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> These hybrid setups, which combine solar panels with batteries, are now standard in many regions and allow solar energy to be stored and released when needed, turning it into a more reliable, dispatchable source of power that helps balance grid demand.

On one hand, I think people underestimate how much energy our grids demand in a 24 hour cycle. The amount of lithium it would take to handle an unusually cloudy week would be astronomical.

On the other hand, one of the ironies of electric cars is that they are one of the least effective uses of battery capacity. A Tesla with a 60kwh battery is probably touching less than 20kwh of capacity every day.

So theoretically if you use the batteries for grid storage and actually cycle them regularly from 80% down to 20%, the battery capacity would be well over 2x - 4x more effective at offsetting carbon sources. (Even more so if you are offsetting worse sources like coal).

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> The amount of lithium it would take to handle an unusually cloudy week would be astronomical.

I don't think it's astronomical. At most a few dozen kg per person. Compare that to the amount of steel that we produce per person just to give everybody access to cars!

And it's certainly not more astronomical than the amount of natural gas that we already extract, transport, and burn for electricity.

We have built big things in the past, there's no reason we can't do it again today. In fact, it's going to be far easier today because our tech is better and our factories' productivity is so much higher than in the past.

During the height of the industrial revolution, humans were able to double steel production roughly every 6 years. We've doubled global lithium production in the last 3!

Even so, if you do the math about how much lithium we need to get to a few dozen kg per person given that rate of growth, we're still looking at 20-30 years. (There are also a lot of elemental and labor bottlenecks).

So you're right that it's not astronomical! We just might have speedier expectations for when it's achievable.

Well, lithium is not the only option. For fixed storage, sodium is more and more feasible everyday.

I think the underlying point is that it production capacity, no matter the tech, takes time to grow.

It's not lithium that's the bottleneck, it's building a big enough supply chain to get the lithium into battery factories. It's about building enough factories.

For the particulars of sodium, it's similar enough to lithium that factories for one can be repurposed into factories for the other without a total rebuild or even total retooling.

There are also many different lithium chemistries that are economical and feasible, and we see big swings in chemistries when there's a temporary supply block for, say, cobalt. So perhaps sodium would add a bit more to that flexibility, actually... However even when lithium was at its maximum in 2023, nearly 6x more expensive than it is now, it wasn't the main blocker for expanding battery production capacity

(Sorry for the rambling, when I get some coffee in me sometimes it just pours out!)

A few dozen kg is quite generous. There's 160 g of lithium in a kWh of lithium batteries. A typical household uses less than 30kWh per day. At 2.6 people per household, let's round to 10 kWh per person per day. So 1.6kg of lithium per day, 11kg for a week. But you don't need that much battery -- solar produces power even on cloudy days.

Fortunately other chemistries are making their way down the learning curve lithium's been on, and after a few moment reflection it would be astounding if the same types of storage that are optimal for mobile consumers also happen to be optimal for grid balancing, as daily grid balancing can be done pretty reasonably with a c rating[0] of about .2 or even .1, and as long they aren't so heavy they need to be placed on massive foundation piles, weight is not really a factor. Just need to make it as cheap as possible.

[0] battery c rating is what fraction of the battery can discharge in 1 hour https://wikibattery.org/en/wiki-us/battery/charging-rate-cha...

Also, sodium batteries are now coming online. Slightly lower energy density, but potentially vastly lower cost. From looking at cost trends and increased production, it also seems pretty obvious at this point that we probably are going to get those vast quantities of battery storage everyone is so surprised about.

I'm still a little bit skeptical because chemical energy storage is inherently corrosive and unstable and so maintaining installed capacity is more expensive.

Unlike power generation, where you can build a facility and it can more or less run for decades with basic maintenance, batteries effectively have a limited number of cycles they can be relied on for. So you would effectively have to remanufacture your entire storage capacity every 10-15 years. So scaling up on storage would theoretically get exponentially more expensive the more of the grid you take over.

Obviously battery technology is improving and each 1% gain in improvement represents drastic savings. But I think there is still lots of reason to diversify technologically and continue to look into complementary sources of base power like nuclear.

I think the exponential works in the opposite direction. Let’s say your manufacturing capacity is increasing by 30% per year. That means hypothetically at the end of a 15 year period you’re building fifty times what you were able to install in year one. We don’t know if that will happen for batteries, but for solar PV the rate was about a 37% average yearly increase over the past 20 years.

Can't you apply same workflow as there is for storage in data center: install, monitor and constantly replace degraded modules with new?

> The amount of lithium it would take to handle an unusually cloudy week would be astronomical.

Unusual events shouldn't be handled by high capex, high efficiency storage. They should be handled by lower capex, lower round trip efficiency storage (as should long term/seasonal storage).

I will once again point to Standard Thermal.

https://www.standardthermal.com/

https://www.orcasciences.com/articles/standard-thermal-copy

https://austinvernon.site/blog/standardthermal.html

Ten cents per kWh of storage capacity!

Grids don't need "batteries" as consumers think about them. They can store energy using gravity, for example pumping water up into a reservoir (to store) and letting it drain through a turbine using gravity (to convert back into electricity).

At grid scale, all sorts of different batteries become feasible. My favorite is the one that uses solar during the day to lift heavy objects, which then turn a generator at night when they come back down.

Smart water heaters are interesting, too (though not grid scale). They can use a power surplus during the day to overheat water, reducing the power demand at night. I assume they're smart enough to keep delivering water at a safe temperature.

At some point of adaption everything becomes grid scale

https://en.wikipedia.org/wiki/TV_pickup

> On one hand, I think people underestimate how much energy our grids demand in a 24 hour cycle. The amount of lithium it would take to handle an unusually cloudy week would be astronomical.

but thats why you have more than one energy source right?

Even on a cloudy week, I still generate power, just not enough. Thats why I'm not truely off grid, otherwise I'd need to move from 5kwp(3 electrical) to 15kwp.

Mind you, the most expensive thing for doing that is either the inverters, or the mounts. Its got to the point that solar panels are cheaper than 18mm plywood.

I don't think it's a fair argument to say that EVs are an ineffective use of battery capacity. They are certainly more affordable and accessible than home batteries.

Have you seen the cost of home batteries? Napkin math shows their installed-cost in my region of the US is the same as the fractional cost of an EV. But the EV comes with a free drivetrain, seats, and airbags!

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