U.S. Emissions Rise 4.2%, China's Fall 2.7%

U.S. already migrated massive amounts of its energy sector from coal to natural gas over the last couple of decades, which reduced emissions from that replaced capacity by 60% years ago. If and when solar truly makes economic sense to justify the switching costs, it will happen, period. A lot of it is. Solar is growing healthily in the U.S.

Problems with solar remain, however. It's neither practical nor safe to build 100% solar grid. You must overbuild capacity on solar, because weather happens. No energy is generated at night. Therefore you have to factory battery install cost as well. Finally there are black swan weather events that DO happen in nature that NO ONE can prevent:

https://en.m.wikipedia.org/wiki/Year_Without_a_Summer

Whereupon solar would be rendered useless precisely when humanity would need power the most.

> If and when solar truly makes economic sense to justify the switching costs

Already does. https://upload.wikimedia.org/wikipedia/commons/a/af/20201019...

> neither practical nor safe to build 100% solar grid

No one is suggesting a 100% solar grid. You combine solar, wind, geothermal, hydro, and nuclear.

> battery

Battery prices have been in free-fall for a while, and there are a bunch of interesting tech for grid-scale energy storage. The vanadium redox battery is appealing for grid-scale energy because the energy capacity is determined by the amount of liquid you store in its tanks, so scaling that is trivial. Sodium ion batteries are appealing since they're made with abundant materials and their lower energy density compared to lithium ion isn't a concern for grid-scale storage.

> black swan weather events

Which is why no one is suggesting 100% solar. You do a mix like I described earlier.