[telchar]

There are different types of storage with different trade-offs. In my opinion we'll eventually see lower-efficiency but low cost-per-kWh storage like CO2->hydrocarbon storage used for longer-term seasonal or disaster-preparedness storage, while higher-efficiency higher cost-per-kWh or limited-capacity means like battery and pumped hydro will be primarily used for short term day/night storage.

The cost of inefficiency is a function of energy stored, not storage capacity per se, so effectively its cost scales as (storage capacity) * (# of times charged/discharged). Therefore low efficiency isn't particularly expensive for long-term storage.

So maybe we'll see gas turbines continue to provide power that ultimately is sourced from wind and solar via hydrocarbon conversion, but that's perfectly OK since it would be carbon neutral.

The upshot is this is all a reason to be sanguine about solar and wind.