Poland has huge salt formations, so I spit on your "optimism" slur.
OF COURSE it's much higher if you turn off hydrogen and try to use batteries and curtailment to deal with high seasonality environments. This is Dumb Engineering. Don't do that. You multiply the cost in Poland by more than a factor of 2 when you turn off hydrogen.
Poland, as I've said elsewhere in these comments, is also close to the worst place in the world for renewables. That's hardly a condemnation of renewables in the entire world. Maybe industry will just leave Poland to somewhere it makes more sense to operate.
I bet your 15-25x also is looking at the nameplate capacity on the renewables, before adjusting for the expected capacity factor. But LCOE already takes that into account. Just looking at raw peak output, wind and solar are massively cheaper than nuclear.
The salt formations we have aren't necessarily accessible for those purposes. I would not mind being wrong though.
As for overbuilding including capacity factor - the size of renewable powerplant tends to be reported in nameplate capacity, not the adjusted for capacity factor, so I'm just trying to keep within common units. And I'm all for building more renewables anyway, I'm just against building fossil backup for them. Which means also not greenwashing things by "we will add storage in the future". We need it now, not in some murky future.
There are many places that are "bad for renewables" - that doesn't mean people who live there have to be forcefully resettled or removed to support religious combination of laissez-faire with german green philosophy.
People aren't forcefully resettled. Their livelihoods just evaporate if they try to compete with places with natural advantages. I mean, we don't say agriculture is impossible because we can't feasibly grow bananas in Alaska.
If a place that's a renewable energy ghetto tries to compete with sun-soaked places by using nuclear, it won't go well. When solar is being pumped out at $0.013/kWh in UAE, trying to drive internationally competitive heavy industry with nuclear that's an order of magnitude more expensive just won't work. This is a disconcerting new reality for places that have been competitive in a fossil fuel era. They are competing with the best case renewables in a global market.
OF COURSE it's much higher if you turn off hydrogen and try to use batteries and curtailment to deal with high seasonality environments. This is Dumb Engineering. Don't do that. You multiply the cost in Poland by more than a factor of 2 when you turn off hydrogen.
Poland, as I've said elsewhere in these comments, is also close to the worst place in the world for renewables. That's hardly a condemnation of renewables in the entire world. Maybe industry will just leave Poland to somewhere it makes more sense to operate.
I bet your 15-25x also is looking at the nameplate capacity on the renewables, before adjusting for the expected capacity factor. But LCOE already takes that into account. Just looking at raw peak output, wind and solar are massively cheaper than nuclear.