The Energy Department's National Renewable Energy Laboratory (NREL) is providing critical support to two new microgrid projects coordinated by the Electric Power Research Institute (EPRI) and General Electric Company (GE).
The Energy Department recently announced its award of more than $8 million for seven microgrid projects-including $1.2 million each for the EPRI and GE projects-to help cities and towns better prepare for extreme weather events and other potential electricity disruptions. Microgrids are localized grids that are usually connected to the more traditional electric grid but can also disconnect to operate autonomously and help mitigate grid disturbances.
NREL will test microgrid controllers developed by EPRI and GE using its megawatt-scale power hardware-in-the-loop capability, which is part of the Energy System Integration Facility (ESIF). Power hardware-in-the-loop allows researchers and manufacturers to conduct integration tests at full power and actual load levels in real-time simulations to evaluate component and system performance before going to market.
"Microgrids support a flexible and efficient electric grid, enabling the integration of renewable and distributed energy resources such as wind and solar energy, combined heat and power, energy storage, and demand response," NREL's Associate Director for Energy Systems Integration Bryan Hannegan said. "NREL is excited to be working with EPRI and with GE to accelerate the development of microgrids that can provide a reliable, affordable, and sustainable electricity supply."
EPRI, which conducts research for the electric power industry, is developing a commercially-viable standardized microgrid controller that can allow a community to provide continuous power for critical loads. Standardizing functionality will ensure that the controller can be easily adapted for a wide range of electric grid characteristics and allow grid operators to leverage distribution assets to support both autonomous and grid-connected operation.
GE will also develop an enhanced microgrid control system with two main goals in mind: to provide resilient, high-quality power delivery to the local community and efficient, reliable grid services to the local utility. The program will be closely aligned with the specific energy needs and power resources available in and around Potsdam, New York, with the option to include resources like three megawatts (MW) of combined heat and power generators, two MW of photovoltaic generation, two MW 1Mwhr of energy storage, and 900 kilowatts (kW) or more of hydro-electric generation. Additionally, the system will feature specially-designed control algorithms with a graphical user interface for the operator. The control system will be flexible, scalable and secure and will have a hierarchical structure of three controllers operating on different timescales to maximize efficiencies and ensure all assets function as needed to maintain high-quality power to critical loads including emergency service providers, utilities, and other essential services, during power disruptions
NREL will test GE's microgrid controller in a 200 kW microgrid operating within the ESIF. To mimic real-world operating conditions, the microgrid will be powered by a variety of on-site distributed energy resources, while other energy resources will be simulated using the power-hardware-in-the-loop technology.
The 182,500-square-foot ESIF provides researchers with a unique set of resources and capabilities in one location, including megawatt-scale hardware testing; self-contained electrical, thermal, and fuel distribution busses; high -performance computing; and data analysis and visualization.
"The ESIF offers our industry partners a place to study and develop new energy technologies and practices in real time and on a large scale in an environment that is friendly to exploration," Hannegan said. "In its first year of operation, we already we have more than 40 partners doing work at the ESIF, and many more have expressed interest."
The ESIF is part of a concerted effort at NREL to explore energy systems integration (ESI). Interactions and interdependencies are increasing among the pathways and across the physical scales of the energy system as well as between the energy system and other systems, such as data and information networks. By focusing on the optimization of energy systems across multiple pathways and scales, ESI will lead to a better understanding and greater use of potential co-benefits that increase reliability and performance, reduce cost, and minimize environmental impacts.
"ESI is about optimizing our various energy systems and squeezing more value out of every unit of energy we use, while reducing costs and minimizing environmental impacts," said Hannegan.