If you want to keep your devices powered anytime and anywhere, all you need is a solar panel and a power pack. That's it. The solar panel will collect the power and the power pack stores the energy for you to use. GOAL ZERO power packs can be charged by the sun through the solar panels, but can also charge from the outlet on your wall or even through a 12-volt car adapter. GOAL ZERO power packs have a variety of outputs: USB ports for cell phones or tablets, 12-volt for DC accessories, and AC ports for laptops, fans, CPAP, etc… It's easy to use – no electrician required.