Comment by Havoc
20 hours ago
More stoked for when the same is said for storage.
Solar is cool but solar that can make it through the night and a couple cloudy days is way cooler
20 hours ago
More stoked for when the same is said for storage.
Solar is cool but solar that can make it through the night and a couple cloudy days is way cooler
> Solar is cool but solar that can make it through the night and a couple cloudy days is way cooler
The fun part is that we're still well before the point when this even matters.
Almost 60% of the US grid is still fossil fuels, with around half of that still happening during the day. Which means you can get down to ~30% fossil fuels without any storage at all because all you do is go from burning fossil fuels during the day and at night to burning fossil fuels only at night.
> at night to burning fossil fuels only at night
only natural gas plants can do this. a coal plant cannot spin up just for the night and turn back off when the sun comes up - it's incredibly inefficient and probably causes more premature wear/tear too.
Full startup and shutdown of a coal plant can take days, but throttling down to about half power during low-load periods is normal. Power plants do this every day. Late at night, load decreases and plants throttle down. Every morning, between 0600 and 0900 local time, there's "morning load take-up" as load increases.
The big issue is what's called "ramp rate" - how fast can output power be increased or decreased? This tends to be around 1% to 3% of capacity per minute. See Figure B-2 in [1], which is a detailed discussion of how to improve your coal-fired power plant's ramp rate.
Natural gas plants have much higher ramp rates, and for batteries, it's under a second. Nuclear plants can be ramped up and down, slowly, but since it's all capital cost, cutting output raises the price of the power.
[1] https://www.epri.com/research/products/3002012979
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"Increased rates of component life consumption due to thermal fatigue, mechanical fatigue and wear caused by differential thermal expansion comprise the bulking of cycling (costs)," according to the International Energy Agency's Coal Industry Advisory Board.
"Every time a power plant is turned on and off, the boiler, steam lines, turbine and auxiliary components go through unavoidably large thermal and pressure stresses," the National Renewable Energy Laboratory (NREL) wrote in a report on cycling costs published in April 2012.
"
https://www.reuters.com/article/business/energy/to-survive-c...
Yep, I live in Finland where we are quite far ahead of the curve when it comes to renewables and nuclear. This is one large problem. When it's winter and cold and dark, solar does not help. Wind only helps when its windy.
Batteries are coming, and will solve it, but it will still take time for them to be come cheap enough.
Only once we have ~7 days of storage (~100 GWh of storage) will we be able to get rid of the last fossil plants.
Yeah the US will lag behind on this.
Other countries are better positioned. e.g. UK has really spiky wind energy. Right this second more than half the grid is wind. Which is both cool and problematic for managing the grid.
Grid scale cheap storage would dramatic help manage that chaos
Other countries are better positioned already because they don't have an administration funded by the fossil fuel lobby - but even that doesn't explain some of the decisions, like preferring to reimburse $1 billion in already paid leases rather than letting a company build wind farms on the leased area (https://edition.cnn.com/2026/03/23/climate/trump-totalenergi...).
Spain suffered a black out partially due to the lack of momentum (spinning generators).
For Europe to get rid of more fossils without putting the grid at risk we will need more storage.
I surprised we can’t, or rather don’t, make more use of tidal energy.
That and low energy density storage located at sea with the turbines.
The issue with this logic is that you build a cliff where, at some point, you need to massively invest in storage, and the storage industry hasn't had time to mature alongside the solar/wind industry.
Hmm, how much of that is base load versus the dramatic rise of natural gas plants that respond to dynamic demands? Even in daytime, I think you need storage to get rid of those, right?
I don't know why this is downvoted. Solar and wind both essentially suck at anything other than baseline throughput. That doesn't mean they're useless, it just means that solar can't be our only solution unless we have, like... 30 breakthroughs tomorrow. We otherwise need something to handle spikes, which are both common and important, as well as periods when there is extended cloud cover even for typically-dark months.
Even if we handwave all the science needed to build batteries big enough to power cities for days, I don't think it's realistic to handwave the science needed to power a city for weeks. We don't even have enough oil for that.
"Power when it is inconvenient" is pretty much the basis for a modern society.
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It doesnt make economic sense to serve the entirety of daytime electricity demand from solar without batteries. Youd have to tons of fossil fuel plants that turn off during the day and then back on every night. For solar to take the next step batteries are a requirement
It's not quite as bad as that, since you don't consume fossil fuel resources when plants aren't running, but this is mostly a benefit for oil/gas plants, not coal (since the coal is likely useless without the power plant consumer anyway)
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That might work in The SouthWest of the USA, but the Northern bits dont get enough sun to get through the day, so you'll need fossil fuel plants all day night for the Winter. If they're there already its cheaper to use all day in the summer as well.
