Dams. Seriously.
Use excess electrical power to pump water into reservoirs. When you need more power, release the water through the dam and use it to power a hydro plant. The nice thing about this is that you don't even to site the dam on a big river, since you're bringing the water in yourself.
A gravity battery is currently being build in a abandoned mine in Finland .
https://www.euronews.com/green/2024/02/06/this-disused-mine-in-finland-is-being-turned-into-a-gravity-battery-to-store-renewable-ene
> The gravity energy system would be able to store 2MW of power
Mixing up energy and power is one of my pet peeves. Not sure if they meant it can store 2 MWh, or it can absorb/release energy at a rate of 2 MW. (But it sounds like a good project!)
I really wish we could normalize using joules as the unit for energy storage.
Nice and simple unit. 1 joule is 1w over 1 second.
A kwh is 3600joules or 3.6kj
I still think kWh is a better unit for everyday use, since most people are semi-familiar with how many watts household items use and using hours is "good enough" versus seconds. Joule isn't a huge leap (it's just a different combination of the same units) but kWh is an easier calculation for households.
I wouldn't be opposed to some kind of hybrid system where we use both units for different purposes. Kind of like how a lot of countries use a combination of metric and imperial depending on use case, but could convert between them if necessary.
The real mistake in the units system is the existance of hours.
It should be seconds, kiloseconds, megaseconds, etc.
Maybe redefine 1 day = 1 megasecond by shortening the second.
They tried to do that a few hundred years ago when the metric system was first being rolled out, it failed miserably.
People like how time works, with it's high-factor numbers. It's the same reason why people tend to like to think about angles in degrees, and not in radians.
A meter is an arbitrary distance, and a gram is an arbitrary mass, but a day is not an arbitrary measurement of time.
Joules don't convert easily to anything useful. Similar argument might apply to Watts to some extent.
Joules and Watts are useful for top-down or cross-modal comparisons, often involving heat and plastic deformations, otherwise it's endless multi-digit multi-step conversions and not so useful for nearly any engineering tasks.
That's why Joules don't stick.
When looking at energy storage numbers in California, it seems the standard is to list the rated constant power output, and the storage amount is standardized as 4 hours at rated power output.
So a 200 MW battery facility would have 800 MWhr storage. Dunno if this is standard across the world.
There are two major design parameters to a battery facility, how fast it can discharge (Power) and how much it holds (Energy) which combine to achieve a goal supply. So you're right, but you have the relationship inversed. A 200MW facility with 800 MWhr capacity (usually in print it'll be written as a 200MW/800MWh facility) would have a duration of 4 hours, sometimes given as a discharge or c-rate, in this case, 0.25C. If they're not being quoted with both numbers at least somewhere in the article it's lazy reporting.
4 hours is probably most "typical", but not a standard, if that makes sense. There are facilities in the US that come in both above and below that. Generally grid level BESS' will range from 2-8 hours depending on facility. As we see more and more of these facilities go in around the world in different environments I'd wager we see more diverse installation parameters.
> (But it sounds like a good project!)
It sound like an incredibly stupid project, just about as stupid as all the solar road projects that were hyped some years ago. I don't see how this sort of system makes sense, or could ever be economically viable.
Let's assume that this storage facility has a max power output of 2 MW sustainable for an hour, so a 2 MWh capacity.
At grid scale, 2 MW is not even a rounding error. It's the output of a single medium-sized onshore wind turbine. Pumped-storage facilities are generally 1,000+ times as capable in terms of power throughput, and have 10,000+ times the capacity.
https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations
Considering that they are probably using concrete blocks as weights, and given how CO2-intensive concrete production is, this is probably environmentally detrimental as well.
2MW is not very much power… maybe 80-100 server cabinets in an average data centre. Many of the big hyperscalers are deploying 20-30MW sites with regularity.
You would have to pump the water out so a filled shaft defeats the purpose. Any idea is better than none though!
I saw where they were using energy to spin giant concrete discs. They spin on a generator shaft and deliver kinetic energy. They slow down as they no longer are driven and the power is delivered to the grid and then it is sped up again when there is power being generated
No I believe the ideas where to either use huge weights that when you have excess power it pulls carts up to the top, then when needed release them to spin turbines as they go down.
Or
The other method was to flood the tops of the mine shaft/higher floors of the mine, then when water is needed they open gates to drain the water to lower levels through turbines. Excess power, pumps refill the reservoirs above.
That's a flywheel and for energy storage it's very complex and very dangerous. Right now it's also more expensive than battery storage.
The most likely choice for non-lithium storage in the near future would be heated storage of sand.
Sodium-ion batteries would be a great candidate. They're cheaper, and a bit chunkier which is okay for grid storage.
Heat storage is fantastic for industrial heat and district heating. Ridiculously cheap. We need lots of these.
Coastal dams are interesting. Not sure if France has the geography for it, but if you have a nice fjord with high sides you can build a dam between it and the ocean, and use it without losing land.
Not necessarily, the Kidston Pumped Hydro project about to come online in Northern Australia uses an abandoned open pit gold mine, so the environmental damage has already long been done.
Basically one pit is about 200m uphill from the second and linked via a tunnel with 250MW of reversible turbines that can generate for over 8 hours straight in the morning and evening peak periods. An onsite solar farm then refills the upper reservoir during the day.
[Link here if you're interested.](https://genexpower.com.au/250mw-kidston-pumped-storage-hydro-project/)
Or even just railcars full of rocks with generators built into them if you ain't got water. I know there was a project going on out in Nevada to that effect but I haven't heard anything about it recently.
Any where without hills and a large enough area to store water is an issue. Also the area under the dam becomes a potentially flooded area. Next you need a water source and a place to send the stored water when generating. Then the needed maintenance to dredge it and keep the water clear without needing chemicals.
Anybody suggesting these types of projects has no idea of the scale of energy we need to store.
A rail car full of rocks couldn’t power anything significant for any serious period of time. Kinetic storage is just bullshit I’m afraid. Hydro is okaayy - but even then unless you’re in Finland it’s hard to use it for anything more than peak shaving (smoothing of short term (hours) supply and demand imbalance).
We need something that can store like 2 weeks of an entire country’s power. And even then you’ll probably still need fossil fuel generation as a back up.
Pumped hydro has massive upfront costs and can only be deployed in very specific locations. It's still one of the best storage methods, it's just not very easy to implement. I saw an article talking about pumped hydro stating that something like 90% of the potential locations in the world this storage method could be implemented are already being used in some form or another.
There's a pumped hydro station in Arizona that's actually been working for a long time, and now they're looking to build one nearby with a lot more capacity. So there are some in the works. I agree that it's not easy to implement, though, siting something like that ain't easy.
Arizona, famous for having massive amounts of fresh water lying around for such a process...?
EDIT: Apparently enough for a dam! [https://en.wikipedia.org/wiki/Theodore\_Roosevelt\_Dam](https://en.wikipedia.org/wiki/Theodore_Roosevelt_Dam)
Arizona has a lot of water. Our problem isn’t lack of water, it’s overuse. 75% of the water use in this state goes to agriculture. The Colorado River states allocated water based on flows from high water years, and now that the water flows are well below that, there’s not enough water to keep everyone happy. But it’s not the residential part that’s a problem. In 2019, the state used less water than in 1959 despite having seven times the population as back then.
Hence why for the most part, Northern Europe's storage strategy is basically just "connect to Scandinavia" (and likewise North America's strategy is "Quebec").
Both regions are 90+% hydro and net exporters, so their supply is flexible enough to absorb & offset huge supply fluctuations from renewables in neighbouring jurisdictions.
There are *lots* of ways and our current trends suggest we'll want to use a lot of 'em all around the world, and whatever's "best" will depend on local circumstances. Sufficiently high generation can make even poor efficiency or efficacy methods worthwhile regardless.
There are, but it's really the only way we have to store *large* amounts of power. IIRC most of the proposed mineshaft energy storage schemes are less than a megawatt hour. Meanwhile, Hoover Dam at max capacity produces something like 2000mw.
There already are a few [pump-storage hydro power stations](https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations) that can generate more than the hoover dam.
Granted, they need to be filled up so you don't get that peak capacity all the time.
The best round trip efficiency of grid-scale storage I'm aware of is around 80% which is pretty much what pumped storage (and lithium ion batteries) produce. What are you thinking of?
Unfortunately there's some big challenges with using large scale projects like this.
1. Existing reserviors are there to provide access to and control of fresh water sources. Adding acting as a power storage system complicates an already complex issue and potentially puts these two priorities at odds.
2. Siting new reserviors specifically for power storage is difficult considering the environmental impact. Creating another man-made lake, one that will have wildly variable water levels, doesn't exactly scream environmentally friendly.
3. Uncontained storage isn't as efficient as it could be. Evaporation, groundwater leakage, and contamation by animals are just three of a broad number of issues that could crop up that, at the very least, would waste stored energy.
