[Retric]

That might be useful for aircraft, but not cars or the grid. Batteries are already cost competitive with peaking power plants and prices just keep dropping.

Run some numbers and you find batteries are surprisingly cheap at grid scale. Grid solar is already tied into the grid and does DC>AC conversion anyway as part of it’s 2c/kWh pricing. So, rather than AC>DC>AC>DC you can just use solar panel’s AC power directly. Which means your just adding minimal cabling, batteries, some electronics, and a basic box for weather protection. So, ~100,000$ for 200kWh of storage x ~5,000 cycles that’s 10c/kWh for storage + (2c/kWh solar / 90% efficiency) = ~12.2c/kWh.

Granted that ignoring some real world costs like interest payments, but battery costs are also dropping so it’s a reasonable ballpark. Especially vs a theoretical system that’s never been scaled.

PS: By comparison if your at 50% efficiency to chemical storage and world record 63% thermal efficiency at combustion that’s 2 /.5 /.63 = ~6.3/kWh just for electricity plus the cost of your combined cycle gas turbine and chemical plant.

[tgflynn]

What about the cost of transporting the energy from where it's generated (say Nevada) to where it's needed (say New York) ?

EDIT: I think for that use case you'll find that a reasonable technology doesn't exist for transporting electrons over that distance (I don't think there are any superconducting transmission lines in actual use) but pipelines have been around for a long time.

[Retric]

“A 1,100 kV link in China was completed in 2019 over a distance of 3,300 km with a power of 12 GW.” Which is rather close to your example. By comparison a major gas pipeline runs around 8 Million dollars a mile or ~16 Billion over that distance meanwhile that link cost under 6 billion USD. Granted our construction costs would be higher, but it’s not the kind of massive savings that changes the equation much.

[tgflynn]

In that case how far are we from being able to supply all US electric needs with solar ?

I think I've heard that with current solar cells you could produce that much power with a 100 mile x 100 mile installation in a sunny location.

If battery storage and power transmission are solved problems, are the obstacles now only economic ?

[Retric]

Wind and Hydro are going to be part of the mix. So, outside of Alaska it’s largely a question of economics at this point. We already have huge investments in Coal and Nuclear which are being phased out of the market. But, cheap natural gas is a very different beast. As long as supply is abundant market forces are going to keep the price low enough to be attractive vs storage.

IMO, we are headed to about 70% renewables in 30 years baring major changes.