Powering the farm with low carbon energy

Of all the different sources of greenhouse gas (GHG) emissions, fossil fuels top the list as the emitter most people connect to climate change. Many technologies are available to replace fossil fuel energy on farms.

The cost of the technology used to produce renewable energy for on-farm use has fallen at a time when electricity, gas, petrol and diesel prices have risen overall. This economic shift has opened up opportunities for farmers to reduce their own energy costs while cutting GHG emissions.

Displacing fossil fuel usage with renewable energy and low-carbon sources reduces GHG emissions from burning fossil fuels.

Shifting to a different energy source often comes with high upfront investment but over time that outlay can become cost neutral from opportunities to save money by removing reliance on fossil fuels. Indeed, it can generate an income too. The most favourable economic return on investment is possible when the power generated is used on-site to replace expensive electricity imported from the grid, or alternative fuels generated by low carbon sources.

This should always be done first. Reviewing energy efficiency within the business can create cost savings and reduce emissions from fossil fuels by simply reducing the amount of energy used.

Lighting, heating, ventilation, air circulation and refrigeration equipment offer opportunities for significant savings if inefficiencies can be identified. It might be an action as simple as switching off machinery and equipment when these are not being used, installing time switches, or adjusting building control systems. Small changes made during maintenance can optimise energy efficiency as can matching the size of equipment to the job it needs to perform.

Invest in equipment for larger scale energy efficiency improvements. For example, heat recovery units can use the heat from milk refrigeration to heat water.

Solar Photovoltaic (PV) panels are one of the most established renewable electricity technologies available. They can be placed on the land or be installed on farm buildings to keep land free.

Solar thermal can be used to heat water and is a good alternative when there is high hot water demand, as in milk production for example.

AD processes crops, agricultural slurry and manure and/or plant residues to produce biogas which can be:

• Used in a boiler for heat
• Burned in an engine to produce combined electricity and heat
• Refined and injected into the national gas network as biomethane

Full-scale AD is usually a significant investment and diversification of the farm business.

Micro AD options work on the same principles but on a smaller scale and may be more suitable for those simply looking to decarbonise their energy needs and provide some return on investment (ROI) through the process.

Turbines come in multiple sizes and power to match a farm’s requirements and budget.

That said, the more common turbine sizes will produce more than the farm requires and the logistics of grid connection and exporting electricity will have to be considered.

Planning legislation has often limited their use more widely on farms but policy changes introduced in 2024 could make it easier to secure consent.

The Government removed the de facto ban on onshore wind in England, which had been in place since 2015. Planning policy has been revised to put onshore wind on the same footing as other energy development in the National Planning Policy Framework (NPPF).

Heat pumps work by extracting heat from the ground, air or water body using temperature differentials.

They have been shown to be much more energy efficient for producing heat than a gas-fired system or electric heating elements.

As the pump needs electricity to operate, ideally, they are paired with a renewable electricity technology. 

Agriculture is a source of ammonia, methane and hydrogen. These are gases that can be converted into ‘green’ fuels.

When hydrogen is extracted from ammonia and methane in slurry it can be burnt or used in fuel cells. These technologies are relatively new and not as widely available. Some are still in the research stage.

Tractor manufacturers have developed models that run on hydrogen and methane. This means a farm could, in theory, produce its own green fuel from slurry to run those engines. Doing so could lower diesel costs, cut fossil fuel use, and reduce GHG emissions, decreasing a farm’s carbon footprint.

With a wide range of options available, individual farm businesses should determine which is best for their farms.

Some installations require consents, including planning permissions, and landowner approval for tenants.

Even if a farm business is not planning to export electricity, if it is already connected to the grid it needs to apply to the grid operator to confirm any new generation.

For solar PV, consider what is a reasonable size system for the available roof space.

Lead-in times for renewable projects can be lengthy so engage with an expert early in the process.