’ll never pay off” MAGAlomaniacs are everywhere these days. Given the supposed 50+ year lifespan of such a battery, I find it hard to believe it doesn't turn a profit at some point. And I understand that debunking low-effort accusations is asymmetric…
The battery (am assuming it's just sand and metal) should be very cheap compared to Lithium especially in the places where you generated solar energy (they are hot and have a lot of sand).
The problem is: is it profitable to even store energy there? There is no mention beyond "In operation, the sand battery has demonstrated a round trip efficiency of 90 percent.". That doesn't mean much if you do not compare it to Lithium and you don't give me a breakdown of the costs.
The other thing: Size. Is that big thing enough to store energy for a city? a neighborhood? A building? A house?
If it's enough just for a house, then I have trouble seeing this scale.