The Santa Rita do Sapucaí prison has created an unprecedented way to produce renewable energy and keep inmates fit and busy -- through pedal-powered prison sentences, in which inmates help the prison create green energy in exchange for shorter sentences.
The institution has placed two exercise bikes, connected to batteries, in the prison's courtyard. Here, inmates can cycle to create kinetic energy, which is converted into electricity to charge the batteries, and these charged batteries are then used to power the city's street lamps. According to Springwise, a day's worth of cycling can create enough power to run six light bulbs. In exchange for pedaling away, the inmates get reduced prison sentences -- every 16 hours they spend cycling means one day is taken off of their sentence.