Backup Gateway 2 makes metering simple with built-in options for Site and Solar metering:

• Internal Primary Meter (Meter X) – This Site meter may be used when the Grid connection is at the Supply terminals. No additional steps are needed during install. If there are any loads or solar upstream of the Supply terminals, Tesla 100 A CTs connected to the Internal Auxiliary Meter can be used to measure loads less than 100 A, or a Remote Energy Meter can be used to meter the Grid connection point.
• Internal Auxiliary Meter (Meter Y) – Metering solar circuits inside the Gateway or in adjacent switchboards is simple with the three (3) internal CT connections for use with Tesla 100 A CTs. One Tesla 100 A CT is included in the Accessory Kit, and additional CTs (Tesla P/N 1467316-00-x) may be ordered individually.
• Factory Installed Solar Meter – Powerwall+ includes a factory-installed Neurio meter inside the Powerwall+ solar assembly; this meter is used for measuring solar circuits for revenue grade metering (RGM) purposes. Additional Neurio CTs (Tesla P/N 1622277-00-x) can be ordered for use with the factory-installed Neurio meter, which has (2) unused and accessible ports at the time of installation.
  Note

  With the factory-installed Neurio CT measuring solar circuits inside the Powerwall+ solar assembly, no field-installed CTs are required to measure Powerwall+ solar production.
  Note

  Each Neurio meter has (4) CT ports; (1) is used by the factory-installed CT and (1) is blocked by the installation location in the solar assembly, leaving (2) ports unused and accessible.

The Tesla 100 A CTs may be extended a max distance of 330 ft (100 m) by splicing twisted pair or using the Tesla 100A CT Extension (10 ft/3 m) (Tesla P/N 1467274-00-x). Use 20 AWG (0.5 mm²) conductors or larger to extend CTs up to 330 ft (100 m). Voltage rating of the extension wire must be equal to or greater than all other adjacent circuits.

Depending on site layout it may not be possible to use internal Gateway 2 meters, and Neurio Remote Energy Meters will be required. Neurio CTs may be extended up to 15 ft (4.5 m) using a Neurio CT Extension kit (Tesla P/N 1622289-xx-y), and can be plugged into the factory-installed meter or into a newly installed Remote Energy Meter. See Appendix F: System Energy Metering for Remote Neurio Meter installation instructions.