Solar energy systems enable homeowners or businesses to take advantage of the abundant energy source that sunlight provides. While there are several different solar technologies, there are two major types that are used in residential and commercial applications: Photovoltaics (PV) for electricity and solar water heating, (also referred to as solar heating and cooling or solar thermal.)
Photovoltaics, PV systems directly produce electricity from sunlight. An inverter is used to change the direct current (DC) power they produce to alternating current (AC) power that is used in the house.
Solar Heating & Cooling (SHC) systems change the temperature of water and air. These technologies are often used in hot water systems for domestic or commercial use but can also be used to heat or cool air in buildings and for swimming pools.
PV systems are a simple technology that requires no moving parts and only a few components so the systems are basically maintenance-free once installed. There are many different types and brands available for solar contractors to use in installations but the basic idea remains the same.
A PV system starts with solar panels that are mounted to a roof using stainless steel mounting hardware and racks. The panels use the sun’s light to create DC (direct current) energy.
Wiring takes the DC electricity to an inverter, placed on the side of the house that converts the DC electricity to the AC (alternating current) electricity that homes are wired to use.
From the inverter, electricity is sent to the main breaker box from which the energy is
distributed to your meter and the appliances in your home.
In a grid-tied system, the excess energy produced is sent to the grid to power homes
nearby. The owner of the PV system gets credit for this extra energy if they are signed up for net metering.
While PV technology has been around for more than a century, it is only in recent decades that it has become inexpensive enough for broad usage. With recent advances and cost reductions, solar power is ready for mass adoption right now.
When we think of solar power most of us first think of solar panels since this is the most widely seen product on the rooftops of homeowners or businesses that have adopted this energy source. There are also solar shingles, paints, roadways, and windows. There are quite a few different types and manufacturers bit they are quite similar in basic function.
Solar panels are made up of five different components: (a) a protective layer, which is typically tempered glass; (b) anti-reflective sheet; (c) solar cell that converts solar radiation into electricity; (d) thin polymer sheet for the rear surface; and (e) the frame required to hold it all together.
Solar inveters convert the direct current (DC) energy generated from your solar panels into alternating current (AC) electricity that is compatible with the AC voltage you use in your home or business. A central or string inverter is the most common. This type of inverter will serve all the panels in an installation, wired together in series. Another option is micro-inverters that convert DC generated by a single solar module to AC. The output from multiple micro-inverters, each tied to a separate panel, is combined and fed onto the grid. Micro-inverters are used when the solar panels are mounted on multiple surfaces or there are shading issues. They offer more flexibility in system design, yet are more expensive and labor intensive to install. Your installer is the best person to recommend what type of inverter to use with your system.