Off Power Grid Plant
The other type of home solar electric system removes the electric grid from the equation. These off-grid systems store that excess electricity in batteries rather than rely on the utility for power at night.
Operations
- Solar radiation strikes the PV panels , creating electric current. That current must then pass through a charge controller.
- The charge controller regulates the voltage running through it so that the batteries will not be damaged from overcharging. It acts sort of like a bottleneck, preventing too much electricity from “spilling” out at once.
- From the charge controller, the current is sent to the battery bank (most residential solar electric systems require several batteries). Remember that this is still DC electricity.
- It is from the batteries that power is drawn for use in the home. But first, it must pass through the inverter to become usable AC electricity.
- Once converted to AC, the electricity is ready for use, passing through the breaker panel, where it is distributed around the house as appliances and light switches are turned on.
On Power Grid Plant
Solar electricity is the energy source for the new millennium, and engineers now have it down to a science. Someday soon, every home could be powered from this clean, renewable resource (with substantial help from other renewable energy sources). Solar electricity is based on a natural phenomenon known as the photoelectric effect. Photoelectricity is simply the emission of electrons from a substance due to its interaction with light. The art of corralling those electrons into an electric current is called photovoltaics (PV). It is this process that drives the basic solar electric system.
Operations
- Sunlight strikes a solar PV panel . Inside that panel are one or more semiconductors that facilitate the creation of an electric current from sunlight.
- That electricity is sent through wiring to an inverter , where the direct current (DC) is converted into alternating current (AC) compatible with your home appliances and the utility grid.
- From the inverter, the AC voltage passes through the breaker panel, where it is sent one of two places – either into the home to power electrical devices or to the utility meter on the outside of the home (as excess energy).
- The utility meter measures the amount of solar electricity as it is sent to the electric grid for use somewhere else. For homes with solar power systems, this meter counts in both directions . That is, when the solar panels are sending energy to the grid, the meter rolls backward, and at night when the grid is providing power to the home, it rolls forward.