Solar panels, made of photovoltaic (PV) cells composed of silicon, convert sunlight into electricity. Panels, typically 3x5 feet and coated in tempered glass for durability, are connected in arrays to power homes or businesses. These arrays can be roof-mounted or ground-mounted. Solar panels produce direct current (DC) electricity, which needs to be converted to alternating current (AC) for use. This is done with inverters. Central inverters convert DC to AC from a single location but are affected by shading. Microinverters and DC optimizers, mounted on each panel, help maximize energy output even in shaded areas, making them ideal for installations with variable sunlight.

Consider your solar array as a long-term investment with a lifespan of 25 years. Solar panels are designed to produce electricity for at least this duration. Although they will continue to generate energy beyond 25 years, their output will gradually decline, typically maintaining at least 80% of their initial energy production in the 25th year. While microinverters are expected to last as long as the photovoltaic (PV) system, central inverters may need replacement after approximately 15 years. Curious about solar system warranties? Jump to our warranties section for more information.

You earn credits for the solar electricity generated by your system through net metering. This policy allows you to offset your utility consumption with the solar energy your panels produce. When your system generates more electricity than your home needs, the surplus is sent to the grid for your neighbors to use. With net metering, you receive full credit for the excess electricity you contribute. Your monthly electric bill reflects your total consumption minus the solar energy you produced. Solar arrays often produce excess electricity during sunny days, leading to surpluses that flow back to the grid. These credits can cover your electricity purchases at night or during low solar production periods, and any unused credits roll over to the next month. Net metering ensures you maximize the financial benefits of your solar array. Most states have laws supporting this policy, guaranteeing your right to net metering regardless of your utility company. If net metering is unavailable, it’s best to consume as much electricity as possible on-site to capture the full value of your solar production by scheduling energy-intensive tasks when the sun is shining.

Several factors affect the optimal size of your solar array. Solar panels are measured in watts (W), with most panels rated between 400 and 450 W. To calculate the total capacity of your system, simply add the wattages of each panel. For example, ten 400 W panels would equal 4,000 W, or 4 kW. Installers determine the ideal system size based on your roof’s footprint, shading, and available budget. They may suggest high-efficiency panels if space is limited. Additionally, geospatial data is used to optimize panel placement, and factors like roof orientation and climate influence energy output. For an estimate of your roof's potential, tools like PV Watts can be helpful.

Designing your solar array and obtaining initial permits from your local government and interconnection agreements from your electric utility usually takes one to two months. The timeline can vary based on your solar permitting office and utility interconnection team, ranging from a few weeks to several months. Once the initial permits and agreements are secured, your installer typically needs just one to two days to install the array, including the panels, inverter, racking system, and wiring. Final approval from the municipal permitting office and the utility’s interconnection can take an additional one to three months, depending on the jurisdiction.