Of course it does depend on how you measure cost.

If you just measure generation costs then you are missing the other key element of a nation grid - it always working - and that characteristic costs as well, not just the electrons provided.

So those improved transmission and storage investments need to be put on the renewables total costs.

Nuclear also has significant decommissioning costs.

However the biggest cost here is probably that required to adapt to the effects of climate change if we don't take steps.