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.
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.
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.
That is all absolutely correct, and that is all completely irrelevant. That scenario only exists after shaping efforts have failed to match supply and demand.
The purpose and intent is to sell power at a profit. Where demand cannot be increased enough for rates to remain profitable, demand shaping has not achieved its intended purpose. Negative rates are not an example of demand shaping. Negative rates are an indication that demand shaping has failed.
The dumpster behind the grocery store is “disposal”, not “demand”. The solution to negative rates is not for the power companies to find a dumpster in which to dispose of their excess power.
The supply shaping solution to this problem is reduced solar and wind production, augmented by flexible peaker plants, and drawing on previously stored grid power.
The demand shaping solution to this problem is flexible loads that can be added or removed from the grid as needed, and storing grid power for future use.
I don’t know why you’re framing this as solely a demand problem, or why you think the elasticity of demand won’t extend to negative prices. Negative prices tend to show up only during periods of very high supply, due to a confluence of factors like weather, so supply is part of it (low or even negative prices can induce producers to curtail production). There’s nothing special about the number zero.
And negative prices therefore take the place of disposal: oversupply and the need to expand real resources taking that energy off of the grid in that particular moment. That’s demand, too: incentivizing people to do what needs to be done, and get rid of that excess energy by disposing it or whatever.
That is a very good question that has a very simple answer:
The supply shaping solutions to excess solar and wind power are to figure out how to store power, or to stop building renewables. Both of those approaches absolutely suck. We need more renewables, not less, and grid scale storage isn’t sufficiently scalable to meet our needs.
Demand Shaping offers a wide variety of potential solutions compatible with increased renewable adoption, and without massive infrastructure projects.
Until 100% of our demand is continuously met by renewable generation, curtailment is not a solution. Curtailment is what you do when you can’t find a solution.
Disposal is not a solution. Disposal is what happens when you can’t find a solution.
Until 100% of our power needs are met by renewables, curtailment and disposal both suck.
Demand Shaping is a solution. Demand Shaping moves subtracts load from when it can only be met with non-renewables, and adds load when it can be met with renewables. Demand Shaping makes non-renewables less profitable and renewables more profitable.
Demand Shaping fixes the problem in such a way that encourages renewable growth. Curtailment and disposal makes renewable less profitable. Curtailment and disposal resolves the problem in such a way that discourages renewable growth.
Or just export it - there must be nearby counties that don’t have such a good renewable electric situation.
“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
Lithium isn’t going to be the way to store electricity on the grid. I wish people would stop bringing it up.
There isn’t going to be a single thing. Pumped hydro, flywheels, sodium-ion, flow batteries, and heating up sand all have a place.
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!”
The “places with different weather conditions” are across the equator. Everyone in the northern hemisphere has summer at the same time. The best we can do with interconnects up here is shift the problem around by a couple hours.
Now, if we convert that excess power into cryogenic hydrogen, load it aboard a tanker, and drive that tanker to the end of the earth currently experiencing winter, they can then burn it in gas turbine generators.
Hell, we can put such generators on ships and move them back and forth every 6 months.
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
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
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.
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.
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.
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.
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”.
That’s simply not true. This has been well studied, and a 100% renewable + storage option is quite feasible. It’s even easier if you focus on going 95% first (that last 5% gets much, much harder).
https://www.amazon.com/dp/1009249541/
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”.
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.
ok just so we’re clear here, you wouldnt ramp up or down nuclear power output, unless you’re doing maintenance. It’s at or near 100% power output, always. Most plants sit at a capacity factor of about 80-90%
You would however, ramp down wind turbines, or dump solar, or even store that solar since you’re in a peaking cycle.
Solar and wind are cheaper and potentially more plentiful, more distributed than nuclear. Renewables are going to be the primary source of power; nuclear and every other type of generation will augment the renewables.
What you’re saying is what nuclear has been, not what it will be.
potentially, that’s always an option, but unlike something like oil where it’s a generic concept, energy is kind of an ethereal concept. I see it much more likely that if nuclear plants get sufficient development time and funds, that they will pair nicely with renewables as you can buy the electricity wholesale at price, but the versatility of the pricing will offset the increased cost as you can subsidize it using cheaper renewables.
Allowing you to minimize energy storage and some amount of renewable production as well.
I wouldn’t be surprised if grids ended up using solar primarily for day time production consumption and short time storage (evening consumption time) and then used nuclear as the primary producer for power consumption over night, along with wind somewhere in the mix. But this would require nuclear power to be built in the first place.
Exactly. Nuclear carries us overnight, renewables meet our needs during the day.
Negative rates aren’t caused by excess solar. Negative rates are caused by excess overnight demand. Overnight demand is too high, necessitating the continuous nuclear output to be set too high. The sum of the continuous nuclear and the daytime solar exceeds daytime demand; rates go negative to correct.
The solution is to remove nighttime demand. Now the continuous nuclear output can be reduced. This is exactly opposite of what the grid needed before renewables, but it is the only viable approach moving forward. The other half of the solution is to add daytime demand, perhaps the same demand we removed from overnight; perhaps an entirely new way to turn power into profit.
(Nuclear plants won’t actually reduce their output. Coal plants will go offline, and nuclear will take over their customers.)
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.
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.
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.
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.
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.
Ignoring the paragraphs of mansplaining about how nuclear works . . .
Wind speed at 100m tends to drop in the late afternoon and pick up during the night. See page 49 here:
https://www.nrel.gov/docs/fy15osti/61740.pdf
What? No. Much of the Ercot failure in Texas to deal with the 2021 winter weather was nuclear plants being knocked offline.
homie that’s just me being autistic.
that’s interesting, though i was speaking as an average throughout the whole day. Could very well still be true though.
yeah idk about that one chief i mean, you can clearly see it’s combined cycle gas causing the problem primarily, there’s also a bit of drop in gas, and it appears other sources also do, but that appears to be a graphing artifact more than anything.
It was literally reported that gas plants couldn’t fire due to the pipes being frozen, while nuclear may have contributed, i believe the plants in question were already shutdown for maintenance or non operation to begin with. Also compounded with the grid being excessively depended on, due to electric resistive heating.
https://energy.utexas.edu/sites/default/files/UTAustin (2021) EventsFebruary2021TexasBlackout 20210714.pdf
in fact scrolling through an investigation in what happened it appears about 1300 MW of nuclear went offline, which is the collectively equivalent of, one plant. And it looks like it was an automated shutdown, which should’ve been expected.
In fact, considerably more coal, gas, wind power died out. The only thing less significant was solar power.
And if we go forward in history just a year we can find an example of similar grid mismanagement, though this time it was during the summer and due to improper grid configuration, nearing a potential grid outage. And with solar instead of gas.
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
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.
Unfortunately a ground loop can be expensive, especially for those of us in urban areas.
I read an analysis once that you could never make back the cost on energy saved. Whether or not that’s always true, I know I live in a high cost area with a yard that a drill couldn’t get to, cris-crossed with 80 years of utilities.
that’s true, though to be fair i’d be the one installing it, i’m not paying other people to dig a hole lol.
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
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
https://stash.energy/en/
or you know, we could subsidize spending some of this excess power on something like “folding at home” except its actually in a government datacenter subsidizing power production peaking.
Although that’s like, really boring.
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
You mean something like this?
Yep exactly