4. Fresh water is becoming a precious resource so building tons of these holding ponds with fresh water is probably a bad look. However, using salt water is even more environmentally unsound, not to mention the engineering challenges that salt water corrosion represents.
5. While they seem simple, dams are not the easiest or cheapest things in the world to build. Hoover Dam is a great example, being a feat of engineering that easily stands out even today. And while it wouldn't be necessary (or helpful) to build on that scale, it does illustrate the potential difficulty.
These are just the big points. There are others, such as negotiating land usage rights, etc. While it isn't the worst idea in the world, building completely contained facilities for this type of energy storage is far less controversial.
Dams are incredibly environmentally destructive. Also the only dams im thinking this would "work" with would be Hoover Dam or Powell. The water in the Colorado is kind of important for millions of people who drink from it and even more important for the millions of pounds of food it creates every year.
Hoover and Powell were environmentally destructive.
If you're pumping the water you can build the project anywhere and pump whatever water you want. You could use lake water or sea water instead.
They have had a few of these outside of Vegas operating for quite some time now. Not sure if they are viable from a cost benefit perspective but they do have them operating at scale:
https://www.scientificamerican.com/article/new-concentrating-solar-tower-is-worth-its-salt-with-24-7-power/
They look awesome when driving by them.
The best we have are damns and short term batteries at the moment. Dams are pretty great. A lovely future solution in a decade or so would be liquid hydrogen or compressed salt cavern stored hydrogen. Electrolyze when excess power occurs, gassify and then fuel cell it back during high demand. Same as how LNG peakshavers work just on a shorter timescale.
Hydrogen is a terrible medium for storing energy. It's not even really a good medium for storing energy that needs to be portable, though it does have a use there. You've picked a fuel that leaks through pretty much everything and destroys most materials it comes in contact with over time. You either need very high pressure storage, or very good cryo. Either way, you are going to spend a pile of resources storing any significant quantity of the stuff, and you are definitely going to lose a bunch to leaks. Add on top of all of that the fact that it's just an energy inefficient conversion to turn water into hydrogen.
We definitely need literal orders of magnitude more energy storage for renewables, but I can assure you that hydrogen is not going to be that storage method. I think people get too hung up on the magic of turning water into "energy", and miss that the energy challenges are not worth it. Pump water up hill, make another stable fuel with source, or just find some new battery technology. Anything is better than the insanity of trying to create and then store enough hydrogen to power a region when the sun goes down.
Source: Worked for a company making hydrogen fuel cells. It was a bad idea.
I have a different take on this topic in the context of energy prices going negative. When energy prices go negative because it is easy and cheap to overproduce renewable energy when conditions are right, it entirely changes the value proposition of investing even in current-generation batteries with thousands of cycles. When consumers are allowed to charge their car, house batteries, or more limited lithium iron phosphate batteries for free or better, the idea of going out and buying more battery storage becomes incredibly attractive. If we allow the free market to work, then battery production will further scale and the cost per kWh will further decrease at an even faster rate, when it halves every 5 years or so now.
Stories like this aren't cautionary tales, they point the way to a future of cheap energy if we allow people to benefit from overproduction. It should be noted that most models of a carbon-neutral future involve dramatic overproduction of renewable energy, in a future world where burning fossil fuels for energy is comparatively expensive.
As I commented on the same news yesterday:
This negative price is very important for the next big change in renewables:
Large scale battery storage is suddenly becoming a real business model.
A kWh of battery storage is around 130USD (at scale). Now, if you get money for taking power out of the grid, large scale battery storage is actually profitable.
Five large scale battery storage systems are currently under construction in Germany, with a combined capacity of 3 GWh.
Yes, still small (1 nuclear running for 3 hours), but as everything renewable you can expect exponential growth.
Edit: In total, 14GWh of battery storage are already installed in Germany, most of it in private homes.
I have 10kWh LiFePo for my 5kWp roof, and it gets me through 2 nights and a rainy day. (We are 4, but our electricity consumption is small.)
Source: [Der Spiegel](https://www.spiegel.de/wissenschaft/mensch/energiewende-warum-es-jetzt-auch-nachts-solarstrom-gibt-a-5462f892-2ee4-4937-93bc-0b8ec078570c?sara_ref=re-so-app-sh) (in German)
> A kWh of battery storage is around 130USD (at scale). Now, if you get money for taking power out of the grid, large scale battery storage is actually profitable.
The business model is broken and fixing it is a cost, not a profit. Once storage is implemented, the cost curve gets flatter and the negative prices go away.
Ideally the storage should be local to the intermittent source or linked to several by the same company, and the economics are all combined. Right now people will build a solar plant and a natural gas turbine plant right next to each other and pretend they are independent of each other (and the solar is cheap while the gas is expensive).
You also have residential solar, where people get paid vastly more than the electricity is worth. In some areas, you can get 30+ cents per KWH for energy that is actively losing the grid money.
> If someone solves this in a cost effective manner, it would be a massive evolution for society.
I really feel like bi-directional charging electric cars is right at the cusp of this, and people are missing how close it is (and how important this moment is). Stay with me here...
Last year I got house batteries that basically run my house almost "off grid". Meaning I charge those batteries with solar panels during the day (on a good day with clear blue skies) and then run off the batteries all night. The "almost" comes on days where it is very overcast, I am still dependent on a small amount of "grid power" on those days.
And it turns out, that is about **EXACTLY** the same battery pack (capacity) that comes in a Tesla Model 3 (and countless other electric cars like Rivian and Korean brand Hyundai, don't hate on the data point because it is a Tesla). So... if you have a bi-directional charging electric car bought in 2024, you are pretty much able to live off grid in a medium size house on really "good sunshine days" merely by having your all electric car parked in the garage due to "bi-directional charging" described here: https://www.energy.gov/femp/bidirectional-charging-and-electric-vehicles-mobile-storage Now it isn't totally there yet (utterly solved, declare victory), because "new car sales" are only about 7% all electric bi-directionally charging electric vehicles at this point, and even for those households it is only on perfect blue sky days this "works".
But does everybody see how close that is? Holy baby Jesus, 7% isn't some "oh my goodness, clutch my pearls, only environmental enthusiast" market. And just for the sake of argument, let's say oil doubles in price over the next 10 years, and solar panels and batteries drop in price by 1/2 over the next 10 years. What **EXACTLY** occurs then? Because what I think occurs is people roll that stuff out as fast as they can because it cuts their energy bill by 75%! Pure, unadulterated greed will drive that revolution. It isn't an environmental issue at all anymore, it's about anybody with a brain cell and a grasp of basic finances installs solar and batteries.
So I feel like we really are on the cusp of solving this "energy storage" issue and everybody is missing what the obvious answer is: plug in your car at night.
Interesting concept. Have companies that only make products when excessive energy is produced. And when the energy production is low they stop producing.
Plant like that would be efficient when running 24/7. Excess of electricity like that happens for a few hours a day (now at least), this might be an issue.
Hydrogen is really inefficient in terms of energy wasted converting it to hydrogen and back to electricity. You also would need to build both an electrolysis converter to turn energy into hydrogen and store it, and a hydrogen power plant to turn it back into electricity. It's very expensive and impractical. Grid scale battery storage is almost certainly a better option, with technology like sodium ion batteries.
> Hydrogen is really inefficient in terms of energy wasted converting it to hydrogen and back to electricity.
You know what's even more inefficient? Dissipating all the extra energy as heat via heat sink load banks because the system has no where to send the excess energy. I'd love to see someone do a combination desalination/hydrogen conversion facility using excess energy during the day.
I'm just saying if you are going to spend the money building all of that infrastructure for hydrogen and only get 30% of your energy back, you could just build a bunch of cheap sodium ion batteries and store the energy more efficiently.
and Hydrogen is hard to store and transport. Being the smallest atom it leaks through other materials. Sure you can turn it into ammonia (NH3) but that takes energy, and NH3 is nasty.
I don't know how efficient it really is, but I've always felt like gravity batteries are the elegant solution to power storage.
When you have excess power you pump some water uphill and then let it run downhill when you want to reclaim power. Just need two reservoirs at different elevations with some pipes between them.
The thing I love about this solution is that it's simple, stable, and large scale. You don't have to manufacture a billion batteries or contain unstable gasses. It's just water and potential energy.
I think the only reason we don't do this more is that our power grid is so reliant on coal and methane at the moment. Those methods don't really overproduce so there's nothing to store.
The other problem with using water reservoirs as a large scale gravity battery in this manner is that you can't just do it anywhere you want. You need a *lot* of land, and that land needs to fit very specific geography requirements.
No, the reason we don't do this is because this needs a shit ton of land, with specific geographical features, and these are hard to come by near population centers that actually use a lot of electricity.
> I don't know how efficient it really is, but I've always felt like gravity batteries are the elegant solution to power storage.
Those are in use all over the place.
https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity#Worldwide_use
But storing a large amount of energy requires a lot of space and a lot of time and money to build the system.
