These solar panels are the most advanced, sturdy, durable, and efficient panels. They are worth paying every penny. What I bought is a residential off-grid solar system, and the system works very well during use. I purchased all the components including modules, batteries, brackets, inverters, and so on from Sunpal. So far, I am very satisfied with this solar system and accessories. So far, my solar panels have not had any problems. Good product, highly recommended.