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Large-scale ‘sand battery’ goes online in Finland

energy-storage.news

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

#201

Post by [deleted] »

kitd wrote: post #146
pavon wrote: post #8

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.

I once visited a geothermal plant about 20km outside Reykjavik that supplies hot water for heating the city. Even in the depths of Icelandic winter, the temperature only drops 1 deg C between the plant and the city. A lot of Rockwool around the pipe IIRC.

[deleted]

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

#204

Post by Gasp0de »

killerpopiller wrote: post #185
2Gkashmiri wrote: post #170

Earlier quoted context omitted.

i have been thinking about getting a solar water heater>heat pump>radiator to warm up my home but the costs just dont make sense because of the heat pump. i am told the life expectancy of a good heatpump is like 10 years, that amount divided by only 10 winters it is expected to see is more than what we currently pay for electricity in winters, accepting that we don't currently have whole house heating, (we rely on pe…

that can't be true. In Germany it is quite a trend now, but they are installed for many years. What I can read in the boards is not that discouraging. Where does this 10 year number come from?

The internet tells me that split-ac systems (basically small heat pumps) have a life expectancy of 10-20 years. That's not too bad, for example an oil-based heating system (as we have in our german basement) also only has a life expectancy of 20 years and has way less moving parts.

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

#205

Post by wikfwikf »

riku_iki wrote: post #119
tjmc wrote: post #101

Earlier quoted context omitted.

HVAC engineer here. At the residential level this is already achievable with hot water storage from either solar thermal and/or heat pumps. Plus you get to use the hot water (assuming you've sized the tank correctly!) Storing heat in rocks or sand doesn't make sense from a thermal efficiency standpoint unless the temperature is high and that isn't economically viable unless you have large volume storage - typically d…

Article says they heat sand up to 500C, which is not very possible with water.

They have to heat to 500C, because recovering the energy is slow unless you have those high temperatures. The advantage of water is that it's easy to extract the heat energy and transmit it to where you want it.

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

#207

Post by wikfwikf »

gebruikersnaam wrote: post #13
htk wrote: post #3

The whole thing seems so inefficient but I am not an expert. Can anyone here expand on this?

They are using waste heat that otherwise would just disappear. 50% efficient is still better than 100% not used.

They are not using waste heat but low-cost electricity. A system heated to 500C is not running on waste heat.

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

#208

Post by krageon »

mcosta wrote: post #180
arka2147483647 wrote: post #161

Earlier quoted context omitted.

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.

You can sort of tell from the other responses, but really the core of this argument is not the one you think it is: You think this means it is less appropriate for New York because of this fact. It is the opposite. Your population density is higher, so these types of solutions are easier and more cost-effective. This makes the fact that you don't already have it seem even more incompetent, which is the opposite of what you wanted to achieve.

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

#209

Post by krageon »

Symbiote wrote: post #171
thombat wrote: post #165

Earlier quoted context omitted.

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.

When the sidewalks are melted, it becomes waste heat. The rest of the year, it is waste heat. No matter how cold it is, if you accidentally leak heat it is wasteful - even if the side effect is something you may otherwise want.

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

#210

Post by mgiampapa »

scotty79 wrote: post #191
mcosta wrote: post #180

Earlier quoted context omitted.

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

Which only makes more sense for the New York to be heated by a network of pipes.

Portions of NYC are heated by pipes. ConEd operates the largest commercial steam system in the world.

https://en.m.wikipedia.org/wiki/New_York_City_steam_system

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