Q1: What's the difference between watts and watt-hours? A: Watts measure power (instantaneous energy rate), while watt-hours measure energy (power × time). Understanding these units isn't just academic—it directly impacts your ability to make informed decisions about energy consumption. . Choose appliances, adjust wattage, usage hours, and quantity. The calculator updates results in real-time. Purpose: It helps solar energy users and installers determine how much energy their system will generate over a specific period. How Does the Calculator Work? The calculator. . With residential panels reaching 480 watts and commercial systems demanding precise efficiency calculations, mastering these fundamentals directly impacts your installation success and client satisfaction. Here's the tricky part: two. .