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.

  • AA5B@lemmy.world
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    3 months ago

    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

    • Valmond@lemmy.world
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      3 months ago

      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.

      • AA5B@lemmy.world
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        3 months ago

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

        • Valmond@lemmy.world
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          3 months ago

          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.

    • Rivalarrival@lemmy.today
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      3 months ago

      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.

      • AA5B@lemmy.world
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        3 months ago

        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)

      • frezik@midwest.social
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        3 months ago

        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.

        • Rivalarrival@lemmy.today
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          3 months ago

          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.

          • frezik@midwest.social
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            3 months ago

            The trouble with that kind of variation is that the economics of nuclear don’t make much sense. Nuclear is a large up front investment with (relatively) low marginal cost. If it’s running at a low level for half the year, then it can’t make back that huge initial investment in its expected lifetime.

            • Rivalarrival@lemmy.today
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              3 months ago

              We are currently charging very low overnight rates because we need to increase night time load on nuclear. With solar and wind being cheaper, grid operators are going to want to drive consumers to daytime consumption wherever possible. Night time rates are going to naturally increase, and I would expect artificial incentives on top of that to drive as much consumption as possible to the day, especially to clear, windy days.

              The alternatives to nuclear are pumped storage, (which isn’t sufficiently scalable); traditional baseload generation (which is significantly more expensive); and various forms of peaker plants (which are much more expensive).

              Basically, overnight and winter rates are going to rise to wherever nuclear needs them to be to remain profitable, because every other option has either limited feasibility, or higher costs.

              • frezik@midwest.social
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                3 months ago

                You left out a large number of storage options. There’s plenty out there. Not every one is going to work for everything, but there’s almost always something that’s going to work.

                • Rivalarrival@lemmy.today
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                  3 months ago

                  Storage is important, yes, but it’s mostly a pipe dream. Few grid scale storage options are sufficiently scalable, and all storage is inherently inefficient.

                  We have a steel mill. We currently run it on nuclear power, overnight, during off-peak hours. If we want to switch it from nuclear to solar, do we continue to operate it at night off of pumped storage and batteries? Or do we move it to daytime operations? The former is “supply shaping”: adjusting our production to meet demand. The latter is “demand shaping”: adjusting our consumption to meet available supply. That’s the kind of thing we need to focus on.

                  At home, the single most important thing we need is mixing valves on our hot water tanks. These add cold water as needed to maintain a constant output temperature. This allows a variable, smart thermostat on the tank, that will superheat water when power is cheap, and let it fall when power is expensive. When solar excesses push rates too low, all of our water heaters start kicking on, sucking up cheap power during the day, and holding it through our night and morning showers.

          • Thadrax@lemmy.world
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            3 months ago

            And don’t forget that the plants are really expensive. Having them produce very little or even no power for half the time doesn’t help that at all.

          • frezik@midwest.social
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            3 months ago

            But, it can be very useful for leveling the seasonal variation.

            Which isn’t actually necessary. Winter has less sunlight, but also more wind.

            We can be smart about this. We have weather data for given regions stretching back decades, if not more than a century. We can calculate the mix of power we’d get from both wind and solar. There will be periods where both are in a lull. Looking again at historical data, we can find the maximum lull there ever was and put enough storage capacity to cover that with generous padding.

            And then you just don’t need nuclear at all. Might as well keep what we have, but no reason to build new ones.

            • Rivalarrival@lemmy.today
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              3 months ago

              Looking again at historical data, we can find the maximum lull there ever was and put enough storage capacity to cover that with generous padding.

              Baseload storage is a pipe dream. The storage and generation capacity necessary to make that work would be about two orders of magnitude more expensive to maintain and operate than the equivalent nuclear capacity, and the environmental impact would be far greater still.

              That’s not to say that storage is useless; it certainly isn’t. But its utility is in leveling spikes and dips, not replacing baseload generation during a “lull”.

                • Rivalarrival@lemmy.today
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                  3 months ago

                  Depends on your definition of “feasible”.

                  It is certainly within the capabilities of humanity to do it.

                  It would cost far more, and have much higher ecological impact than alternatives.

                  To me, that is not “feasible”.

                  • frezik@midwest.social
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                    3 months ago

                    It’s feasible and cost effective. The academic research on this has been quite clear, but it isn’t the sort of thing that generates headlines. Nuclear just isn’t necessary.

    • perviouslyiner@lemmy.world
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      3 months ago

      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.

      • AA5B@lemmy.world
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        3 months ago

        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

    • Thadrax@lemmy.world
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      3 months ago

      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.

      • AA5B@lemmy.world
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        3 months ago

        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/