Comment by nicois
8 hours ago
In Australia, the real value of these big batteries is not necessarily to provide emergency power, but more to respond in milliseconds to variations in demand and to smooth out the 5 minute spot market.
Having a sink and a source for spikes aids grid stability and somewhat helps to reduce the need to build more infrastructure to handle transmitting power from the generators during those peaks.
It also helps avoid the viability of gas powered generators which are very expensive and carbon intensive.
When I worked with medium-sized scale batteries one of the most surprising use-cases was to use them _together_ with diesel generators. Diesel generators are incredibly wasteful because they don't vary the power output / fuel-consumption very well based on demand.
When you couple a large battery with a diesel generator the generator turns off when the battery is full so the generator always run at optimal efficiency.
I feel like this is one of those things that isn’t surprising to Factorio players
Factorio power generators always run at 100% efficiency, so it is not really the same thing, you still consume the same amount of coal if you have batteries or not.
I guess it applies for nuclear power if you do that jank thing to not put fuel cells unless you need power. But then it is a thermal battery...
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We did this many years ago for remote First Nations sites with an energy monitoring startup I worked for - saving them enormous sums of money (and carbon!) in the process. It's actually quite amazing how low some of the low hanging fruit is once you start looking.
Yep, this is the fully hybrid electric path. Generators work much more efficiently when ran at a fixed RPM.
Not just fixed but most engineers design with UL standards so while they advertise maximum output they're all most efficient somewhere around 80% their maximum.
The batteries help the grid because they can maintain a minimum demand the power plants need and compensate for any excess demand that would tax the grid infrastructure.
I've never tested a generator, are they all producing pure sine waves?
Unless its a Chevy Volt. That was a really interesting car in many ways, but they kneecapped fuel efficiency by eating transformer losses twice instead of licensing Toyota patents.
That's literally how hybrid cars work, yeah.
The biggest challenge is keeping the energy almost perfectly in phase. US power runs at 60Hz and most grid equipment fails quickly if that changes even a little bit.
If I'm not mistaken, that was what hit Spain when much of their grid went down for hours. The analysis I heard was that they were running entirely on renewables and it fell out of phase causing large scale safety shutdowns.
Fortunately, interconnects cannot go out of phase easily. If one region is out of phase with another, massive currents flow down the transmission lines within milliseconds, causing generators at one side or the other to slow down or speed up. I have seen this effect live at a hydroelectric dam. We were watching the turbine shaft spin at the moment they switched on some giant interconnect. There was a phase-alignment dial and it just instantly pinged up to 0 while the spinning shaft shuddered, slightly altering its rate of rotation in the blink of an eye.
That's the usual failure mode of any grid, aggressive load shedding will be used as a last resort to keep the frequency within tolerances.
The renewable aspect is because historically they were installed with "grid following" inverter systems instead of "grid forming" which can maintain frequency even if temporarily islanded in a partition without spinning mass generators to set frequency.
There's nothing intractable about a 100% renewable grid, the technology exists and has already been deployed in new installations.
That is ancillary services. And where all battery implementations started before saturating those marketss.
We've now past that and batteries are actively killing the business case for fossil gas peakers while renewables are doing the same for legacy thermal producers.
I worked at a company for a while trying to make a battery control device that predicts the peak daily demand and discharges the battery to offset it.
It's kind of crazy how much money you can save by shrinking your peak demand during the time of day it's most expensive.
Where I live, hydro is the dominant power producer.
My electricity costs 40% less from 11 pm to 7 am and 30% more from 4 pm to 9 pm.
A hydro dam can also be thought of as a battery. When you are not using it, the dam fills up (charges).
My utility buys inexpensive excess power from the NA grid when electricity is cheap and drains the dams when third-party electricity is expensive. Adding other renewables to the mix plays a similar role. The pricing incentives shrink peak demand as you suggest.
One of the reasons residential solar is a tough sell for me is that electricity is relatively inexpensive and likely to stay that way.
There are interesting large scale projects that use hydro directly as power storage for renewables.
When the sun is out or wind is blowing, use excess energy to pump water up hill. When you're low on energy supply, open up the dam to run the water back down hill and through a hydro plant.
I've toyed with the idea of doing the same thing at a small scale on our farm but would need to build a second decent sized pond up hill of our main one.
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Have you priced residential batteries and time of use to charge at night? That's Base Power's value prop, they partner with ComEd, install batteries at your home and become your power provider charging a lower rate than ComEd. Batteries charge at night when nuclear generators are still humming and demand is low, and then serve daytime load.
