The Danes had offshore windmills for over a decade. Here is the results. Large windmills require a minimin windspeed to just turn. If the wind drops below it, the windmill (i.e power) comes to an instant stop. Functionally that is unacceptable and unsafe for community power. One cannot be in the middle of a critical function and the power just shuts off instantly when the windspeed at the mills drop below acceptable minimum speeds. The solution is to have a utility power plant at standby at all times as instaneous backup power. The cost of burning fuel for the backup power plant more than overshadow the savings from the windmills. It was cheaper and less complicated to power directly from the power plant than using the power plant/windmill combination.