At this year’s Vienna Design Week, an exhibit proved that coffee can deliver more than just a caffeine jolt. In a twist on a classic middle school science experiment, conceptual design duo mischer’traxler used recycled Nespresso coffee capsules – soggy grounds included – to generate electricity.
Making “batteries” out of lemons and oranges has long been a staple of grade school science experiments. By suspending two metals with high electric potential in an acid solution, like salt water or citrus juice, it’s possible to generate a small electrical current, enough to power a tiny lightbulb.
In their exhibit for the Nespresso Austria window, mischer’traxler used aluminum and coffee grounds from 700 Nespresso coffee capsules, salt water and copper, to make coffee-powered batteries. The batteries were suspended from the ceiling and used to power a series of small clocks.
Each battery generated between 1.5-1.7 volts, and together, the entire installation could power a small radio. The 700 capsules mischer’traxler used reflect the average person’s yearly coffee consumption.
The eco-friendly exhibit aligned with Nespresso’s efforts to embrace recycling and sustainable sourcing. Long criticized for its single-use aluminum capsules and lack of fair trade certification, Nespresso has announced that its coffee will be 80 percent Rainforest Alliance certified by 2013. Nespresso has also worked to implement recycling programs for its capsules in many European countries.
On its website, Nespresso states that both aluminum and coffee grounds from used capsules can be salvaged. Coffee grounds can be used both as fertilizer and as “a source of green energy for domestic heating.”
Experimenters have attempted to use coffee as a power source before. Besides mischer’traxler’s batteries, other coffee-powered projects include a coffee-powered car, developed by the producers of British TV show “Bang Goes the Theory”. Like mischer’traxler’s batteries, the car works – but not very well.
The experimental car can reach 60 miles per hour, but costs 35-50 times more to run than a gasoline-powered car. Also, drivers needed to stop every hour or so to remove soot and tar from the car’s filters. The coffee batteries may not generate a lot of electricity, but they made an important point: even something as banal as used coffee grounds can be repurposed for good use.
Although coffee batteries aren’t likely to replace alkaline batteries anytime soon, like most forms of biomass, coffee grounds can be burned or processed to generate power. And like other forms of organic waste, coffee can enrich your garden: it breaks down rapidly in a compost pile and provides a rich source of nitrogen.