How much energy can solar panels generate?

November 19, 2021

Solar panels generate energy, so when comparing solar panel options, output or wattage is an essential factor to consider. How do solar panels generate power? When shopping around, you might see numbers like 245W, 300W, or 345W next to the panel’s name. These are all referring to a solar panel’s wattage, capacity, and power output. All solar panels are rated by the amount of DC (direct current) power they produce under standard test conditions. Solar panel output is expressed in watts (W) units and represents the panel’s theoretical power production under ideal sunlight and temperature conditions. Most home solar panels have power output ratings ranging from 250 to 400 watts.

Let’s look at an example: You are using solar panels rated at 290 W, and you install 30 of those solar panels on your roof-that nets you at 8.7 kW for your solar system. Let’s say you get 5 hours of sunlight a day X 8.7 kW, which puts you at 43.5 kWh of electricity produced per day. Take 43.5 and multiply by 365 days in a year; we get approximately 15,800 kWh of electricity produced in a full calendar year. Considering the US’s average electricity use per year is around 10,600 kWh, that’s more than enough to power your home with solar.