TYPES OF SOLAR
An on-grid (or "grid-tied") system is connected to your local electrical grid. This system works by using a two-way electrical meter. When your house or building needs more energy than what the solar panels are generating, the system pulls extra electricity from the grid. When you system is generating more energy than your house or building needs, the system sends the excess electricity to the grid. On-grid systems sometimes include battery storage as well, but most system owners prefer to not use a battery as it increases the complexity.
Off Grid Solar
Grid-Tied Solar with Battery
Going off -grid means going it on your own. You have to produce and store all your own power and if you run out you start up the backup generator. There is no power utility to fall back on. On the other hand, neither is there a power bill.
Off-Grid Solar and Wind Power System. An off-grid system requires a storage system for the electricity that you produce so that it will be available for times when there is no source of electricity. This storage system is one of the main features that distinguish an off-grid system from a grid-tied system. The other is a backup generator for long periods of cloud or calm.
Grid-tie solar systems with battery backup are designed for those who already have electric utility service, but want the security of uninterrupted power in outage-prone locations.
While batteries may add cost and maintenance to a grid-tie solar system, the peace of mind gained by knowing your alarm system or essential loads will be "up" when grid power is "down," may be worth the added startup costs.
In the event of a grid blackout, these grid-tie systems with battery backup will draw power stored in your battery bank to power your critical loads in your home, such as refrigerator, well pump, and furnace fan, while using your solar panels to recharge your battery bank.