Now that spring has sprung, it's a good time to clean outdoor solar lights so they shine even brighter. Solar lanterns have integrated panels on top that use the sun's rays to charge internal rechargeable batteries; when the sun goes down, they use that power to illuminate energy-efficient LED bulbs. But if the solar panels are dirty, they can't charge, and the lights won't work. Use a damp cloth to wipe the lanterns. It's a quick task that will make a big difference.