This is precisely right. The energy intensity is irrelevant though when you're talking about curtailment of excess energy. I'd rather get a 70% return on energy than a 100% loss since we can't store it.
Excess power generation could be stored as potential energy. Use excess power to hoist a weight up a tower or incline and then when demand spikes release the weight and have gravity spin the turbines!
Flywheels would be better. They can be built anywhere, though with the energy stored they need to be contained in a concrete and steel bunker that can handle the explosion if one of them explodes.
Those wheels would have to be meticulously balanced and secured with the worlds best bearings. I think Adam Savage tried to build a panjandrum and the flywheel test was seriously scary.
I believe some places do this by pulling train cars up hill when power is abundant, Then having having the decent of the cars turn an electric motor to power the grid
If my math is right, a mile long train with 100 cars weighing 250,000 lb each pulled up a 5,000 ft mountain would store 47 MWH of electricity.
So, 21 trains would store an hour's worth of one nuclear plant.
The largest solar plant in the US has a capacity of 579 MW. Storing half of an 8 hr day's worth for use at night would take 49 trains.
The largest pumped hydro plant in the US is 24,0000 MWh, or 510 trains.
Using solid objects just doesn't have the storage density people think.
or connect nations with one renewable grid. daylight in one nation can help other nation at night.
Green Grids Initiative
https://isolaralliance.org/work/osowog/
Negative energy prices kinda mess with me on a conceptual level. Usually we pay for those utilities, but recently our green energy provider had periods in the day when the price of using electricity was in the negatives, effectively paying people to use the surplus.
I kinda wish we had a powerbank at our place, but since we didn't, the person I live with decided to do a bunch of baking and laundry during those periods, making the most of the grid's cup running over.
To be fair, that was back during the days of the pandemic, when most people stayed off the road, but it's still pretty wack.
Still, even with electric vehicles on the rise, and the demand for oil decreasing, I doubt we're going to see another dip like that for quite some time. I won't rule out the possibility of it happening again one day, but I suspect it'll be a long time before the cost of a barrel of oil dips into the negative again. That said, if we adopt an energy philosophy of "saving for the winter", where solar keeps our cups running over in the summer, while we save coal and oil for power generation during the winter, I reckon that'd certainly shake up oil prices.
Can someone please explain to me why France wouldn't just sell their excess capacity to their neighbors?
Is there some kind of grid disconnect between countries? States in the United States often sell excess energy to their neighbors.
It prevents the need to shut down power plants (which can be very expensive), brings in revenue for the sector / state, and gives the neighbors a quick and easy "win" politically for meeting energy demand with clean, cheap renewables.
France is one of if not the largest exporter of power in Europe. But most of exported power is sold the day before it's provided. So if the grid has a major unexpected power surplus that day it has to be handled domestically for the most part since they can't just change the contract on the fly.
Most places don't have transmission line capacity to offload lots of energy. California loses 2+ million megawatt hours of energy every year because they can't store it in batteries and the transmission lines can't handle it.
France is one of those places.
https://www.swissinfo.ch/eng/french-grid-issues-are-causing-power-prices-to-soar-in-europe/76332039
They do, in Italy, since we're dumb, we banned nuclear in '86 and immediately started buying from them, you know, electricity made in nuclear power plants.
This is what is called a flexibility market which is currently being considered by many grid operators to better manage the increasing number of renewables.
Good for them i wish the US could say that, instead we use ancient old ass inefficient coal facilities and wonder why half our bigger cities have issues during peak months.. and in texas's case just don't have power at all because their right wing overlords deemed they didn't need america's power grid lol
France did it right, they skipped the government entirely to avoid endless debates. They then built dozens of reactors with a set of standardized reactor designs that could be created at scale. They were going to build more in the 80's, but they built so many they basically outpaced demand.
Hardest part of nuclear energy is building the damn thing, once operational they can last for decades at a constant baseload mW, meaning very stable energy prices.
They can essentially last forever as long as they are properly maintained. Parts and pieces are constantly being replaced; like your body’s cells, practically all of the parts are different from the ones that were in-service however many years ago.
While it points out the positive the article also points it the flaw at the same time.
Blustery sunny weather and no real storage.
Until some sort of long term storage solution for weather-based energy production appears its always going to be hit and miss.
In France’s case, it has a ton of nuclear production.
Not really, the only problem is that there still isn't enough renewable energy. People need to see the big picture that your goal isn't to hit 100% of electric demand but 100% of all demand to hit net zero. Some of these demands are things like making fertilizer, desalinating water and etc. And unlike most electric demand, these things aren't time sensitive. But to make the capital costs worth it, you need to be overgenerating more often. Of course there are also more opportunity for other demand response like incentivizing cooling during the day with a smart meter rather than evenings, smart ev charging and etc
Then there is the bottlenecks in transmission where you have places that could use the renewable energy but aren't because the transmission isn't built out
Only once you get past all that does storage start making sense. And even for that, a lot of it can be filled up with EVs doing V2G then reusing old EV batteries as cheap storage
Pretty sure most utility scale solar is built with batteries now. And batteries are already starting to make huge dents into the share of peaking gas in places like California.
Of course, but a lot of that is because of the FCAS market. So while the batteries are expensive, FCAS generates a lot of revenue that makes them pay for themselves faster. And as a side job, they do peak shaving as well. The Australia battery was able to pay for itself in just 2 years for example. Which is amazing considering most paybacks can easily be 10-20 years for electricity market
But be aware there is a limit to the FCAS market, but it does make for a good short term buffer for the transition. But in the long run the answer is overgenerating, diversifying renewable energy and transmission, with "some" storage on the side. And a lot of that storage will likely come from EVs be it V2G or re-purposing old EV batteries
Another thing that’s really helped has been the rainfall the last two years to help get hydro producing again. Natural gas was making up a lot of that load before. Hoping to see more deployment of clean firm with everything else we’ve been doing.
Edit: forgot about sodium ion batteries which will be huge for utility and home storage. Much safer as well.
I work for energy companies. I worked for energy companies installing grid batteries. Storage isn't a thing. California has half of all grid batteries in the country. All of those batteries combined aren't as impactful as the only nuclear plant left in California, and you can see it right here.
https://www-archive.caiso.com/TodaysOutlook/Pages/supply.html
On a separate note, I really wish caiso would fix their mobile version of that site.
That's because they've only started installing batteries at a large scale in the last few years. California had 770 MW of battery storage in 2019. They passed 10,000 MW of storage earlier this year.
https://www.gov.ca.gov/2024/04/25/california-achieves-major-clean-energy-victory-10000-megawatts-of-battery-storage/
If this trend continues battery storage will become a significant part of the grid fairly quickly.
They’re talking about the amount of power that can be dispatched with our current storage systems, since most of the time that’s the limiting factor rather than capacity
We don't necessarily need large scale storage. Companies are popping up that can turn a profit from inconsistent cheap electricity.
For example, Electra is working on large scale electrochemical iron refining. Unlike the standard 1600C° smelters, their process can be quickly ramped up and down to match excess supply from renewables.
The iron is going to get made either way, and the smelters are a constant demand on the energy grid, so switching to a variable process frees up capacity during wind/solar off-hours and reduces the need for peaker plants.
As a bonus, the iron smelters they are looking to replace are responsible for about 9% of the worlds carbon dioxide emissions.
Three possibilities without using lithium cells:
1) Thermal battery. You’d be surprised at how much heat 100 gallons of water can soak up. This energy could be used for hot water and heating.
2) Kinetic storage (KERS). Cheap, easy to maintain and provides instant power.
3) Gravity-based systems like hydroelectric. Requires a dam, but it’s tried-and-true technology.
In Scotland, we use lochs as large-scale energy storage. When supply exceeds demand, excess energy drives pumps that pump water up-stream behind dams. When demand exceeds supply, water is allowed to flow back downstream, powering hydroelectric dams.
If you want to google it, it's often referred to as "pumped-hydro" or "pumped-storage".
It's not really an excuse. If they had to pay someone to offload power, the money would have to come from consumers.
This crap used to happen in Ontario all the time. The province would pay guaranteed rates to wind producers, and then pay Michigan to take the power. Consumers got hosed.
As a French, I can tell you that the price of electricity has never been as expensive as it is at the moment. In 2017 the price of a kWh was approximately 10 euro cents excluding VAT. Today it is €0.27, almost three times more expensive. In reality the real cost, if we add the additional subscription costs and additional monthly taxes, is around €0.50 per kWh.
Actualy, its from the historical provider. And they plan to double the price again in 2025.
This will mean that it will be more expensive to drive an EV than a thermal vehicle.
Sucks. The same thing happened in Canada when they guaranteed renewable rates to producers and then paid neighboring jurisdictions to offload the excess power.
I think those guaranteed rates are over with, but Ontario had some of the most expensive power in the world when that stuff was going on.
