We usually measure or convert the watts into amps of solar panels to figure out how much current (amps) is being stored in the battery. Or we measure the amperage of the solar panel output to select the wire sizefrom solar panels to.
Solar organizations and associations, both local and international, have done so much not just for the solar industry but also for the entire world. They create all these programs, researches, studies, and solar conferences just to inform and convince people that solar is the way to go.