The biggest issue with batteries is that they are not a prime source.

In a healthy grid with a diverse generation mix, batteries are almost certainly the perfect option for peak demand handling. The problem is that many grids are not healthy or do not have very diverse generation mixes.

You are effectively borrowing from yesterday (or last hour) to pay for today with batteries. Which is amazing, until it isn't. The Texas winter crisis comes to mind as an example where batteries would be regarded with intense derision. I think the current capacity market accreditation process is massively underrepresenting the tail risk of a black swan event. Four hours of battery storage should not be in the same room as a gas turbine when we are talking about capacity and multi-day emergencies.

Four-hour grid-scale batteries wouldn't have helped the Texas winter crisis much. But something like a 10 or 20kwh home battery would have helped a lot (it wouldn't sustain normal energy usage for that long, but the individual home owner could choose to ration the available power for critical functions).

Making demand responsive to supply costs is critical for increased efficiency. Part of that is making appliances smarter and educating users on loading washers/dryers/dishwashers and letting the machine handle energy usage. There are efficiencies in forecasting demand so supply can be negotiated and scheduled, and also being responsive to short term load shedding requirements.

They're talking about open-cycle gas turbines which have a specific set of jobs to do for the grid. And which batteries are better at now.

Those turbines aren't great for longer periods, they're pointlessly inefficient if you don't need their ability to peak for short periods.

The article does the annoying thing of using a technical term without definining it.

An open-cycle gas turbine is the "simple" configuration that draws in air through a pressurization stage, into a combustion chamber for fuel combustion, producing high-pressure hot gases that drive a turbine and generate power, with exhaust gases released into the atmosphere.

In other words, there is no recovery of heat from the exhaust, it's basically an aircraft jet engine core mounted on the ground and connected to a generator. They aren't very efficient but they are compact, relatively cheap, and quick to spin up during peak demand times.

Aren’t they also cheaper to built? Cheap backup capacity seems more important than efficiency and cost to run for Dunkelflaute scenarios to me

Gas turbine plants?

Maybe, right now (even as battery prices keep falling), if you can wait 10 years for your plant.

They’re also a lot more expensive to operate.

I guess the point is that when combined with a source of dispatchable base load power like a combined cycle gas turbine or nuclear, batteries are now cheaper than open cycle gas peaker plants for bridging short (4 hours or less) spikes in demand.

This is exactly what they are going for. To not have to build and run expensive gas plants just for a few hours in the evening. It also allows you to run the few gas plants that you do build for longer to better amortize their build costs, making them less expensive overall.

Ideally you would pair these 4-hour batteries with CHEAP sources of electricity. Fill the battery when electricity is cheap, empty the battery when electricity is expensive (ie, when demand spikes or when other sources of generation drop off the grid).

The cheapest source of electricity today is noontime solar. Batteries can fill up on noontime solar and discharge into the evening peak. They could also charge on wind or traditional baseload sources overnight, and discharge into the morning peak.

This where system thinking, or the lack there of, becomes an issue. You would be right if we only had exactly enough capacity for four hours of power. But of course with batteries now being produced by the multiple twh per year, each of them capable of cycling on a daily basis for a decade or longer, we soon will have quite a bit of battery connected to the grid. If you have a hundred of those four hour systems connected you'd blow fuses throughout the country if you dumped all that power on the grid all at once. That could be days of power under normal usage.

And grids can actually be connected together via cables now. The cliche is that solar panels don't generate at night. But if you connect grids via a long cable running east to west you can actually have solar power at night. And when you connect them north to south you can have solar power on a dark winter day as well. And when you add batteries to the mix (on both sides), you can keep those charged as well and use that power regardless of what time or season it is.

And that's ignoring wind (on and offshore), hydro, nuclear, and other clean forms of power that we currently don't use at scale (geothermal, fusion, etc.). If you add all that to the mix. And cables. And lots of battery. Grid connected car batteries, balcony solar, and all the rest, you end up with a lot of capacity.

Gas power is not going to way. But we probably already have too much of it and it shows in the poor utilization of existing turbines. Ironically, adding more gas turbines to the grid only makes that poor utilization worse for owners of these plants.

