It's always gas right now, because gas is the cheapest.
But if CO2 is taxed, hydrogen (from water electrolysis with surplus renewable electricity) becomes cheaper. And with cheap renewables, renewables + batteries + hydrogen would be cheaper than a system including nuclear.
> And with cheap renewables, renewables + batteries + hydrogen would be cheaper than a system including nuclear
* Definitely not. Looking at France, Solar and Wind are "cheap" because producers can sell on the grid, and the national operator _must_ buy it, at a higher cost than its own electricity, in a move to prop it up.
* Water electrolysis + electricity generation from hydrogen hasn't been proven to work cheaply at scale, what's the biggest project in existence ?
* Batteries are already not cost-effective at high scales
* All of those imply that storage will be on the same site as production; if not, the grid needs to be overhauled (it is built for few stable sources, not for numerous variable sources) and that cost is never taken into account by those who root for this kind of solutions
When I say renewables are cheap, I mean in comparison to NEW nuclear plants. Of course nuclear plants that already exist, where the sunk costs of construction can be ignored, will be more competitive. But France would spend less money building solar and wind instead of building new nuclear plants.
There is little electrolytic hydrogen today because hydrogen is mostly produced from chemical reforming of natural gas and other fossil fuels. Of course, this ignores the cost of CO2 emission from that process.
Batteries are already being installed in the real world, at very large scale. What exactly prevents them from being installed at even larger scale? And their costs are dropping rapidly, just as the cost of wind turbines and PV modules did.
But if CO2 is taxed, hydrogen (from water electrolysis with surplus renewable electricity) becomes cheaper. And with cheap renewables, renewables + batteries + hydrogen would be cheaper than a system including nuclear.