GTM Research estimates a record 16 gigawatts of solar utility-scale installations will occur in the United States this year, more than doubling the benchmark of 7.3 gigawatts of solar utility-scale installations in 2015. This figure represents a massive 119 percent increase, according to GTM Research’s U.S. Solar Market Insight Report 2015 Year in Review. Americans clearly have a growing appetite for solar energy, but many of us are unsure how this technology works. Discover how solar panels convert the sun’s energy into usable power.
Solar Photovoltaic Panels: Collectors and Converters
Solar photovoltaic panels are the physical panels that most of us think about when we think about solar panels. However, these panels are only one part of a solar panel system.
The photovoltaic cells that form these solar panels collect energy from the sun’s rays and convert it into electricity. The most common solar panels sold in the United States, comprising 95 percent of the market, are polycrystalline and monocrystalline solar panels.
Polycrystalline panels result from raw melted silicon poured into square molds. The resulting products get cooled and cut. Since the manufacturing process is simple, these panels are the least expensive to create. However, since the silicon molecules can’t be perfectly aligned, these solar panels can’t convert solar energy into electricity as easily as their monocrystalline peers. Monocrystalline solar cells get cut from high quality silicon ingots, making them more uniform and more efficient.
No solar panel can capture 100 percent of the 1,000 watts of energy per square meter of the Earth’s surface that the sun’s rays emit. Monocrystalline solar panels can be up to 21.5 percent efficient, compared to polycrystalline panels, which are typically between 13 and 16 percent efficient.
Neither option may sound particularly impressive, but these panels should suit the needs of most households and businesses. Experts suggest you need only the most efficient solar panels if you have limited space on your roof. If you have the space for several panels, as most Americans do, the array of these panels matters more than each panel’s singular efficiency.
Monocrystalline panels may be the most efficient workers, but they’re also the most expensive. Consider your budget and any rebates you’ll receive when deciding whether to buy monocrystalline or polycrystalline solar panels.
Solar Inverters: Make Energy Usable For Your Home
While your solar panels do the heavy lifting by collecting the sun’s energy and converting it into power, that power isn’t usable until your system’s inverters get involved. Solar panels convert the sun’s energy into direct current, or DC, electricity. However, most American homes and businesses use alternating current, or AC, electricity.
Three common types of solar inverters exist: microinverters, string inverters, and power optimizers. A single string inverter, sometimes called a centralized inverter, can connect a number of solar panels to a property’s electrical panel. Since you need only one string inverter, this setup is the most inexpensive option. However, if one of the panels fails — even if the failure is due to something as simple as temporary shading — the system itself can stop working.
Microinverters are a more expensive but more reliable solution. A microinverter gets installed at each solar panel to maximize energy production. These tiny inverters reduce performance issues, making them ideal for homes or businesses that spend large amounts of time in the shade or in places where panels need to face different directions. However, their higher cost can turn off some consumers.
Power optimizers, a hybrid of microinverters and string-inverter systems, combine the best aspects of both systems. These power optimizers get installed at each solar panel, just like microinverters. Rather than converting the DC electricity to AC power, these optimizers simply condition the electricity before transporting it to a centralized inverter. Power optimizers perform reliably in a range of conditions and typically cost in the price range between microinverter and string-inverter systems.
Racking and Mounting Systems: Keep Your Panels in Place
Your solar panels need to stay in place — in a spot where they can catch the most sun — to function effectively. Here’s where racking and mounting systems come into play. These systems attach your solar panels to a roof or to the ground at the best angle for catching the sun’s rays.
Two key types of racking and mounting systems exist: fixed mounts and track mounts. As their names suggest, fixed mounts hold solar panels stationary, while track mounts move the panels so that they can follow the sun. Single-axis track mounts follow the sun’s path using a set path that does not vary from day to day, while dual-axis track mounts vary their movements for the changing seasons.
Track mounts are efficient, increasing electricity production by 30 percent or more, but they’re suitable only for solar panels installed on the ground. People with roof-mounted solar panels, the most common type for residential properties, must choose fixed mounts. Fixed mounts are less expensive than track mounts.
Performance Monitors: Assess Solar Panels and Their Effectiveness
Performance monitors aren’t strictly required for a solar panel system to work. However, the feedback they offer makes them an important part of any solar panel system for many homeowners and businesspeople. These monitors provide detailed information about a solar panel system’s performance, including how much electricity it’s generating every hour. By regularly checking your performance monitor, you can learn how much energy your system should produce and isolate problems with your panels and ways that they’re performing. These monitors can also give you a great idea of how much money you save with the solar panels.
You’ll find two main types of performance monitors for solar panel systems. On-site monitoring devices are physically on the same property containing the solar panel installations. Users can read the information they record directly from the device. In addition, you could use remote monitoring systems; these types communicate a solar panel system’s performance to a remote location. Users can then read this information by accessing a website or app with their mobile devices.
All these parts of solar panel systems work in harmony to convert the sun’s ultraviolet rays into clean, green energy in homes across the country and the world.