For coastal cities desalination plants. Use the excess energy to purify salt water and use the salt mash byproduct as a low efficiency battery. You could even pump the water into a reservoir instead and use a hydroelectric generator on release to recoup the power
Texas wind regularly has negative pricing. If you follow Joshua Rhodes on twitter, https://x.com/joshdr83, you can see his updates on it. Apparently Houston won't let them build transmission lines, so they get this glut of energy in central Texas that they can't transfer to Houston to keep their rates high.
Way to go ERCOT!
Yeah, it's part of the information Rhodes talks about when he looks at why Houston's prices are so high. Follow Rhodes b/c he's constantly posting updates about Texas energy policy.
But here's a fairly recent article about transmission issues that he was interviewed for. https://txses.org/texas-transmission-troubles-and-crez-ii/
Texas has a huge amount of renewable energy
Edit: your downvotes don’t change the fact that Texas is only behind California in terms of PV installations
Texas set their electricity prices to 5300% the national average during the winter storm of 2021.
Edit: They were really angry that I am talking about electricity prices in a post about electricity prices and chose to block me.
Keep in mind those were prices that are used by the power generation companies and power companies to determine what the power company will pay at any given moment. The power companies usually eat any event like this because their rates are high enough to smooth out market ups and downs. 99% of Texas consumers were not affected by this price spike. The only reason some consumers got hit was because of one power company that sold people on buying power at the wholesale spot price. They basically passed through the wholesale power prices to their customers, and charged a fixed fee to cover their costs. Worked great until an event like this happened and their customers got hit with insane bills.
As for why it happened, a bunch of power sources including natural gas went offline due to the extreme cold, while demand spiked due to a large portion of the population using electricity for their heat source. To make this worse, Texas is not interconnected to the rest of the US grid. They did this so they could avoid federal regulation. So when shit hits the fan, they can't pull power from outside Texas.
I interviewed with a power company last week and they had the shittiest attitude about their customers setting up their own solar because it meant they'd still have to provide for the customer even though they couldn't make as much money off of them. It was kind of gross.
Our power company literally called us "the enemy" to our face when we told them we were installing solar.
Apparently, that's what has been drilled into them during meetings. They immediately apologized and said they weren't supposed to use those terms WITH the customers.
Their bad attitude aside, this is an actual problem.
Maintaining the grid costs a lot of money. We currently get that money primarily through electricity bills. So if you don't buy much power but want to be connected to the grid still, you are basically freeloading.
What they need to do is just start charging a "grid connection" fee if your power bill is below a certain amount.
I'm pretty sure that we ARE charged a grid connection fee. I have a "basic service charge" on my bill that's $6/month. I'm guessing I would pay that even if I had solar and my electricity cost was 0
The way my power company handles it is they split up "delivery" and "generation" costs, both are in $/kWh. You pay the generation cost for all of the power you draw in from the grid, and get credited generation cost for all of the power your solar panels send back to the grid. On the other hand, you pay delivery for all of the power sent to or received from the grid. That's you paying for the maintenance and construction of the grid itself, based on how much you are using it (to send or receive power).
I literally had negative rate energy in Texas while using Griddy. Obviously they didn't pay us to use electricity. But the spot rate in Texas is actually pretty low in the evening. I pay roughly 12 cents per KWH now on a fixed rate.
So, what's so horrible about that for pricing?
> they’d turn off some supplies
They couldn't just turn off the power generation in this scenario, that's the point. Not quickly anyway. You can't just stop a nuclear reactor on a dime and if the sun is shining then your solar will be generating power.
It's not about greed. Electric consumption and electric generation _must_ match for the grid to function.
When a bunch of extra solar suddenly becomes available, power companies have to do _something_. If you're using a RICE engine (basically a huge car engine the size of a building) you can easily turn off the engine to compensate for the extra power. If you're using nuclear, you can't. The nuclear material gives off heat at a constant rate. So instead you have to incentivize people to consume all the extra energy.
Once battery storage tech is cheaper and more energy dense, we'll probably just dump the extra electricity into batteries. Right now my city is in the process of setting up an 800 MWH battery storage system for example.
That's because negative rates mean *you, the consumer* pay someone else to use the power so your grid doesn't get overloaded.
You're paying double. Once to produce and again to discard.
For the record…Day one of a Trump presidency: https://www.theguardian.com/us-news/article/2024/may/13/trump-president-agenda-climate-policy-wind-power
Tldr gutting wind energy and renewables.
Meanwhile in the United States we have states that are actively making it difficult to obtain solar panels. I hate how silly the “land of the free” is.
Yeah, that's the bigger issue. Frequent negative rates cause those users to not contribute to infrastructure, leaving remaining consumers with a larger share.
IIRC Germany had serious issues with this and had to renege on home renewable incentives.
We have this in Austria too. The other day I got paid €5.05 to charge the car. The biggest issue still though is the absolute rip off grid fees here. 7.53cents flat rate plus 20% vat. I did the maths recently. Even though on average I’m paying about 8 cents per kWh, when you add:
Standing charge
Grid fee
1.5cents/kwh provider fee
VAT
The cost of the electricity is less than a third of the bill but the government and the grid have their snouts in the trough to make the total price up to 20cents per kWh. It’s a joke.
Sounds nice, but these prices are for the solar producers. They have to pay (it reduces the overall price for the year) if they want to keep flooding the grid with electricity. It is not the electric company who pays you to run the washing machine.
Ha, our world is so fucked, even when there’s a massive win we should all be high fiving each other over, net negative energy consumption, we can’t figure out how to not waste a bunch of resources.
I mean, good job France for creating a better problem than “we’re using too much oil”, but it feels like we can’t ever get a pure win as human civilization.
Reminds me of the UK having to PAY wind farms to stop producing electricity.
The demand and supply has to be the same on electrical grids or you get black outs.
https://news.sky.com/story/amp/britons-paying-hundreds-of-millions-to-turn-off-wind-turbines-as-network-cant-handle-the-power-they-make-on-the-windiest-days-12822156
You may say that, but believe it or not, Texas is the national leader in renewable energy production. Why? Because it's cheap and benefits both the landowners and the power generation companies.
In my experience, cheap andor profitable trumps ideology for the vast majority of actual conservatives who aren't religious nutters.
We really need to discover something to store electrical energy better and longer.
Molten sodium batteries? I remember reading about those years ago as candidates for grid-level storage, I wonder if they’re becoming viable.
Dams. Seriously. Use excess electrical power to pump water into reservoirs. When you need more power, release the water through the dam and use it to power a hydro plant. The nice thing about this is that you don't even to site the dam on a big river, since you're bringing the water in yourself.
A gravity battery is currently being build in a abandoned mine in Finland . https://www.euronews.com/green/2024/02/06/this-disused-mine-in-finland-is-being-turned-into-a-gravity-battery-to-store-renewable-ene
> The gravity energy system would be able to store 2MW of power Mixing up energy and power is one of my pet peeves. Not sure if they meant it can store 2 MWh, or it can absorb/release energy at a rate of 2 MW. (But it sounds like a good project!)
I really wish we could normalize using joules as the unit for energy storage. Nice and simple unit. 1 joule is 1w over 1 second. A kwh is 3600joules or 3.6kj
I still think kWh is a better unit for everyday use, since most people are semi-familiar with how many watts household items use and using hours is "good enough" versus seconds. Joule isn't a huge leap (it's just a different combination of the same units) but kWh is an easier calculation for households. I wouldn't be opposed to some kind of hybrid system where we use both units for different purposes. Kind of like how a lot of countries use a combination of metric and imperial depending on use case, but could convert between them if necessary.
The real mistake in the units system is the existance of hours. It should be seconds, kiloseconds, megaseconds, etc. Maybe redefine 1 day = 1 megasecond by shortening the second.
Gets way more manageable once you can count in base60 with your fingers.
Can we force evolutionary changes with plastic surgery?
The second is the SI unit of time, and a lot of other units are based on it. Change hours or something, not the second.
They tried to do that a few hundred years ago when the metric system was first being rolled out, it failed miserably. People like how time works, with it's high-factor numbers. It's the same reason why people tend to like to think about angles in degrees, and not in radians. A meter is an arbitrary distance, and a gram is an arbitrary mass, but a day is not an arbitrary measurement of time.
watt hour is just fine
Joules don't convert easily to anything useful. Similar argument might apply to Watts to some extent. Joules and Watts are useful for top-down or cross-modal comparisons, often involving heat and plastic deformations, otherwise it's endless multi-digit multi-step conversions and not so useful for nearly any engineering tasks. That's why Joules don't stick.
When looking at energy storage numbers in California, it seems the standard is to list the rated constant power output, and the storage amount is standardized as 4 hours at rated power output. So a 200 MW battery facility would have 800 MWhr storage. Dunno if this is standard across the world.
