Energy Systems Integration Newsletter

A monthly recap of the latest happenings at the Energy Systems Integration Facility and developments in energy systems integration (ESI) research at NREL and around the world.

February 2018

Competitive Procurement Expands Microgrid Research

Following a rigorous, 21-week, dual-stage procurement program, NREL purchased a Schweitzer Engineering Laboratories (SEL) microgrid controller for installation at the ESIF, enabling new research capabilities to more effectively evaluate microgrid systems and their components.

SEL’s microgrid controller was evaluated against those made by four other companies in a unique competitive procurement process in which NREL researchers ran each company’s microgrid controller through a series of 100-minute simulated sequences based on a model network. The competitive procurement process provided comparative research on multiple controller technologies that will help shape industry standards for advanced microgrid functionalities.

“This was a challenging project that generated a lot of enthusiasm at SEL,” said Dave Whitehead, SEL chief operating officer. “We were able to leverage our expertise in protection, communications, and automation with our deep understanding of power systems to meet the demanding requirements of NREL’s microgrid research facility.”

The SEL controller is programmed to handle any problems that may surface during the operation of a microgrid, protecting it from outages and cybersecurity threats. Until now, microgrid research at the ESIF has largely been focused on evaluating controllers themselves or relying on third-party controller technologies to validate other microgrid components, such as inverters. With the installation of SEL’s microgrid controller, the ESIF can more readily conduct research on the hardware, communications, and security performance of a microgrid and its components—from small, local levels to those interfaced with utilities.

Learn more and read the full story about the competitive procurement program, SEL’s technology, and what it means for microgrid research at the ESIF.

2017 ESIF Annual Report Now Available for Download

From new partnerships in grid modernization, to breakthroughs in sensing and forecasting, to high-impact projects spanning microgrids and residential energy storage, it is hard to know everything going on at the ESIF. A great place to start, however, is with the recently published ESIF 2017 annual report.

Research at the ESIF in 2017 centered on reliable and resilient grids and their ability to accommodate a growing and diverse portfolio of renewable generation. To this end, and with the support of partners across domains, ESIF researchers expanded knowledge in power system control, prediction technologies, and, critically, cybersecurity.

Download the 2017 annual report to learn more about recent research, partnerships, and updates at the ESIF.

The Duck Curve Is Ten: Get the Details on How It Started and Ongoing Work to Fatten (or Flatten) the Duck

In February, 2008, researchers at NREL published a paper that started to look at the impact of high penetrations of PV on the electric grid. One of the challenges identified—how to accommodate the ramp rate and range needed to take full advantage of solar energy—was illustrated in a chart. This chart was the early iteration of what California Independent System Operator (CAISO) later named the “duck curve,” a term that became industry shorthand for the hurdles to integrating large amounts of PV.

Read this article for a brief history of the now famous duck curve and NREL’s work to tame it.

Solar Plus: Getting the Most Out of Residential Photovoltaics Under New Rate Structures

Although changes in electricity rate structures, such as the elimination of net metering, could make stand-alone photovoltaics (PV) less economical for many residential customers, NREL researchers have found that adding energy storage or controllable devices to a PV-equipped house can significantly improve customer economics under such rate structures. This combined approach—called “solar plus”—is presented in a new article in Applied Energy.

The authors used NREL’s REopt model to simulate optimal configurations of PV, controllable air-conditioning units, controllable domestic water heaters, and batteries under different rate structures and customer electricity use profiles. By avoiding the use of grid electricity in some cases and shifting more peak period loads earlier in the day in other cases, solar plus could reduce customer costs and increase the net present value of the customer’s total investment—by several times, as demonstrated in many of the case studies. Applying the solar plus concept more broadly could reduce peak period ramping requirements and thus reduce strain on the grid. 

Q&A with Adam Warren: Expanding Capabilities in Energy Systems Integration

NREL's Integrated Applications Center (IAC) supports ESI research by addressing technical, financial, and policy hurdles to energy transitions, and has been newly incorporated into the ESI directorate at NREL. Adam Warren is the director of IAC, and is excited to leverage the center's resources in the broader world of ESI. We sat down with Adam for a Q&A to learn more about IAC and what's on their plate for 2018.

NREL Researchers to Showcase Work at ARPA-E Summit

Look for ESI researchers next month at America’s premier energy technology showcase, the 2018 ARPA-E Energy Innovation Summit. ESI researchers Bri-Mathias Hodge and Bryan Palmintier will be presenting their SMART-DS research, researchers Emiliano Dall’Anese and Andrey Bernstein will be presenting their work on real-time distributed optimization and control of electric distribution systems and microgrids, and Blake Lundstrom will present work led by the University of Minnesota on a flexible power grid framework. They will be joined by a handful of other NREL researchers whose research is sponsored by ARPA-E, including work in efficient plastic solar cells and renewable organic battery designs, among others.

The ARPA-E Energy Innovation Summit convenes experts from different technical disciplines each year to share transformational energy technologies and help move those technologies out of the lab and into the market. ARPA-E projects have high potential and high impact, and the technologies are often in stages that are too early for private-sector investment. The summit will take place from March 13–15 in Washington, D.C. Stay tuned for next month’s newsletter to learn more about ARPA-E research at NREL.

