Certain supplies of electricity by electricity utilities
4.—(1) A person who is an electricity utility shall be treated for the purposes of the CCL chargeable under paragraph 5(1) of the Act (CCL on supplies of electricity) as not being an electricity utility to the extent of any part of a supply he makes of electricity—
(a)produced in a fully exempt combined heat and power station, and
(b)not supplied to him at any time by another person.
(2) Where an electricity utility makes a supply of electricity on which CCL would be chargeable, but for this paragraph, under both paragraph 5(1) and either paragraph 5(2) or 5(3) of the Act—
(a)that electricity utility shall be treated, for the purposes of the CCL chargeable under paragraph 5(1), as not being an electricity utility to the extent of that supply, and
(b)CCL shall, accordingly, only be chargeable on that supply under paragraph 5(2) or 5(3).