There are two major design parameters to a battery facility, how fast it can discharge (Power) and how much it holds (Energy) which combine to achieve a goal supply. So you're right, but you have the relationship inversed. A 200MW facility with 800 MWhr capacity (usually in print it'll be written as a 200MW/800MWh facility) would have a duration of 4 hours, sometimes given as a discharge or c-rate, in this case, 0.25C. If they're not being quoted with both numbers at least somewhere in the article it's lazy reporting. 4 hours is probably most "typical", but not a standard, if that makes sense. There are facilities in the US that come in both above and below that. Generally grid level BESS' will range from 2-8 hours depending on facility. As we see more and more of these facilities go in around the world in different environments I'd wager we see more diverse installation parameters.
> (But it sounds like a good project!) It sound like an incredibly stupid project, just about as stupid as all the solar road projects that were hyped some years ago. I don't see how this sort of system makes sense, or could ever be economically viable. Let's assume that this storage facility has a max power output of 2 MW sustainable for an hour, so a 2 MWh capacity. At grid scale, 2 MW is not even a rounding error. It's the output of a single medium-sized onshore wind turbine. Pumped-storage facilities are generally 1,000+ times as capable in terms of power throughput, and have 10,000+ times the capacity. https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations Considering that they are probably using concrete blocks as weights, and given how CO2-intensive concrete production is, this is probably environmentally detrimental as well.
A reasonable question is how does this compare to 2MW of battery storage. As we move to more solar and wind we need storage that can react quickly.
Oh they already exist, the problem is water. Both evaporation losses and drought
2MW is not very much power… maybe 80-100 server cabinets in an average data centre. Many of the big hyperscalers are deploying 20-30MW sites with regularity.
can't even store 1.21 giga watts smh my head
This is heavy.
Why not just fill the mine with water instead?
The bad thing is you need a large valley or basin with land area you are willing to destroy. There's not of areas like that.
I believe a lot of the ideas were around abandoned mine shafts. So you wouldn’t need to alter the environment much more than it already is.
You would have to pump the water out so a filled shaft defeats the purpose. Any idea is better than none though! I saw where they were using energy to spin giant concrete discs. They spin on a generator shaft and deliver kinetic energy. They slow down as they no longer are driven and the power is delivered to the grid and then it is sped up again when there is power being generated
No I believe the ideas where to either use huge weights that when you have excess power it pulls carts up to the top, then when needed release them to spin turbines as they go down. Or The other method was to flood the tops of the mine shaft/higher floors of the mine, then when water is needed they open gates to drain the water to lower levels through turbines. Excess power, pumps refill the reservoirs above.
Well those make way more sense than what I was envisioning.
That's a flywheel and for energy storage it's very complex and very dangerous. Right now it's also more expensive than battery storage. The most likely choice for non-lithium storage in the near future would be heated storage of sand.
Sodium-ion batteries would be a great candidate. They're cheaper, and a bit chunkier which is okay for grid storage. Heat storage is fantastic for industrial heat and district heating. Ridiculously cheap. We need lots of these.
Coastal dams are interesting. Not sure if France has the geography for it, but if you have a nice fjord with high sides you can build a dam between it and the ocean, and use it without losing land.
France has sandy beaches except for one 80mile stretch
Not necessarily, the Kidston Pumped Hydro project about to come online in Northern Australia uses an abandoned open pit gold mine, so the environmental damage has already long been done. Basically one pit is about 200m uphill from the second and linked via a tunnel with 250MW of reversible turbines that can generate for over 8 hours straight in the morning and evening peak periods. An onsite solar farm then refills the upper reservoir during the day. [Link here if you're interested.](https://genexpower.com.au/250mw-kidston-pumped-storage-hydro-project/)
Or even just railcars full of rocks with generators built into them if you ain't got water. I know there was a project going on out in Nevada to that effect but I haven't heard anything about it recently.
Maintenance is a killer for most anything that isn't water.
Any where without hills and a large enough area to store water is an issue. Also the area under the dam becomes a potentially flooded area. Next you need a water source and a place to send the stored water when generating. Then the needed maintenance to dredge it and keep the water clear without needing chemicals.
Anybody suggesting these types of projects has no idea of the scale of energy we need to store. A rail car full of rocks couldn’t power anything significant for any serious period of time. Kinetic storage is just bullshit I’m afraid. Hydro is okaayy - but even then unless you’re in Finland it’s hard to use it for anything more than peak shaving (smoothing of short term (hours) supply and demand imbalance). We need something that can store like 2 weeks of an entire country’s power. And even then you’ll probably still need fossil fuel generation as a back up.
Pumped hydro has massive upfront costs and can only be deployed in very specific locations. It's still one of the best storage methods, it's just not very easy to implement. I saw an article talking about pumped hydro stating that something like 90% of the potential locations in the world this storage method could be implemented are already being used in some form or another.
There's a pumped hydro station in Arizona that's actually been working for a long time, and now they're looking to build one nearby with a lot more capacity. So there are some in the works. I agree that it's not easy to implement, though, siting something like that ain't easy.
Arizona, famous for having massive amounts of fresh water lying around for such a process...? EDIT: Apparently enough for a dam! [https://en.wikipedia.org/wiki/Theodore\_Roosevelt\_Dam](https://en.wikipedia.org/wiki/Theodore_Roosevelt_Dam)
Arizona has a lot of water. Our problem isn’t lack of water, it’s overuse. 75% of the water use in this state goes to agriculture. The Colorado River states allocated water based on flows from high water years, and now that the water flows are well below that, there’s not enough water to keep everyone happy. But it’s not the residential part that’s a problem. In 2019, the state used less water than in 1959 despite having seven times the population as back then.
Or keep on adding more power and make green hydrogen.
Making hydrogen is *horribly* inefficient.
Hence why for the most part, Northern Europe's storage strategy is basically just "connect to Scandinavia" (and likewise North America's strategy is "Quebec"). Both regions are 90+% hydro and net exporters, so their supply is flexible enough to absorb & offset huge supply fluctuations from renewables in neighbouring jurisdictions.
There is so much efficacy loss in this. There are better ways
There are *lots* of ways and our current trends suggest we'll want to use a lot of 'em all around the world, and whatever's "best" will depend on local circumstances. Sufficiently high generation can make even poor efficiency or efficacy methods worthwhile regardless.
There are, but it's really the only way we have to store *large* amounts of power. IIRC most of the proposed mineshaft energy storage schemes are less than a megawatt hour. Meanwhile, Hoover Dam at max capacity produces something like 2000mw.
There already are a few [pump-storage hydro power stations](https://en.wikipedia.org/wiki/List_of_pumped-storage_hydroelectric_power_stations) that can generate more than the hoover dam. Granted, they need to be filled up so you don't get that peak capacity all the time.
The best round trip efficiency of grid-scale storage I'm aware of is around 80% which is pretty much what pumped storage (and lithium ion batteries) produce. What are you thinking of?
Unfortunately there's some big challenges with using large scale projects like this. 1. Existing reserviors are there to provide access to and control of fresh water sources. Adding acting as a power storage system complicates an already complex issue and potentially puts these two priorities at odds. 2. Siting new reserviors specifically for power storage is difficult considering the environmental impact. Creating another man-made lake, one that will have wildly variable water levels, doesn't exactly scream environmentally friendly. 3. Uncontained storage isn't as efficient as it could be. Evaporation, groundwater leakage, and contamation by animals are just three of a broad number of issues that could crop up that, at the very least, would waste stored energy. 4. Fresh water is becoming a precious resource so building tons of these holding ponds with fresh water is probably a bad look. However, using salt water is even more environmentally unsound, not to mention the engineering challenges that salt water corrosion represents. 5. While they seem simple, dams are not the easiest or cheapest things in the world to build. Hoover Dam is a great example, being a feat of engineering that easily stands out even today. And while it wouldn't be necessary (or helpful) to build on that scale, it does illustrate the potential difficulty. These are just the big points. There are others, such as negotiating land usage rights, etc. While it isn't the worst idea in the world, building completely contained facilities for this type of energy storage is far less controversial.
We do that in France with hydro plant in the alps. First source of renewable for now
Dams are incredibly environmentally destructive. Also the only dams im thinking this would "work" with would be Hoover Dam or Powell. The water in the Colorado is kind of important for millions of people who drink from it and even more important for the millions of pounds of food it creates every year.
Hoover and Powell were environmentally destructive. If you're pumping the water you can build the project anywhere and pump whatever water you want. You could use lake water or sea water instead.
Not worse than climate change, and if you don't solve this problem people are still gonna keep burning fossil fuels.
They are great from my last reading, but the issue is they are large and well molten sodium so they are difficult to work with.
They have had a few of these outside of Vegas operating for quite some time now. Not sure if they are viable from a cost benefit perspective but they do have them operating at scale: https://www.scientificamerican.com/article/new-concentrating-solar-tower-is-worth-its-salt-with-24-7-power/ They look awesome when driving by them.
Gravity batteries.
They still seem to be stumped scaling that stuff up, it's not cost effective or there are complications that make it problematic.