Usually solar and storage are a package deal these days for grid scale solutions. Mostly, storage is not really about providing long term storage but short term. It used to be that the sweet spot that makes the most economic sense was something like 2 or 4 hours of power (relative to the maximum output of the solar panels) but these days batteries are a lot cheaper and 8 hours or more is becoming fairly common. The point of storage is not really to cover for all the downtime when the sun doesn't shine but to give grid operators enough lead time to bring online extra generation or buy capacity on the open market and adjust their planning. Mostly a few hours is all they need to ensure the grid stays up and running through daily peak usage windows.
In aggregate, grid operators have a lot of other tools at their disposal via flexible pricing, flexible demand, and automated systems that can adapt to this to e.g. charge cars when there is a surplus of energy, turn on/off water boilers, etc. There's a lot of innovation around this topic in this space. This by the way is as much as making sure generated power doesn't go to waste than it is about ensuring there is enough power. They use batteries to time shift excess power to when they can utilize it.
Interconnected grids means that e.g. an operator in Denmark can import/export to and from the UK, Norway, Germany, etc. On a windy day they'll be exporting wind power. On a sunny day, they might add some solar to that mix. When there's no wind or sun in Denmark, they might pull in Scottish/German wind, Norwegian hydro, Swedish nuclear, etc. Batteries are being deployed all over the place at a pace that is only exceeded by the pace at which solar is being deployed. Whenever there's a surplus energy, batteries get charged up. It's very rare for all of the available generation to disappear all at the same time for long enough to drain all the batteries. And for those times of course fossil generation is still a thing as well, and will be for decades to come. There are a lot of gas based plants throughout Europe. As well as some nuclear plants of course. Singling out the EU market here but it's going to be similar elsewhere.
The point here is that there's no need to pair solar setups with days/weeks/months worth of storage. A few hours goes a long way.
Good news: batteries on are a similar exponential curve. Just a decade or so behind.
Its important to qualify that:
A decade or so behind, in the US.
If the US didn't block import of Chinese tech, we could have electrified a decade ago.
The tech available at the current moment, is even more capable of replacing petroleum based electricity.
But our government is banning Chinese tech to serve our outdated industries instead of importing it to serve the population.
As any wise country would do when faced with superior technology, we should import it with the condition of technology exchange. Chinese manufacturers should be training US workers and industrial ownership how to produce cheap, efficient, sodium batteries.
This benefits the populous immediately, and the industries are able to advance into the current century's tech.
>>> As any wise country would do when faced with superior technology, we should import it with the condition of technology exchange.
If it were a matter of industrial protectionism against a country which was not hostile, not authoritarian, didn't rely on slave labor, etc., then I'd agree with you. Countries have other pressing reasons besides immediate economic advantage to prevent this sort of thing.
To greatly oversimplify: Japan fought against opening their markets, as did China, out of political and social concerns for the stability of their states, far more than economic ones.
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>> As any wise country would do when faced with superior technology, we should import it with the condition of technology exchange.
Europe tried doing that. And our green technology sector promptly collapsed, because it couldn't compete with Chinese undercutting our prices. The only thing left now are wind turbines, but Chinese are making inroads there too. In the meantime, the green transition barely moved a needle when energy shock arrived in 2022 or this year. Rendering rest of our industry, especially chemical industry, uncompetitive.
All fine and dandy until your grid goes mysteriously offline the day after China moves on taiwan.
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> But our government is banning Chinese tech to serve our outdated industries instead of importing it to serve the population.
It protects American companies who operate in the green energy generation and storage arena from Chinese competition.
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13kW on the roof and a 48kW battery. It produces on cloudy days, and battery alone can last 3-4 days with regular unmoderated use with 6 adults at home. That includes split system air-conditioners on eco mode.
It produces enough on cloudy days to still.top the batteries up to full.
I had a day recently where production topped 80kW and was exporting bulk before late afternoon grid production limiting kicked in. That's a lot of juice, and Ive basically not touched the grid in 7 months.
Sounds awesome! How much was your upfront investment if you don't mind me asking?
Where are you located? I hear comments like this and get excited and then find out they're based in, like, Australia and well duh. Whenever I look into it here in Chicago, it seems I don't get nearly the same production on cloudy days, and especially in winter.
Diurnal storage is solved by batteries. Longer term storage will very likely be solved. For several days, cheaper batteries (perhaps with lower specific power). For longer periods, either thermal storage or e-fuels.
My guess is seasonal will be handled with flow batteries. A big tank and cheap-ish electrolyte, with the expense being in the electrodes sized for whatever max power is required. Tanks good for multiple cubic meters worth of liquid storage aren't exactly difficult to find, nor to place in a garden.
Then again, I'm basing this opinion on a recent-ish video from NightHawkInLight: https://www.youtube.com/watch?v=eq7fR9ISuCw
Flow batteries might be ok for a week or so, but their market window has been shrinking as Li-ion has gotten cheaper.
