What happens when the power goes out?
Most solar arrays are grid-tied, meaning they are connected to the local power grid. This allows solar homeowners to use their solar electricity when the sun is shining, and to switch seamlessly over to utility electricity on cloudy days or at night. For grid-tied solar arrays, it’s important to understand how a power outage will affect your solar panels and your home. Firstly, when the power grid goes down, your solar panels will automatically stop producing electricity. This is a required safety feature, designed to prevent your panels from feeding electricity onto the grid and injuring the utility linesmen who are servicing the wires. As a result, when the grid is down and your solar panels stop producing electricity, your home will not have power (even if the sun is shining).
If you want your solar panels to continue producing electricity even when the grid goes down, you will need to pair your solar array with batteries. This pairing – called solar + storage – allows your panels to produce electricity while remaining isolated from the grid, avoiding any safety issues. Your solar electricity will be stored in the batteries and can be consumed by your home when the grid is down, allowing your home to remain powered during a grid outage.