£54 bn over eight years is around 0.2% of the UK's GDP. A lot of money, but doesn't sound unreasonable for a major overhaul of a central price of infrastructure.
Ruling out the possibility of storing energy at industrial scale might also not age terribly well.
Especially if the energy being stored is heat. Heat is embarrassingly storable, much more cheaply per unit energy than electrical energy. Any industry that uses heat can be a target for thermal storage of renewable energy.
Ruling out the possibility of storing energy at industrial scale might also not age terribly well.