I'm looking into buying solar panels, there are all kinds of ranges of energy output...but my question is, when ti says...say 50 watts of power...does that mean 50 watts a day, an hour, a minute, what?
A 50-watt rating means the panel will produce 50 watts as long as the standard conditions are maintained. So if you had this bright sun and cool temperatures for 6 hours, the panel would deliver 50 x 6 = 900 watt hours, or a little shy of kilowatt-hour. Kilowatt-hours (kWh) is the reading on your electric bill. However, like most advertising, the 50-watt number is not realistic. They assume that the air surrounding the panel is very cold. 25 watts is a better number to use for this size of panel for engineering purposes.