For homeowners in Ontario considering solar, net-metering is the mechanism that makes the economics work. It allows a home with a renewable energy system to power itself when the sun is shining, and to send any surplus back to the grid for credit against future consumption.
How it works
Once a system is installed, your utility replaces your standard meter with a bi-directional one, capable of tracking electricity flowing in both directions. When your system produces more than the home is using, the surplus flows to the grid and is credited to your account. When the home needs more than the system is producing, power is drawn from the grid as usual, and any accumulated credit is applied automatically to offset the cost.
What is worth knowing before you commit
Grid capacity for net-metering is not unlimited. Securing it requires an application to your local utility to confirm available capacity in your area, a step a competent installer manages on your behalf as a matter of course.
Credits do not last indefinitely. Ontario’s program carries credits forward for up to twelve months before resetting to zero, which means a properly sized system matters: oversize it, and you are generating credits you will never use; undersize it, and you leave savings on the table. Right-sizing a system to your actual annual consumption is a design discipline, not a guess.
A properly sized system is the difference between net-metering working for you, and simply working.
Every kilowatt-hour generated under this program also does quiet work beyond your own bill: it is a kilowatt-hour the grid does not need to generate from carbon-intensive sources, a small but genuine contribution to the broader shift already under way.