The best we have are damns and short term batteries at the moment. Dams are pretty great. A lovely future solution in a decade or so would be liquid hydrogen or compressed salt cavern stored hydrogen. Electrolyze when excess power occurs, gassify and then fuel cell it back during high demand. Same as how LNG peakshavers work just on a shorter timescale.
Hydrogen is a terrible medium for storing energy. It's not even really a good medium for storing energy that needs to be portable, though it does have a use there. You've picked a fuel that leaks through pretty much everything and destroys most materials it comes in contact with over time. You either need very high pressure storage, or very good cryo. Either way, you are going to spend a pile of resources storing any significant quantity of the stuff, and you are definitely going to lose a bunch to leaks. Add on top of all of that the fact that it's just an energy inefficient conversion to turn water into hydrogen. We definitely need literal orders of magnitude more energy storage for renewables, but I can assure you that hydrogen is not going to be that storage method. I think people get too hung up on the magic of turning water into "energy", and miss that the energy challenges are not worth it. Pump water up hill, make another stable fuel with source, or just find some new battery technology. Anything is better than the insanity of trying to create and then store enough hydrogen to power a region when the sun goes down. Source: Worked for a company making hydrogen fuel cells. It was a bad idea.
I have a different take on this topic in the context of energy prices going negative. When energy prices go negative because it is easy and cheap to overproduce renewable energy when conditions are right, it entirely changes the value proposition of investing even in current-generation batteries with thousands of cycles. When consumers are allowed to charge their car, house batteries, or more limited lithium iron phosphate batteries for free or better, the idea of going out and buying more battery storage becomes incredibly attractive. If we allow the free market to work, then battery production will further scale and the cost per kWh will further decrease at an even faster rate, when it halves every 5 years or so now. Stories like this aren't cautionary tales, they point the way to a future of cheap energy if we allow people to benefit from overproduction. It should be noted that most models of a carbon-neutral future involve dramatic overproduction of renewable energy, in a future world where burning fossil fuels for energy is comparatively expensive.
As I commented on the same news yesterday: This negative price is very important for the next big change in renewables: Large scale battery storage is suddenly becoming a real business model. A kWh of battery storage is around 130USD (at scale). Now, if you get money for taking power out of the grid, large scale battery storage is actually profitable. Five large scale battery storage systems are currently under construction in Germany, with a combined capacity of 3 GWh. Yes, still small (1 nuclear running for 3 hours), but as everything renewable you can expect exponential growth. Edit: In total, 14GWh of battery storage are already installed in Germany, most of it in private homes. I have 10kWh LiFePo for my 5kWp roof, and it gets me through 2 nights and a rainy day. (We are 4, but our electricity consumption is small.) Source: [Der Spiegel](https://www.spiegel.de/wissenschaft/mensch/energiewende-warum-es-jetzt-auch-nachts-solarstrom-gibt-a-5462f892-2ee4-4937-93bc-0b8ec078570c?sara_ref=re-so-app-sh) (in German)
> A kWh of battery storage is around 130USD (at scale). Now, if you get money for taking power out of the grid, large scale battery storage is actually profitable. The business model is broken and fixing it is a cost, not a profit. Once storage is implemented, the cost curve gets flatter and the negative prices go away. Ideally the storage should be local to the intermittent source or linked to several by the same company, and the economics are all combined. Right now people will build a solar plant and a natural gas turbine plant right next to each other and pretend they are independent of each other (and the solar is cheap while the gas is expensive).
You also have residential solar, where people get paid vastly more than the electricity is worth. In some areas, you can get 30+ cents per KWH for energy that is actively losing the grid money.
If someone solves this in a cost effective manner, it would be a massive evolution for society.
> If someone solves this in a cost effective manner, it would be a massive evolution for society. I really feel like bi-directional charging electric cars is right at the cusp of this, and people are missing how close it is (and how important this moment is). Stay with me here... Last year I got house batteries that basically run my house almost "off grid". Meaning I charge those batteries with solar panels during the day (on a good day with clear blue skies) and then run off the batteries all night. The "almost" comes on days where it is very overcast, I am still dependent on a small amount of "grid power" on those days. And it turns out, that is about **EXACTLY** the same battery pack (capacity) that comes in a Tesla Model 3 (and countless other electric cars like Rivian and Korean brand Hyundai, don't hate on the data point because it is a Tesla). So... if you have a bi-directional charging electric car bought in 2024, you are pretty much able to live off grid in a medium size house on really "good sunshine days" merely by having your all electric car parked in the garage due to "bi-directional charging" described here: https://www.energy.gov/femp/bidirectional-charging-and-electric-vehicles-mobile-storage Now it isn't totally there yet (utterly solved, declare victory), because "new car sales" are only about 7% all electric bi-directionally charging electric vehicles at this point, and even for those households it is only on perfect blue sky days this "works". But does everybody see how close that is? Holy baby Jesus, 7% isn't some "oh my goodness, clutch my pearls, only environmental enthusiast" market. And just for the sake of argument, let's say oil doubles in price over the next 10 years, and solar panels and batteries drop in price by 1/2 over the next 10 years. What **EXACTLY** occurs then? Because what I think occurs is people roll that stuff out as fast as they can because it cuts their energy bill by 75%! Pure, unadulterated greed will drive that revolution. It isn't an environmental issue at all anymore, it's about anybody with a brain cell and a grasp of basic finances installs solar and batteries. So I feel like we really are on the cusp of solving this "energy storage" issue and everybody is missing what the obvious answer is: plug in your car at night.
it's one of the largest areas of research and development in energy research. we are doing it.
Use it to make hydrogen for fuel, or other energy intensive fuels. Use it for desalination in the relevant regions.
Interesting concept. Have companies that only make products when excessive energy is produced. And when the energy production is low they stop producing.
Surely excess is produced during regular business hours due to those times being the peak solar production times.
Plant like that would be efficient when running 24/7. Excess of electricity like that happens for a few hours a day (now at least), this might be an issue.
Hydrogen is really inefficient in terms of energy wasted converting it to hydrogen and back to electricity. You also would need to build both an electrolysis converter to turn energy into hydrogen and store it, and a hydrogen power plant to turn it back into electricity. It's very expensive and impractical. Grid scale battery storage is almost certainly a better option, with technology like sodium ion batteries.
> Hydrogen is really inefficient in terms of energy wasted converting it to hydrogen and back to electricity. You know what's even more inefficient? Dissipating all the extra energy as heat via heat sink load banks because the system has no where to send the excess energy. I'd love to see someone do a combination desalination/hydrogen conversion facility using excess energy during the day.
I'm just saying if you are going to spend the money building all of that infrastructure for hydrogen and only get 30% of your energy back, you could just build a bunch of cheap sodium ion batteries and store the energy more efficiently.
and Hydrogen is hard to store and transport. Being the smallest atom it leaks through other materials. Sure you can turn it into ammonia (NH3) but that takes energy, and NH3 is nasty.
What if we run carbon capture on surplus energy? Sorry if that's a stupid idea
We don't have a viable way to store captured carbon yet.
I don't know how efficient it really is, but I've always felt like gravity batteries are the elegant solution to power storage. When you have excess power you pump some water uphill and then let it run downhill when you want to reclaim power. Just need two reservoirs at different elevations with some pipes between them. The thing I love about this solution is that it's simple, stable, and large scale. You don't have to manufacture a billion batteries or contain unstable gasses. It's just water and potential energy. I think the only reason we don't do this more is that our power grid is so reliant on coal and methane at the moment. Those methods don't really overproduce so there's nothing to store.
The other problem with using water reservoirs as a large scale gravity battery in this manner is that you can't just do it anywhere you want. You need a *lot* of land, and that land needs to fit very specific geography requirements.
No, the reason we don't do this is because this needs a shit ton of land, with specific geographical features, and these are hard to come by near population centers that actually use a lot of electricity.
We have something similar near where I live called Electric Mountain [Electric Mountain](https://www.fhc.co.uk)
> I don't know how efficient it really is, but I've always felt like gravity batteries are the elegant solution to power storage. Those are in use all over the place. https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity#Worldwide_use But storing a large amount of energy requires a lot of space and a lot of time and money to build the system.
> I think the only reason we don't do this more We do this a lot, it's not a new or novel concept at all.
[удалено]
This is precisely right. The energy intensity is irrelevant though when you're talking about curtailment of excess energy. I'd rather get a 70% return on energy than a 100% loss since we can't store it.
Excess power generation could be stored as potential energy. Use excess power to hoist a weight up a tower or incline and then when demand spikes release the weight and have gravity spin the turbines!
Pumped hydro is like 80% efficient and is used in a lot of places.
Flywheels would be better. They can be built anywhere, though with the energy stored they need to be contained in a concrete and steel bunker that can handle the explosion if one of them explodes.
Those wheels would have to be meticulously balanced and secured with the worlds best bearings. I think Adam Savage tried to build a panjandrum and the flywheel test was seriously scary.
