Embedded Generation on Master Subtractive Metering Sites

What is happening?

To assist ASPs with installation of metering for embedded generation on Master Subtractive Metering (MSM) sites, Essential Energy has created a detailed fact sheet available on the Document Library.

Key fact quick view:

1. A Master Subtractive Meter (MSM) site is any combination of meters in which a master meter measures total power supplied to one or more subtractive meter/s. There are three types of MSM configurations:
   • Simple – 1 customer, 1 retailer, 1 master meter, 1 subtractive meter only
   • Complex – 1 customer, 1 retailer, more than 1 master and/or subtractive meter
   • Multi-Premise – more than 1 customer
2. MSM sites are not compliant with the National Electricity Rules or AEMO metrology procedures and will be phased out by Essential Energy (see Master Subtractive Metering webpage).
3. To prevent incorrect billing, the MSM configuration must be rectified before smart meter installation can occur.
4. The MSM configuration may be rectified on simple and complex sites by removing subtractive meters and load control devices or, where possible, establishing a new metering point in the customer switchboard.
5. A smart meter must not be installed on a multi-premises site. Essential Energy will initiate rectification of multi-premise sites as required.

What do you need to do?

1. Review the fact sheet and MSM NMI report located on the Document Library.
2. Communicate this information to relevant members of your organisation.

Further Information

If you need further information, please email master.sub@essentialenergy.com.au or call 13 23 91.