gathering_data

Section 1: Energy Management
Gathering or collecting energy data

4. The smart meters

The smart meters now used by retailers at contestable customer sites have a much wider range of features than the traditional billing meters used previously. Most of these are electronic polyphase units that measure and record the following energy parameters:

energy consumed in kWh
power demand over 15 or 30 minute intervals. This is recorded for demand profile purposes
the kVAh and KVA over the same interval
instantaneous voltage and currents on each supply phase
power factor (average and instantaneous).

Using this data

Any or all of these variables can be logged for analysis purposes. This data is used by the retailer for market management purposes, but is equally useful to the energy user to enable it to check potential for:

peak demand management
off peak power wastage
power factor improvement analysis
supply voltage check.

This data is normally available through the retailer or its meter service provider; however this is on only as past usage.

Ideally an output from the meter should be sourced and used as an input into the plant’s internal energy management system. This will then allow demand and use to be monitored and managed in real time.

The output from the meter can be either a direct contact closure pulse for demand control and/or a RS 232/RS 485 interface to interrogate the inbuilt data logger on the meter. The cost of this will vary depending on the features on the installed smart meter. It is best to discuss the available options with the retailer or network provider.