Tuesday 30th of October 2018 | Posted In: Generate, Generating energy

Coffee... the gift that keeps on giving

Many of us love a decent cup of coffee in the morning to get the day started and now for the first time scientists have turned coffee waste into electricity to help farmers in the developing world.  Whether it be ‘proper’ coffee (remind me to tell you about my new bean to cup machine!) or the ever-reliable freeze dried instant, coffee has the power to make the world go round… in fact, 9.5m tons of the stuff is produced every year.

But, with all this goodness comes the inevitable issue of waste and what to do with it. 

At home, used coffee grounds can be used in the garden, or on the allotment for compost, did you know that worms love coffee too?  I didn’t, but I’m certainly taking advantage of my coffee waste in my wormery now! Commercially, it can be compacted into coffee ‘logs’ that can be used to burn for heat generation, but what of the waste from the process of turning the coffee ‘cherries’ into our beloved beverage?

A huge amount of liquid waste is created from the washing of these cherries, or beans, as well as the process of making instant coffee, which is incredibly water-intensive.

However, thanks to a team here in the UK, led by the University of Surrey, farmers may be able to get a little more out of their crops, as well as giving back to the environment. 

This team have worked alongside Colombian researchers to develop a fuel cell, roughly the size of a drinks can, which uses microbes to eat the waste matter in this water and generate a small amount of energy.  Although the initial lab versions cost between £300-500, they have worked to produce a more cost-efficient version for less than £2, which is made from slightly easier to obtain materials like disposable plastic boxes etc.

This is still very dependent upon funding in order to build a prototype in the field in Columbia, but if successful, it means that the farmer can not only produce coffee beans but electricity as well.