Solar panels, also called photovoltaic modules, are produced by connecting specially treated slices of a semiconductor (usually silicon) together and laminating them under a sheet of glass. When exposed to sunlight an electrical current is generated. This is called the “Photovoltaic Effect.”
The energy created by a solar panel is DC, which stands for Direct Current. This is the type of energy you would find in a battery, as opposed to AC, or Alternating Current. Alternating current is the type of energy you buy from your local utility provider for use in your home. With the help of some additional specialized equipment called an Inverter, you can transform the DC energy into AC energy and use it to offset the energy you would otherwise purchase through a process known as interconnection and net metering.
A photovoltaic, or PV system, is thus composed of the following:
At the most basic level of a solar energy system we find the “cells.” Just like in our bodies, these cells are where energy is created. The raw material for creating these solar cells, usually silicon, is the second most abundant on earth and makes up 27% of our planet.
There are two main types of silicon cells:
Each solar cell generates about half a volt of electricity. By linking cells together into panels and by linking those panels together, we can generate energy at the current levels needed to convert it for use in our homes and businesses.
A typical solar panel will have 60-96 cells sandwiched between a layer of high tech foil called Tedlar. Tempered glass on the front protects cells from the elements, including withstanding repeated impacts of 1” hailstones and hurricane force winds. Most solar panels have an aluminum frame around them which adds rigidity and is used for mounting the panels to your roof.
Each solar panel has a particular wattage rating based on its factory performance test. 1000 watts of solar (about 4 panels) is known as a “kW.” Groups of panels are connected together to form a solar array. The wattage, or power, of a solar array is typically measured at STC, or “standard test conditions.” STC conditions are defined as 1000 watts of sunlight per square meter at 25 degrees Celsius.
Since solar panels produce differently according to temperature, intensity of sunlight and their own unique characteristics, STC creates an industry benchmark so that solar panel output can be compared on a level playing field.
In the real world, conditions change so the energy production of your system varies depending on weather, temperature, and time of day. Energy production will start early in the morning and taper off late in the day with a “peak production” period that occurs at noon or whenever the sun’s rays are striking the array most directly.
Different solar panels respond better than others to various conditions. By choosing a solar panel that performs well in real world conditions you can increase the energy harvest and profitability of your investment. Contact our installation experts at SunPower by South Coast Solar for more information.
A solar inverter is a package of high-quality electronic components that transforms the DC energy of your solar array into alternating current so it can be used in your home or business or injected into the utility grid via net-metering. In a nutshell, an inverter stores the DC energy from your solar array in a bank of capacitors, which work like batteries. As these capacitors get charged the power electronics of the unit release the energy in a controlled sequence and through a series of filters to create power with a waveform that is identical to your utility grid.
Although many of us would love to “cut the cord” and live “off the grid” the fact that the utility grid is available most of the time is a huge benefit to solar. Net-metering creates a mechanism for turbo charging the return on your solar investment since solar users no longer need to purchase expensive batteries to harness the sun.
It is, however, important to note that most “grid-tie” systems require a connection to the utility grid to work and do not provide power during outages. For emergency power, you still need a battery bank and other equipment.
Our knowledgeable team provides residential, commercial, and government solar panel installation to properties throughout South Carolina, Louisiana, Mississippi, and Texas.
Call South Coast Solar at (803) 626-0552 to schedule your free estimate.