"Brazil’s Santa Rita do Sapucaí prison has found a new source of alternative energy: its own prisoners. The prison has offered to shave time off of prisoners’ sentences if they’ll charge batteries using special bikes and their own two legs.

Jornal Nacional reports that city judge José Henrique Mallmann got the idea for his battery-charging bikes from other prisons that offer prisoners incentives for riding bikes. For example, in Phoenix, Ariz.'s Tent City Jail, female prisoners are required to pedal a stationary bicycle when they watch television, with the bike generating enough energy to power the TV set. Under Mallmann's plan, however, prisoners can actually reduce their sentences by pedaling, albeit a little bit at a time. For every 16 hours a prisoner pedals, he shaves a day off of his sentence. ..."