Burning Straw for Low-Cost, Low-Carbon Heat

As harvest season gets into full swing, it’s an ideal time for farmers and agri-businesses to consider how straw can be used to create low-cost and sustainable energy. 

Straw offers a cheaper, low-carbon alternative to fossil fuels when used in biomass boilers to heat your farm or business. This can deliver significant cost and carbon savings. As well as this, existing Renewable Heat Incentive (RHI) credits can also be transferred to a new straw-burning biomass system - making the transition even more attractive. 

Although the UK Government have not implemented a ‘Carbon levy or tax’ for business yet, the European trading price for carbon has averaged at around £50 per tonne of emissions over recent years. With the Government’s commitment to zero carbon emissions by 2050, the potential financial impact of such a tax could be substantial.  

The UK agricultural sector produces over 12 million tonnes of straw each year from crops like wheat, barley, oilseed rape, oats, rye, triticale and miscanthus. While some is used for bedding, composting, and feed, large volumes remain available annually for energy generation. 

Unlike fossil fuels, straw is considered a low-carbon fuel. The carbon released during combustion is reabsorbed during the next growing cycle, creating a short and sustainable carbon loop. Straw typically contains 14-19% moisture, with the dry matter being rich in carbon, hydrogen, and oxygen. This makes it energy-dense and ideal for combustion when handled correctly. 

Straw delivers around 4,200 kWh per tonne (at 17% moisture), equivalent to about 400 litres of heating oil. That energy can translate into significant financial savings: 

• A modern 6 house poultry unit switching from LPG to straw with an annual heat consumption of 3,000,000 kWh/year can save £200,100 per year in fuel costs   

• An agri-food processing business switching from LPG to straw with an annual heat consumption of 8,000,000 kWh/year can save £568,000 per year in fuel costs. 

Fuel cost comparison chart - January 2025

CFE has worked closely with manufacturers and agronomists over the last decade to tailor

straw-burning boiler systems for the UK market. Systems are available for whole bale combustion (using automatic bale feed tables and shredders) or for straw pellets, which offer easier logistics, storage, and handling. Although producing pellets consumes energy, the recent spike in fossil fuel prices has made straw pellets more competitive. Pellets also open up the accessibility for businesses which are unable to handle whole bales. 

With the flexibility to transfer RHI support; the long-term cost savings and the environmental benefits, switching to a straw-fired biomass boiler is a practical and strategic investment for your farm/business.  

For more information on biomass and our services, please visit our website: Home | CFE  

 contact Jules on: 07811 199 585   or  Matt: 07878 189150