Grid-tie systems connect to the public utility grid. Your panels feed electricity into the grid, and the utility credits your account for the power you generate. You can draw on that power whenever you need it (at night, for example, when panels aren’t producing energy from the sun).
The downside is that grid-tie systems are still vulnerable to power outages. Because you are tied to the grid, your system shuts down as a safety measure when the grid power goes out. (This feature, called anti-islanding, protects utility workers making repairs to the grid.)
The solution? A grid-tied system with energy storage. Batteries offer emergency backup power when the grid goes down. During an outage, the batteries take over as a backup power source to power critical appliances. Battery backup can provide much need peace-of-mind, especially in areas with harsh weather or unreliable power grids.
Batteries also allow you to store energy and use it during peak periods. Your panels generate energy during the day when the sun is out, but most utilities charge much higher rates during peak usage periods (around 5-10pm, when people come home from work and school).
By pairing a battery bank with your grid-tie system, you can store energy generated during the day for use during the evening, bypassing peak usage rates and maximizing the money you save.
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