I was in a conversation with @natureboy, @Trog, and @PaulSwanee1 on power/energy costs in another thread but seeing how this one is more current, I will post here. I agree that coal is close to dead (in the US anyway - as @SkepticTank points out different economics are in play in countries that don’t have as strict a (non-CO2) pollution set of requirements). However it doesn’t look like renewables can survive/thrive without subsidy or a carbon tax against the alternatives just yet.
For some quick numbers, I looked at https://www.eia.gov/todayinenergy/detail.php?id=31912. This is 2017 but it’s not like there has been a revolution since then - just the same trend down probably:
First per capacity weighted average power (kW):
natural gas: $696
battery storage: $864
solar PV: ~$2,800
(coal is not listed)
I doubt seriously that installed wind cost has gone below natural gas - that would be huge news. Now as to how much of the battery storage costs you have to add to the wind cost, that just isn’t obvious to me yet. I presume because the wind and solar numbers are leveled (average power), you need to (for power purposes) book another 864/kW, but what isn't clear is whether that money will buy you enough depth of storage that you can ride through a period of no-wind long enough to be able to say you have a wind + battery storage solution that competes with a natural gas plant of the some average power. Ultimately, here is where I need a /kWh estimate for a given plant at a given location that is either a) natural gas and book some accepted depreciation cost curve for the plant and how much gas costs currently, b) wind and enough battery power to be a stand along provider (no natural gas generator load filling) and whatever maintenance/depreciation is involved (no fuel input cost). The /kW number is important because we have to install a lot of renewable energy soon and the lower /power the easier the initial investment will be. But of course what a rate payer ultimately cares about is the $/kWh more.
I agree with Ralph Nader on a recent radio show where he said even a nuclear advocate he knew in the past would essentially admit defeat if solar got to within 2.5x the cost of nuclear (which he claimed it had - I don’t have the nuclear costs above but given how expensive pre GIV reactor costs have been, that would not surprise me). So in other words, I’m not requiring for renewable to be cheaper than natural gas, coal, or nuclear before I would say we’d have to give up on those other paths - but we must use real numbers to make an argument for how much more we are willing to/have to pay.