How Solar Energy Works
Solar panels on your roof work by converting sunlight into electricity using photovoltaic (PV) cells. PV cells are made of materials that generate electrons when exposed to light. The electrons flow through a circuit and produce direct current (DC) electricity, which can be used to power various devices or stored in batteries.
Solar panels are actually made up of many smaller units called photovoltaic cells. Each cell is a sandwich of two slices of semi-conducting material, usually silicon. One slice is doped with phosphorus, which adds extra electrons, and the other slice is doped with boron, which has fewer electrons. This creates an electric field between the slices. When a photon of sunlight knocks an electron free from an atom, the electric field pushes it out of the cell and into a wire. This is how solar panels generate electricity from sunlight.
The amount of electricity that a solar panel on your roof can produce depends on several factors, such as the size, efficiency, orientation, and angle of the panel, as well as the location and hours of sunlight.
According to one source, if you used every square foot of roof space on the average U.S. home, you could fit about 97 solar panels on an average roof resulting in about 31 kilowatts (kW) of solar panels on your roof. That translates to roughly 57,000 kilowatt-hours (kWh) of solar electricity throughout the year!
However, this is assuming that all of the roof space is usable for solar, which is not always the case. Another source estimates that a single 320-watt solar panel can produce about 500-550 kWh of energy per year, depending on the hours of direct sunlight it receives. So, if you have 30 panels on your roof, you could produce around 15,800 kWh of electricity per year.
The optimal direction and angle for a solar panel is south at a tilt equal to 30, but even if you lower the tilt to 5°, production only decreases by about 10 percent. Of course, these numbers are only estimates and may vary depending on your specific situation and location. You can use online tools or consult with a solar installer to get a more accurate assessment of how much electricity you can generate with a solar panel on your roof.
