Yes! Most of the time you’ll hear these terms we are referring to the size of your system and how much it produces.

The size of a panel is referred to by its watts (W), which is a measurement of how much power it can produce. When we talk about a SunPower 360 panel, we’re talking about a panel that is 360 watts.

The size of a system is generally referred to in kilowatts (kW), a term meaning 1,000 watts. For example, if you had 20 SunPower 360 panels on your roof, 20 x 360 = 7,200 watts, or 7.2 kilowatts. So we talk about the size of your system being 7.2 kW. (More specifically, this means it is able to produce 7.2 kW of DC power.) As a frame of reference, most small residential systems come in between 5 and 10 kW.

As we talk with customers we use watts primarily as a way to talk about the size of a system. In addition, pricing is often discussed on a per watt basis as a way to effectively compare prices between differently sized systems. For example, you’ll hear us talk about a system that may cost $3.50 per watt, or $4.00 per watt.

Finally, you may have already heard the term kilowatt-hours (kWh), and this is a way to measure energy over time. Your utility company bills you for the number of kilowatt-hours you use. Your solar system will produce a certain number of kilowatt-hours per day or per year.

The kWh figure we refer to most often is your annual use or your annual production, because talking in yearly terms includes and averages out the changes over the course of the year. For example, a home will use more energy in winter or summer for heating or cooling, or a solar system will produce more energy in the summer because of longer, sunnier days. When we talk about annual use/production in kWh, we take all of those changes into consideration. In general, we try to get a solar system’s annual production to match your annual use.

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