Off Grid Photovoltaic Systems
The following are elements of off grid, independent solar electricity systems. Anyone with an off grid system will need to know how their system works and the basic function of all elements of their solar electric system.
Off-grid systems can be installed by a professional installer. Many amateur electricians and independent power enthusiasts create and engineer their own solar energy systems.
Components you really need to understand:
- Solar panels collect sunlight and convert it into an electrical current. Solar panels are supported by solar mounts (or racks).
- Backup generator. These are required for emergencies and to cover your energy when you get weeks without sunshine. Some true greens will forego these, as they are noisy and polluting.
- An inverter is an important part of many energy systems. It converts direct current (DC) energy into more widely usable alternating current (AC) energy.
- Batteries store energy for later use. To learn more see our page on batteries.
- Wiring to the house's "normal electricity." By this, we mean the house's breaker panel and beyond that, what electricians call your "load."
- A system meter measures how full your battery is, how much electricity the panels are producing and how much electricity you are using.
- A main DC disconnect is found in any battery-based system, between the battery and the inverter. This is a large breaker to allow easy shut off, for battery service.
- Charge Controller protects your battery (battery bank) from being overcharged.
- Rectifier. These could be considered the opposite of an inverter: they change AC to DC. If your solar PV array is getting lots of sunlight, a portion of its generated power can be used to charge the battery.
- The AC breaker panel is the same as you would find in any household.