• Harnessing free electrons in soil, a prototype developed by the start-up can generate 0.2 watts per square metre, enough to provide a sustainable power source for smart agricultural applications.
• A researcher explains that there is virtually no impact on soil quality, which is continually replenished by plants and bacteria.
How can a battery be powered with energy sourced from soil?
Jakub Dziegielowski: Our system uses a fuel cell to harness electrons present in soil to generate electricity. There is a whole circular economy in soil where nutrients are constantly replenished by plants, which secrete organic substances or by fertilisers. This organic matter is converted into free electrons by micro-organisms, so we’ve designed a device to capture these free electrons on one electrode, which is paired with another to create an electrochemical environment that enables them to circulate through a wire and recharge a battery. This is the concept of the prototype that we are adapting for field applications and testing.
Our devices can sustainably generate energy for four years. Right now, they can supply 0.2 watts per square metre.
Is there a risk that this device will have a negative impact on soil quality?
Our devices have virtually no impact on soil ecosystems, and analyses have shown that what effects they do have are more likely to be positive than negative. We have not observed any depletion in soil quality, which is constantly replenished by plants and bacteria. Soil is a complex self-sustaining environment, which is not so easily destabilized. Our company, which is a University of Bath spin-off, officially launched on the 1st of June 2024, and we are now in the process of patenting our technology.
You were saying that it meets a need in agriculture…
Last year, when my doctorate received funding from the British government’s innovation-to-commercialization of university research programme ICURe, I had the opportunity to travel around the world and examine how it might be used in different sectors. Given the feedback I received in Canada and the US, and also in Europe, I concluded that is one area where this kind of technology could be very useful. Farmers are increasingly calling on IoT to make more informed decisions and better manage land and resources. However, the deployment of these devices is expensive, notably because they need to be supplied with power and are sometimes deployed in very remote areas or on very large farms. Solar panels, which can get in the way of work in the fields, are not always an ideal solution. Along with the smart farming market, our technology is also of interest to organizations involved in environmental monitoring and the defence sector.
You conducted your first experiments in 2019. Can you tell us about how have managed to improve the performance of your device since then?
In 2019, we travelled to a very poor region in north-eastern of Brazil where there is very little access to drinking water and no reliable power supply. We wanted to build a soil-powered water purification system using our prototype devices. At the time, we needed 64 of them to treat just three litres of water a day. Now we can treat 30 litres of water a day with only 16 of these fuel cells. Their theoretical lifespan is 25 years, which is how long they will last before their materials deteriorate. So far, we’ve proved that they can sustainably generate energy for four years. Obviously, the size of our devices can be adjusted according to the amount of energy required. Right now, they can supply 0.2 watts per square metre.
A portmanteau of “agriculture” and “technology”, agtech or agritech is the use of technology to increase yield, efficiency and profitability in farming and to help improve the day-to-day lives of farmers. Agtech innovations include the use of specialized software as well as drones and IoT devices.
Jakub Dziegielowski
