Alternative futures: from organic waste to electricity

In the video you can see how a microbial fuel cell was created at Calthorpe Community Garden in London during the Covid-19 pandemic.

Next week in Steps 2.2 and 2.3 we will examine in detail a range of technologies for generating sustainable energy. Here we are introducing an approach that you might not be so familiar with – generating electricity from microbes found in polluted water. Not only does this bioelectrical system produce energy, but it can purify contaminated water and grow plants for food. It is therefore an example of an integrated system with multiple benefits.

Under lab conditions, UCL doctoral researcher Enrique Lopez Arroyo, supervised by Dr Luiza Campos, has been able to create a small scale microbial fuel cell by filling boxes with small bottles filled with digestate (polluted water) and connecting together with electrodes so that their combined electricity output was sufficient to power a string of LED lights. Enrique grew plants in some of the bottles. The plants make the Microbial Fuel Cell much more attractive to have around, since it is a system generating electricity from unsightly waste. By developing the capacity of the system to grow plants, also means that it has the potential to generate food. The researchers are also interested to discover whether the activity of growing plants helps to generate more electricity.

How does the Microbial Fuel Cell work?

Watch this short animation created by Inês Delicioso to find out how the activity of microbes in the soil can be harnessed to create electricity.

If you like this animation, please feel free to share it on social media to raise awareness of this innovative technology.

The Microbial Fuel Cell at Calthorpe Community Garden

The Microbial Fuel Cell project at Calthorpe Community Garden aimed to scale up the lab prototype by constructing a vertical garden from multiple bottles filled with digestate and plants. The ‘curtain’ of greenery hides more boxes of digestate bottles which add to the combined generation of electricity.

The vertical garden was installed during the pandemic by artist Andreea Ionascu, with advice and support from UCL doctoral researcher, Nick Laessing, and Aneeba Rashid, a doctoral researcher visiting from Government College University, Lahore, Pakistan. Pandemic conditions made the installation infinitely more difficult, and longer than anticipated, but the team’s astonishing efforts have been successful.

The project is also an opportunity to learn more about the science behind the Microbial Fuel Cell. In particular, the researchers are investigating ways to reduce the manufacturing cost and improve the efficiency of the system. UCL doctoral researcher, Enrique Lopez Arroyo, says:

we aim to deliver a technology that is on its early stage to the community for them to help us improving it, it requires a multidisciplinary approach and it is a great opportunity to have people from different fields collaborating.

During the course of building the microbial fuel cell, Andreea Ionascu and the team documented their progress and compiled a ‘shopping list’ of equipment that could be used by anybody interested in recreating the Microbial Fuel Cell in their own context. For example, Nation Station, a community support initiative set up following the devastating explosion in Beirut in 2020, is working with Enrique and RELIEF Centre doctoral researcher, Nikolett Puskas, to construct their own version of the Microbial Fuel Cell.

The Beirut project will build on the knowledge and experiences of the Calthorpe project, and transfer the technology to a community setting in a country where it is likely to have the biggest impact. The ambition is to bring the Nation Station community together to develop hands-on knowledge and skills about renewable energy resources and solutions, contributing to community ecoliteracy. By adapting the technology to the Lebanese context, the project will develop the concept and ideas further, and create learning materials to enable communities in the Global South to implement this low cost renewable energy solution.

Look out for more updates!

Over to you

Can you think of an example of a context where Microbial Fuel Cell technology could provide a useful solution to energy needs?