Standards and Interoperability
While the potential for truly smart grid communications exists, and the political pressure for the necessary changes is growing, “a convergence of standards is increasing the ability of utilities to realize true benefits of the technology,” said GE's McDonald. “You can make the investment, however, the technology must comply with the communications standard and be tested for interoperability, which are two separate actions. Compliance does not guarantee interoperability.”
“We're always seeing improvements in interoperability, but what interoperability are we after?” asked EnerNex's Houseman. “Are we after all networks operating together in the field, or where the same software handles the messages coming in, or the ability to talk with third-party devices attached to the network?” There are more types of interoperability than can be named, Houseman observed, from the physical to the application layer in the familiar open systems interconnection communications protocol stack.
“I don't think we want or need interoperability at every layer in that stack,” Houseman stated. “Then everybody will be producing one generic product that is completely identical. We need to leave some room for innovation. On the other hand, I'm clearly of the opinion that we need to think about the level of interoperability we need and want for what we do.”
Many smart grid communications systems fall under the IEEE 802 family of standards, which deals with local area and metropolitan area networks. “They were designed with an extensible architecture to create a family of standards with unique capabilities. Their common heritage and architecture gives unprecedented interoperability between the individual IEEE 802 standards,” said the Electric Power Research Institute's Tim Godfrey, the vice chair of the newly formed IEEE 802.24 Technical Advisory Group (TAG), which includes IEEE 802.3 (Ethernet), 802.11 (WiFi), 802.15.4 (ZigBee) and 802.16 (WiMAX), among others.
However, added Godfrey, these 802 standards have a limited scope. “While they focus on lower layers [of the protocol stack] that are essential for interoperability, they are complementary to many other existing standards that specify higher layers,” he explained. The main goal of the 802.24 TAG “is to facilitate coordination and cooperation among all working groups as they develop or amend standards that apply to grid modernization and utility communications,” he said.
After Sandy, that would seem to be good advice. If the governors in the hardest-hit states follow up and, indeed, work with utilities to develop a strategy to make smart grid communications harder and smarter, everyone would benefit from the shorter outages and improved efficiencies a true 21st century smart grid would deliver.