Solar may not pencil out, but energy arb over system lifetime might, especially if you have any battery subsidies available. Just keep in mind flexibility to add solar in the future so its as trivial as installing racking and panels and running power to the storage and load center (optimize for optionality).
https://www.chicagotribune.com/2026/07/28/base-power-battery...
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I am still a fan of centrifugal systems. The lifecycle costs of a spinning mass seem more manageable than the complexities of chemical batteries. The mass of a block of concrete and steal isn't going to degrade over time. And bearings/motors are such mature tech that they can last decades, even a century without replacement.
If you're going mechanical, why not pumped water storage instead? Nothing has to spin super fast and hydro has a lot of maturity.
(From a guy who got burned buying stock in a centrifugal system as my first "wicked smaht" investment as a 22yo).
there are areas where almost all options for pumped hydro are already developed and there's little room for expansion. additionally, the heat waves from the climate catastrophe affects pumped hydro negatively (evaporation and higher water temperature).
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Mostly because we already used all suitable places. It also has a huge environmental impact, large upfront costs that you can only spend in bulk, permissions, lawsuits, protests from the local population and so forth.
Hydro is limited by geography. It cannot scale in the same way. Rather than giant spinning masses at central locations, current thinking is more about smaller masses scattered throughout a grid. There are even a few studies on whether existing air conditioner/heat pump compressors could contribute.
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> And bearings/motors are such mature tech that they can last decades, even a century without replacement.
This is not true at all for bearings in large industrial systems under constant load. As the mass scales up, the systems become exponentially more sensitive to vibrations from wear of the mechanical parts. Even magnetic bearings max out at about 20 years.
Flywheel systems are more complicated and expensive than simple chemical batteries. Cost also scales much more than batteries as you increase the energy storage. They are also less efficient over time due to friction even with magnetic bearings.
Maintenance on high energy movement hasn't exactly had a great track record either.
There was a giant flywheel company near me about 20 years ago. Maybe it's still there. They had one incident where a flywheel broke.
https://beaconpower.com/stephentown-new-york/
There's a very long waiting list for new synchronous condensers, almost 5 years from order to delivery.
Batteries can serve the same function, while also providing energy arb and additional grid services, so I'm somewhat curious how log the market for syncons continues to exist.
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Yup. Esp. when space is available. But thet benefit heavily from low pressure environments though so it's not just an arm and a mass in a fence.
Producing batteries are not expensive and carbon intensive?
Genuine question - what is the thought process behind this comment?
Because we both know that gas generators also require a production step... arguably one that's quite a bit more complex than a battery, at ~$1,000,000/MW of installation costs. And that installation of that complex is going to be very carbon intensive (even the concrete foundation alone...).
And then on top the plant actively burns hydrocarbons for the entirety of its existence.
So fill me in here - what is the exact argument you are trying to make with this?
their only argument is dont do anything, dont build anything, dont change anything, the Earth is too populated, so we need degrowth degrowth degrowth at all costs and fall of living standards across the board, so that we can achieve true Net Zero Carbon life.
thats the only argument these people make
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People who make these comments are either disingenuous people, or people who aren't thinking carefully repeating the arguments of their tribe.
The good 'ole "Lets start with the premise that all energy in our calculation comes from coal transported by truck, and then work out how "green" these technologies are"
Over the lifetime of the battery it’s not that bad and gets better as the carbon intensity of the grid that runs the factories improves.
that's a one time cost over many years that's quickly amortized. lets assume an upfront cost of ~100kg CO2 per kWh of battery storage and 250g of CO2 per kWh generated by a gas turbine. this means the carbon ROI is there after 400 kWh.
Compared to gas generators? Probably. And unlike gas there's no ongoing cost.
That type of person never thinks about the crazy amount of energy it takes to get fuel out of the ground. I guess they think gas falls out of the sky like rain and the only cost is in collecting it.
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Not particularly, relative to producing anything, including turbines and the fuel to run them. (And then you have to burn that fuel...)
you have to look at CO2/kwh produced over the lifetime, that's the useful metric here
The extraction cost of minerals is only paid once. And a few big batteries will be much easier to recycle than a billion small ones in consumer electronics.
I don't think it's a coincidence that China has developed batteries that neuter the advantage that gas had over coal, but I can't stop wondering if we'd already have solved long-term storage if China hated coal as much as oil and gas.
China does not hate oil and gas.
To put things into perspective, China gets half its energy from coal, and about 10% from natgas (increasing to 15% by 2030) and about 20% from oil. China is rapidly increasing natgas use, primarily by building out new pipelines to get more natgas from Russia.
