I'd look for solar panels intended for camping. Probably eBay or Amazon is the easiest place to look for cheap gear. Hobbyist electronic stores might be a good

I'd look for solar panels intended for camping. Probably eBay or Amazon is the easiest place to look for cheap gear. Hobbyist electronic stores might be a good source too depending on the country (here in Australia Jaycar has some fairly good value panels and PWM solar charge controllers).