The Falmouth USB Solar Festoon Lights are designed to charge year-round using solar power alone, but they can also be fully charged in just a few hours by bringing the solar panel inside and charging it via USB. This warm white set of 25 bulbs are spaced 30cm apart along an 8m string and are backed up with 2 brightness modes which give you the option to extend runtimes by sacrificing a small amount of brightness.