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US Government funds pilot project for heated sand energy storage

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Re: US Government funds pilot project for heated sand energy storage

#91

Post by adrian_b »

chii wrote: post #33
retrac wrote: post #28

Heat storage has an aspect that was counterintuitive to me, but follows from basic geometry. It benefits greatly from large scale, since the ratio of the volume to surface area [1] decreases the larger you make a container. Accordingly, if a heat tank is large enough, the surface area becomes negligible relative to its volume, and it, in effect, becomes well-insulated by its own mass. For really big tanks, like might…

> better than most rechargeable battery technologies you can't compare heat storage to electricity, because you can't directly use heat for anything else other than for heating, where as electricity can be used to perform motion. If you used heat storage as a battery, there's an additional loss when converting to electricity. However, if the heat is cheap/free during summer, storing it for winter is a no brainer.

Heat can be used directly not only for heating, but also for cooling.

There are air conditioning systems that are powered by heat, not by electricity.

There are places where the power plants use the residual heat from the generation of electricity not only for heating during the winter, but also for cooling during the summer, by producing chilled water.

Re: US Government funds pilot project for heated sand energy storage

#92

Post by dubcanada »

michael1999 wrote: post #37
xnx wrote: post #9

Does this differ in design from the Finish sand battery from 2 years ago: https://news.ycombinator.com/item?id=32006791

The Finnish system is just heat->heat. They generate heat when the wind is blowing, and inject heat back into the district system when it isn't. Super simple - resistive heating, and passive heat transfer. This system produces electricity. Exciting, but much fancier.

A stirling engine can generate heat from electricity, such as those used in MicroCHP, you can burn wood, produce heat, and generate electricity from that heat. You could do the same with a pile of sand.

You just need to pipe liquid through the sand, and a supply of cooler water.

Re: US Government funds pilot project for heated sand energy storage

#94

Post by dubcanada »

NewJazz wrote: post #30
ceejayoz wrote: post #23

Earlier quoted context omitted.

https://en.wikipedia.org/wiki/Seasonal_thermal_energy_storag... > In Alberta, Canada, the homes of the Drake Landing Solar Community (in operation since 2007), get 97% of their year-round heat from a district heat system that is supplied by solar heat from solar-thermal panels on garage roofs. This feat – a world record – is enabled by interseasonal heat storage in a large mass of native rock that is under a central…

155 mm huh? Did they use NATO standard mortars to make these boreholes :p?

There is no standard borehole size, 155mm drill head is quite easily acquired in Canada

Re: US Government funds pilot project for heated sand energy storage

#95

Post by NegativeK »

leecarraher wrote: post #62

it seems the primary benefit for sand over water, is a 1:10 operating temp vs. 5:1 specific heat. So it depends on whether the added complexity of working with a hotter, solid is worth not having to build a facility that is 2x bigger. Are there other benefits I'm missing, or is this concrete block gravity storage vs pumped water storage, all over again?

Sand doesn't leak down or up (via evaporation) nearly as much.

It's also far less of a precious resource and non-corrosive, compared to the most common version of water.

Re: US Government funds pilot project for heated sand energy storage

#96

Post by autoexecbat »

adrian_b wrote: post #91
chii wrote: post #33

Earlier quoted context omitted.

> better than most rechargeable battery technologies you can't compare heat storage to electricity, because you can't directly use heat for anything else other than for heating, where as electricity can be used to perform motion. If you used heat storage as a battery, there's an additional loss when converting to electricity. However, if the heat is cheap/free during summer, storing it for winter is a no brainer.

Heat can be used directly not only for heating, but also for cooling. There are air conditioning systems that are powered by heat, not by electricity. There are places where the power plants use the residual heat from the generation of electricity not only for heating during the winter, but also for cooling during the summer, by producing chilled water.

> There are air conditioning systems that are powered by heat, not by electricity.

How does that work?

Re: US Government funds pilot project for heated sand energy storage

#97

Post by lambda »

stingraycharles wrote: post #34
retrac wrote: post #28

Heat storage has an aspect that was counterintuitive to me, but follows from basic geometry. It benefits greatly from large scale, since the ratio of the volume to surface area [1] decreases the larger you make a container. Accordingly, if a heat tank is large enough, the surface area becomes negligible relative to its volume, and it, in effect, becomes well-insulated by its own mass. For really big tanks, like might…

Gravity seems much more natural to me than heat; eg pumping water up a dam and releasing it again when you need the energy. It strikes me that heat has the problem that it always loses energy in its “stable state” because the surrounding environment absorbs the heat, and gravity doesn’t have this problem.

Pumped hydro is great, but only in certain areas where you already have the elevation gain available.

Compressed air storage is another one that's pretty good, but it's only particularly good if you can store it in underground caverns or unused mines, so it's also geography dependent.

For longer term storage, producing hydrogen can be a good one.

And batteries are actually fast becoming competitive with some of these options from the other end, generally better for shorter term storage but getting better at longer term. Even shorter term, flywheels can be a good option.

There's room for several different types of grid-scale energy storage, based on how efficient they are at different energy storage periods and numbers of charge-discharge cycles, and also in some cases on local conditions, like the availability of terrain and water sources for pumped hydro.

There's a good paper here which shows what the most efficient energy storage systems are for various combinations of length of storage (hours per discharge) against number of discharges per year, and for each one shows the current cost, and a predicted cost based on trends in technological advancements: https://www.sciencedirect.com/science/article/pii/S254243511...

There's a lot of the chart that is dominated by pumped hydro currently, but plenty of other storage technologies that are more cost effective on different timescales and numbers of discharges. But it looks like it's predicted for prices of battery storage and hydrogen storage to fall relative to the others, causing a different predicted landscape in 20 years.

And some of these, like pumped hydro, are dependent on geographic features, or access to certain resources, so even when one dominates overall, there can be others that dominate in particular geographical regions.

Re: US Government funds pilot project for heated sand energy storage

#98

Post by [deleted] »

lambda wrote: post #97
stingraycharles wrote: post #34

Earlier quoted context omitted.

Gravity seems much more natural to me than heat; eg pumping water up a dam and releasing it again when you need the energy. It strikes me that heat has the problem that it always loses energy in its “stable state” because the surrounding environment absorbs the heat, and gravity doesn’t have this problem.

Pumped hydro is great, but only in certain areas where you already have the elevation gain available. Compressed air storage is another one that's pretty good, but it's only particularly good if you can store it in underground caverns or unused mines, so it's also geography dependent. For longer term storage, producing hydrogen can be a good one. And batteries are actually fast becoming competitive with some of these…

[deleted]

Re: US Government funds pilot project for heated sand energy storage

#99

Post by dsp_person »

spxneo wrote: post #84

I go to the beach fill up 50 gallon drums with it and then pipe hot water through it so that you can enjoy heat without electricity or gas. im obsessed with it. i love the way it feels on my body. i take warm sand baths with it. i have cold feet so i use nylon socks, fill it with sand providing endless massage and keeping it warm. ive yet to try different types of sand from other regions but Canadian beach sand does…

i can't tell if you are trolling or not

Re: US Government funds pilot project for heated sand energy storage

#100

Post by xkcd-sucks »

autoexecbat wrote: post #96
adrian_b wrote: post #91

Earlier quoted context omitted.

Heat can be used directly not only for heating, but also for cooling. There are air conditioning systems that are powered by heat, not by electricity. There are places where the power plants use the residual heat from the generation of electricity not only for heating during the winter, but also for cooling during the summer, by producing chilled water.

> There are air conditioning systems that are powered by heat, not by electricity. How does that work?

https://en.wikipedia.org/wiki/Absorption_refrigerator
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