Grid-tied and Off-grid Solar 101

By Deep Patel
17 July 2012   |  

 

Will I need batteries for my solar system?  How much does it cost to go completely off the grid? 

These questions often come up as people start thinking about going solar.  So, what does it really mean to go "off-grid" with a PV system?  First, let's take a look at a traditional grid-tied system.

Grid-tied Solar

When most people install a solar electric system, it is connected to the utility grid, hence the name "grid-tied."

When your solar system is connected to the grid, you still have access to energy after dark without batteries.  Your grid-tied system simply pulls the electricity you need from the utility grid.  

A grid-tied system is simple.   When the grid-tied system produces more energy than is being consumed, the excess electricity is sent to the grid, spinning your meter backwards as credit toward your next electricity bill.  When the demand is higher than the energy being produced by the PV system, the home draws energy from the grid.  This is called net metering. 

Just think of the grid as your battery.