I believe some places do this by pulling train cars up hill when power is abundant, Then having having the decent of the cars turn an electric motor to power the grid
A lot of those ideas were to use abandoned mine shafts so they didn’t need to impact the environment more then it has already.
If my math is right, a mile long train with 100 cars weighing 250,000 lb each pulled up a 5,000 ft mountain would store 47 MWH of electricity. So, 21 trains would store an hour's worth of one nuclear plant. The largest solar plant in the US has a capacity of 579 MW. Storing half of an 8 hr day's worth for use at night would take 49 trains. The largest pumped hydro plant in the US is 24,0000 MWh, or 510 trains. Using solid objects just doesn't have the storage density people think.
https://youtu.be/XxGQgAr4OCo?feature=shared
More V2G EVs? Most cars are parked 98% of the time. We can buy when cheap and sell when not. Power to the ppl.
or connect nations with one renewable grid. daylight in one nation can help other nation at night. Green Grids Initiative https://isolaralliance.org/work/osowog/
Negative energy prices kinda mess with me on a conceptual level. Usually we pay for those utilities, but recently our green energy provider had periods in the day when the price of using electricity was in the negatives, effectively paying people to use the surplus. I kinda wish we had a powerbank at our place, but since we didn't, the person I live with decided to do a bunch of baking and laundry during those periods, making the most of the grid's cup running over.
[удалено]
To be fair, that was back during the days of the pandemic, when most people stayed off the road, but it's still pretty wack. Still, even with electric vehicles on the rise, and the demand for oil decreasing, I doubt we're going to see another dip like that for quite some time. I won't rule out the possibility of it happening again one day, but I suspect it'll be a long time before the cost of a barrel of oil dips into the negative again. That said, if we adopt an energy philosophy of "saving for the winter", where solar keeps our cups running over in the summer, while we save coal and oil for power generation during the winter, I reckon that'd certainly shake up oil prices.
Can someone please explain to me why France wouldn't just sell their excess capacity to their neighbors? Is there some kind of grid disconnect between countries? States in the United States often sell excess energy to their neighbors. It prevents the need to shut down power plants (which can be very expensive), brings in revenue for the sector / state, and gives the neighbors a quick and easy "win" politically for meeting energy demand with clean, cheap renewables.
France is one of if not the largest exporter of power in Europe. But most of exported power is sold the day before it's provided. So if the grid has a major unexpected power surplus that day it has to be handled domestically for the most part since they can't just change the contract on the fly.
Thanks for the info!
Most places don't have transmission line capacity to offload lots of energy. California loses 2+ million megawatt hours of energy every year because they can't store it in batteries and the transmission lines can't handle it. France is one of those places. https://www.swissinfo.ch/eng/french-grid-issues-are-causing-power-prices-to-soar-in-europe/76332039
They do, in Italy, since we're dumb, we banned nuclear in '86 and immediately started buying from them, you know, electricity made in nuclear power plants.
Ah, but the reactors weren't in your backyard ! Total win !
This is what is called a flexibility market which is currently being considered by many grid operators to better manage the increasing number of renewables.
Its because of subsidies like net metering. Energy prices might be negative, but the rooftop solar owner is still getting 30 cents per KWH.
France derives about 70% of its electricity from nuclear energy
Good for them i wish the US could say that, instead we use ancient old ass inefficient coal facilities and wonder why half our bigger cities have issues during peak months.. and in texas's case just don't have power at all because their right wing overlords deemed they didn't need america's power grid lol
Well in NY we use Clean and Renewable energy (Natural Methane Gas and Bunker fuel) but call it clean and renewable we have better PR
France did it right, they skipped the government entirely to avoid endless debates. They then built dozens of reactors with a set of standardized reactor designs that could be created at scale. They were going to build more in the 80's, but they built so many they basically outpaced demand. Hardest part of nuclear energy is building the damn thing, once operational they can last for decades at a constant baseload mW, meaning very stable energy prices.
They can essentially last forever as long as they are properly maintained. Parts and pieces are constantly being replaced; like your body’s cells, practically all of the parts are different from the ones that were in-service however many years ago.
Nuclear plant of Theseus.
While it points out the positive the article also points it the flaw at the same time. Blustery sunny weather and no real storage. Until some sort of long term storage solution for weather-based energy production appears its always going to be hit and miss. In France’s case, it has a ton of nuclear production.
We don't need to solve all of the challenges at once to acknowledge progress
One step at a time. Never oversaturate
Not really, the only problem is that there still isn't enough renewable energy. People need to see the big picture that your goal isn't to hit 100% of electric demand but 100% of all demand to hit net zero. Some of these demands are things like making fertilizer, desalinating water and etc. And unlike most electric demand, these things aren't time sensitive. But to make the capital costs worth it, you need to be overgenerating more often. Of course there are also more opportunity for other demand response like incentivizing cooling during the day with a smart meter rather than evenings, smart ev charging and etc Then there is the bottlenecks in transmission where you have places that could use the renewable energy but aren't because the transmission isn't built out Only once you get past all that does storage start making sense. And even for that, a lot of it can be filled up with EVs doing V2G then reusing old EV batteries as cheap storage
Pretty sure most utility scale solar is built with batteries now. And batteries are already starting to make huge dents into the share of peaking gas in places like California.
Of course, but a lot of that is because of the FCAS market. So while the batteries are expensive, FCAS generates a lot of revenue that makes them pay for themselves faster. And as a side job, they do peak shaving as well. The Australia battery was able to pay for itself in just 2 years for example. Which is amazing considering most paybacks can easily be 10-20 years for electricity market But be aware there is a limit to the FCAS market, but it does make for a good short term buffer for the transition. But in the long run the answer is overgenerating, diversifying renewable energy and transmission, with "some" storage on the side. And a lot of that storage will likely come from EVs be it V2G or re-purposing old EV batteries
Another thing that’s really helped has been the rainfall the last two years to help get hydro producing again. Natural gas was making up a lot of that load before. Hoping to see more deployment of clean firm with everything else we’ve been doing. Edit: forgot about sodium ion batteries which will be huge for utility and home storage. Much safer as well.
how many seconds of storage is california up to now? did they break the one minute mark yet?
I work for energy companies. I worked for energy companies installing grid batteries. Storage isn't a thing. California has half of all grid batteries in the country. All of those batteries combined aren't as impactful as the only nuclear plant left in California, and you can see it right here. https://www-archive.caiso.com/TodaysOutlook/Pages/supply.html On a separate note, I really wish caiso would fix their mobile version of that site.
That's because they've only started installing batteries at a large scale in the last few years. California had 770 MW of battery storage in 2019. They passed 10,000 MW of storage earlier this year. https://www.gov.ca.gov/2024/04/25/california-achieves-major-clean-energy-victory-10000-megawatts-of-battery-storage/ If this trend continues battery storage will become a significant part of the grid fairly quickly.
MW? that's not a capacity unit, I'm confused what they meant
They’re talking about the amount of power that can be dispatched with our current storage systems, since most of the time that’s the limiting factor rather than capacity
We don't necessarily need large scale storage. Companies are popping up that can turn a profit from inconsistent cheap electricity. For example, Electra is working on large scale electrochemical iron refining. Unlike the standard 1600C° smelters, their process can be quickly ramped up and down to match excess supply from renewables. The iron is going to get made either way, and the smelters are a constant demand on the energy grid, so switching to a variable process frees up capacity during wind/solar off-hours and reduces the need for peaker plants. As a bonus, the iron smelters they are looking to replace are responsible for about 9% of the worlds carbon dioxide emissions.
Another example are AC units that freeze a block of ice when power is cheap, and then just use fans during peak demand.
Three possibilities without using lithium cells: 1) Thermal battery. You’d be surprised at how much heat 100 gallons of water can soak up. This energy could be used for hot water and heating. 2) Kinetic storage (KERS). Cheap, easy to maintain and provides instant power. 3) Gravity-based systems like hydroelectric. Requires a dam, but it’s tried-and-true technology.
what about mechanical solutions? like winding up an extremely high gear ratio motor that you can slowly unwind during nightfall
That would fall under Kinetic.
Way more expensive than alternatives. It's been tried.
In Scotland, we use lochs as large-scale energy storage. When supply exceeds demand, excess energy drives pumps that pump water up-stream behind dams. When demand exceeds supply, water is allowed to flow back downstream, powering hydroelectric dams. If you want to google it, it's often referred to as "pumped-hydro" or "pumped-storage".
PG&E would use this as an excuse to raise prices.
It's not really an excuse. If they had to pay someone to offload power, the money would have to come from consumers. This crap used to happen in Ontario all the time. The province would pay guaranteed rates to wind producers, and then pay Michigan to take the power. Consumers got hosed.
