Portable and rooftop solar panels use the same monocrystalline cells. Portable panels are lighter though, because the frame isn’t as rigid and heavy. Some models don’t even have an external frame. This makes a panel less sturdy but drastically reduces weight. Many manufacturers of portable modules don’t add a glass layer over the solar cells, which is a must for rooftop solar.You can look at it like this: rooftop solar system is a long-term investment for your house, a powerful clean energy generator for everything you have. Portable panels are something that you can take with you and use on your trips. Just like flexible solar panels, they are popular among campers and boondockers and can become your saving grace if your GPS or smartphone battery charge gets too low.