The technology I'm most excited about is ultra low capex thermal, as being done by Standard Thermal. Capital cost per unit of energy storage capacity as low as $0.10/kWh(th), so it can work with seasonal storage and just a few tens of charge/discharge cycles over its lifespan.
Standard Thermal has raised $11M and is building in Germany, where they say they can deliver 365/7/24 solar resistive heat (400 C or perhaps 600 C) for half the cost of heat from burning natural gas there.
Flow batteries keep coming up again and again, but they just don't work well in practice. The power density of electrodes is too low to be practical, and this is a fundamental problem.
A regular 18650 cell has about 0.1 square meters of electrode surface. And you have thousands of these cells in a car battery, resulting in literal football fields of electrode area.
Wood burning heat is perfect compliment to solar in remote areas.
Agreed, e-fuels seem to be far and ahead the front-runner.
We can get to 95% using just short term storage. I suspect that most jurisdictions will just say "95% is good enough" rather than paying for ridiculously expensive long term storage.
We've got the nat gas capability already; keeping it around for the 5% is quite inexpensive, making the massive investment in long term storage for marginal benefit hard to justify.
OTOH, while the premium for e-fuels seems excessive, if you're only running that nat gas plant 2 days a year that premium is not so scary.
> Agreed, e-fuels seem to be far and ahead the front-runner.
For covering Dunkelflauten? Yes.
For seasonal storage with a prolonged discharge (so, low power/storage capacity ratio)? I think thermal storage wins there.
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I don't think the winner takes all mindset can be applied in electricity generation. But I think the clever arrangement between these technologies will work:
- Solar.
- Wind.
- Nuclear.
- Pumped hydro.
- Battery.
Won't be long, battery installation is bigger by GW than wing or gas:
https://www.eia.gov/todayinenergy/detail.php?id=67205
But for the most part it will trail solar, because the first chunk of the solar doesn't really need storage. But once there's a healthy percentage of solar, all new solar will have storage or it won't get paid.
Aren’t lead acid batteries great for this purpose? They have advantage over lithium in stationary setups because weight is not an issue and they can be “daisy chained” many many times. I’m unaware of more cutting edge alternatives and the way the electrical companies handle solar is confusing IME
Lead acid batteries don't much like being cycled heavily. Even the ones explicitly designed for it (the average car battery is not) have about a tenth of the lifespan of lithium ion.
LiFePO4 is probably the chemistry best suited to it ATM. Lasts a long time, more stable, pretty cheap, and just a bit less energy density than other lithium ion options. Sodium-ion is looking promising but only just entering the market AFAIK.
A tenth is perhaps an exaggeration. It depends on how you count your lifespan.
A lead-acid battery mainly ages by cycle count. If you keep a decent quality battery charged up, and don't regularly discharge it too much, then there are claims they will last ten years. If you discharge them excessively each day, then you'll kill them really quickly.
A LiFePO4 battery has a quoted cycle count. But really what matters is simply elapsed time - the battery will last about ten years if it isn't abused, and you'll be hard-pressed to actually do that many cycles in that ten years. It ages mainly by elapsed time, not cycle count.
I used to argue that for an off-grid solar solution, you should get lead-acid batteries with capacity so that you are normally never discharging below 70%, and that this was still cheaper than getting LiFePO4 batteries with smaller capacity that you would discharge down to 20% each night. The lead-acid would then give you a larger reserve capacity for those instances where the weather is foul for a bit longer than normal and you don't get meaningful charging.
However, since then LiFePO4 batteries have continued to decrease in price, there are new Sodium batteries available now, and I haven't done the calculations again - the best option may have switched over, or it may be so close that it doesn't really matter which one you choose.
Does this mean LA would be a feasible option for longer-cycle storage, IOW keeping a reserve topped up most of the year for those duldrums weeks with little solar or wind?
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I dumped my 24V dual LA battery setup for a single 24V LFP battery for my inverter/UPS backup. LFP supposedly has a 10-15y life based on the 4-5000 charge cycles most cells claim. Sodium ion is on the way as well. My setup gives me about 10-12h of backup for critical loads (my PC, lights, fans).
I have a 5 kWp solar plant that produces ~25kWh per day, but it is grid-tied. I considered a hybrid setup with LFP battery back up, but decided to separate the two systems to avoid a single point of failure.
They're not great.
LiFePo4 however is excellent and reasonably low cost these days
"PO" not "Po" (I was wondering what Polonium was doing in here lol)
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We can simulate storage with overcapacity and broader geographical distribution networks, even if storage doesn’t become as cheap.
Fortunately that doesn’t seem like it will be an issue since battery storage costs are also seeing an exponential reduction.
Electricity is cheaper at night but only 20% of my consumption is at night, so I wouldn't mind if the situation was reversed.
