B grade chipped or broken solar cells work just as well as whole ones. You may loose a few watts overall, but they work and they are cheap.br br I got 600 watts worth of broken cells for $50 online in an auction. They are all half cells, but work fine. Just tape them together and make your solar panels. My 65 watt panel shown here cost $14.95 for the cells.br br The plexiglas for the cover is the most expensive part of the solar panels, at about $22 for a 2x4 sheet.br br br Make your own cheap solar panels.