Electric Power Research Institute Demonstrates Distributed Generation Control Architecture

In the near future, integrating hundreds, even thousands, of diverse distributed energy resources (DERs) with the grid will be commonplace. In theory, these resources can be used flexibly to support grid operations, but an intermediate step between theory and field test was needed. Orchestrating that control effectively has been the subject of ongoing work in NREL’s INTEGRATE project.

As part of INTEGRATE, the Electric Power Research Institute (EPRI) recently demonstrated a successful architecture at the ESIF, designed to coordinate DER control for advanced grid services. The architecture is open source and configured to communicate with various advanced distribution management systems (ADMS), such as that of Schneider Electric, which partnered with EPRI for the research.

At the ESIF, a simulated 10-mile-long feeder connected to hundreds of DERs successfully managed requests from Schneider’s ADMS. The architecture that EPRI employed in the simulation was capable of interoperability among the resources and demonstrated a potential mode of operation for distribution feeders with high levels of DERs and demand response.

EPRI Journal covered the demonstration, and the article included an explanation of the EPRI architecture. 

Cyber Expert Erfan Ibrahim Discusses NREL's Cybersecurity Research Platform in EE T&D Magazine

NREL’s cybersecurity research platform demonstrates the value of layered security against a variety of threats for distributed grid management. In a recent “Security Sessions” article in Electric Energy (EE) T&D Magazine, Acting Director of the Cyber-Physical Systems Security and Resilience Center Erfan Ibrahim elaborated on the components of NREL’s cybersecurity research platform, which incorporates a nine-layer security architecture with a protected enterprise station and two substations.

“The assistance that enterprises need today is in developing a sound cybersecurity architecture based on business applications running across multiple sites and on profiles of end users to minimize vulnerabilities that can be exploited,” wrote Ibrahim, adding that NREL’s Cyber-Physical Systems Security & Resilience Center is uniquely qualified to provide this support. Read the full EE T&D Magazine article to learn more about how NREL’s cybersecurity research platform can effectively evaluate the security of today’s emerging technologies for an advanced energy grid. 

ESIF Call for High-Impact Integrated Projects: Coming Soon

Through a combination of advanced capabilities, the ESIF provides researchers, entrepreneurs, and utilities with the necessary tools to identify and resolve the challenges associated with large-scale integration of renewable energy and energy-efficiency technologies.

As a U.S. Department of Energy (DOE) user facility, the ESIF will be accepting applications for high-impact integrated research projects that will enhance innovation in the private sector and develop scalable technologies. Qualifying projects must satisfy the goals of the DOE Grid Modernization Initiative, which aims to develop the concepts, tools, and technologies needed to measure, analyze, predict, protect, and control the grid of the future. This call for proposals will be open in March. Stay tuned on the ESIF User Access page below “Current Opportunities” for more information on eligibility requirements and how to apply. 

Research in Review: Data Center Cooling Solution Validated at the ESIF

The Wells Fargo Innovation Incubator Program (IN2) matches innovative companies with NREL’s equipment, facilities, and deep expertise. Among the first companies selected for the $30 million program was LiquidCool Solutions, whose breakthrough server-cooling technology was staged at the ESIF’S high-performance computing center.

After nearly one and a half years of operation within the ESIF, LiquidCool’s technology has succeeded in validation tests, and it will now join other Round 1 companies in preparing for the market. Read more about how NREL helped LiquidCool evaluate their product and what’s next for the company. 

Article in Energy Policy Explores Minimum Generation Problem

One of the biggest constraints in deploying high levels of wind and solar on the grid rests in the belly of the duck—that is, the belly of the duck curve. In the now ubiquitous graph, the duck’s belly corresponds to the midday period when solar generation is at a maximum but energy use is at a minimum. To use this power on the grid, coal and gas plants must ramp down operations. Their ability to do so, however, is operationally constrained to a minimum generation level—which could result in curtailed variable generation.

Slated for April 2018 publication in Energy Policy and available now online, a new article by NREL’s Paul Denholm, Greg Brinkman, and Trieu Mai explores how minimum generation levels limit the benefits of variable renewable energy deployment. The three researchers aggregated data from multiple sources and incorporated case studies from two locations to demonstrate how variable generation curtailment is affected by grid flexibility.

Read the program news article to learn more about the team’s research.

Read more about the duck curve’s history at NREL.

California Marine Corps Air Station Receives $5 Million to Continue NREL-Supported Grid Deployment

In 2011, a blackout in San Diego left the Marine Corps Air Station (MCAS) Miramar without power for 8 hours, emphasizing the base’s need for a resilient solution. Now, following years of demonstrating microgrids at varying scales, the base has been awarded $5 million from the California Energy Commission to scale up and help demonstrate a business case for their advanced microgrid deployment.

In collaboration with the University of California San Diego, Schneider Electric, Naval Facilities Engineering Command, and NREL, MCAS Miramar will demonstrate energy storage on their extensive and renewably-based microgrid with a new project termed SemperGRID.

Miramar has been supported by NREL since 2008, with an initial focus on net zero energy installations. The partnership progressed to a 100% renewably powered microgrid project, and now to an installation-wide microgrid that features intelligent controllers for managing diverse energy sources. NREL has provided support throughout MCAS Miramar’s microgrid work, offering feasibility studies, equipment testing, procurement help, design reviews, and now construction support.

Miramar project support is part of integrated energy solutions (IES) work at NREL. Visit the new IES website, and learn more about work with MCAS Miramar here.