For over a century, diesel has powered the machinery that drives British agriculture. Yet, as the industry faces increasing pressure to decarbonise, the reliance on subsidised red diesel is becoming unsustainable. The RASE Farm of the Future report highlights an urgent need for farmers to transition toward alternative fuels—solutions that are practical, cost-effective, and suited to the unique demands of agriculture. But how can this shift happen in an industry shaped by seasonality, high energy demands, and rural infrastructure challenges?
To create a pathway for a transition to alternative fuels for agriculture, Original Equipment Manufacturers (OEMs), the vehicle manufacturers, the farming community regulators and the government will need to work together. A recent Farm of the Future webinar began the conversation on farm fuels for the future, and included independent consultant Alistair Walshaw, who set out the alternatives and associated challenges with replacing red diesel in agriculture.
What are the alternatives to red diesel?
Diesel, with its plentiful and economic supply, has been the universal solution for the past 100 years, but it’s now recognised as disrupting the ecological balance on our planet.
Battery electric, hydrogen fuel cell, hydrogen internal combustion engines and methane internal combustion engines are all examples of alternatives to red diesel that are either available already, or under development for use in agriculture.
Challenges with moving away from diesel fuel for agriculture
The use of alternative fuels for travel over land – primarily battery electric for passenger cars – is somewhat ahead of a transition to alternatives for heavy-duty vehicles such as agricultural machinery. While a simple ‘cut and paste’ option is the solution in some people’s minds, agriculture does have some unique challenges to overcome.
Seasonality and varying power requirements
Seasonality is a factor in most farming situations, with significant peaks and troughs in energy use, which – depending on type of farming – can be daily, monthly or yearly.
Power requirements also vary according to the task to be carried out, soil type and weather conditions. These factors complicate the energy delivery schedule for an individual farm enterprise.
Vehicle range
Most of the technical solutions being proposed do provide a practical working machine, but the challenge of vehicle range is always a concern to farmers looking to transition to a red diesel alternative.
Speaking in the webinar, Alistair Walshaw highlighted that range anxiety in agricultural vehicles is somewhat exacerbated by the fact that a fossil fuel vehicle has a bigger tank than is actually required to do an average day’s work. He shared the example of a 200-kilowatt diesel tractor with a fuel tank capacity of around 600 litres, that will easily do over 24 hours of average work, so much more than the average day.
However, if an electric vehicle were required to have the same energy storage capacity as the benchmark fossil fuel product, it becomes clear that there simply is not enough space on the vehicle to meet this requirement.
Alternative fuel supply
The other big issue for agriculture and other off highway vehicles is fuel supply and infrastructure. Generally, the fuel needs to be delivered to the point of use. The farm yard is used for bulk deliveries, but in most cases, the real point of use is actually in the field, to avoid running up and down the public highway with large, bulky and often very dirty equipment.
In addition, farms, by their nature, are generally located in rural locations, meaning that grid locations taken for granted in urban areas, like electric, gas, water and internet are not necessarily either available or reliable. Therefore, any acceptable low carbon fuel alternative for agriculture must address these constraints.
Delivery of hydrogen fuel to a farm is a challenge. The current options are compression or liquefaction of the hydrogen fuel to transport it. Compression requires multiple HGVs to carry the equivalent to a 18,000-litre diesel tanker, while liquefication requires some very sophisticated and expensive equipment to keep the hydrogen below minus 250 degrees centigrade.
The key advantage of hydrogen and other gasses, such as biomethane, is a quick fill ability. Biomethane requires similar equipment to hydrogen, but the storage pressures and temperatures required are somewhat less challenging. So, if delivering the fuel to the farm is a challenge, why don’t we make it on the farm?
Hydrogen and methane fuel generation
Generating fuel on farms could be a route to energy independence or provide a diversified income that complements other farm operations.
Hydrogen fuel production
Hydrogen fuel can be generated locally to farms. However, as it is not a naturally occurring element, it has to be extracted from various feedstocks. This takes resources in the forms of raw materials like methane (which farms can supply) or deionized water, along with a lot of energy. Currently, production of compressed green hydrogen by electrolysis needs approximately nine litres of deionized water and 55 kilowatts of power to produce one kilogram.
Biomethane fuel production
Biomethane, on the other hand, can be produced via the anaerobic digestion of organic matter, such as livestock manure, crop residues and other organic products. Industrial biomethane production facilities are major businesses in their own right, and are strongly focused on energy production for injection into the national grid networks – be that gas or electric. These facilities have not generally been set up to produce vehicle fuels and the grid connection requirements generally means they are located in in the less rural farming environments.
However, there are now small but growing number of companies, including likes of Bennamann from Cornwall, QUBE renewables and BioFactory, who have developed micro systems that focus on manure management challenge. In this approach, the cost of manure management system is effectively transformed from a liability into an asset while reducing the carbon impact.
Biomethane is a fuel that is here and now. It is commonly available and reasonably well understood. In many cases it just needs to be captured. With the requirements for all slurry stores to be covered by 2027, maybe a trick has been missed in not optimising the actual benefit of this fugitive energy supply.
In the webinar, Alistair stated that while farmers could have a key role to play in the production of green hydrogen, both for themselves and be a key supplier to other industries, this will need some further technology developments that are a good fit with the farming food system, without displacing food production.
Dual fuel farm vehicles
At a vehicle level, common vehicle architectures and structures for gaseous fuels could be possible. A methane internal combustion engine vehicle can already, with very minor changes, run on hydrogen. With a bit of development, dual fuel products could be an option.
What does the future of farm energy hold?
The road to alternative farm fuels is not without challenges, but the benefits—lower emissions, long-term cost savings, and greater energy independence—are undeniable. Hydrogen and biomethane are already proving their viability in early adopters, and the right policies could accelerate their adoption at scale. However, achieving a successful transition requires a collective effort—from farmers investing in on-farm energy solutions to policymakers providing incentives that make adoption viable. The opportunity to reshape agricultural energy systems is here. The question is: how quickly will the sector seize it?
To find out more, watch the full webinar in the RASE members’ online resources.