NASHVILLE, Tenn. - The USNAP Alliance and the Electric Power Research Institute (EPRI) have announced the joint development of a single specification for smart residential devices combining elements of the EPRI Demand Response Socket Interface Specification and the USNAP Alliance 2.0 specification. This effort was prompted by a request from the National Institute of Standards and Technology (NIST) Home-to-Grid Domain Expert Working Group (H2G DEWG) to harmonize the two bodies of work, in preparation for delivery to a standards development organization.

According to the organizations, research indicates that it is in the public’s best interest to have a standard physical interface that allows smart appliances, energy management consoles, and other products to support a variety of user-installable communication modules. Such an interface would provide consumers and manufacturers with reduced risk of end device obsolescence due to evolving communication technologies. It would also provide flexibility for utilities, allowing the communication systems used for load management to be selected and evolved based on individual needs and circumstances.

The EPRI collaborative research project, initiated in 2008, developed a socket interface specification for residential devices that support simple demand response commands and pass-through messages from a utility or load controlling entity. The EPRI project engaged a number of residential device manufacturers (HVAC, water heaters, pool equipment, white goods, etc.), communication technology providers (Wi-Fi, AMI, PLC, HAN, Cellular, etc.), and electric utilities to identify requirements and draft a specification.

The USNAP Alliance published its 2.0 specification in 2010 defining a low-cost physical interface enabling appliances and other products to share energy related information from utilities and service providers. Using the popular Serial Peripheral Interface (SPI) communication port found in most integrated circuits, the USNAP Specification facilitates connectivity between Smart Grid Devices (SGDs) and Universal Communication Modules (UCMs) installed in a home area network (HAN), local area network (LAN) and wide area network (WAN).

“The two specifications are similar in technical approach and are nearly identical in their basic purpose. Each has broad industry support and provides the range of benefits associated with communication modularity,” said Brian Seal, senior project manager for EPRI. “We are making great progress in merging the specifications, retaining the best attributes from each and coordinating with related standards organizations.”

For more information on the USNAP Alliance, For more information on the Electric Power Research Institute, visit

Publication date:04/18/2011