Inmates in a Brazilian prison can reduce their sentence by producing green energy. The green energy they provide is pedal power. Bicycles have been rigged to produce energy for some street lights.
For every three eight hour days of pedaling and inmate gets a day off of their sentence. This program is considered controversial. I don't know why. They are providing a community service.
If, however, there are other work programs offered by the prison and there is no reduction in sentence, then there is a problem. The article does not mention any other sentence reduction programs.
It does give me that knee-jerk reaction to reject it because of the holy alter that green energy has become. If this is the only project that reduces a prisoners sentence then others need to be implemented. A human hamster wheel is not exactly the most redeeming thing a person can do.