The problem is scale and availability of materials to make batteries.
Right now almost all the batteries are produced for and used in electric cars, however electric cars only make around 10% of all the cars consumed.
Now you wanna store enough solar-generated electricity for when the sun doesn't shine, worldwide? My napkin math says that either the price per kWh will go up, or that some poor country with enough lithium will be "politically destabilized" soon.
There's plenty of capacity for grid connected batteries.
For one thing they can use a bunch of tech that doesn't work well in cars (flow batteries for example).
And the price goes down because the primary constraint is production capacity. More demand means more factories mean cheaper prices. See eg the growth in manufacturing capacity in batteries and their price decreasing:
If you look at 2008, there was 6GWh of battery manufacturing in the world and 97% of it was in China.
In 2019, there was around 365GWh worldwide, split into: China (75%), US (9%), South Korea (7%) Europe (5%)
By 2023 we estimate there will be 1,230GWh worldwide: China (65%), Europe (10%), US (10%) and rest of the world (15%).
Iron redox flow batteries are made from abundant materials and cost less than lithium batteries. Sodium batteries have many of the upsides of lithium and don't require it (they require some other scarce materials). There are enough empty salt mines and similar to build weeks' worth of storage in CAES for less than the cost of either.
But none of these solve the issue of months long weather fluctuations and disasters entirely in regions where pumped hydro isn't viable. For that, grid flexibility (such as variable rate Al production and electrified steel smelting), gas or hybrid heating/cooling, generator backup for essential uses (minimal heating and medical facilities), and methane produced from electricity and biomass is the answer and the only reason it hasn't happened on its own is we don't price in the (absolutely massive) externalities of fossil fuels so they're marginally cheaper. We also need to cut the low hanging fruit that are responsible for most of the emissions either directly or indirectly (poorly insulated, overly large detached homes, cars, and cows).
Are detached homes really responsible for the majority of emissions, and how is that low-hanging fruit? That seems like one of the most expensive options per unit emissions reduced. I’m pretty sure industry and logistics are some of the most intensive, particularly if you don’t pretend that goods imported from China or other countries are emissions free simply because the emissions weren’t emitted domestically.
Detached homes are just one of the simpler low hanging fruit to fix -- subsidies on insulation and regulation rentals and on new homes -- rather than a huge part of the whole. It's an easy 5-10% depending on area (with side effects of helping the poor and reducing strain on infrastructure during extreme weather events) rather than a large part of the whole.
About half for heating and cooling in EU, https://energy.ec.europa.eu/topics/energy-efficiency/heating... iirc 40% of that or around 20% of total was domestic -- it often looks small because it is broken dowm into two subsets of electricity and two subsets of methane use (and decreasingly kerosene) being for water and space heating. Detached homes use at least double compared to a row house (twice as many walls, but they also tend to be larger and have more windows) or far more than a similarly built apartment with one wall, and tend to be poorly insulated in places like the US.
Heating and cooling represents a lower proportion in the US for a variety of reasons (primarily driving/trucking and some differences in industry as well as a colossally wasteful military), but a huge amount is caused by cows, clearing land for cows, moving cows, cooling cow products, moving feed for cows, and producing fertilizer to grow feed for cows.
Unrelated, but detached home suburb design is also responsible for a lot of other emissions indirectly. Larger living space and fewer communal areas leads to more travel and more stuff. Things being spread out leads to low labour high emissions big box store stuff rather than local hand crafted and second hand markets and local in season produce. Transit and pedestrian hostile layout leads to more driving (and one car per person). Car dependent infrastructure leads to more trucking and less freight trains. Large centralised shopping centers like walmart leads to more uniform goods and just in time logistics which depemd on planes. Flight, trucking, driving and fossil fuel heating leads to more dependence on oil and gas. Oil and gas security is maintained by military activity which is responsible for a huge portion of emissions. None of this stops if you build a 5 over 1 and a train line or a medium density village instead of a suburb of course, but you make a small dent in every step.
> almost all the batteries are produced for and used in electric cars
I'm not convinced. I tried a back-of-the-envelope calculation, but there were a few too many variables, but I think the 1.5 billion smartphones sold each year edge out EVs (my main difficulty was comparing smartphone battery EV battery)
From a little Googling, it seems like an EV battery is four orders of magnitude larger than a smart phone battery, so about 150,000 EVs sold per year is the rough equilibrium point (that’s four orders of magnitude lower than your 1.5B figure), and it seems like we’re selling about a million EVs per month, at least as of the end of 2021.
Now you wanna store enough solar-generated electricity for when the sun doesn't shine, worldwide? My napkin math says that either the price per kWh will go up, or that some poor country with enough lithium will be "politically destabilized" soon.