I guess using electricity to heat during the night could be an issue, but we could also accept to let the temperature drop.
Around here late morning to mid afternoon (11 am to 4 pm) is now off-peak, alongside the old 10pm to 6 am.
With enough renewables the cost peaks are in the morning and evening when the sun is rising/setting and people are at home cooking.
There's also, like... winter. I'm fairly sure there's a calculation somewhere you could determine the number of deaths this will cause with pretty good accuracy.
Solar is never gonna be a complete solution. At the end of the day, we could do it more efficiently by just building suns here on earth for the panels, but of course then you've achieved fusion and you're already generating more than solar could ever hope to. We shouldn't hinge our future on half of a technology.
There's still sun during the winter; you just need more solar panels for the same amount of energy. Also, there tends to be more wind during the winter, so wind power makes a good complement to solar.
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Fusion, I hate to say it, is a pipe dream. Why? Because any fusion reactor loses a ton of energy to fast neutrons, which have the added negative of destroying the reactor. So-called aneutronic fusion (eg using He3) isn't zero neutrons. It's just fewer neutrons.
Stars don't have this problem because they're very large so there's only so far neutrons can go.
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This is solvable, but it will require international cooperation on a scale that is unlikely. But you wouldn't need any storage at all, just a large number of long distance HVDC lines to move the energy from wherever the sun is shining to where it isn't.
It solvable but very expensive.
The costs of large number long distance HVDC lines with accompaning invertor stations would be as expensive as a electric generation based on nuclear power.
I don't think that is true. The bigger problem is the international cooperation required, as well as that such a system would be vulnerable to attacks.
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The cheaper solar gets the more of a gold rush there has been to develop projects/technologies that take advantage.
Batteries already kill peaker plants as a grid-scale battery that lasts 4 hours became cheaper than running natural gas turbine to cover the evening demand peak.
Its also tricky to defend in war prone locations.
I think solar is amazing and we need more of it - but I can't stand this solar and storage go at it alone mentality. It's pretty thickheaded to discount the other forms of energy that we can use and will need.
In practice, in Ukraine distributed solar power has been an increasingly important source of resilience in their power supply system.
There are legit reasons to push back against “solar and batteries everywhere” but I find it hard to credit resilience in a conflict situation as one of them.
A nuclear plant in a war zone is a dirty bomb waiting to be set off, which is incredibly easy to do, technically. Gas and coal plants are also end up being easy targets, as the war in Ukraine has shown. The most reliable one is solar because of how distributed it is. You can knock off one solar field, but then there are rooftops. You really need to destroy a city if you want to get it rid of power completely.
(Diesel power generators also work, but they require constant fuel supply, which can be complicated in a war zone)
I think I'd rather a solar panel array be bombed than a nuclear power plant.
Solar has the advantage that it can be widely distributed on buildings rather than in just a few centralized locations.
I don't see how anything would be more resilient than solar.
Gravity just needs mass not fusion but your point remains.
> More stoked for when the same is said for storage
Batteries have use in war and power. It will likely scale faster than PV. What we need is the second derivative, so production of the latter can be turbocharged just before battery production is about to break through.
It's encouraging- when one part improves usually the others follow.
Most of our chemistries are targeting things like cars and consumer electronics.
Ideally we see people like Form Energies, using iron-air (rust) batteries, for much easier to scale storage. https://www.technologyreview.com/2026/10/06/1145020/2026-cli...
https://news.ycombinator.com/item?id=50198882
I am desperate to find a battery inverter that can be used to supplement my existing grid-tied home solar setup. I only need about 5kW and 10kWh of batteries, but everything I can find is geared towards whole-home power at like 12kW. Way way more than I need. I understand I’m in the minority and there’s probably not a market, but I’d love to find something
Transparency: I live in a 240v land, I have a Siggen.[0]
Not sure whether other brands could be better but there seem to be various options that would suit. If you are in 120v land you may need to check if there are models to suit.
Its largely modular, inverter sits on top of modular batteries in 8-9kw chunks.
But they are app-infested. IE wants a wifi connection, app on your phone to their servers... etc etc.
I hate it, but the wife likes it. This is a recent thing so I am still working out if there are possible solutions for privacy and control over my own objects.
[0]https://solarbatterysupermarket.com.au/products/sigenergy-ba...
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Unfortunately, the market is somewhat bifurcated between what Anker, Jackery, Ecopower provide and stepping up to Base Power, Powerwalls, and other bigger system components.
My recommendation would be to see if Ecopower storage and inverters are a good fit for your use case. If you're feeling adventurous, you could build your own battery pack, but I only recommend if you are knowledgeable and confident. This comes with substantial property and life safety risk, only proceed if you know what you're doing and understand the risk (I'll work on my high voltage EV battery packs, but only with a helper nearby holding a 2x4, for example).
https://hackaday.com/tag/battery-pack/