EPRI spec for DR flexibility

Phil Carson | Aug 31, 2010

 

Implementing demand-side management at the residential level promises to relieve peak demand and otherwise shift load to benefit both utility and residential customers. And numerous ways to accomplish this have been put forward.

"Although residential devices are difficult to reach because they are numerous and widely distributed, they are of interest because of their correlation with peak load," wrote Brian Seal, a senior project manager for utility communications systems, metering and demand response at the Electric Power Research Institute (EPRI), in a recent article.

"The issue is particularly complex at the lower layers," Seal noted, due to the plethora of architectures and technologies now in the field, searching for consumer acceptance.

One way around the shake-out-to-come—or simply another option to add to the mix—would be to define an open standard for a modular interface that could accommodate whatever communications technology a utility or market selects. In other words, a standardized socket that could accommodate a variety of communications modules would allow a full range of choice in the marketplace.

Seal offered the analogy of the PCMCIA slot on laptop computers that accommodated communication cards of many types. The slot allowed laptop makers to bring a variety of products to market immediately without having to choose a particular communication technology. The standardized socket allowed various camps to make cards to serve the needs and interests of all consumers, supporting the latters' choice of technology and their need to protect their investment from premature obsolescence.

EPRI has studied this challenge for years and, through a recent industry collaborative project, has developed a draft specification for such a socket that is now being prototyped and field tested. The project, Seal told me, has "recently turned a corner."

"Prior to this point the project focused on use cases and specification development, understanding and documenting the stakeholders' idea of a socket interface," Seal said. "Now, we're moving to the next phase, building prototypes to this specification and taking them into field programs for interoperability testing."

Stakeholders include utilities, end-use device makers and communication system providers. Seal is careful to use the term "end-use devices" as opposed to "appliances."  This is to make sure that it is clear that the device may be a water-heater, HVAC system, or pool pump in addition to traditional white-goods.  Additionally, the "end-use device" may be an energy management console that represents and manages one or more downstream devices.

 "End-use device makers" that are engaged in the prototyping activity include all of these, selling heating-ventilation-air-conditioning (HVAC) gear, water heaters, thermostats, electric vehicle chargers and energy-management consoles. Seal invited any manufacturers or utilities interested in this program to contact him.

According to Seal, a standard socket interface will provide a means for utilities to go from pilot studies to mainstream availability of products and services that can facilitate load shifting, accelerating adoption and innovation.

Two important points here, in Seal's view, one addressing the utility, another addressing the resident.

"EPRI does not see the actual implementation of a standard socket interface on a product as something that should be required, rather it leaves that decision up to device manufacturers' own market strategies, in which modularity may or may not be required," he said. "The thing that eliminates the actual barrier to off-the-shelf demand-responsive products is the mere existence of a standard modular interface specification as an option for manufacturers.  From there, as in the example of the laptop computer industry, manufacturers can freely choose what and when to build something inside."

As for the other side of the meter: "One message we've heard from end-use device makers is that they will not support any scenario in which the consumer cannot override external signals," Seal said. In other words, hard-wired, direct load control is unlikely to be adopted by third parties, regardless of successful agreements between some utilities and their ratepayers.

The goal, understandably, is to shift or shed load with a minimum of inconvenience to the resident.

Also, because residential customers tend to buy "end-use devices" for relatively long-term periods, a standard socket would allow people to move with those devices to different regions or service territories that might require the use of a different communications protocol, Seal said. Similarly, a standard socket would allow utilities the freedom to evolve their demand response programs and technologies over time without making customer end-use devices obsolete.

Once field testing for interoperability reaches a mature stage, EPRI plans to deliver the socket specification and findings to appropriate standard development organizations (SDO) as a contribution towards a national standard, according to Seal.

Folks, is this a proverbial "third rail" that could add to the smart meter-and-home area network paradigm, could this substitute for it, could it replace it? Either way, would this socket specification add flexibility and options for residential customers? Your views are welcome.

Phil Carson
Editor-in-chief
Intelligent Utility Daily
pcarson@energycentral.com
303-228-4757