It usually costs the East Peoria Police Department around $100 to replace a battery whenever the lone source of power breaks down. Since the fleet of vehicles includes 37 of them, more substitution means loss of money and time as well. Just to pay it off, the department is experimenting to attach a $200 panel, about the size of a computer keyboard and weighing 1.5 pounds, to one of its cars. Though the panel might seem to be an overpriced investment as of now, it will extend the battery life and will discourage any replacements in the future.

Once it is established that the power gains are worth the credit, you would see similar panels attached to the rest of the cars.
Via: CI Proud