[manfredo]

The factor that drives up price for grid level storage is scale. Only ~300 GWh worth of batteries is produced globally each year. The world uses 2.5 TWh of electricity each hour. If anyone tries to install battery storage at a significant scale, demand will vastly outstrip supply and drive prices up.

[tzs]

That's lithium batteries, isn't it? For storage to balance out fluctuations in renewable sources you shouldn't need to use lithium.

It's used in cars and consumer devices because it can store a lot of energy for its size and weight and you don't have to mollycoddle it to avoid memory effects.

Those are much less important concerns for this application. You'd build you battery facilities somewhere outside your cities, perhaps near where you build your solar farms, and you don't need the batteries to move. Batteries that take up more room and/or weigh more than lithium batteries for a given capacity should be fine.

[Manfredo_1]

Right. Lithium batteries won't cut it. That leaves geographically-dependent hydroelectricity, which isn't so easy to build. And then proposed solutions that are still in the prototyping phase, and aren't commercially available.

[jeremysalwen]

Assuming there aren't economies of scale. Demand for solar had gone way up in recent decades (e.g. in germany, before it was cheap), and the price subsequently went down.

[mlyle]

It's not clear batteries will do the same. While there's been effort to make batteries less reliant on scarce natural resources and mining, there's no guarantee we really get there. If we don't, price can be expected to go up, not down, with scale.

I would bet on price going down slightly with scale, but one can't really tell now what will happen: it might go up a lot, it might go down a lot, or it might stay flat.