10 Years of Leading Energy Systems Innovation

On the day that the Energy Systems Integration Facility (ESIF) came to life in September 2013, it had already made history. An architectural marvel, the ESIF's design matched the science that it would feature at the facility: domain-crossing, data-infused, radically efficient energy system science. Constructed beside 600-million-year-old lava flows at the edge of the U.S. Department of Energy National Renewable Energy Laboratory's (NREL's) South Table Mountain Campus, the ESIF became a living laboratory where research, the building, and its equipment coevolve.

Over the past 10 years, NREL's ESIF has incubated pivotal clean energy technologies and has primed the world to integrate those technologies. The ESIF and its staff have helped communities and countries to reach record amounts of renewable energy and companies to explore the innovative edge of energy integration.

As a user facility, the ESIF has sustained a rolling flow of close collaborations. Partners of diverse size and scope have engineered solutions in the ESIF ecosystem, tapped ESIF's data and computational tools to catalyze discoveries, or have literally moved their own people and operations in among the equipment for all-access R&D. Now, as the ESIF merges its capabilities with NREL's Flatirons Campus to form the world-class Advanced Research on Integrated Energy Systems (ARIES) platform, the ESIF brand of integrated research will be elevated further.

To recall and celebrate some of the ESIF's most lasting achievements over the past decade, the following list, in no particular order, summarizes 10 advancements that represent its full uniqueness, foresight, and continued importance. With these achievements, it is hard to imagine where renewable energy would be without the ESIF.

One of the first ESIF partners arrived with a problem that proved to be sticky. The Hawaiian Electric Company faced faltering grid voltage following growth in rooftop solar and urgently required new safe controls for inverters, devices that connect renewable energy to the grid. ESIF engineers simulated the Hawaiian system in the lab—complete with inverters in the loop—to recommend the right controls to stabilize grid voltage. These findings have become a playbook for other islands reducing their reliance on imported fuel.

That was just the beginning. Nearly identical work continues today, just larger. Now engineers are asking, "How can we manage a system with 100% inverter-based resources?"—a goal that is only possible because of progressively advanced ESIF experiments. The ESIF helped establish today's inverter standards for grid interconnection and later assisted in an R&D 100 Award-winning product that configures inverter setpoints to streamline rooftop solar applications. When a California utility deployed the tool to keep up with rooftop solar interest, they began processing applications in minutes rather than weeks. Even the modern microinverter design owes some credit to early ESIF projects.

For 10 years, the ESIF has allowed researchers to design and implement inverter controls in hyperreal simulations. That capability is in higher demand than ever, and ARIES extends the ESIF's validation capabilities to new physical and virtual possibilities.

An early visitor to the ESIF would recall a futuristic, transparent CUBE containing a mobile microgrid-forming system suitable for emergencies or military outposts; and a kitchen test bed, where appliance controls evolved into an award-winning smart-home software. These were exploratory projects for a new dimension of energy systems: controllability at the edge of the grid.

Over time, the ESIF added leading hardware for microgrid control, a test bed for utilities to modernize their distribution systems, and inventive controls for real-time device optimization. These allowed the ESIF to export its unique solutions to remote corners of the country with nationally scalable demonstrations. A mixed-technology desert microgrid relied on years of ESIF validation to become the largest clean energy microgrid in the world; an affordable housing neighborhood went net-zero with distributed and autonomous controls designed at the ESIF; and military bases competed for the most resilient microgrid controller using ESIF equipment.

For years, the ESIF has trailblazed the rollout of advanced distribution management systems, which grant utilities and co-ops the controls and sensing to exploit opportunities at the grid edge. This work empowers large utility transitions and has inspired strategies for autonomous control of millions of devices and methods for immediate microgrid recoveries using renewable energy.

Many types of light-, medium-, and heavy-duty electric vehicles (EVs) have passed through the ESIF. In the high-bay labs, an occasional semitrailer or school bus is connected to grid emulators. Or sometimes a group of consumer electric vehicles are charging alongside a replica residential building. This work prepares energy systems for the rapid rise in widespread transportation electrification, like when ESIF engineers contributed modeling to a transit-oriented energy-efficient district and designed smart-charge controls that were then validated using NREL's staff garages.

