1. For each product benchmark sub-installation corresponding to a product benchmark defined in section 2 of Annex I with consideration of exchangeability of fuel and electricity, the preliminary annual number of emission allowances allocated free of charge shall correspond to the value of the relevant product benchmark for the relevant allocation period multiplied by the product-related historical activity level and multiplied by the quotient of the total direct emissions including emissions from net imported heat over the baseline period referred to in Article 15(2) or of the first calendar year after the start of normal operation referred to in Article 17(1)(a), as appropriate, calculated in accordance with paragraph 2, expressed as tonnes of carbon dioxide equivalent and the sum of these total direct emissions and the relevant indirect emissions over the baseline period referred to in Article 15(2) or of the first calendar year after the start of normal operation referred to in Article 17(1)(a), as appropriate, calculated in accordance with paragraph 3.