Advantages of "Smart Grid" technology include helping to avoid, reduce or mitigate power outages by monitoring and communicating area power usages, including any
anomalies, continually back to the power company. When outages occur their locations
are automatically reported, attempts automatically made to isolate, or "island" problem locations, if possible and also to shunt any available power from adjacent substation grids, whenever or wherever possible, to as many customers as possible who might otherwise be in the dark.
But having remote sensing and remote and automatic response capability also improves everyday load management. One notices subtle changes in the brightness of light bulbs when adjustments are made by adding or dropping power sources to meet changing power drain from hour to hour throughout the day and night, for instance. Multi-tap transformers and banks of capacitors can be switched to optimize efficiency by matching changing loads at the substation level.  "Smart Grid" automation means this can be extended remotely, out to the neighborhood substation level where capacitors were manually switched in or out seasonally to match anticipated neighborhood peak demands. Such capacitors can compensate for localized under voltages by raising the average voltage by 1% to 2% but such is overcompensation for hours of lighter demand during peak seasonal use periods; their insertion under lighter loads deforms the sine-wave from its optimal shape for driving motors.
WiMAX Repeater, Barry Rd. near Salisbury St. and Moorland St. Photo by Lysander Spooner*
Massachusetts DPU issued an order for grid modernization in 2013.  Its rationale for modernization, including the use of Smart Metering, is outlined in the document along with an invitation for comments. HaltMAsmartmeters.org has organized these into a table  . Their page on DPU 12-76 [32a] gives linkage to the original, official comments.
Microwave repeaters send meter readings and load sensing data to National Grid. The utility, in turn, can remotely control their equipment (and customers' non-essential appliances) by sending commands outwardly. See below for more on the rationale of why utilities, the government and third party vendors are promoting the compelling advantages of implementing "smart grid" features.
In June, 2016 National Grid submitted its 10 year Grid Modernization Plan to Mass. DPU.  The company proposed four options ranging from a full rollout to every one of its 2 million gas and electric customers, to as little as $524 million for smart meters under an “opt-in” plan. The utility would expand its installed base of Smart Meters to 1.3 million customers across Massachusetts for $1.275 billion under its “balanced” plan, which includes an equal focus on smart meters and smart grid investments. Its options also include two other scenarios that focus either on smart meters or grid investments. [35a]
*Lysander Spooner (January 19, 1808 – May 14, 1887) was an American individualist anarchist, political philosopher, Deist, Unitarian abolitionist, supporter of the labor movement, legal theorist, and entrepreneur of the nineteenth century. He is also known for competing with the U.S. Post Office with his American Letter Mail Company, which was forced out of business by the United States federal government.