It’s still not earning you money to spend electricity because you still have to pay the transfer fee which is around 6 cents / kWh but it’s pretty damn cheap nevertheless, mostly because of the excess in wind energy.

Last winter because of a mistake it dropped down to negative 50 cents / kWh for few hours, averaging negative 20 cents for the entire day. People were literally earning money by spending electricity. Some were running electric heaters outside in the middle of the winter.

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6 points
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When I was growing up, my parents house had thermal storage electrical heating. Generally the heat was only “on” at night when electricity was cheap, then we’d control the temperature during the day with circulation fans. I remember it working really well while saving a ton of money.

Where is the thermal storage heating now? I specifically could use a mini-split heat pump, where the head unit is thermal storage, but I don’t see any such thing online

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1 point

Thermal storage needs to be quite large though, at least with the stone/brick like mass they used back then. And you need to isolate it, otherwise you have no control over the release of that stored heat. I wonder if new materials, maybe something that undergoes phase change in that temperature range, could be a lot more space efficient.

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1 point

It doesn’t have to be large, or the size is related to the use case. In the house I grew up, they were similar size and shape to standard radiators and worked well through cold winters in upstate NY

Consider a single radiator in a house. You only need storage sufficient to use that radiator for one day. And it doesn’t matter too much if it can’t cover extreme temperatures, as long as it is sufficient to cover peak prices most of the time

I finally found one. Why aren’t there choices like

https://stash.energy/en/

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1 point

Technology Connections has been arguing to just use the air in your house for this purpose - e.g. running air conditioning only at night, or allowing the power company to run it in advance of peak demand.

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2 points
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I got this, works decently for a short period.

My smart thermostat allows me to opt in to a program where the power company can adjust the AC during peak periods, and I get an annual bonus on my bill. It does actually precool the house: sets the temp down two degrees for a bit, before peak where it sets the temp up two degrees.

However my house isn’t sufficiently weatherproofed: their changes can be 2-3 hours but the pre-cooling doesn’t help for that long

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1 point

thermal storage is kind of complicated and sucks a little bit, probably.

You can still do the heating thing, using your home as a thermal battery for example. You could also put a large thermal mass within your home, thousands of gallons of water (for example) directly integrating a thermal battery and optimally using it probably just isn’t as viable as not worrying about it and doing something else.

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1 point
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It doesn’t have to be complicated, or the complexity is related to the use case. Does not need water or moving parts.

Consider a single radiator in a house. You only need storage sufficient to use that radiator for one day. And it doesn’t matter too much if it can’t cover extreme temperatures, as long as it is sufficient to cover peak prices most of the time

I finally found one. Why aren’t there choices like

Edit to circle back to the goal: now I can move toward cleaner energy by electrifying my house. I can save energy/money by using the most efficient heating technology. If there was thermal storage, I could save even more money with “time of use” metering and the utility can shift their load to make up for the peakiness of sources like solar. If I installed solar on my roof, I could potentially heat my house entirely with “free” energy

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1 point
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yeah, but if you’re not doing it in a complicated manner you could just stick an IBC tote full of water in the middle of your home and it would provide a similar effect.

Personally i would probably just install a ground loop, and then use that to provide a source for heating and cooling, it’s also very consistent year round, though if you live in an area of deep frost lines, or permafrost, it’s probably going to be more exciting.

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2 points

Generally the heat was only “on” at night when electricity was cheap

That is exactly why rates are going negative during the day now. Baseload generation benefits from artificial increases in the base, off-peak load. With solar and wind generation increasing, we now have a need to reduce that base, overnight load, and increase peak, daytime load.

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2 points
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At risk of starting a whole new fight, this is why hybridizing renewables with nuclear doesn’t work. They don’t cover for each other’s faults very well.

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0 points

ok so, solar, naturally produces the most power during the daytime, when the sun is up, which in places where it’s warm is when you get the most significant energy bump due to AC and what not. There is also a bit of a trailing period in the evening where people get back from work and cook dinner/relax and whatever. But that’s not super far off from noon peaking in the grand scheme.

Nuclear plants are baseload, so they produce 100% power output for 100% of the time they exist (at least in an ideal world) usually they have a capacity factor of about 80-90% though i’ve seen plants go past 100% before. This load is super useful for leveling out the power demand overnight, as well as shortening the day time peak loading a little bit. As well as providing a very consistent and regular source of power than can be used for things like hydro storage, and battery charging for example. So paired with a large thermal battery a nuclear plant might even be able to adapt to the midday loading cycle pretty functionally, as it can recoup most of it’s lost energy over the night, through the baseload averaging out.

Nuclear plants are actually really well suited to be used with a thermal battery solution (given that they output thermal power, obviously) It’s more common for modern plant designs to integrate thermal battery technology to some degree, but those are all gen IV designs, so they don’t exist yet.

As for wind, i’m not sure what the effects on it during the day/night cycle is, but i imagine during the day they generally produce more power, though they will also produce some power over night. So those are a relatively low yield but high regularity power source, similar to nuclear, however you have much greater control over them as you can change the blade pitch during rotation in order to increase/decrease output as needed. Though ideally you would always be outputting, as often as possible.

Even in the event that you have a total grid blackout, nuclear plants are a potential source of blackstart power sources, though presumably it’s not nearly as big of a deal in a solar plant for example. It’s unclear how much those rely on being secondary producers, or how well they can function as primary producers to me. Presumably it will be dealt with at some point if it hasn’t been already.

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2 points

Nuclear isn’t particularly good for leveling the daily demand curve, no.

But, it can be very useful for leveling the seasonal variation. Slowly ramping up nuclear production to make up for the short winter days of December, January, February. Slowly rolling it back for the long summer days of June, July, August.

Nuclear is also an excellent option for meeting overnight demand.

But you’re right: it is terrible for making up for inclement weather, and other short-term variation. We will continue to require short- and medium-term storage. We will continue to need peaker plants, although we will hopefully be able to fire them with hydrogen instead of carbon-based fuels.

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3 points
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Let me rephrase: “ the heat was only “on” … when electricity was cheap” which at the time was overnight. That was 1970’s tech so basically a mechanical timer, but the timer could be set to whenever, plus surely current technology could be used for a smarter solution

Edit: I currently opt into a program to shift load, in return for a bonus on my bill. My smart thermostat is able to pre-cool the house before the peak time, and only shaves off two degrees at peak, so it maintains adequate comfort while helping shift load (assuming enough consumers join)

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3 points

I read about a, Finnish?, project whete they heated up sand, but in large silos in IDK 500°C or more. Could sit there for months apparently.

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2 points

Yeah, I’m sure the solution would require both large scale storage and point of use storage

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1 point

Sure, not to mention they should probably cut out all the electric stuff that eats up like 80-90% of the suns efficiency and use mirrors directly. I mean if you gave the “battery” close.

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