How Do Rooftop Solar Panels Work?
Millions of people every year experience the power of the sun’s radiant energy when they hit the beaches. And without UV protection it doesn’t take long for a sun tan to become a sun burn. So, it’s not surprising that we would want to harness powerful source of energy to power our homes.
Solar power has been around for more than half a century. In 1954, Bell Labs produced the first silicon Photovoltaic (PV) panel. But it’s only in the last decade that technological advancements and generous tax credits have resulted in significant cost reductions that are making solar panels more economical for residential homes. In fact, solar power is the world’s fastest-growing source of energy, according to a recent report by the International Energy Agency (IEA).
How Do Solar Panels Work?
Solar panels contain tiny semiconductors that generate electrons on a wafer-thin silicon chip encased in a glass shell with an anti-reflective coating. When the photons from the sun’s rays hit the PV cells the stored electrons wake up. It is this mingling of photons and electrons that generates an electrical current. Since each PV cell generates a small amount of electricity, multiple panels are often wired together in a rooftop solar array to generate the amount of electricity homeowners need.
But that’s only half the battle. Since PV panels generate DC electricity, an inverter is installed as part of a solar power system to convert the DC electrical current into AC power that is used to power everything in our homes.
What happens if my solar panels produce too much or too little electricity? This is where net metering comes into play. Net metering is a billing agreement with a local utility that ensures you will always have access to the amount of electricity you need daily. On the days solar panels aren’t producing enough energy for the home, the additional power will automatically be supplied from the local utility without interruption. On the other hand, when solar panels are producing more energy than can be consumed, the excess power is sold back to the utility. You will see these amounts appear as debits and credits on your monthly utility bill.
Storing Solar Energy
Although solar panels capture energy from the sun, they do not store AC power. But that doesn’t mean it can’t be done. If you want to store AC power for later use or to live off the grid, excess solar energy can be transmitted to a battery system. A battery backup system is also recommended for the DC-AC inverter to protect against a power outage at the local utility. The amount of energy that can be stored depends on the size of the battery which could equate to about a day’s worth of electricity. In the event of a power failure, the battery backup will use its stored energy to power the inverter until the utility is back online.