1. An application for free allocation of allowances may not be made under this Regulation in respect of:

(a) [deleted]

(b) an electricity generator, except in relation to measurable heat:

(i) produced by an electricity generator that produced measurable heat by means of high-efficiency cogeneration (as defined in Article 2(34) of Directive 2012/27/EU of the European Parliament and of the Council of 25 October 2012 [OJ No L 315, 14.11.2012, p. 1.]); or

(ii) exported for the purposes of district heating.

2. For the purposes of this Article :

(a) the "relevant period" is:

(i) in the case of a deemed application for free allocation in the 2021-2025 allocation period or an application for free allocation in the 2026-2030 allocation period under Article 4, the baseline period;