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Interoperability Glossary

The interoperability glossary and definitions below include terms used by expert speakers throughout NARUC's Interoperability Learning Module videos and publication Smart Grid Interoperability Prompts for State Regulators to Engage Utilities. For more detailed set of terms for the cyber-physical electricity grid, please NIST Framework and Roadmap for Smart Grid Interoperability Standards, Release 4.0, Section 2.3.

The American Recovery and Reinvestment Act of 2009 (ARRA): ARRA) was a stimulus package enacted in February 2009 in response to the Great Recession. Through one portion of ARRA, the U.S. Department of Energy and the electricity industry invested $8 billion in public and private funds for 131 smart grid projects. Source: U.S. Department of EnergyReferenced Learning Module: Utilities Working with Suppliers on New Technologies and Interoperability.

Backward Compatibility: Backward compatibility is the ability of new technology operating under a new version of a program to work with an older version of the program without losing data or communication. Source: Smart Grid Interoperability Prompts for Regulators to Engage Utilities.

Demand response: Demand response is a change in consumers' power consumption as they reduce or shift their electricity usage in certain periods. Some electric system planners and operators use demand response programs as resource options for balancing supply and demand. Source: U.S. Department of Energy. Referenced Learning Module: Michigan Leverages ZigBee Standards.

Distributed Energy Resource (DER): A DER is a resource sited close to customers that can provide all or some of their immediate electric and power needs and can also be used by the system to either reduce demand (such as energy efficiency) or provide supply to satisfy the energy, capacity, or ancillary service needs of the distribution grid. If providing electricity or thermal energy, the resources are small in scale, connected to the distribution system, and close to load. Examples of different types of DER include solar photovoltaic (PV), wind, combined heat and power (CHP), energy storage, demand response (DR), electric vehicles (EVs), microgrids, and energy efficiency (EE). Source: NARUC DER Rate Design and Compensation manual. Referenced Learning Module: Minnesota Updates Interconnection Standards.

Distribution System Operator (DSO): is the entity responsible for planning and operational functions associated with a distribution system that is modernized for high levels of DERs. The term DSO is not intended to imply the need for a different entity from the existing utility. Source: Lawrence Berkeley National Laboratory. Referenced Learning Module: Minnesota Updates Interconnection Standards

Documentary Standard: A document established by consensus and approved by a recognized body that provides for common and repeated use, rules, guidelines, or characteristics for activities or their results to achieve the optimum degree of order in a given context. Source: NISTReferenced Learning Module: Interoperability: Standards, Profiles, and Testing & Certification

Energy Services Interface (ESI): An ESI is a bi-directional, service-oriented, logical interface that supports the secure communication of information between entities inside and entities outside of a customer boundary to facilitate various energy interactions between electrical loads, storage, and generation within customer facilities and external. Source: GridWise Architecture Council. Referenced Learning Module: Interoperability Strategic Roadmap.

Future-proofing: An approach to ensure that investments continue to be of value in the future and will not be superseded by a future version. Future-proofing occurs when systems or technologies are designed to include future advancements in a standard or technology that minimizes the need for modifications to the installed system. Source: Smart Grid Interoperability Prompts for Regulators to Engage Utilities. Referenced Learning Module: Leveraging Standards to Support Future-Proofing of Grid Investments.

Green Button: A standard overseen by the Green Button Alliance, which was industry-led and established by NIST, which, if adopted by a state or utility, allows utility residential and commercial customers to download their own energy usage data. This data standard leverages the Energy Services Provider Interface (ESPI) data standard released by the North American Energy Standards Board (NAESB). Source: U.S. Department of Energy. Referenced Learning Module: Example of Standard Development and Adoption.

Interface: the point where interacting parties connect. Referenced Learning Module: What is Interoperability?

Interoperability: The capability of two or more networks, systems, devices, applications, or components to work together and to exchange and readily use information—securely, effectively, and with little or no inconvenience to the user. The smart grid will be a system of interoperable systems; that is, different systems will exchange meaningful, actionable information in support of the safe, secure, efficient, and reliable operations of electric systems. The systems will share a common meaning of the exchanged information, and this information will elicit various agreed-upon responses. The reliability, fidelity, and security of information exchanges between and among smart grid systems must achieve required performance levels. Source: NISTReferenced throughout the Learning Modules

IEEE 1547: A standard established by the Institute for Electrical and Electronics Engineers (IEEE) that provides a set of requirements and criteria for the interconnection of distributed energy resources to the electric grid. Referenced Learning Module: Minnesota Updates Interconnection Standards.

