How does solar work?

Photovoltaics, or PVs, are solar panels you’ve seen on rooftops, backyards, or in fields. As the sun shines onto a solar panel, photons from the sunlight are absorbed by the cells in the panel, which creates an electric field across the layers and causes electricity to flow. An inverter then converts the electricity generated by the solar panels, direct current (DC), into alternating current (AC), which can power your lights and appliances.

Just as homes come in all sizes, so too do solar panel systems. The system is to be sized according to use; the power produced is designed to match or offset the power consumed. The size of a solar panel array, or the number of panels, depends on the amount of electricity needed.

To determine the system output, sizing must account for your annual kWh use, which may be found on your most recent bill. You can estimate solar system output by using an online calculator (PVWatts Calculator is a good one), or by asking a reputable solar company to provide an estimate for you. You must also consider the addition of battery storage.

Please keep in mind that most systems we see are sized to simply offset monthly use and not to replace a home’s total energy usage. In such cases, members continue to receive a moderate bill from MEC. Accordingly, it is of utmost importance to compare your annual energy consumption to the annual output of the proposed system to determine if this is a worthwhile investment.

Thoroughly comparing these numbers will ensure your system is not over- or undersized. Remember, prior to installation your Cooperative must approve the size of your system; typically, this is handled by the installer.