In 1954, scientists at Bell Telephone discovered that, when exposed to sunlight, silicon, an element contained in sand, produced an electric charge. This discovery led to the creation of solar cells collecting energy from the sun and turning it into electricity. The technology has advanced since then, and solar power systems now offer increasingly lucrative financial benefits for consumers, companies, and non-profits throughout the U.S.
We have access to an inexhaustible source of electricity – the sun, thanks to solar panels. The cells on your solar panels are receiving the energy from sunlight during the day. Circuits inside the cells capture the energy and turn it into electricity from direct current ( DC). DC power is passed through a system called an inverter to transform it to the energy of the alternating current ( AC) used by most homes and businesses. Such energy can be used in your house, stored with a solar battery or sent back to the grid.
Solar PV systems are composed of four main components:
1. Photovoltaic solar panels ("Solar panels")
2. Inverters
3. Installation and mounting system
4. Energy control devices
Solar panels collect energy from the sun and turn it into electricity. They are a main component of a network of Solar Panels. Both poly-cristalline or mono-crystalline solar panels are the most widely available today.
The main differences in performance and cost between poly- and mono-crystalline panels are. Mono-cristalline panels are usually more powerful (and therefore more expensive) than poly-crystalline panels.
Not all panels are made equal: How to compare options for your solar panel
There are a range of considerations to bear in mind for choosing the right solar panels for your home and wallet, including product quality, longevity and long-term efficiency. Read all on how solar panels can be tested in the EnergySage Buyer's Solar Guide.
The cells in your solar panels absorb the energy from the sun and convert it into electricity from direct current ( DC). Nevertheless, most households and businesses use alternating current ( AC). Inverters change the electricity from DC to available AC electricity from your panels. There are three basic Solar Inverter types.
String (or centralised) inverter: A single inverter is used to connect all of your solar panel array to your electrical grid. String inverters are often the least expensive inverter alternative, and are a very durable technology which has become the most commonly installed type of inverter in history. Several strings of panels may be linked to each inverter, but, if the output of electricity from one of the panels drops in a string (as can happen due to shading), the performance of the entire string can be temporarily cut.
Micro-inverters: When you select micro-inverters, one will be mounted at each solar panel to optimise output for each panel. If some of your panels are shaded at different times of day or if not all of them facing the same direction are installed, microinverters will minimise performance problems. Microinverter costs tend to be higher than string inverter costs.
Power optimizers: Devices using power optimizers are a combination of micro-inverter systems and string inverters. Power optimizers are mounted at each panel as are microinverters. However, instead of transforming DC electricity from the solar panels into AC electricity, DC electricity is "conditioned" by the optimizers until it is sent to a centralised inverter. Unlike microinverters, when one or more panels are shaded, or when panels are mounted in various directions, they perform well. String inverter systems tend to cost more than string systems, but less than microinverter systems.
Racking and mounting systems are used to either connect your solar panels to your roof or to the concrete. They also allow you to place your panels at an angle best suited for catching the rays of the sun.
Solar panels should be facing south and installed at an angle between 30 and 45 degrees (depending on how far you are from the equator) to perform to their best. Panels facing east or west will still operate well at a pitch angle of five degrees or more but will generate 10 to 20 percent less energy than those built under ideal conditions.
There are two types of mounts: fixed mounts, in which the panels remain stationary, and track mounts that allow panels to "ignore" the sun as it travels through the sky during the day (single-axis track mounts) and during the changing seasons (dual-axis track mounts). Track mounts are only suitable for floor-installed screens.
The discrepancy between Fixed mounting systems and Track
Fixed mounts are less costly, and the only option if your panels are mounted on your roof. Track mounts are more costly but they allow you to increase the electricity generation of your panels by 30 percent or more.
Because of their additional costs and increased maintenance, track mounts are best suited to situations where you have limited space and want a limited number of solar panels to maximise the electricity production.
Performance monitoring systems provide you with detailed information on your Solar Panel System performance. You can measure and track the amount of electricity your system produces on an hourly basis, using a monitoring system.
Although some solar installers charge extra for installing a monitoring device, it can provide valuable value over your solar panels' lifetime. Monitoring systems help you detect any performance problems to ensure you optimise your solar panel system's electricity production (and thus its financial returns).
Monitoring devices come in two types:
On-site control: The control system is installed physically on your property and records the amount of electricity produced.
Remote monitoring: The solar photovoltaic device transmits its output data to a monitoring service that can be accessed online or by smartphone.