I'm not sure how bleak it even is. I have some solar powered lights. On a fully cloudy day they maybe are down 50-60% their usual run time by my guess. Not great but not some terrible loss that couldn't be accounted for with more solar buildout overall it would seem.

Maybe there's an argument for managed forests for charcoal energy production too. That would technically be carbon neutral.

The UK relies far too much on gas turbines, rather than renewables and as a consequence we have energy costs far higher than other European neighbours.

Gas is not cheap, it basically doubles your costs.

Well the goal is to only run the backup a few hundred hours a year, the question is which technology can provide close to 100% of demand a few percent of the time in the cheapest way. Turbines or even gas motors are relatively cheap in capex and gas is easy to store in large quantities.

Gas turbines have a manufacturing backlog of at least a half decade. The longer is takes to build them, the more favorable battery storage is (as it can be installed today), and the faster more battery storage manufacturing spins up, this further drives down the cost.

https://www.enverus.com/blog/the-queue-before-the-queue-gevs...

https://www.energyconnects.com/opinion/thought-leadership/20...

> For its part, China – a battery manufacturing powerhouse – has no such supply chain issues. It dominates global lithium battery production accounting for two-thirds of it. This relative strength gives it the confidence to relentlessly amplify its BESS footprint as evidenced in the capacity build-up between 2021 and 2026.

> In fact, China’s battery storage build-out has no global parallel thanks to this one factor alone, according to Ember. It estimates that nearly all (i.e.149.8 GW) of China’s “new energy storage” consists of lithium-ion batteries.

> In terms of the future, following a June update to its 15th Five-Year Plan, China is now aiming to deploy 300 GW of new energy storage by 2030. That would keep the country’s BESS industry progression, that outgrows all other countries combined, firmly on track.

(battery storage printer goes brrr)

Renewables require gas in the UK. There is no realistic route to 100% renewable grid without gas currently. I did some modelling of this and you'd require something on the order of 4000GWh of battery storage. We currently have 40GWh.

Gas is far, far cheaper than building ~£1T worth of battery storage. Even if prices dropped, you are still looking at multi-hundred billions, and you still need the renewable capacity on top of that.

Arguably if we had spent the £100bns (in subsidy and transmission upgrade and curtailment costs) we've already spent on renewables on nuclear instead we would have a very clean grid, even at crazy UK nuclear build prices, and stable electricity prices.

Last time I did the maths based on data from gridwatch the storage capacity required dropped dramatically if you over built the on the production side.

But ok, 30 million homes, 100kWh storage each, that's 3000 GWh

A 100kWh battery is about £25k, less than 1/10th the cost of the house, and less than the average new car

That doesn't seem unrealistic.

The issue is you need to design for 1-2 weeks of little to no wind and very little solar in winter, when demand is it its greatest. This is what is so tricky, unlike more southern climates where you have pretty reliable solar year round (even if its reduced, its not close to 0 which is the case in the UK). Instead of storing a day or so, you need to store weeks of energy.

Also you're forgetting residential electricity is maybe 1/3rd of total demand.

Where do you get "close to 0"? From what I read the output is still 15-30% of the summer peaks, which is very different from "close to 0".

On average. That doesn't mean there aren't sunny weeks where you get a lot more, and dark weeks where you get less. For instance if you get snow, output is pretty much 0 unless you clean them.

I believe there were 7-10 days in January 2025 where both solar and wind were in the single % digit for instance.

Of those 7-10 days, how many were consecutive? A couple days of single-digit efficiency each winter would be trivial to manage with batteries. I'm sure we can figure out a solution for the snow issue, especially since panels are usually angled.

Don't get me wrong, I get where you're coming from! But especially in the last 2-3 years, it seems like people always evaluate solar under the worst 0.01% chance scenario, which other power sources never have to survive. For example, not even half the days in January 2025 had single-digit outputs, yet they're still called "close to 0".

What I'd love to know is e.g.: in 99% of years, what's the worst Dunkelflaute we can expect? How much battery storage/solar overbuilding would we need to cover that, how much would it cost, and how much will it cost in a few years (based on current development rates)? I'd argue it'd be okay to reduce power-hungry industry for at worst few days, in case a once-in-a-century year happens.

