An off-grid solar energy system is not connected to the utility grid, whereas a grid-tied (aka on-grid) solar energy system is connected to the utility grid.
What is a grid tied solar system?
Grid-tied systems are solar panel installations that are connected to the utility power grid. With a grid-connected system, a home can use the solar energy produced by its solar panels and electricity that comes from the utility grid. If the solar panels generate more electricity than a home needs, the excess is sent to the grid.
Are solar panels integrated with the electricity grid?
The relationship between your solar system and the electricity grid determines whether you're a self-sustaining energy producer or you rely, at least partially, on public energy. Most solar panels are integrated with the grid, according to a 2015 study from the MIT Energy Initiative. Read on to learn about their differences.
Grid-connected systems generally use abilling process called “net metering” or “netbilling.” In this process, any energy generat-ed by the solar modules that your home doesnot use immediately is sent to the utility grid.However, when the solar electric system isproducing less power than is needed, youcan draw additional power from the grid.
Why do solar panels need to be connected to the grid?
The simple answer is that remaining connected to the grid allows your home to draw additional power when solar panels can't generate enough electricity, including nights and cloudy days.
"If people have solar as well as a battery, they can use the solar in the day to feed their houses and charge their batteries. And at night, the batteries will serve their houses instead of the grid," Quirk said. "It makes people a bit more independent from the grid when we tend to see big spikes." Grid-tied systems are dependent on utilities.
Going solar doesn't mean going off the grid -- unless you choose to. Grid-tied systems have a give-and-take relationship with the wider electrical system, drawing from it when needed and sending excess energy back. Off-grid systems place you on your own solar island, which means you'll be responsible for producing all of your own energy.