Electrofuels (or e-fuels) are synthetic fuels that are created by combining electrolysis derived hydrogen with a carbon molecule (e.g. biogenic CO₂ or CO₂ from direct air capture) to make a gas or liquid fuel. These fuels are identical in composition to conventional hydrocarbon fuels and can use existing infrastructure. An additional advantage is that they contain virtually no other contaminants. The technology to make e-fuels exists already, yet costs are high and uptake of these fuels will take time. European SAF mandates include e-SAF from 2030.

Within e-fuels, Cepsa has a particular focus on e-methanol. Alongside partner company C2X, the firm is investing in a €1b ($1.1b) e-methanol plant in Huelva, with FID expected in 2025.