(music) Welcome to the Enphase homeowner video series. Ever wonder what happens to your grid-connected
solar system when the power goes out? In this video, we'll tackle that question. Many solar customers assume that if the sun is shining they will still have electricity
when there is a power outage. Traditional solar arrays without backup storage
can deliver many benefits but they can't deliver power during an outage. There is one specific reason why this is. Traditional solar arrays are grid tied.
Let's talk about what it means to be tied to the grid.
When you decided to go solar,
you or your installer on your behalf, submitted an interconnection
application to your utility to allow your solar array to connect to the grid. Your solar system generates electricity
during the day when the sun is shining and your utility delivers electricity
to you all day, especially at night, or when your array isn't providing
enough electricity to meet your needs. On exceptionally sunny days,
or when you're using very little electricity, you may even generate more than you need. You may feed this excess electricity
back to the grid for credit on your utility bill. This is what it means to be grid tied.
You have a mutually beneficial relationship
with the utility. You reduce demand on the grid
during peak production times and the grid provides the delivery infrastructure and the
electricity you need when your solar array cannot. But why can't you have electricity when the power is out
even when the Sun is still shining? Here's why. Grid-tied systems are designed
with a great deal of safety in mind. When the power goes out, your utility
may have to make repairs on its distribution network. There may be a line down
or a failed transformer that requires repair. Now imagine you're a utility worker
who has the assignment to restore power to several thousand customers. Would you work on the lines
if you thought the lines might be live? No, of course not. This is why traditional grid-tied solar systems
must turn off during a power outage, to prevent creating an island of power
that could put a line worker at risk.
This basic safety requirement is called anti-islanding. International standards define anti-islanding as a critical
behavior of all compliant grid-tied inverter equipment. Enphase microinverters meet this
and all other requirements for grid-tied inverters. Now you know.
Traditional grid-tied solar systems without backup storage must shut down
to protect line workers during a power outage. To learn more visit our video page at