Appendix C: Example Metering Diagrams

Power measurements are needed for a Powershare system to operate properly, and for system data to appear in the customer's Tesla app. An energy meter accomplishes this by measuring voltage (by voltage tap) and current (by Current Transformer) at key locations in the system.

Site Metering

Site meters show the overall power flow to/from a site from the Grid’s perspective, i.e. the Grid is treated as the source of power and the home is a consumer of that power. Site meter(s) must be installed upstream of all solar production, the Powershare system, and home loads. Multiple Site meters can be installed together where needed, but their sum should capture all of the power flows from load, solar, and the Powershare system.

Powershare Gateway (Meter Z) has two integrated CTs which can measure either all of the Site power flow (for instance when Powershare Gateway is the main service disconnect), or a portion of the overall Site power flow (in a partial home backup configuration).

Figure 1. Powershare Gateway Performing Site Metering in Whole Home Backup System


Energy to be Metered	Meter	CT(s)	CT Configuration in Tesla One
Site Backup Loads	Powershare Gateway Meter Z	Powershare Gateway Meter Z	Preconfigured as Meter Z: Site
Site Non-Backup Loads	N/A
Solar	N/A

Backup Switch (Meter Z) has two integrated CTs which can measure either all of the Site power flow. Backup Switch performs all Site metering when installed in a Powershare system.

Figure 2. Backup Switch Performing Site Metering in Whole Home Backup System


Energy to be Metered	Meter	CT(s)	CT Configuration in Tesla One
Site Backup Loads	Backup Switch Meter Z	Backup Switch Meter Z	Preconfigured as Meter Z: Site
Site Non-Backup Loads	N/A
Solar	N/A

For systems with partial home backup, a Tesla Remote Energy Meter is required and can be installed in the non-backup panel, with CTs installed to measure the non-backup loads or the entire Site measurement. See Install the Tesla Remote Energy Meter and CTs for complete instructions to install the Tesla Remote Energy Meter.

Figure 3. Tesla Remote Energy Meter and Powershare Gateway Performing Site Metering in Partial Home Backup System

Figure 4. Tesla Remote Energy Meter Performing Site Metering in Partial Home Backup System

Energy to be Metered	Meter	CT(s)	CT Configuration in Tesla One
Site Backup Loads	Tesla Remote Energy Meter	Field-installed 200 A Tesla Remote Energy Meter CTs	Site
Site Non-Backup Loads
Solar	N/A

Note

In this configuration, Meter Z is configured as None as the Remote Energy Meter is monitoring all Site loads (backup and non-backup).

Solar Metering

Solar meters capture production from solar inverter(s). A Tesla Remote Energy Meter is required to measure any Solar in a Powershare system; install a CT to monitor each solar inverter.

Note

A single CT can be installed to measure a split-phase solar inverter, as total power output is calculated by software. If installing a single CT to measure Solar, toggle 1CTx2 ON during system setup. Using a single CT and not configuring it as 1CTx2 will prevent the system from measuring Solar correctly.

Figure 5. Tesla Remote Energy Meter Performing Solar Metering

Figure 6. Tesla Remote Energy Meter Performing Solar and Site Metering