The issue is though that you are saying 0.01% chance scenario, but gas/nuclear doesn't all go down at once at the same time every year. It's a somewhat fair counter that you might have serious gas disruptions, but LNG does massively diversify potential supply (and in the UKs case we have and will have a fair amount of domestic production for the next while).

Also keep in mind the overbuilding a massive problem anyway _outside_ of those 1-2 weeks worst case scenarios. We already have highly negative prices occurring more and more, and IMO this is the definition of policy failure, because the negative prices only arise because subsidies _encourage_ plants to keep producing even though the value is quite literally negative of the output.

Finally I don't think it's once in a century, probably most years have a significant Dunkelflaute event. And not all industry can be shut down like that (eg aluminium production) without causing catastrophic damage, and even if they can it makes them an unreliable supplier.

> The issue is though that you are saying 0.01% chance scenario, but gas/nuclear doesn't all go down at once at the same time every year.

Over this summer, a huge number of nuclear plants in Europe went down all at the same time, because they either would have killed the nearby river ecosystem by overheating it, or because they didn't have enough water to operate safely. This issue is only going to get worse as climate change progresses, and unlike most Dunkelflauten, the heat & drought really affect most of the continent at once.

> Also keep in mind the overbuilding a massive problem anyway _outside_ of those 1-2 weeks worst case scenarios.

It's only a problem because power generation tech like nuclear is so expensive, and it would become even more expensive if they couldn't run as much as possible. If we had a fully renewable+battery-driven grid, the issue would disappear.

> Finally I don't think it's once in a century, probably most years have a significant Dunkelflaute event.

I think you might unknowingly be ideologically motivated, because I specified that we should build enough to cover every Dunkelflaute in 99% of years. The amount of battery storage in this scenario by definition suffices for 99% of years, which makes the point about unreliability moot.

You said your modelling needed "something on the order of 4000GWh of battery storage"

That's not outlandish given the cost of distributed batteries.

Are you upping that model?

(If you build more generation -- for example have renewable peak generation of 80GW rather than 40GW, that reduces storage requirements drastically, as on a dull quiet winter week where you're only getting 10%, you'd be generating 8GWh in a given period of time, instead of 4GWh)

Yes, I have no doubt we can hit even a 90-95% renewable grid. It's the last 5% that is impossible to do without gas.

The cost of those last few percent is absolutely eye watering. The current plan to get it to 100% net zero is by having gas for the final 5% then using carbon capture and storage to offset the emissions.

you don't even need to use carbon capture and storage if you use green gas instead of fossil gas.

It is not even the final 5%, it is the final 1-2%, because you need a multi-week dunkelflaute across Europe for the gas turbines to be needed in the future. A lot will also just be curtailing. For instance EV charging might be restricted in the future in such a winter black out scenario.

> For instance EV charging might be restricted in the future in such a winter black out scenario.

Or indeed when petrol runs out as happens occasionally (in 2022 most recently). Of course there's also the problem of gas supplies stopping

You are making the mistake of thinking that if the grid could provide 100% renewable energy on a windy day at noon in summer, it could also provide 100% renewable energy at night in winter with no wind. Obviously that’s not accurate. Renewables provide energy in a highly volatile sine wave. It’s the bottom of the sine wave which determines the capacity required for base load and dispatchable generation, not the top of the wave.

[Gas is about 11-13x cheaper than renewables with externalities like grid restructure and volatility imputed.](https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4028640) That’s not to say renewables don’t have their place in modern grids. In fact an optimal allocation is around 80% renewable in the UK. However, until battery storage becomes about 95% cheaper, it would be ASTRONOMICALLY expensive to make the grid 100% renewable. Trillions of pounds in the UK. An order of magnitude more expensive than just paying higher gas prices.

People often make the mistake of thinking that because wind and sun is free, the cost of energy generation is basically free. Those people don’t understand how many fixed and marginal costs there are. If you’re interested, the paper above provides good insights into those costs.

Those don't really happen at continent scale.

I believe we just had one last winter in Europe. They happen from time to time and you don't want people to freeze once every couple of years.

