From manure to energy: Might horse poo prove a valuable asset?

According to the British Equestrian Trade Association, there about 850,000 horses in the UK (Haseler et al., 2024). The average 500 kg horse will produce about 25 kg of manure daily and, where horses are kept in stables, another 4 to 7 kg of waste bedding can be added to this (Wheeler, 2008).

Currently, the main use for horse manure in the UK is as fertiliser for fields, and the quality of horse manure makes it an ideal product for this, producing many beneficial effects for the soil (ScienceDirect Topics, 2025).

However, UK legislation distinguishes between this agricultural use, and management of horse manure as a waste product. In the latter case, horse manure can be used as biomass for anaerobic digestion to produce methane. In the face of a growing equine population, it has been suggested that this could even help mitigate unwanted production of methane linked to either storing manure before its use in the fields or to its disposal in landfills (Elghandour et al., 2019).

In Finland in 2019, during the Longines FEI World Cup Jumping qualifier event in Helsinki, horse waste was used to supply electricity to the whole event. Even more impressive, the 100 tonnes of manure yielded surplus energy that was redirected to the grid to produce heating for Finnish homes. According to the FEI press release, 20 ml of horse waste is enough to recharge a phone, and one horse’s daily output is sufficient to heat a family home (FEI, 2019).

Fortum, the energy company collaborating on the project, highlights the promising opportunity to reduce the amount of waste from one industry by recovering its refuse and employing it as input for another economic activity (Fortum, 2025).

Albeit exciting, it is true that this model is not without its drawbacks. Firstly, it is only possible where there is a high population density of horses. When we consider anaerobic digestion, horse manure is less rich in methane when compared to ruminant, with production varying according to feeding regimes and hindgut microbes. In addition, a specific type of bedding is needed as traditional bedding materials are rich in lignin and cellulose which cannot easily be digested to produce methane (Elghandour et al., 2019).

However, one similar project has proven successful in Germany by using a combination of cattle and horse manure: The biogas power plant in Lehrte produces electricity through a method called solid state fermentation, currently producing electricity for about 230 houses (Renergon, 2024).

What about the UK? Well, although no such projects have been successfully implemented so far, the Government has made grants available for anaerobic digestion plants. These could run on waste from equine or farm species, and be used to satisfy some or all of the on-site demand for energy. Otherwise, in the right geographical context, a centralised plant could recover the waste produced by horses and cattle together to produce energy at a larger scale.

It is clear that this technology is just at its inception and, perhaps like many other energy solutions, it is not a silver bullet to resolve the problem of pollution caused by energy production. However, if the current climate crisis is a result of many small but incremental changes towards the disruption of the natural equilibrium, hopefully the reverse path can be built upon many small changes in the opposite direction. If we are to act decisively on climate change, it must be worth exploring.

Elghandour, M.M.M.Y., Adegbeye, M.J., Barbabosa-Pilego, A., Perez, N.R., Hernández, S.R., Zaragoza-Bastida, A., Salem, A.Z.M., 2019. Equine Contribution in Methane Emission and Its Mitigation Strategies. Journal of Equine Veterinary Science 72, 56–63.

Haseler, C.J., Shrubb, J.L., Davies, H.G.D., Rendle, D.I., Rathbone, P.C., Mair, T.S., 2024. Environmental impacts of equine parasiticide treatment: The UK perspective. Equine Veterinary Education 36, 381–392.

Horse Manure - an overview | ScienceDirect Topics [WWW Document], n.d. URL https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/horse-manure (accessed 1.3.25).

HorsePower: from the stable to an energy resource | Fortum [WWW Document], n.d. URL https://www.fortum.com/media/2017/11/horsepower-stable-energy-resource (accessed 9.29.24).

Lehrte, Germany, n.d. . RENERGON - ANAEROBIC DIGESTION. URL https://www.renergon-biogas.com/en/portfolio-items/biogas-plant-lehrte-germany/ (accessed 12.29.24).

Natural horse power provides heat and electricity to Helsinki [WWW Document], 2019. . FEI. URL https://inside.fei.org/media-updates/natural-horse-power-provides-heat-and-electricity-helsinki (accessed 9.29.24).

Wheeler, E.F., 2008. Horse Stable and Riding Arena Design. John Wiley & Sons.