Most batteries can leak toxic heavy metals into the soil when discarded.
But Dylis' batteries are easier on the environment, because they're made entirely of plastic. It took a lot of fiddling to find a durable blend of conducting plastics capable of providing the supply of loose electrons needed for a current. So Guha and a team found a way to hide them in the roofing material itself, in the form of solar shingles. Made of stainless steel coated with silicon, semiconductor and plastic, the shingles look and are installed just like regular ones, except that they also have wires that run through the roof. Thomas Brumleve Southern California Edison et al.