The ESIF has always unlocked new opportunities for EV-grid integration. Vehicle partners first came to the ESIF to create an open interface for EVs to provide grid services, then later to develop a universal megawatt-scale high-power charging standard for heavy-duty EV trucks, and recently to study improvements to the cybersecurity of charging stations. Now, with additions to the ESIF and ARIES, electric vehicle research will be more integrated, scalable, and comprehensive than ever.

Buildings are a cornerstone of distributed energy systems. They also consume 75% of all electricity used in the United States and 40% of the nation's total energy. ESIF buildings research uses hardware-in-the-loop to prepare clean energy technologies to be integrated in buildings. The ESIF has been used to evaluate solar-aware building controllers, a startup's “peel-and-stick" energy meters, and liquid-submerged servers. For a period, it also hosted a full-size modular unit for apartment-in-the-loop validation.

The ESIF has consistently channeled building innovations, including throughout the facility itself and with regards to how it facilitates collaborative research. Notable successes came with harnessing reinforcement learning for building energy management and with market-responsive controls for home energy systems. Within the facility, the number of energy-efficient features is too large for this list, but several piloted technologies became a part of ESIF on their way to deployment or were routed through enduring commercialization programs.

Accomplishments at all levels of hydrogen science have occurred among the pipework and high-pressure chambers of the ESIF. The facility features a continuum of equipment to produce, compress, store, transport, and use hydrogen—and of course, how to integrate hydrogen technologies with energy systems.

As ESIF research into component and system design chipped away at hydrogen's costs, engineers were also designing safe and standardized hydrogen-grid connections. The ESIF helped answer how fuel cells can form parts of the power system and how electrolyzers can capture curtailed renewable power. The ESIF has been especially prominent in connecting hydrogen with other infrastructure. A memorable example is the 25-foot bioreactor that originally provoked interest in exotic waste-to-fuel pathways. The ESIF helped incubate the bioreactor from a kernel of an idea, through collaborative R&D, all the way to a pilot with one of the nation's largest natural gas distribution utilities.

Fueling just outside, hydrogen vehicles have had a lifetime presence at the ESIF. When light-duty hydrogen vehicles first hit the streets in appreciable numbers, the ESIF helped standardize a safe fueling and commissioning process that is still used by hydrogen fuel stations today. Meanwhile, ESIF engineers have systematically reduced vehicle fuel times, setting a record for heavy-duty refueling in 2022, which could open new avenues for hydrogen to replace fossil fuels in emissions-heavy long-haul trucking.

As cyberattacks and severe weather became a rising concern over the past decade, the ESIF quickly mobilized a research base for energy resilience. An increase in sophisticated cyber threats prompted ESIF engineers to design new tools that could monitor data networks for energy anomalies, others that could authenticate communications between energy devices, and another that leverages 5G network slicing to protect from common cyberattacks. In the ESIF, cybersecurity is now a cross-facility focus. It especially pairs with work around control and communication of devices and with resilience strategies using microgrids.

In one of the more significant updates to the ESIF, a dedicated cyber-resilience lab was added with a custom NREL tool as the centerpiece: a cyber range to emulate and visualize energy cyber systems. This buildout has brought the orbit of cybersecurity around NREL, where workforce training and student competitions suggest a tidal change toward a security-conscious generation.

From day one, the ESIF's high-performance computing (HPC) data center was designed to be the world's most energy efficient. It hosts profoundly energy-efficient supercomputing resources that turned heads and was recognized as Laboratory of the Year after its debut in 2013 with its pioneering use of warm-water liquid cooling and waste heat recapture. While the HPC equipment consumes considerable power, the overhead to cool the data center has been diligently optimized. Most production data centers utilize an additional 40%–60% overhead energy on cooling, whereas the ESIF regularly uses just 3% additional energy to cool HPC systems in the data center.

Across generations of supercomputers, the data center continued to impress, demonstrating the world's first carbon-free data center, with the help of a hydrogen fuel cell and innovative cooling products. The record-setting design for water efficiency cut the data center's water usage in half and led to a commercial product. The ESIF data center is still the world's most energy efficient and supports leading computing innovation, and that is not saying anything about what our HPC can do.

