What's the difference between Net Energy Metering (NEM), Net Energy Meter Aggregation (NEMA), and Virtual Net Energy Metering (VNEM)?

While net metering policies share similar names, they serve different customer situations. Understanding which applies to you is important for accurate project planning and financial analysis. Here's a breakdown of the three primary policies:

Net Energy Metering (NEM)

Net Energy Metering is the foundational net metering policy for individual customers. It allows residential and commercial customers who generate their own electricity from solar to feed excess generation back into the grid.

Here's how it works: When your solar system produces more electricity than you're using, the excess goes to the grid. Your utility meter records this export and credits your account at the applicable rate. You can apply these credits to future consumption when your system isn't producing enough (nighttime, cloudy days, winter months).

NEM applies to a single customer with a single meter on their property. It's the simplest net metering arrangement and the most common for standard commercial solar installations.

Net Energy Meter Aggregation (NEMA)

NEMA, sometimes called "meter aggregation," extends net metering benefits to customers with multiple meters. If your property has several buildings—each with its own utility meter—NEMA allows you to combine electricity generation and consumption across all those meters.

This is powerful for properties like office parks, industrial campuses, or multi-building facilities. Instead of sizing a solar system to match the production of one building, you can install a larger system that serves all buildings collectively. Excess generation from Building A can offset consumption at Building B. This flexibility maximizes your use of generated electricity and can significantly improve project economics compared to single-meter scenarios.

Virtual Net Energy Metering (VNEM)

VNEM allows customers to receive credits for solar energy generated at a different physical location. This is the key enabler for community solar and multi-tenant properties.

With VNEM, a solar system installed on a separate property (such as a community solar farm or on a property's roof where an individual tenant cannot place panels) can serve multiple customers. The system's output is virtually allocated among participants. Each customer receives bill credits for their share of generation, even though they may not have solar panels on their own roof.

VNEM is particularly valuable for:
- Multi-tenant office buildings where individual tenants can't install solar on the building's roof
- Renters or businesses without suitable roof space
- Community solar projects serving neighborhood participants
- Businesses with limited property or shading issues

Policy Availability

Not all states and utilities offer all three policies. Availability varies significantly by region. Before designing a project, verify which metering policies are available