>Solar energy is going to be a minor part of the world's energy strategy unless a revolutionary breakthrough happens
It doesn't really need a revolutionary breakthrough, just for solar and battery costs to drop 50% or so such that they become the cheapest option. A 50% drop will probably happen just from the existing trends continuing.
Indeed. I'd say we are in the midst of a "revolutionary breakthrough" right now. The cost-per-kwh of solar/wind electric power is now lower than fossil, and still dropping. Consumer options are growing on the low end, and experience with industrial-scale installations is growing on the high end.
There's another breakthrough I'm looking forward to, however - really good instantaneous pricing and metering. When prices are set on demand and fully automated, then energy caching hooked to the grid becomes viable. This creates a good arbitrage financial model. Store energy from solar/wind when the sun is shining and the wind is blowing, and sell that stored energy when demand is up and supply is down.
Once that's working, the whole grid gets remodeled. Then we can make a real dent in the coal-fired baseload plants and aging nuclear plants that desperately need retired. Economies of scale and experience will reduce production cost for whole suites of energy storage technologies (batteries, compression, thermal, flywheel, gravity, etc), even if they don't become more efficient.
We don't even need the price drops you quoted. Installing new solar is already the cheaper than installing coal or gas in many locations. At this point we just need to continue to deploy. The panels themselves are already very cheap! Having out local governments and utilities simplify the permitting process would bring down some of the soft costs and make things even better though.
Yeah that's kind of why we need another 50% or so to really be cheaper after you allow for the problems with peaker plants, upgrading the grid and so on.
It doesn't really need a revolutionary breakthrough, just for solar and battery costs to drop 50% or so such that they become the cheapest option. A 50% drop will probably happen just from the existing trends continuing.