How Solar Works
Energy radiating directly from the sun has always been available to us.
Since the development of the first solar cell in the US in 1954 at Bell Laboratories, its usage has continued to grow steadily, along with its efficiency. If you have ever used a calculator that operates without a battery, you have seen solar energy at work. Solar calculators use solar cells to harness light from the sun. In the same way, people can use solar energy on a larger scale to power their homes and buildings.
How do solar cells convert sunlight into electricity? The photovoltaic (PV) cells are made up of special materials. The element silicon is particularly important because it allows the cells to absorb light. Silicon is a semiconductor due to its absorptive and insulative properties.
In solar cells, silicon is placed under non-reflective glass to collect photons (units of electromagnetic energy) from the sun. The PV cells contain one or more electric fields that essentially force the electrons, harnessed by the absorption of sunlight, to move in a certain direction. This movement of electrons, called a current, is further guided by metal contacts on the PV cell.
Individual solar cells are packaged into solar panels that can be mounted on your roof, on the ground,on a building’s façade, shutters, and more, due to BIPV (Building-integrated photovoltaic) methods to take advantage of the free energy landing there every day.
Photovoltaic systems can either be grid-connected or stand-alone. In a grid-connected system, the PV cells produce power parallel to the electrical utility plant (i.e. your local power company), which uses a utility grid to connect and distribute power to users. In contrast, a stand-alone system is off-the-grid, that is, it requires an energy storage system separate from the main grid-connected network.
How Solar Works in your Home or Business
Once installed, solar panels absorb the sun’s rays, even on cloudy days. The DC current, collected from the solar panels, is then converted to AC current, which is used to deliver power to houses, office buildings, etc. AC current runs through a standard utility meter to track your net power usage, while also recording the amount of electricity produced from your solar energy system.
During sunny days, when your solar panels generate more power than needed, your electric meter reverses direction and spins backwards tobring the excess energy to the public utility grid. When the sun goes down, your panels will effectively retrieve that energy when you need it. This process is known as net metering.
So- how powerful is solar energy? When you consider that enough sunlight falls on the earth's surface each minute to meet the world's energy demands for an entire year, it’s clear that sunlight is a fantastic alternative energy opportunity.
Today, solar power is considered the most abundant, reliable, clean source of energy-and we've only just begun to tap its potential.