Question: What happens to a solar power system when the power goes out?
Answer: It helps to think of a solar power system as one giant funnel.The panels are the funnel and the bottom of the funnel is where the inverter lives.
The sunshine (direct current) pours through the top of the funnel, filling it up with sun rays.
When it’s time for the sun rays to pour out of the bottom of the funnel, the inverter steps in. The inverter converts the sunshine into electricity (alternating current) for your home. The more the inverter converts sunshine through the bottom of the funnel, the more new sunshine can come in.
So far so good so? Let’s pause right there.
Now we begin to diverge based upon whether a system is grid tied or off-the-grid.
GRID TIED
When the system is tied to the utility company (the grid) and the power goes out, the inverter shuts off. When the inverter shuts off the sunshine (direct current) will just continue to sit in the funnel because the bottom is now “plugged up” do to the inverter not working. So, when the power goes out your system doesn’t produce any electricity for use in your home (alternating current).
OFF-THE GRID
When the system is off-the-grid and the power goes out, the inverter can still remain on. The inverter, in an off-the-grid system is powered by two possible sources- a battery or a generator. When the sunshine goes down the funnel and gets converted into direct current, and isn’t consumed by the household, it needs a place to be stored- that’s what the batteries do. When all the direct current electricity is used up in the batteries, a back up generator will take care of electricity needs.
