There has been a lot written about installing solar power at home, but unless you have specifically set-up your system for emergency backup or disaster response, then it won’t automatically provide off-grid power.
There are several reasons why your system doesn’t work after the storm passes.
- If you have a grid-tie system (solar power on your home that feeds into the grid when you have an excess of power to improve your electrical bill)and it is not set-up with a backflow stop for when the grid shuts down, then you will not have power during a blackout. If the grid is down, then all your power will flow into the “empty” grid leaving you with none. This flow could also put a charge into lines that are being worked on and inadvertently electrocute utility workers or others around downed lines, so for safety reasons, your system automatically shuts down when the grid shuts down.
- Many on-grid systems use a type of inverter that synchronizes with the incoming power from the grid. If there is no power coming in, then there is nothing to sync to and your inverter won’t work.
- Hurricanes and tornadoes involve high winds and flying debris. Most people have photovoltaic solar panels on their roof or on post stands. When a major storm comes in, the panels are either ripped off their mountings completely or damaged by blowing debris. A damaged panel or one that is partially shaded will shut itself off completely and produce no power. Even a broken corner will result in most solar panels not working at all.
There are solutions. If you have a grid-tie system, make sure you have battery backup and a way to isolate your power from the grid. This may involve a hardwired switch to isolate your house from the grid or may need you to physically disconnect your battery bank from your house power. Make sure that your inverter can either synchronize the AC power to your battery power or create its own sine wave. Some more expensive systems like the Tesla power wall have this capacity built in already.
If you have back up battery power and have physically disconnected the batteries from the house power, then you need to have an inverter (to create AC power) and extension cords to run power from the batteries to your essential equipment and appliances. To run most home appliances with a motor, you will need a pure sine wave inverter. Wire your outside solar panels to the battery bank, but make sure you have a charge controller between the panels and the batteries to control the power flow to the batteries.
The solution to the problem of wind damaging or destroying your panels is an easy one. Take the panels down before the storm hits and store them out of the wind. Then when the storm passes, put the panels back up. Make sure your electronics are either waterproof or stored in waterproof cases. Off-grid portable systems makes this easy with quick set-up and take down. Alternatively, some lightweight panels also have additional protection that the rest of the solar panel still functions if one cell is damaged.
If you are in a hurricane or tornado prone area, and you have lost your solar panels to the recent storms, consider replacing them or offsetting them with portable panels and/or making your system emergency backup ready.