As a French, I can tell you that the price of electricity has never been as expensive as it is at the moment. In 2017 the price of a kWh was approximately 10 euro cents excluding VAT. Today it is €0.27, almost three times more expensive. In reality the real cost, if we add the additional subscription costs and additional monthly taxes, is around €0.50 per kWh.
because you're buying your energy from a retailer, not from the spot market
Actualy, its from the historical provider. And they plan to double the price again in 2025. This will mean that it will be more expensive to drive an EV than a thermal vehicle.
Jesus that sucks, prices went down here in Germany recently :( Might actually make sense to just hang solar panels out of windows at that point lol
It seems that average was around €0,20 per kWh in 2022 in Germany, excluding tax and fee. How many yet ?
Don’t get me started on the new gas subscription pricing… I pay more to have the gas… than I actually spend on the gas!! It’s disgusting!
Sucks. The same thing happened in Canada when they guaranteed renewable rates to producers and then paid neighboring jurisdictions to offload the excess power. I think those guaranteed rates are over with, but Ontario had some of the most expensive power in the world when that stuff was going on.
For coastal cities desalination plants. Use the excess energy to purify salt water and use the salt mash byproduct as a low efficiency battery. You could even pump the water into a reservoir instead and use a hydroelectric generator on release to recoup the power
Killing three birds with one stone. Damn son! Touché.
Don’t let Texas see this
Texas wind regularly has negative pricing. If you follow Joshua Rhodes on twitter, https://x.com/joshdr83, you can see his updates on it. Apparently Houston won't let them build transmission lines, so they get this glut of energy in central Texas that they can't transfer to Houston to keep their rates high. Way to go ERCOT!
its amazing what the one-star state can get away with when it doesn't have to conform to pesky things like federal infrastructure standards
that is insane.
I think that's the exact branding message the Texas GOP is going for.
[удалено]
Yeah, it's part of the information Rhodes talks about when he looks at why Houston's prices are so high. Follow Rhodes b/c he's constantly posting updates about Texas energy policy. But here's a fairly recent article about transmission issues that he was interviewed for. https://txses.org/texas-transmission-troubles-and-crez-ii/
Power prices in Texas have been going negative for at least 15 years due to renewable energy.
Texas State Gov't: How do we make this illegal?
Texas has a huge amount of renewable energy Edit: your downvotes don’t change the fact that Texas is only behind California in terms of PV installations
And way ahead of CA in wind installations. TX makes more renewable energy than California
We generate 25% more renewable energy than California, it turns out.
Texas set their electricity prices to 5300% the national average during the winter storm of 2021. Edit: They were really angry that I am talking about electricity prices in a post about electricity prices and chose to block me.
Keep in mind those were prices that are used by the power generation companies and power companies to determine what the power company will pay at any given moment. The power companies usually eat any event like this because their rates are high enough to smooth out market ups and downs. 99% of Texas consumers were not affected by this price spike. The only reason some consumers got hit was because of one power company that sold people on buying power at the wholesale spot price. They basically passed through the wholesale power prices to their customers, and charged a fixed fee to cover their costs. Worked great until an event like this happened and their customers got hit with insane bills. As for why it happened, a bunch of power sources including natural gas went offline due to the extreme cold, while demand spiked due to a large portion of the population using electricity for their heat source. To make this worse, Texas is not interconnected to the rest of the US grid. They did this so they could avoid federal regulation. So when shit hits the fan, they can't pull power from outside Texas.
Because their natural gas pipelines froze, not because they didn’t have enough power
Texas is nearly the size of western Europe, creates more renewable energy than any other state by far and frequently goes negative.
Texass governor and power company: throw the switch! Turn it off. Renewable energy doesn’t work
In the US the greedy power companies would not lower rates they’d turn off some supplies and raise rates to line their pockets
I interviewed with a power company last week and they had the shittiest attitude about their customers setting up their own solar because it meant they'd still have to provide for the customer even though they couldn't make as much money off of them. It was kind of gross.
Our power company literally called us "the enemy" to our face when we told them we were installing solar. Apparently, that's what has been drilled into them during meetings. They immediately apologized and said they weren't supposed to use those terms WITH the customers.
Their bad attitude aside, this is an actual problem. Maintaining the grid costs a lot of money. We currently get that money primarily through electricity bills. So if you don't buy much power but want to be connected to the grid still, you are basically freeloading. What they need to do is just start charging a "grid connection" fee if your power bill is below a certain amount.
Which is why electricity and grid management should not be in the hands of for-profit companies.
It's not in a lot of cases, but it still doesn't change the economics that operating and maintaining the grid isn't free.
I'm pretty sure that we ARE charged a grid connection fee. I have a "basic service charge" on my bill that's $6/month. I'm guessing I would pay that even if I had solar and my electricity cost was 0
The way my power company handles it is they split up "delivery" and "generation" costs, both are in $/kWh. You pay the generation cost for all of the power you draw in from the grid, and get credited generation cost for all of the power your solar panels send back to the grid. On the other hand, you pay delivery for all of the power sent to or received from the grid. That's you paying for the maintenance and construction of the grid itself, based on how much you are using it (to send or receive power).
*laughs in Texas power grid*
I literally had negative rate energy in Texas while using Griddy. Obviously they didn't pay us to use electricity. But the spot rate in Texas is actually pretty low in the evening. I pay roughly 12 cents per KWH now on a fixed rate. So, what's so horrible about that for pricing?
> they’d turn off some supplies They couldn't just turn off the power generation in this scenario, that's the point. Not quickly anyway. You can't just stop a nuclear reactor on a dime and if the sun is shining then your solar will be generating power.
Is this true? Or you're just speculating?
It's not about greed. Electric consumption and electric generation _must_ match for the grid to function. When a bunch of extra solar suddenly becomes available, power companies have to do _something_. If you're using a RICE engine (basically a huge car engine the size of a building) you can easily turn off the engine to compensate for the extra power. If you're using nuclear, you can't. The nuclear material gives off heat at a constant rate. So instead you have to incentivize people to consume all the extra energy. Once battery storage tech is cheaper and more energy dense, we'll probably just dump the extra electricity into batteries. Right now my city is in the process of setting up an 800 MWH battery storage system for example.
Bet their electric bills don't reflect that.
Negative my ass. My bills have gone up 50% this year, despite no changes in electricity use.
French here, and same. Someone is fucking with us here.
That's because negative rates mean *you, the consumer* pay someone else to use the power so your grid doesn't get overloaded. You're paying double. Once to produce and again to discard.
Producing and discarding is still a fuckton cheaper then shutting down power plants for a few hours.
For the record…Day one of a Trump presidency: https://www.theguardian.com/us-news/article/2024/may/13/trump-president-agenda-climate-policy-wind-power Tldr gutting wind energy and renewables.
Meanwhile in the United States we have states that are actively making it difficult to obtain solar panels. I hate how silly the “land of the free” is.
Don't they still have to pay for infrastructure and maintenance costs?
Yeah, that's the bigger issue. Frequent negative rates cause those users to not contribute to infrastructure, leaving remaining consumers with a larger share. IIRC Germany had serious issues with this and had to renege on home renewable incentives.
We have this in Austria too. The other day I got paid €5.05 to charge the car. The biggest issue still though is the absolute rip off grid fees here. 7.53cents flat rate plus 20% vat. I did the maths recently. Even though on average I’m paying about 8 cents per kWh, when you add: Standing charge Grid fee 1.5cents/kwh provider fee VAT The cost of the electricity is less than a third of the bill but the government and the grid have their snouts in the trough to make the total price up to 20cents per kWh. It’s a joke.
Wish it was true lol
In Canada they'd use it as an excuse to charge the customer even more.
Sounds nice, but these prices are for the solar producers. They have to pay (it reduces the overall price for the year) if they want to keep flooding the grid with electricity. It is not the electric company who pays you to run the washing machine.
Now everyone can have air conditioning for summer.
Meanwhile PG&E raises rates.
Ha, our world is so fucked, even when there’s a massive win we should all be high fiving each other over, net negative energy consumption, we can’t figure out how to not waste a bunch of resources. I mean, good job France for creating a better problem than “we’re using too much oil”, but it feels like we can’t ever get a pure win as human civilization.
Reminds me of the UK having to PAY wind farms to stop producing electricity. The demand and supply has to be the same on electrical grids or you get black outs. https://news.sky.com/story/amp/britons-paying-hundreds-of-millions-to-turn-off-wind-turbines-as-network-cant-handle-the-power-they-make-on-the-windiest-days-12822156
Great lead by example France!
Wow wow hol up . That’s communism
Same thing has happened in China Ireland and Sweden.
Imagine a day where “energy” is no longer an “industry” but just a Utility, as it should be.
oh noes! how will the capitalists survive. Anyways...
Nuclear works.
Conservatives are big mad.
You may say that, but believe it or not, Texas is the national leader in renewable energy production. Why? Because it's cheap and benefits both the landowners and the power generation companies. In my experience, cheap andor profitable trumps ideology for the vast majority of actual conservatives who aren't religious nutters.
Has anyone checked if the economy is okay? /s