Energy from a PV system is produced whenever the sun is shining. Any solar power first supplies the load – your refrigerator, washer, or computer – in your home. Excess electricity is fed onto the utility grid, spinning your utility meter backward. The actual electricity will likely be used by your neighbors, and you will be credited for all the energy you send onto the grid. Like depositing into a checking account, you will be “banking electrons” for later use. Drawing electricity from the grid in the evenings or when the sunlight is insufficient spins the utility meter forward. The system knows when to switch between utility power and solar power and does so with no interruption whatsoever. The solar electricity flows through and works with the same house wiring, lighting and appliances that you already have. You have a small renewable energy electricity generating station at your home, and have a relationship with the utility that allows you to push or pull energy from the grid as needed.

Depending on your site conditions, energy usage patterns, and system size, your solar-generated electricity will provide anywhere from 10% to 100% of your annual power needs; 50% to 80% is typical. Once you have purchased your PV system, the solar energy is free. This means that for the life of your solar system, you won’t need to worry about utility rate hikes for the portion of your electricity supplied by your PV system.

Solar modules are wired together and mounted on your roof or on the ground . The solar modules convert sunlight directly into electrical power. This power runs from the solar modules through a safety disconnect to an inverter , usually located in your garage or an outside wall. The inverter converts DC (direct current) power generated by the solar modules to clean AC (alternating current) power used in your home.

If you live in PNM (Public Service New Mexico) or EPE (El Paso Electric) territories in New Mexico, wires connect your inverter to a special solar utility meter called a REC (Renewable Energy Certificate) meter that tracks the solar energy output. Wires run from this meter to a dedicated breaker in your main breaker panel. The REC meter tracks the power produced by your solar power system before it reaches the breaker panel, meaning that you are credited for your clean power whether you use it in your home or send it into the utility lines.

The solar power becomes another source of power for your house, generating electricity that first supplies the electric loads in your home with power. When you generate excess power, the excess is fed back onto the grid, spinning your regular utility meter backward and crediting you for future use. When your solar system generates less electricity (due to cloudy days or evenings or excess household use), your utility company supplies you with the rest. The regular utility meter tracks the net power supplied by the grid. The typical grid-tied system is battery-less and maintenance free.

If there is a power outage during the day the solar system automatically shuts down, meaning that even if the sun is shining you will not have power during an outage. This is because your PV system feeds into the same breaker panel that is served by utility power. In order to prevent your solar energy from backfeeding into the grid and injuring a utility lineworker, your inverter must instantly shut down. Once utility power is restored, the inverter checks for steady power and reconnects after five minutes.