Question to the Department for Transport:

To ask Her Majesty's Government what metrics they use to calculate the emissions from transport run on (1) hydrogen, (2) biomethane, (3) biogas, and (4) electricity, when allocating funding for transport infrastructure; and what plans they have to publish their methodology.

In general, emissions specifically from hydrogen, biomethane and biogas are not estimated when allocating funding for transport infrastructure, as they account for a very small share of the energy used by transport. However, the blending of biofuels in petrol and diesel is accounted for more generally, including in the emission estimates presented in the Department for Transport’s TAG data-book, which is used for transport appraisal. Where the use of these fuels is important, for example funding to support their uptake, estimates of their g/CO2e are based on the latest scientific analysis and evidence, including emissions across the well-to-wheel cycle wherever possible, as well as from indirect land-use.

There are no plans to publish further details on methodologies at this stage, but these will be shared alongside policy proposals where appropriate, and in the event that these were important to funding decisions.

Estimates of kg CO2e/kWH from electricity used in transport are based on emission factors published by BEIS, and presented in the Department for Transport’s TAG data-book.