What costs aren't being paid for exactly?
Say it's a cold cloudy day with no wind and it's been so for a week. You'll need the capacity of that coal/nuclear plant those days. And let's say every other day of the year solar and wind make enough power. So who pays the extremely high fixed cost of the nuclear and coal plant so it's available that one week you need it? No one wants to, so they're shutting them down. The power company could still be paying the bond for the plant, but ultimately that's the consumer's money. Then, surprise, you end up with blackouts or you pay for new natural gas plants to be built. Prices and fragility go up.
It's likely cheaper to make demand more flexible, but that has a cost too.
It'll take time to build out capacity but it'll take more time AND cost to build new nuclear plants.
If you don't believe me go back and have a look at how big the batteries were. The 500 million dollar project installed 130 MWh worth of electricity storage. That is enough to produce the same energy as a power station for 10 minutes before being fully drained.
Either way, conservatively speaking, $50-60/MwH for battery backed wind/solar on the mainland seems fairly doable. Prices will likely keep dropping too.
By contrast, in the UK Hinkley Point C is being paid $124/MwH guaranteed for 20 years. It doesn't exist because it's a cost effective way of supplying green energy that's for sure, but it does bolster the nuclear economy. The military do like to hire nuclear technicians and buy parts for PWRs in nuclear subs, etc. and somebody has to pay for these things. Rate payers, I guess.
Assume enough energy is supplied to charge the batteries. So lets say we want 1kWh during 4 hours, that puts our capital cost at 4 kWh*200$/kWh = 800$. Now we assume this system runs every day for 4 hours during ten years. Ten years sounds reasonable, but it could be less. 7 years maybe? So about 1kWh*365,25*10=14610kWh in total. That gives us 800$/14610kWh = 0,0548$/kWh or 54,8 $/MWh in 2030 if I didn't make a major mistake somewhere and assuming no efficiency losses. That's pretty good.
California has more than 1.5 GW of utility-scale chemical batteries interconnected to it's grid with another 1 GW anticipated to enter service by the end of the year. Most of these batteries can sustain full output for four hours. This is in addition to the more than 3.0 GW of pumped hydro "batteries."
1 GW is roughly the output of one nuclear power plant.
Source: I develop power plants in the western US.
We'll need at least half a day's worth of storage, likely much more if we want to use wind for a significant portion of power generation.
Then over the course of a few years there was a lot.
All that really matters is A) is it cost effective B) will there be scaling problems C) will there be political impediments.
When the wind is blowing really hard? Wind turbines?
The texas winter was a bit of an anomaly. It got so cold that every power source ending up failing because none were set up to deal with it even though all of them in theory could have (& would have if they were in, say, alaska).
It'll take time to shift to using green energy and there will be problems but the same would be true for any other kind of shift to any new sources of power.
Probably not 16 years like the new UK nuclear plant will take though :/
What if it's been so for a month?
What if the country is Sweden?
What if the month is January?
What if the average temperature is -20C?
>So who pays the extremely high fixed cost of the nuclear and coal plant so it's available that one week you need it? No one wants to, so they're shutting them down.
Those who don't want to freeze, they want to pay.
You can keep big gas plants around in a high intermittent grid and fire them up 10% of the time. The way we view LCOE right now, those plants would be insanely expensive while wind/solar would be super cheap. But we would still pay for the backup capacity. This kind of system cost is what matters dramatically more than LCOE.