Community Microgrids From All Angles
NREL To Play a Major Part in Microgrid Innovation for American Communities
A modest description of microgrids would mention their role in energy resilience. A National Renewable Energy Laboratory (NREL) description might go further and describe microgrids as the cornerstone of future energy operations. In either case, integration comes first, which is why the Solar Energy Technologies Office (SETO) announced in 2020 that it would award $34 million to energy systems integration projects, with a portion committed to developing community microgrids.
With a share of SETO funding, NREL will lead and contribute to multiple projects that emphasize microgrid controls and stability for community-scale systems. NREL will be joined by industry and academic collaborators to build and demonstrate the new microgrid designs in a variety of real-system scenarios.
Self-Organizing Microgrids in Aspen
NREL’s greatest involvement will be as project lead for an effort to create autonomous and distributed microgrid controls, named Reorg: Resilience and Stability Oriented Cellular Grid Formation and Optimization for Communities with Solar PVs and Mobile Energy Storages.
Reorg will apply concepts of the Autonomous Energy Systems research portfolio, including cell-based power grids and distributed control for self-organizing microgrids. Reorg will also build on a previous partnership with Colorado utility Holy Cross Energy to once again demonstrate advanced grid controls in a community that is familiar with extreme weather and the value of resilience.
The Reorg demonstration will take place near Aspen, Colorado, and will apply newly developed controls for multiple assets including rooftop solar, energy storage, electric school buses, and Holy Cross Energy’s new 5-MW photovoltaic (PV) plant, among other devices.
“This project is about how we can use distributed control methods to handle a massive number of distributed energy resources, like solar and energy storage, on the grid,” said Fei Ding, a senior research engineer at NREL and the project lead. “We will create new grid operation approaches that enable self-evolving and resilient grid configurations, and that use grid-edge intelligence.”
Project partners include Mississippi State University, Minsait ACS, and the National Rural Electric Cooperative Association, and project results will be scalable and adaptable to other microgrid systems and communities.
Operational Resilience for Microgrids
Another of the projects will team NREL with University of North Carolina-Charlotte and others to integrate resilient operations into microgrid management, including pre-disturbance strategies and post-disturbance restoration. The project’s name is Resilient Community Microgrids with Dynamic Reconfiguration to Serve Critical Loads in the Aftermath of Severe Events.
“NREL will contribute metrics to quantify the resilience of microgrids, which will establish a measure for moment-to-moment operational resilience. NREL will also create new protection methods, which include dynamic fault detection and adaptive relay settings,” said project principal investigator Rishabh Jain.
These improvements to microgrid operations will address the uncertainty associated with PV and distributed energy resources, and the impact of that uncertainty on protection settings.
This project will be unique for its use of a real-time connection of experimental resources—a digital-twin system will link real microgrid data from North Carolina to NREL and partner laboratories. The North Carolina demonstration will take place at Duke Energy’s Hot Springs microgrid.
Breaking Through Business Barriers to Microgrids
A final project that NREL will participate in will be led by the Electric Power Research Institute and is named SECURE—Solar Energy CommUnity Resiliency.
The aim of this project is to overcome business and technical challenges that impede resilient community microgrids—specifically with communication and control architectures for system-wide microgrid coordination, said Jing Wang, an NREL researcher and project lead.
For this project, NREL will help develop a decentralized autonomous control architecture that maximizes community benefit during normal conditions by interfacing upstream with central systems and, during emergency events, isolates and coordinates with peer systems to provide power to local communities. This architecture will then be demonstrated at the Energy Systems Integration Facility on NREL hardware, along with a separate demonstration of adaptive, islandable communication systems that maintain community microgrids when communications such as cellular and internet are unavailable.
Additionally, to benefit all projects, NREL will contribute to advanced inverter controls that enhance grid-forming capabilities for solar PV inverters. The new inverter design will also be evaluated on real grid hardware. Overall, NREL will validate and demonstrate three important technical aspects to tackle the key challenges of achieving resilient community microgrids, which paves ways for successful field demonstrations in multiple utility sites.