Solar energy is the most abundant resource on the planet. In a single hour, we receive enough energy from the sun to power 2,880 trillion lightbulbs for an hour or our entire global civilization for a full year. A home solar system lets you use a fraction of this energy to power your home and life. But how does it all work?
As the sun’s rays reach the earth’s surface, they carry energy from the nuclear reactions happening on the sun in the form of photons (or tiny particles of light). A solar system captures these photons and turns them into clean, renewable power through the photovoltaics in solar panels, power inverters and wiring, your home’s electricity meter, and the local utility grid. Here is how these pieces work together.
Sunlight and Solar Cells
A photovoltaic (PV) home solar panel consists of around 60 cells of semiconductor material. These cells are tied together to form a solar module, and solar modules are in turn tied together to form a system. Residential rooftop solar systems generally average 20 to 25 modules, but each is specific to the needs of the homeowner.
PV solar panels are primarily made of semiconductor materials like silicon. The PV cells are connected and mounted in a frame, usually made of aluminum. The frame is then covered with glass or plastic to protect the PV cells from damage and harsh weather conditions. (This article provides a more in-depth overview of how solar panels are made.)
When photons from the sun strike a PV cell, they either reflect off, pass through the cell, or are absorbed by the semiconductor material. The absorbed photons generate electricity. The U.S. Energy Information Administration (EIA) describes it this way:
When the semiconductor material absorbs enough sunlight (solar energy), electrons are dislodged from the material’s atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to the dislodged, or free, electrons so that the electrons naturally migrate to the surface of the cell.
As these free electrons are drawn into an electric field between the negative top layer and the positive-charged semiconducting silicon of the bottom layer of the solar cell, they create a voltage potential like the negative and positive terminals on a battery. When these conductors in an electrical circuit are connected to an external receptor, like a battery, energy can flow as direct current (DC) electricity into a power inverter.
The power flowing through electrical power lines is typically alternating current (AC). This is what’s used to power your household appliances, heating and cooling systems, and all electronic devices in your home. This means the DC electricity generated by your solar panels needs to be converted to AC to make it usable.
Inverters are used on PV modules or in solar arrays to convert DC electricity to AC electricity. In DC applications, electricity is maintained at a constant voltage in one direction. In AC, electricity flows in both directions within the circuit as the voltage changes from positive to negative. Inverters are crucial equipment in solar power systems to help regulate the flow of electrical power.
As part of your solar system installation, a power inverter is wired in to make the necessary electrical conversion and create a gateway between a solar array and the home’s main electrical panel.
Every outlet, light, or power source in your home is connected to the home’s central electrical panel through copper wires. To add solar energy converted to AC electricity to a home’s power supply, the main electrical panel requires some new wiring and additional circuit breakers. Once the new solar power supply is converted and wired, the electrical panel can distribute the power to the other circuits throughout the home.
Your Utility Meter
When your home was built and connected to the local power grid, a utility meter was installed to track how much power you use so the local utility company could bill you accordingly. When you switch to solar energy, your meter needs to be updated to also monitor the energy your system adds to the power grid.
Net metering is a tracking and billing arrangement which enables utility companies to keep track of the power their customers add to the grid. These programs add credits to your account for the power your system contributes, which you can use to offset any energy you need to pull from the grid when your panels aren’t producing—which often happens at night when your panels have no light to convert to electricity. For net metering to work, the power meter attached to your home must be rewired to track electricity flowing to and from your home.
To learn more about net metering and the different policies governing how this arrangement works in your local area, review What is Net Metering?
Local Utility Grid
The amount of energy striking your panels each day will vary depending on geographic location, time of day, season, and weather conditions. Due to these variables, and local regulations in some areas, most homeowners choose to remain connected to the power grid so they can take advantage of net metering programs and draw power if needed.
The U.S. power grid distributes electricity generated from a diverse set of sources:
- Natural gas: 40%
- Coal: 19%
- Nuclear: 19%
- Hydroelectric: 7%
- Wind: 8%
- Solar: 4%
- Other renewables: 3%.
Residential solar systems can go a long way in helping boost the percentage of power coming from renewable sources, though large-scale, utility-level solar power plants also exist and are important. Individual homeowners can produce their own electricity with their own rooftop solar systems and sell excess electricity back to the grid.
Blue Raven Solar Extras
At Blue Raven Solar, we’re on a mission to make homeowners’ lives better by reducing their energy bills and increasing reliance on clean and abundant renewable energy. Making the switch to solar gives you the opportunity to harness the power of the sun while saving money.
Blue Raven Solar has two innovative financing options, BluePower Plus+ and Smartstart, both of which start at $0 down and help keep your custom solar system affordable. We also provide a quality warranty, an exceptional customer experience, and top-of-the-line equipment.
Home solar is a win-win. When you go solar with Blue Raven Solar, our team works hard to keep the whole experience trouble-free from capturing sunlight to energization.