Soil power: the UK start-up generating sustainable energy from the earth

A new start-up is aiming to a new form of sustainable power by creating a battery that recharges itself when placed in soil.

Bactery, a University of Bath spin-out company, has developed bacteria-powered batteries – or ‘Bacteries’ – which harvest green energy from soil by taking advantage of natural processes that occur in microorganisms within it.

The company’s CEO, Dr Jakub Dziegielowski, who undertook a PhD in Chemical Engineering at the university before setting up the company, explained: “Our initial goal is to leverage the unique Bactery technology to accelerate the shift toward digitalisation within the agriculture sector.”

As precision agriculture continues to demonstrate its effectiveness in boosting yields and conserving resources, the demand for sensors and Internet of Things (IoT) devices continues to rise. These electronics collect and relay data on the state of the fields, empowering farmers to make well-informed decisions.

However, current ‘on-farm’ power delivery methods, such as obstructive cabling, single-use chemical batteries, and weather-dependent solar panels largely restrict deployment of agri-data solutions.

These sensors also typically require a power supply. For this reason, researchers are investigating the use of soil microbial fuel cells, a type of earth battery, to power these sensors directly from the soil they are monitoring. An earth battery is a pair of electrodes made of two dissimilar metals, such as iron and copper, which are buried in the soil or immersed in a conductive liquid like seawater. The soil or liquid acts as an electrolyte, allowing a flow of electrons between the two metals to generate an electrical current.

How the technology works  ​

Bactery, meanwhile, says it wants to offer a more practical, affordable, and reliable means of powering these electronics – through soil itself.

The technology has a useable lifespan of over 25 years, and an anticipated cost of around £25 per unit with no maintenance expenses, with the company promising ‘install and forget’ functionality.

Bactery’s technology builds on Soil Microbial Fuel Cells (SMFCs), which harness energy from the metabolic activity of specific microorganisms known as electrigens, naturally present in soil. Electrigens have the unique ability to generate electrons during the consumption of organic compounds. These electrons are ‘grabbed’ by the SMFCs and are forced to travel through an external circuit, producing electricity.

The team proved the concept in 2019, by building a soil-powered water disinfection system for decentralised communities. The prototype was tested in Icapuí, a fishing village in a remote semi-arid part of North-East Brazil, where the main source of drinking water is rainwater and access to a reliable power network is scarce.

Since then, the company has developed a way to effectively scale and sustain electricity generation. They achieved this using innovative designs and custom energy harvesting strategies, tailored to the biological processes in the ground. The firm will spend the upcoming 12 months refining their prototypes before advancing towards small-scale production. Ahead of the 2026 product launch, the team is inviting potential collaborators and investors in relevant fields to get in touch. 

Farmers are increasingly valuing the importance of data​

Bactery’s directors also include Chemical Engineer Professor Mirella Di Lorenzo, and Electronic Engineer Dr Ben Metcalfe. Both are based in the University’s Faculty of Engineering & Design and are Deputy Directors of CBio, the Centre for Bioengineering & Biomedical Technologies.

Prof Mirella Di Lorenzo said: “Farmers are increasingly valuing the importance of data to make informed decisions towards resource-efficient agricultural practises. We are removing the barrier to generating that data by creating a sustainable way to power sensors, and making them always-on, cheap, low-maintenance and low-impact.”

Dr Ben Metcalfe added: “This is a powerful illustration of how our Bactery technology could be used, but this is just the first application of what we believe is a great method of generating clean energy in an innovative, sustainable way.”

Dr Jakub Dziegielowski concluded: “Bringing our product to this stage and putting theory into practice through several years of research has been a challenging, yet incredibly rewarding experience. It wouldn’t have been possible without our great team and the support of many others along the way.

“I am excited to see the company make a positive difference in agriculture, and in other sectors. We look forward to sharing more about the upcoming advancements of Bactery technology and future applications in the near future.”