If you are developing products for the smart grid space, be sure to check out these new white papers from Texas Instruments.
 

Energy efficiency + MSP430™ MCUs (the world's lowest power microcontrollers) = VERY smart!

Developing robust power line communications (PLC) with G3 

Channel modeling of medium to low voltage links for AMI applications of PLC 

Evaluating the low-frequency power line communications channel in Rural North America 

Sub-metering made easy using Texas Instruments energy measurement ICs