By Steve Widergren
As machines and automated systems are integrated into our society, interoperability becomes a necessary capability of systems and devices to provide and receive services and information between each other, and to use the services and information exchanged to operate effectively together in predictable ways without significant user intervention. When people talk about the “modern” or “smart” grid, the ease of integration that delivers interoperability is a necessary foundation of that concept. Many regions are experiencing a growing need to deploy smart grid technology to address efficient operation and new challenges to grid operations based on changing demands of business and society often spurred by ambitious environmental policy goals that further emphasize the value of interoperability.
To advance the integration of smart technology in the electric power sector, grid modernization stakeholders must first agree on a common vision of the concepts, structures, and characteristics for interoperability. To that end, the Grid Modernization Laboratory Consortium a multi-National Laboratory initiative formed by the US Department of Energy to advance smart grid technology, issued its Interoperability Strategic Vision whitepaper in March 2018. The 20-page paper describes the desired future state of an interoperable grid, how that vision can be applied to integrating distributed energy resources (DERs), and which tools and techniques can be used to advance that vision.
The whitepaper aims to promote a common understanding of the meaning and characteristics of the process to make things interoperable and to provide a strategy to advance the state of interoperability as applied to integration challenges facing grid modernization. This includes addressing the ease and reliability of integrating devices and systems and the discipline to improve the process of successfully integrating these components as business models and information technology improve over time.
The strategic vision for interoperability applies throughout the electric energy generation, delivery, and end-use supply chain. However, a transformational aspect of a vision for interoperability in the future electric system is coordinated operation of intelligent devices and systems at the edges of the grid infrastructure. The growing penetration of distributed energy resources (DER), often encouraged by government policies, presents new issues for integrating these devices and systems and coordinating their operation with the electric system.
The vision imagines that integrating DER will be driven by information and communications technology standards that are DER technology agnostic. That is, different standards will not exist for photovoltaic (PV), electric vehicle (EV), various types of electric storage, or flexible demand-side resources. Instead, digital connection rules will be based on architectural principles that enable independent DER operators to offer the one or more types of DERs in a facility (e.g., a campus, building, EV parking lot, house, etc.) to safely and securely interact with a party responsible for proper operation with the electricity system. This will be done by evolving existing codes, standards, and guides in specific directions. These directions form the basis of a vision for the integrated operation of DERs with the electric power system.
This vision of integration will enhance interoperability through policies and standards-driven interface agreements such as those discussed below.
- The interface between DER facilities and the electricity delivery system as well as the responsibility of each interacting party will be clearly understood and guided by accepted grid architecture principles3 to protect system safety and security.
- A common set of grid services (e.g., energy scheduling, energy reserves, frequency support, and voltage support) will evolve that will drive service-oriented agreements from electricity market providers.
- Operators responsible for safe and secure operation of the distribution system will have clearly understood roles to support “open access” by any qualifying DER facility.
- The operator of each DER facility (not the distribution operator) will be responsible for direct operation of its DER equipment to meet the comfort and productivity needs of the facility while participating in service-oriented agreements with electricity market providers and distribution operators.
- Different DER will qualify for participation in a grid service agreement based on their ability to meet the services’ performance requirements (e.g., amount of response, speed of response, and duration of response).
- For each grid service agreement, DER interface specifications will stipulate registration qualifications, the negotiation process, the operations process, measurement and verification, and settlement/reconciliation. These specifications will be subject to regulations and, therefore, will change from place to place. However, they will follow a common contract model to support machine-readable agreements.
- These DER integration and coordination interfaces will be supported by robust distributed information technology integration platforms used in many business domains and will not be restricted to the electric industry.
The whitepaper proposes that ecosystems of organizations integrating smart technology use such a vision to align their directions and transcend immediate challenge. It then offers a framework for developing a stakeholder roadmap for these integration ecosystems to achieve their vision, including tools to measure the state of interoperability, and a process to identify gaps and prioritize technologies, policies, and timelines.
Steve Widergren is a principal engineer at Pacific Northwest National Laboratory where he directs electric power projects and supports the U.S. Department of Energy. He is a past member of the board and Plenary Chair for the Smart Grid Interoperability Panel (now SEPA) and was also the founding administrator for the GridWise® Architecture Council – both groups formed with the mission to enable interoperability of automated systems related to the electric system. Prior to joining the Laboratory, Steve worked in industry for an electricity control center supplier, and electric utility service providers. In these positions, he engineered and managed energy management systems products for electric power operations and supported power system computer applications, including information modeling, SCADA systems, and power system reliability assessment tools. He received his BS and MS degrees in electrical engineering from the University of California, Berkeley, and is actively involved in the IEEE Power & Energy Society and participates in standards efforts that bridge power engineering with information technology.