Agriculture is a large industry in Scotland, representing approximately 19% of the nation’s emissions, according to data from 2020.

The Scottish Government’s Climate Change Plan update requires a 31% reduction in agricultural emissions by 2032, from 2018 levels, a pace nearly four times faster than has been achieved up to now.

Agricultural machinery is estimated to contribute around 5-10% of Scottish agriculture’s greenhouse gas emissions and its energy use has increased 14% since 2008. Therefore, decarbonisation of machinery could play a key role in Scotland’s transition to net zero by 2045.

However, there is a lack of reliable information on emissions from mobile agricultural machinery and the options, costs and pathways to decarbonisation. This evidence review aims to address this evidence gap to inform policy development for the fourth Climate Change Plan, due in 2024.

This study has assessed the suitability of biodiesel, biomethane, battery electric vehicles (BEV) and hydrogen to power mobile machinery.

Key findings

• Biomethane offers the highest short-term emission reduction potential, of 77%. This is due to the availability of this technology and its suitability to current farming practices, offering a like-for-like replacement for current diesel machinery.
• Battery electric vehicles (BEV) and green hydrogen offer the highest emission reduction potential by 2035 (98.8% and 94.8% reductions, respectively), assuming both technologies will have matured significantly by then.
• Biomethane and biodiesel may be the favourable alternative fuel option in the short term. In the long term, battery electric and hydrogen will be the preferred technologies as they mature. Emerging technologies need to be evaluated as they proliferate the market to avoid locking in potentially undesirable technologies in the short term.
• Short-term uptake of biomethane and biodiesel on dairy farms where there is the potential to generate fuel with waste materials could be prioritised. For those farms where generation of biomethane is not feasible or access to a collective source of biomethane is not possible, there could be a long-term focus on preparing infrastructure for battery electric vehicles or hydrogen.
• It is likely that a mix of alternative fuels will be needed.

For further details on the study and findings, please read the report attached.