There are MANY mistakes here.

Offshore wind especially in the north sea is barely tapped and powerful all year round. There are many other constant green energy options such as hydro, waves, currents, geothermal, etc. The value is in including a wide variety of all and over a large enough territory so surplus in one area can compensate a shortfall in another.

Grid energy storage includes MANY creative and easy to implement ideas. Tesla style batteries are the most mundane. The cost and setup of grid scale storage is much lower than the alternative.