Anyway, the cost of energy with solar / wind is obviously not 0. You have to produce the panels / windmills, perform maintenance, for solar you need to clean, etc. Additionally, the energy isn’t available always so you need energy reserves like batteries, pumped water, etc to store it for use which increases the cost further. Finally, there are energy demands that solar / windmills can’t meet where you need *really* hot temperatures.
That’s why fission repeatedly is shown as the only solution to reduce dependence on fossil fuels. Fusion is great but we should be building insane amounts of nuclear reactors right now to meaningfully decarbonize our energy generation.
* EDIT: Here’s a talk [1] by Michel Laverne CSO of General Fusion. He starts talking at the ~6 minute mark and explains why renewables will never see more than 10-20% market penetration.