By Kristen Bailey
The phrase “home solar panels” likely brings to mind an image of shiny black rectangles arranged on the roof of a house. While these panels are the most conspicuous component of a home solar-electric system, there are other crucial pieces that come together to turn sunlight into electricity to power your home. A home solar power system—also called a photovoltaic, or PV, system—isn’t as complicated as most people think. The individual components are fairly straightforward, and understanding how these parts work together can help demystify the solar power process.
Solar Panels are Composed of Solar Cells and Mounted in Arrays.
Let’s start with that ubiquitous black rectangle known as the solar panel: A traditional solar panel is, in essence, an arrangement of hundreds of small solar cells, also known as photovoltaic cells. It is inside of these solar cells that the actual conversion of sunlight to electricity takes place. The vast majority of solar cells are made of silicon, which is available in mono- and polycrystalline varieties.1 Polycrystalline cells are the most popular type for home solar systems.2
As photovoltaic cells make up a solar panel, solar panels make up a photovoltaic array. In most home solar installations, the solar panels are combined into roof-mounted arrays. However, if the roof is too small to accommodate the necessary number of panels, the solar array can be installed as a freestanding or ground-mounted system.
Both roof-mounted and freestanding systems can be installed with either fixed mounts, or tracking mounts. Fixed mounts secure individual panels at a preset height and angle. This type of mount is less expensive than the tracking type, but it doesn’t allow the panels to change angles for maximum sun exposure. Tracking mounts are designed to move with the sun, adjusting the angle of the array to catch more sunlight as the sun moves across the sky.
Solar panels require additional equipment in order to provide useable electricity
Inverters convert electricity for home use
The primary function of an inverter is to convert the power produced by the solar panels into electricity suitable for the household. While solar cells generate direct current (DC) power, most homes are wired for alternating current, or AC power. The inverter is the critical component that enables a solar array to power a home.
While the two main types of inverters—string inverters and micro-inverters—serve basically the same purpose, they do so in slightly different ways. String inverters convert electricity from a string of panels rather than from an individual panel. This type of inverter offers a lower initial cost and easy installation, but if there’s a problem with one panel, the problem resonates across the entire string of panels. Micro-inverters, on the other hand, convert electricity from a single panel. If a problem occurs with one panel, it won’t affect the performance of the others. However, these inverters are more expensive and complicated to install unless they’re built into the solar panel.
Electric meters are important for monitoring the system
In the majority of residential photovoltaic systems, the home remains connected to the traditional electrical grid. A vital component of home solar, therefore, is a metering system. Power meters measure various aspects of the system’s performance–from how much electricity the solar system is producing, to how much electricity is being used by the home. Meters help homeowners monitor the overall health and efficiency of the system, and plan ahead for electricity usage.
Solar Batteries Store Surplus Power and Provide Backup as Needed.
While it’s not entirely necessary for grid-connected homes, a battery bank can be included in a home solar power system for added peace of mind. Solar batteries store surplus electricity generated by the array, and provide backup at night or in emergency situations. When fully charged, batteries for off-grid systems can typically keep a household running for three days without sun.3 However, with batteries come additional costs and ancillary devices, such as charge controllers.
Solar Electric Systems Don’t Need to be Complicated to be Effective.
The truth about home solar is that the components required for a residential PV system are fairly simple and straightforward. Choosing the best solar panel inverters, batteries, meters and other components is largely a matter of doing a little research and relying on a knowledgable solar installer to help homeowners navigate the various aspects of a home solar system.
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- Davison, Alan. “Common Types of Solar Cells.” Alternative Energy. Alternative Energy, n.d. Web. 20 Dec. 2016.
- Zipp, Kathie. “What are solar panels made of?” Solar Power World. WTWH Media, LLC, 2 May 2013. Web. 20 Dec. 2016.
- Sanchez, Justine , and Ian Woofenden. ”PV Systems Simplified.” Home Power Magazine. Home Power, Inc., Aug. & Sept. 2011. Web. 20 Dec. 2016.
Editor: Kelsey Tollefson
Executive Editor: John Lenker