Synthetic fuels are produced from a synthesis gas using so-called synthesis processes. The starting material for this synthesis gas can be produced from biomass or electricity-based, i.e. from electrical energy, water (H₂O) and carbon dioxide (CO₂). Synthetic fuels can therefore be both biofuels and electricity-based fuels.

In contrast to the biofuels described above, the original molecular structure of the source resource is completely broken down and reassembled during synthesis. This allows more consistent properties to be achieved for synthetic fuels, regardless of the source material used.