“(3C)

To the extent that an exempt electricity storage facility forms part of a generating station (or is expected to do so, when the generating station is constructed or extended), any capacity provided by the facility is to be disregarded for the purposes of determining whether the generating station is within subsection (2), (3), (3A) or (3B).

(3D)

The construction or extension of a generating station is not within section 14(1)(a) to the extent that the generating station comprises or (when constructed or extended) is expected to comprise an exempt electricity storage facility.”.

“(6)

In this section—

“electricity storage facility” means a facility which generates electricity from energy that—

(a)

was converted from electricity by that facility, and

(b)

is stored within that facility for the purpose of its future reconversion into electricity;

“exempt electricity storage facility” means an electricity storage facility which is not a pumped hydroelectric storage facility;

“pumped hydroelectric storage facility” means an electricity storage facility that stores the gravitational potential energy of water that has been pumped to a higher level so that its return to a lower level can be used to generate electricity.”.