Among the advantages of HPC and high-powered data resources is the ability to visualize experiments, and the ESIF makes the most of it. 2D, 3D, and immersive visualizations have been a portal for new energy understandings, such as the exact perspective needed to locate impurities in solar panels or optimize wind turbines. For example, turbulent wakes in wind farms can wear on turbines and lower their efficiency. Using high-fidelity simulations, engineers discovered wind plant design and operation strategies to mitigate those impacts.

Engineers and partners at ESIF remark that scientific visualizations provide a unique vista into their projects that is otherwise inaccessible. Not just visual, but tactile and audible—researchers can exist in their science. The engineers behind data immersions regularly conjure new environments to imagine phenomena like power flow and engine combustion, guaranteeing that scientific immersion will be a force for renewable progress for years ahead.

High-performance computing unlocked another differentiating capability of the ESIF: whole-system simulation and design. This cutting-edge analysis closes the gap between clean energy ambitions and real-world deployment. Through programs like Clean Energy to Communities (C2C), communities model and test clean energy plans that meet their priorities before installing them in the field. This capability brings together the best of the ESIF in service of communities asking big questions on resilience, affordability, equity, and health. The projects leverage simulations of energy networks and their customers, real hardware in the loop, and scenario analysis to study decades into the future. With these ingredients, HPC in the ESIF has allows communities, cities, and countries to play with the variables and project their future decisions.

These projects usually become the foundation for landmark energy investments. Supercomputing in the ESIF had a historic part in modeling how to interconnect the national power system across transmission seams and, not long after, a low-carbon future for all North America. It presented Los Angeles with pathways for decarbonization and is now doing the same for Puerto Rico and Lithuania. Governments cannot analyze all the costs, interests, and policies affecting energy transitions, but ESIF's HPC can, and it is better equipped than ever for large system planning.

The future of ESIF is inseparable from ARIES. ESIF will continue to be a base of technology deployment and integration experiments at up to the 2-MW scale—while the Flatirons Campus will add scale and technological range up to 20 MW, and a virtual emulation environment will provide essentially limitless scale. ARIES will be able to support everything from the fine-tuning of device integration to complex multitechnology deployments at local, regional, and national scales.

Crossover will remain close between ESIF and ARIES. For example, the data center and energy security and resilience laboratory at the ESIF combine to provide the virtual emulation space for modeling and visualizing cyber-physical systems. Or another synergy, the ESIF's hardware-in-the-loop infrastructure—all the buildings, vehicle, hydrogen, and grid technologies—can be linked to ARIES hardware-in-the-loop assets like commercial wind turbines, solar arrays, and battery energy systems.

The ESIF and ARIES are now a pipeline of grid research equipment that covers energy generation, transmission, distribution, and use. Their combined force is multiplied by the ability to model, virtualize, and cosimulate systems and through hardware-in-the-loop of diverse, multiphysics energy devices and controllers. With ARIES, the ESIF is equipped for the challenges ahead in energy systems transitions.

The ESIF is the flagship user facility of the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), but, true to the focus on integration, many different DOE offices have launched projects inside the facility and sponsored capabilities that make the work possible. The ESIF is the product of contributions from the program offices of EERE; the Office of Cybersecurity, Energy Security, and Emergency Response; the Office of Electricity; the Federal Energy Management Program; the Grid Modernization Initiative; and the DOE Golden Field Office. In addition, more than 300 external partners have engaged in ESIF research over the previous decade.

The versatile configuration of research capabilities and diligent stewardship of the ESIF Operations team makes this level of productivity possible and ensures the ESIF can pivot to meet new system integration challenges and research questions as they arise.

What lies ahead? In energy systems, new directions seem to be just a discovery away. But whichever technologies and ideas take off, they will likely pass through the ESIF, where eager researchers and operations teams will adapt lab spaces and invent capabilities to provide a link to real world integration and where users will converge and build common ground. In this way, the ESIF continues evolving with energy systems to prepare us for the challenges ahead.

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