How It Works

Solar electric systems, also known as solar photovoltaics or solar PV, convert sunlight into electrical energy through an array of solar panels that connect to a building's electrical system or directly to the electrical grid.

Solar electricity is often a cost-effective way for homeowners, businesses and municipalities to reduce their energy costs, while also reducing their environmental impact. As you consider whether solar electricity is right for your home or business, you can familiarize yourself with how the technology works. Here is a list of resources:

You can also see photos of residential and commercial solar electric systems installed in Massachusetts on MassCEC’s Flickr pages.

How It Works


Panels are made up of a series of individual solar cells that convert sunlight into direct current (DC) electricity. The more intense the sunlight is striking the panels, the more electricity they produce. Once the electricity is produced, it is sent to the inverter.


The inverter is responsible for converting the DC electricity produced by the panels into alternating current (AC) electricity, which can be used in a home or business. Inverters include a range of technologies, from central inverters that convert the electricity from many solar panels, to microinverters that are attached to each individual panel in a system. In grid-connected systems, inverters are designed so that if power from the utility goes down, the electric system will shut down as well - a critical safety precaution for utility workers and public safety personnel.

Electrical Panel

The electrical panel is where electricity enters a home or business from either the solar panels or the utility. The electrical panel will automatically draw additional power from the utility when the solar system is unable to meet the building’s electricity demand. If the solar electric system is producing more electricity than needed, the electrical panel will send the excess electricity to the utility grid through a net meter. 

Net Meter

A net meter is an electric meter that can spin backwards and forwards, depending on whether electricity is being pulled from or sent to the utility grid. Over the course of a month, a net meter will measure the amount of electricity consumed and generated on site to determine if the property owner receives a credit or a bill from the utility.