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Large-scale ‘sand battery’ goes online in Finland

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Re: Large-scale ‘sand battery’ goes online in Finland

#171
post #92

Earlier quoted context omitted.

The University of Idaho uses district heat. The pipes run under the sidewalks so the waste heat keeps the sidewalks clear in winter.

By German standards that's still poor insulation. In winter in Leipzig the district heating pipes have snow sitting on them.

Sometimes this is intentional to keep paths clear. Idaho is much colder than Leipzig in winter.

Re: Large-scale ‘sand battery’ goes online in Finland

#172
post #124

Earlier quoted context omitted.

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…

Here in Poland we pay much LESS with district heating than decentralized one. If I would have to pay for decentralized heating of my flat, I'd need to use natural gas. But even before nat gas proces went to the moon, it was at least Here in Poland we pay much LESS with district heating than decentralized one 2x more expensive than district heating

Weird - natural gas was, up until last year, the cheapest of all options in Austria. My father used to pay more in base fees and taxes than the actual gas. For some people, prices now went up by x8, so it’s now the most expensive option. Many are looking into heat pumps + solar right now.

Re: Large-scale ‘sand battery’ goes online in Finland

#173

Earlier quoted context omitted.

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…

Yeah I'd hate having District heating. A friend had this in the past and she couldn't even regulate it. The house was way too hot for her. It would not work for me as I usually have the house around 16 degrees C in winter. Needless to say my energy bill is very low :)

This does not sound right. You can regulate district heating when it enters your house.

Re: Large-scale ‘sand battery’ goes online in Finland

#174
post #24

Earlier quoted context omitted.

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.

Sand (much denser = sinks in water) has low thermal conductivity, and isn't much more expensive. Simply put, in two bodies of equal volume and 'heat capacity', the one that's hotter stores more heat. Sand properties: [ https://material-properties.org/sand-density-heat-capacity-t... ]

From your link, sand has much worse heat capacity than water at 800 J/kgK vs 4000 for water.

Re: Large-scale ‘sand battery’ goes online in Finland

#175

Earlier quoted context omitted.

I think the real problem is how susceptible houses in US/Canada (maybe elsewhere) are to water leaks of any sort. Drywall, wood, MDF, insulation, etc., are all immediately destroyed with water in a short amount of time. A typical house lasts for 100 years or more and will likely experience many water leaks of various kinds over the course of its lifetime.

Houses last 100 years? They can, but typically after 20 years it starts to make economic sense to scoop the remains of the house into a dump truck and build a fancier house on the now much more expensive land under it. In my neighborhood (admittedly, originally built in the 50s) every single sale I can remember from the last 15 years has resulted it a complete teardown and rebuild bigger. And one of those rebuilds re…

20 years!? That's absurd.

It never makes economic sense to tear down a house if you're paying for it (above the land value). It depends on building codes in your area and such but my house is nearly 40 and it's not even close to end of life. Hell, the house I grew up in is still there and it's gotta be approaching 80.

Re: Large-scale ‘sand battery’ goes online in Finland

#176

Earlier quoted context omitted.

>They last as long as the expected tank life these days. Kinda seems like a self-fulfilling prophecy or one could even say planned obsolescence.

Or an accurate estimate??? I don't really get how you can extract a conspiracy out of something lasting as long as the manufacturer expected it to last.

Many manufacturers design things to wear out or break earlier than they would with minor changes to the design.

It is an accurate estimate, done to increase sales.

Re: Large-scale ‘sand battery’ goes online in Finland

#177

I've proposed several times on HN a "box of rocks" at the house level to store heat/cold when electricity is cheap, and release heat/cold when electricity is expensive. It was ridiculed every time. I should have patented it :-)

Don't listen to other people.

Re: Large-scale ‘sand battery’ goes online in Finland

#178

Earlier quoted context omitted.

Yeah I'd hate having District heating. A friend had this in the past and she couldn't even regulate it. The house was way too hot for her. It would not work for me as I usually have the house around 16 degrees C in winter. Needless to say my energy bill is very low :)

This does not sound right. You can regulate district heating when it enters your house.

I have seen this several times in 1950s/1960s eastern bloc apartments.

I was only visiting, so I don't know if it was the original design, or if the valves have jammed.

Re: Large-scale ‘sand battery’ goes online in Finland

#179
post #136

Earlier quoted context omitted.

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…

>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. True, my sister's family lives in a house with centralized heating and they pay 3-4 times more (!) per month compared to our home which simply uses an on-demand heater.

That sounds like some terrible bureaucracy coupled with some hybrid privatisation. I would be livid if my politicians allowed some company to profit off their de facto monopoly on a central heating grid.

Re: Large-scale ‘sand battery’ goes online in Finland

#180

Earlier quoted context omitted.

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

From finnish point of view, those seem small. In finnish, the term is ”kaukolämpö”, literally ”far heat”. You dont heat a ”district”, you heat the entire city. I mean, electricity wires go everywhere, why not heating pipes. And so the network for Helsinki looks like this: https://twitter.com/energiahelen/status/1511998227008176129?... The red lines is the heat pipe network, it covers the entire city. When Americans t…

More people live in New York than in the whole of Finland.
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