Bidirectional Meter / Net Meter

A bidirectional meter (also called a net meter or bi-directional meter) is an electric meter that can measure electricity flowing in both directions — power drawn from the grid into your home and excess solar power sent from your home back to the grid. It is required for net metering.

Standard electric meters only measure consumption (one-way flow). When you install a grid-tied solar system, your utility replaces your old meter with a bidirectional meter (or reprograms a compatible smart meter) that tracks both import and export. The meter records how much grid electricity you use and how much solar electricity you send back, allowing the utility to calculate your net usage for billing. Some modern smart meters already have bidirectional capability and only need a firmware update. The meter replacement is typically handled by the utility as part of the interconnection process, often at no charge to the homeowner. Your bidirectional meter may display two readings: one for energy consumed from the grid and one for energy exported. The difference between these readings determines your net metering credit or charge for each billing period.