Will rain clean my solar panels?
or can I hose them off myself?
Your solar panels need to be exposed to sunlight in order to produce power. So, unless you live somewhere with low amounts of smog, dust or wind, your solar panels need to be cleaned at least once a year. In some cases, occasional rain will be enough to naturally and safely keep your solar panels clean. But it's always a good idea to have a professional freshen up your panels annually with a good scrub if you live in an area with heavy particulates in the air.