Generally the solar they sell is peak rate power — generated when it is most needed, thus it doesn't impact on baseload power generation, but what it does do is reduce the need for far more expensive and carbon producing capacity to
sit idle during off peak periods.
Importantly, in the present context, the court will not
generally grant an injunction which would have the effect of forcing a party to
sit idle or to perform an agreement for «personal services» (Page One Records Ltd v Britton [1968] 1 WLR 157).