China is also increasing oil consumption as well as exploration, particularly starting with the 14th 5 year plan as well as a special seven year action plan to increase oil production, doing deep water drilling, unconventional (e.g. fracking) drilling as well as a massive shale oil boom. Over the course of that 5 year plan, China discovered more than 225 oil fields and oil production increased from 3.8 million barrels per day to 4.6 mbpd as a result of a ~500 billion CNY investment to increase production. Still China imports about 10 mbpd, so it has developed a massive 1.5 billion barrel strategic reserve, which allows China to weather disruptions in global oil supply even as it races to increase domestic production.
And China is also investing in battery capacity, with installed capacity now at 140 GW or 5% of their energy usage.
The statement that somehow "batteries neuter the advantage that gas has over coal" is not something I understand. Both coal and natgas are reliable forms of energy and are unaffected by battery capacity; you need batteries for unreliable energy such as wind or solar so that you can turn the variable output into something stable that a grid can consume.
> The statement that somehow "batteries neuter the advantage that gas has over coal" is not something I understand.
In thermal electricity plants it takes a lot longer to go from cold & dark to generating electricity with coal than with either Combined-Cycle gas or especially the Open-Cycle "peaker" gas plants. Both types of gas plant also AIUI have a lot better ability to "throttle" their power output.
This means if you have a bunch of CCGT like Britain, you can use those directly to "top-up" the power from your fleet of solar PV and wind turbines, whether that's 1GW of top-up or 20GW of top-up. The change from weather (sun goes down, wind picks up, clouds appear, etc.) is relatively slow compared to what a gas plant can do, whereas it's too fast for coal to keep up as I understand it.
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Here's a detailed breakdown of China's energy picture since 2020 [1]. The big story is that fossil fuels are relatively stable or in decline and solar is exploding. Hydro is down because of drought and they're building an even bigger dam than the Three Gorges Dam (ie Medog) but it'll be ~7 years before it comes online.
There has been an uptick in coal this year to replace oil imports, which have fallen off a cliff because of the Iran war [2]. The real story of 2026 is how China essentially saved the world economy by doing this [3].
China is dependent on oil and gas imports but clearly sees the writing on the wall. All of these projects are an effort to wean themselves off of oil. So is a lot of domestic policy like the electrification of vehicles. This has had a global impact, reducing global oil demand by almost 2% in the last 5 years [4].
I agree with you on your point that I don't see the connection between batteries and gas vs coal either. If anything, batteries are to stabilize energy demands when the Sun is down.
[1]: https://energyandcleanair.org/china-energy-and-emissions-tre...
[2]: https://tradingeconomics.com/china/crude-oil-imports
[3]: https://www.cnbc.com/2026/09/10/china-crude-oil-iran-hormuz-...
[4]: https://www.intellinews.com/china-led-ev-boom-cuts-global-oi...
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Username doesn't quite fit here
China can't hate coal (yet). In case of an armed conflict with the West, they will be cut off completely from oil and gas. Renewables don't cover all their energy needs. So they are building a lot of coal plants as backup.
> cut off completely from oil and gas
China is the world's 4th largest oil & gas producer. They're dependent on imports because they're the 2nd largest importer. However, they are simultaneously increasing production and decreasing consumption. Those two lines will cross some day. It might be a dangerous day for the rest of the world when China stops becoming dependent on imported oil.
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China coal use has dropped below 50% [1], and they currently curtail renewable generation roughly total annual generation of Spain and the Philippines combined every six months [2] (~401 terawatt-hours of power). They are rapidly deploying battery storage to accelerate electrification and making use of energy that would otherwise be curtailed, which should continue to drive down coal use (their electricity markets are currently reconfiguring to use market signals and incentives to encourage this outcome).
They will, in the next five years (at current renewables and battery storage deployment rates [60% of their energy currently comes from renewables, and this increases 10% YoY]), become a low carbon (hard to say net zero yet) electrostate [3] that will continue to scale manufacturing clean tech for the world [4] with minimal carbon footprint.
It cannot be overstated how fast they are going.
[1] China Crosses Energy Milestone as Coal Falls Below 50% of Power - https://ember-energy.org/data/china-cleantech-exports-data-e...
Can they procure their own uranium? Coal still has the advantage of being more local, much simpler, faster to get up and running. Smaller plants also means smaller distribution radius etc. so more infrastructure decentralization. I imagine that's part of the thought process too.
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In the case of armed conflict with the West all Chinese inverters will be weaponized to burn homes in the West. The shops will be empty in the West and West will be in very ugly situation outsourcing all the manufacturing. Better it doesn’t happen.