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.
This is not a good thing. Any time generation has to pay to produce, solar and wind rollouts are slowed.
We need better demand shaping methods, to increase load on grids during periods of excess production, and decrease loads during shortages. We need to stabilize rates at profitable points to maintain growth of green energy projects.
We also need long-term grid storage methods, to reduce seasonal variation. A given solar project will produce more than twice as much power during a long summer day as it will during a short winter day. If we build enough solar to meet our needs during October and March, we will have shortages in November, January, February, and surpluses from April through September. We will need some sort of thermal production capability anyway; hydrogen electrolysis or Fischer-Tropsch synfuel production can soak up that surplus generation capacity and produce green, carbon-free or carbon-neutral, storable fuels for thermal generation and/or the transportation sector.
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
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.
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
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.
Yeah, I’m sure the solution would require both large scale storage and point of use storage
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.
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)
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.
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.
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
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.
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
Negative pricing IS a demand shaping method, you need to have a certain % of the electricity produced that is consumed at the same time, otherwise you risk having an unstable electricity grid.
Variable pricing is a demand shaping method. Negative rates are an indication of insufficient flexibility to adequately shape demand. If we were able to adequately shape demand to match available supply, rates would fluctuate, but they would never go negative.
If we were able to adequately shape demand to match available supply, rates would fluctuate, but they would never go negative.
I don’t see why that would follow.
If supply is higher than demand, then getting rid of that excess supply costs money, and the producer might have to pay someone to take it away. It applies to grocery stores that over order inventory of perishable goods, to oil companies that run out of space to store oil, and electricity grids that need to get rid of damaging/dangerous excess power.
Or just export it - there must be nearby counties that don’t have such a good renewable electric situation.
and who will you sell it to? the other countries will be building their own infrastructure eventually and they’ll be trying to sell to you.
You sell it to places with different weather conditions (or as noted, to places with storage capacity) - and if everyone in the grid becomes as successful as Finland, well “good job, everyone!”
“just export it” sounds so simple, but the required infrastructure is actually incredibly expensive. Also most of Europe is already pretty tightly connected and trade does happen to a significant degree, but I have no idea what the actual percentage is or if it’s used to balance oversupply and/or shortages. Kinda hard to find reliable sources for that.
Luckily, several interconnects already exist and more are planned.
As to percentages, most electric grids will publish those - for example FinGrid’s current status.
Or water batteries for dams if your neighbors don’t need your surplus, this way you don’t need to extract lithium to produce regular batteries to store the surplus
https://www.science.org/content/article/how-giant-water-batteries-could-make-green-power-reliable
In a region like Finland, sand batteries appear to be worthwhile for seasonal storage. Might be an avenue to pursue
Then there’s always green hydrogen as well