>For that gas currently seems cheape

Well, other than destroying the planet, but hey, let's just hide those costs.

Hydrogen is a gas too and you can make it without emitting carbon. If you want you can also make methane from atmospheric carbon and water.

FWIW, the latest analysis I've seen seems to suggest that biomethane is probably the way to go for last-resort long term backup. Hydrogen is just too fickle.

biomethane aka methane from rotting plants? extremely inefficient and requires intensive agriculture

Alternatively: captured cow farts, rotting food waste.

Remember, it is only needed for a few dozen hours a year. It doesn't need to scale.

What does it mean for a gas to be 'fickle'? Hydrogen gets stored long term all the time. It's made in refineries and used in chemical plants all over the world every day. It's expensive to store, but it's certainly doable with the right metallurgy. If your goal is reducing carbon emission as much as possible, it's way better than methane, regardless of source.

Thank goodness that around 99% of our current hydrogen is made from fossil fuels!

If your going to burn the power turning it into hydrogen then you save a shitload of that power by putting it in batteries instead.

Hydrogen is a storage medium. It's fundamentally different than natural gas. Think of it more like a more complex, expensive, and inefficient battery; with the only advantage being that you can store more energy per unit volume at large scales.

Of course. But the point was that it could also be burned in these turbines, and is also storable underground like methane.

The very small molecule makes it much harder to store than methane, and unlike anything else on the planet other than Helium, lost hydrogen is lost forever.

Hydrogen leaked into the troposphere is quickly oxidized back to water. Only very little makes it to the very upper atmosphere where it can escape.

Storage of hydrogen in underground caverns is demonstrated technology.

Interesting, thanks. I really should have double checked before posting on HN.

Well, not really.

Methane is basically just hydrogen gas, but with one carbon for every 4 hydrogens. This means you can do stuff like liquefy it at higher temperatures and lower pressures, and it doesn't diffuse out of materials or otherwise destroy the materials (or seals) it's stored by.

>with the only advantage being that you can store more energy per unit volume at large scales.

In a vacuum, maybe; in real life, absolutely not. Hydrogen that is stabilized by a sufficient number of associated carbon atoms can be stored in plastic containers at standard temperature and pressure; naturally, we use the fuel that has just enough carbons that, while nominally a liquid, but would really rather be a vapor.

Because that stabilizer is part of that reaction, the best one from a CO2 perspective is the one that has as little of that stabilizer as possible. Which is what methane is.

With enough stabilizing carbon you can even store hydrogen as plastic containers.

I don't think parent was against gas because of its physical but rather because it's a fossil fuel

but not all gas is fossil

Just almost all of it to a staggering percent.

not sure about the accuracy of that, but it can change anyways.

i suspect that thinking is similar to the ideas people had that got them to buy hybrid cars because of EV range anxiety.

but hybrid cars are saddled with a maintenance heavy complex system that isn't used much.

nowadays we know the solution is just a bigger EV battery.

Studies have shown that hybrids have fewer issues than ICE or BEV, though for different reasons. BEVs have new technology issues, and ICE has maintenance issues. Having a mostly understood ICE car that rarely uses the ICE and has the most reliable (battery+motor) part of the BEV makes a better solution short term.

hmmm... looked up current stuff. I didn't know all the issues.

Looks like 5 year reliability: ICE > non-plugin hybrid > pure EV > plugin hybrid

But EVs seem ok 5+ years

I found this article interesting:

https://autoedgeview.com/ev-reviews/consumer-reports-ev-reli...

Still significantly better than running everything on fossil fuels burned by the power company.

Are you saying that gas turbines don't burn fossil fuels?

No, I'm saying that using a gas generator as a backup for solar is better than not using solar at all.

They can burn non-fossil fuels.

A non-carbon containing fuel that is almost entirely created by burning fossil fuels is effectively the same (and often worse) than just using the fossil fuels directly.

Biodiesel or biomethane looks at first glance to escape this, but it has serious other costs.

Is almost entirely fossil-fuel created doesn't mean it has to be almost entirely fossil-fuel created. You know, just like observing that cars are almost entirely burning fossil fuels doesn't mean cars must burn fossil fuels.