Interpreting interval data

Interval data is in Eastern Standard Time (EST) and any adjustments due to Daylight Savings Time (DST) must be taken into consideration if you are being billed on a time based tariff such as Time of Use. To do this, you will need to shift the data by 1 hour, forward or backwards at 2am on the date that daylight savings time changes.

The below identifies the format of the interval data that will be provided to customers with interval metering. We have identified all the relevant fields that you can use to interpret the data.

(Click here for a detailed view).

NOTE: The fields highlighted in the above table in red text are fields used by retailers to automate data processing and are for information purposes only. These fields may not help you interpret your data, but for completeness we have provided an explanation of the field.

What is a NMI Suffix?

In the second row of the data sent to you, there are some fields which we have identified as “NMI Suffix’s”. A NMI Suffix is a collection of interval data readings associated with each meter on site.

It is important to note that one meter could contain more than one NMI Suffix and more than one NMI Suffix may be needed to determine the total energy consumption at the premise. 

For example:

  • the below file has an E1 and an E2 NMI Suffix, in this case the E1 NMI Suffix is associated with the domestic load and the E2 NMI Suffix is associated with the off peak hot water system.
  • In some cases where you have more than one meter onsite you will be required to add NMI Suffix’s together to determine the total consumption. 

If you have 3 interval meters measuring your electricity consumption you may have 3 NMI Suffix’s E1, E2 and E3, to determine the total consumption, you will need to add together each corresponding interval of data (i.e. align the date and time of each interval for each NMI Suffix).

If you have a generation system at your premises, you will also have a B1 NMI Suffix in the file we send you. The reading you get here will be vastly different depending on if you have a “Net” or “Gross” generation system. (Find out more in How Solar Power Generation Works).

The data associated with the B1 NMI Suffix is energy that your installation is generating back into our distribution network.

What will the Interval data look like?

This is what the file will look like if opened in Microsoft Excel, for example:

(Click here for a detailed view).