The sun, that giant power plant in our sky, generates more power in 1 second than we have used throughout all the history of mankind. Wouldn’t it be nice if we could harness some of that energy to power our planet? Oh wait, I think we already can! The discovery of solar power has revolutionized the way we think about electricity. After all, the sun’s energy is practically limitless, free, and doesn’t pollute the atmosphere. But how exactly does solar power work? Let’s take a closer look at the technology behind solar energy systems.

How Solar Works

When sunlight hits an object on earth, the energy usually transforms into heat. However, when the same light hits certain materials, like the photovoltaic (PV) cells of a solar panel, that energy is converted to an electric current. Because the electricity generated by solar cells flows in a direct current (DC), an inverter must be used to change it into alternating current (AC) electricity, which is then ready to power a home. A complete home solar system requires multiple components to produce/store electricity and maintain safety.

Components of a Solar PV System

Solar Cells

PV cells are thin, square-shaped films of semiconductor material ─ usually silicon ─ that convert the photons of sunlight into electrons, creating a direct current of electricity.

Solar Panels or Modules

Solar panels are the most noticeable parts of a solar electric system. They contain rows of silicon PV cells that convert sunlight into electricity. PV Panels vary in size, electrical output, efficiency, and even color; most panels are about 3’ by 5’ and have either a black or silver frame. Panels are typically mounted to a building’s roof or on a ground-mount racking structure.

Generally, solar panels are categorized as either monocrystalline or polycrystalline. Both types have the same function and are made from silicon cells, but the outward appearance and price of each is significantly different. Solar panels are given output ratings in watts. This rating is the maximum produced by the panel under ideal conditions.

Inverter

An inverter is an electrical device that changes the DC electricity produced by solar panels into AC electricity, which is then fed into the home’s electrical system. AC electricity is necessary for all appliances that plug into a wall, like a toaster, TV, or refrigerator. There are several different types of inverters. Micro inverters convert electricity from one panel, whereas string inverters convert electricity from multiple panels or a string of panels.

Monitoring System

The monitoring system consists of the electric meter and the circuit breaker panel. This system allows you to view and measure the production and efficiency of your solar powered system.

For systems that maintain a tie to the utility grid, the power meter measures the amount of power used from the grid, as well as the amount of power sold to the grid. For more information about net metering see: https://hahasmart.com/blog/61/net-metering-explained

The breaker panel is where the power source is joined to the electrical circuits in a home. The role of circuit breakers is to prevent the appliances on a circuit from drawing too much electricity and causing a fire hazard. The circuit breaker will automatically switch off when appliances demand too much electricity for it to handle.

Racking

A racking system is used to mount solar panels onto a roof or attach them to the ground. Racking allows an installer to adjust and angle solar panels for optimal performance and also helps to attach the array to your roof without causing damage. Ideally, solar panels should face southward, tilted at an angle of 30 to 50 degrees. Racking equipment will vary slightly depending on roof type.

Battery

Because solar PV systems only produce electricity during the daytime, when the sun is shining, many people choose to store extra electricity with a battery to offset those long winter nights and stormy days. Solar batteries work by collecting the AC electricity flowing out of an solar power system and storing it as DC power for later use. Installing a solar battery to a home solar panel system allows homeowners to keep any electricity they have not used instead of sending it back to the grid. As a bonus, batteries also offer short-term backup power in the even of a power outage.

Backup Generator

Some solar panel systems are not tied to the utility grid, and rely on a backup generator to provide power when their system is not producing enough to keep up with demand. However, installing a generator requires advanced skills beyond those of homeowners and novice installers. Generators must be set up and programmed to work automatically, and must be tested regularly to remain reliable.