For situations where sub-metering is not appropriate, Plexus has a supply arrangement for a range of wireless products.  These products use ZigBee mesh wireless technology to reliably pass information around a site by using multiple, self organising, communication paths.  This allows electricity consumption to be monitored and reduced, whilst reducing the time, cost and disruption involved in deploying a sub-metering solution.

LEM Architecture Example

NXE-LEM Data Sheet