Grid architecture: A way of thinking about and describing the electric grid that uses system concepts, structure, and organizing principles. Referenced Learning Module: Interoperability Strategic Roadmap.

Lock-in: In economics, “vendor lock-in,” also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs. Referenced Learning Module: Economic Value of Interoperability and Standards.

Plug-Festival: An (live) event where (typically a prototype) devices are actually connected (such as with a plug) to ensure that they are all interoperable with one another and comply with interoperability standards. Referenced Learning Module: Interoperability: Standards, Profiles, and Testing & Certification.

Single Point of Failure: A single point of failure is where if one part of a system fails, it causes the entirety of that system to fail. For example, if a customer has a router in the house with multiple devices connected to it to access the Internet and the router fails, then all of the devices will no longer be connected to the Internet. Source: Smart Grid Interoperability Prompts for Regulators to Engage Utilities.

Smart Grid Interoperability Panel (SGIP): The Smart Grid Interoperability Panel or SGIP is an organization that defines requirements for a smarter electric grid by driving interoperability, the use of standards, and collaborating across organizations to address gaps and issue hindering the deployment of smart grid technologies. The SGIP was established by the National Institute of Standards and Technology (NIST) in December 2009 to solicit input and cooperation from private and public sector stakeholders in developing the smart grid standards framework. SGIP merged with the Smart Electric Power Alliance (SEPA) in 2017. Source: NIST. Referenced in the Michigan Leverages ZigBee Standards Interoperability Learning Module.

Testing and Certification (T&C): T&C can also be referred to as a conformity assessment. T&C can help ensure that the implementation of interoperability standards conforms to the standards’ requirements. There are several levels of T&C discussed throughout the interoperability learning modules. Testing and certification programs can be offered by recognized entities to test a product against a standard to determine whether the technology successfully abides by the standard. An example of a testing and certification entity is Underwriters Laboratories, which tests technology against a specific set of requirements to ensure the technology meets those requirements.

  • Integration testing occurs when new technologies and devices are tested to ensure successful coupling and communications with existing technologies or devices. 
  • Certification occurs when a technology has been tested against a set of requirements and certified as successfully meeting the requirements. 
  • Compliance is achieved when technology is judged to meet a standard, rule, or order requirements. 
  • A closed environment is where there are no or limited interactions with systems other than the immediate system being tested.
  • Pilot testing occurs when new technologies or systems are allowed to work with a small part of the existing system to ensure successful interaction with the exposed system that limits potential negative impacts on the broader system.

Sources: NIST and Smart Grid Interoperability Prompts for Regulators to Engage Utilities.  Referenced throughout the Learning Modules.

Transmission System Operator (TSO): A TSO is a federally regulated entity responsible for the safe and reliable operation of a transmission system. A TSO may be a functional division within a vertically integrated utility, a separate agency such as the Bonneville Power Administration and Tennessee Valley Authority, or a function of an ISO or RTO. Source: Lawerence Berkeley National Laboratory. Referenced Learning Module: Minnesota Updates Interconnection Standards.

Two-way communication: Two-way communication involves feedback from the receiver to the sender. This allows the sender to know the message was received accurately by the receiver. Referenced Learning Module: Michigan Leverages ZigBee Standards.

ZigBee standard: ZigBee is a wireless technology developed as an open global standard to address the unique needs of low-cost, low-power wireless sensor networks. This standard takes full advantage of the IEEE 802.15.4 physical radio specification and operates in unlicensed bands worldwide at different frequencies. ZigBee-Wireless Mesh Networks (ZigBee-WMNs) is recognized as a cost-effective and flexible solution for building automation and control. Source: NISTReferenced Learning Module: Michigan Leverages ZigBee Standards.

ZigBee Alliance: The Alliance is a group of corporations, including several technology companies that collaborates to create universal open standards for internet of thing (IoT) devices. The Alliance developed the ZigBee standard and several other open wireless communication standards and works to certify product compliance. Source: ZigBee Alliance. Referenced Learning ModuleMichigan Leverages ZigBee Standards