Submetering and MDMA Services
What is submetering?
Submetering, in this context, is the use of a commercially available metering device to measure EV charging energy usage that is a portion of the load on a utility meter (the primary meter), which is a single utility service account. Once installed, the submeter is assigned its own service account id. Data from the submeter is acquired by the Meter Data Management Agent (MDMA), validated, and transmitted to the utility, where a bill is generated for the submeter and--after subtracting the submetered usage--for the primary meter.
For the first time in California, the CPUC authorized third parties (other than the utilities) to provide the meters and data management services. Gridtractor is the first such MDMA in California and the only one approved to provide services in all three IOU territories: PG&E, SCE, and SDG&E.
Gridtractor has developed technology integrations with approved submeters and offers a complete solution to help customers deploy them, enroll in submetering with the utility, and manage their data on an ongoing basis.
Who needs submetering and MDMA services?
Customers that have EV chargers and building or facility load often find that EV charging disproportionately increases their utility bill, especially by adding to demand charges. To address this, California utilities offer rates tailored for EV charging, and the ability to separately meter charging load to take advantage of them. To take advantage of these rates and dissociate EV charging load from the primary bill, customers need to install an approved submeter and submit an application to the utility that names an MDMA.
In addition to cost savings, submetering is useful for cost accounting and tenant billing for EV charging. This can be provided as a separate utility account, as described above, or as an internal accounting input.
How does the submeter work?
Metering capabilities are often embedded into EV charging equipment and can track electricity used during EV charging. If the customer has an EV charger that is not on the approved list, an external submeter can be installed to record the usage.
In many cases, the external submeter is a better and less expensive solution, even for chargers that have embedded submeters.
The recorded usage data will then be transmitted to the utility by the MDMA. Once received, the submeter data will be used to calculate a separate bill under a qualifying EV rate plan. The utility will also perform calculations to adjust the recorded usage on the primary meter account, upstream of the EV charging equipment, to reflect a corresponding reduction in consumption and create an adjusted bill (as appliable). The list of approved submeters can be found here.
How do I get more information or move forward with submetering my EV chargers?
Please fill out the form below and Gridtractor will get back to you with next steps.