We've been doing a lot of hacking around with BLE lately, so I thought I'd start publishing some of it. Sorry in advance about the scarcity of details. 
 
Recently we took apart a Belkin Conserve Insight energy monitor (model # F7C005) and determined that the unit used a simple SPI interface to an Analog Device's ADE7753 Metering IC. After sniffing the SPI comms of the original unit, it was pretty easy to tweak some BLE code we had lying around, and get it working with a Nordic EVK. The only real trick was interfacing the power ... the small (ugly) board in the upper right is a small 5V to 3V LDO, which is used to power the EVK. NOTE that we can not (nor should you try) to interface this set up to a computer for debugging. The 5V power supply in the main housing is non-isolated! 
 
The comparative wattage results from our setup to another F7C005 and a Kill-A-Watt were within 1 - 2W over a 1KW range. 
 
 
 
Image of the cable termination (SPI+Power) on the PCB. 
 
 
Pinout. 
 
 
The unit does a little level shifting (the ADE7753 is a 5V part, and the uC in the display unit is 3V).