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Energy Systems Integration News

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.

October 2017

Read the latest ESI news from NREL.

Photo of solar irradiance equipment on a cloudy day.

Fighting Cloudy Weather for Solar Irradiance Data

Each year, scientists and engineers from as far away as South Korea and as nearby as Boulder, Colorado, drive to the top of South Table Mountain—on a dusty road President Jimmy Carter traveled decades ago—to NREL’s Solar Radiation Research Laboratory for the NREL Pyrheliometer Comparison (NPC). Once there, the researchers unpack their telescope-like instruments, designed for measuring direct-beam solar irradiance, and point them at the sun—or at least that’s how it’s supposed to work.

"Usually we have nice weather, and can wrap up the data collection during the first week of the event," said NREL researcher Mike Dooraghi. "This is the first year that the weather forced us into the second week. It is the longest NPC we have conducted." The 42 participants from 25 organizations made good use of their downtime, however, by filling the cloudy days with presentations, meetings, and discussions.

One important outcome of the event, once the sun finally did come out, was that NREL was able to help participants from Spectrafy characterize their new spectral instrument against NREL's reference spectroradiometer systems. Spectrafy’s instruments offer a low-cost option of measuring outdoor solar spectral irradiance for renewable energy applications. This work was funded through the Trade Commissioner of the Consulate General of Canada.

Check out more photos from this year’s event on Flickr, and learn more about the annual NPC event in a feature story on

IEEE Smart Grid Features NREL Article on Rooftop Photovoltaics and Voltage Regulation

The online newsletter IEEE Smart Grid published a special issue on distribution, customer, and transmission in October 2017 that includes an article by NREL ESI researchers on how to regulate voltages on distribution lines with high penetrations of photovoltaics (PV). NREL ESI researchers Julieta Giraldez and Andy Hoke worked with the Hawaiian Electric Companies to study the impacts of rooftop solar PV on the utility and its customers in Hawaii. The article discusses how NREL and Hawaiian Electric collaborated with inverter manufacturers, system integrators, and solar industry members of the Smart Inverter Technical Working Group Hawaii to research advanced inverter grid support functions.

The NREL and Hawaiian Electric study compared volt/volt-ampere reactive (VAR) control with a fixed power factor of 0.95 absorbing for two high-penetration feeders in Hawaii and found that volt/VAR control is more effective at controlling voltages. As a result, Hawaiian Electric is now proposing the activation of volt/VAR control for new interconnections, with volt/watt functioning as a system protection technique for more extreme voltage deviations. The study found that this combination would result in relatively low annual solar energy curtailment for residential PV customers in the near term. See the article for more information: "Voltage Regulation with Rooftop Solar PV in Hawai’i—What Are the Impacts to the Utility and PV Customers?"

NREL Researcher to Receive Federal Emergency Management Program Award

NREL researcher Greg Martin is being recognized as part of a team receiving a 2017 Federal Energy and Water Management Project Award for a successful demonstration of the islanding capability of a microgrid at the Marine Corps Air Station Miramar in California. The microgrid combined 250 kW of battery storage and a 230-kW PV system at Miramar’s Public Works building.

"Projects like the Miramar microgrid serve to demonstrate the emergence of new technologies in electricity systems, [and they] show us that the incumbent way of doing things is not the best way," Martin said.

The microgrid technologies were tested at the ESIF under simulated loads to ensure that the demonstration would be successful. An innovative zinc/bromide flow battery with titanium electrodes is the system’s key feature; it is paired with the PV system to offset the entire annual electricity demand of the facility. The islanding project demonstrates the increased capabilities of future microgrid developments, particularly those using renewable energy as their primary power source. Building on the success of this facility at the system level, the team is working to develop an installation-wide microgrid.

Collaboration with EasyMile to Boost Research in Intelligent and Autonomous Electric Vehicles

NREL's research on electric vehicle grid integration at the ESIF examines the interactions among electric vehicles, building energy systems, utility electric grids, and renewable energy sources. In an important step toward furthering intelligent, efficient, and autonomous electric vehicles, transportation researchers at NREL plan to partner on research-and-development efforts with EasyMile, a smart mobility solutions company based in France. The collaboration would explore opportunities for how wireless charging can enable intelligent load management in various grid and campus load scenarios.

ECP Co-Design Center Ramps Up Speed with New Software

Funding from the DOE to prepare scientific applications for exascale computers is helping researchers solve problems more efficiently. Researchers at NREL helped build a new AMReX software framework to support the development of block-structured adaptive mesh refinement algorithms. The latest version of the software solves a benchmark problem a couple orders of magnitude faster than the original.

Learn about this new capability in an HPCwire article.

A Closer Look at NREL's New Bioreactor

In August, this newsletter announced the installation of a new 25-foot-tall bioreactor just north of the ESIF as part of collaboration among NREL, the Southern California Gas Company, and Electrochaea. Hydrogen will be produced from electricity using electrolyzers, and then along with carbon dioxide it will be fed into the bioreactor, where microorganisms will convert the gases to methane, the chief component of natural gas. This is the first-ever U.S. demonstration of this power-to-gas technology, which could provide a large-scale, cost-effective solution to storing excess energy produced from renewable resources by using existing infrastructure for storing and delivering natural gas. See the NREL feature story, including a new video, to take a closer look at this technology: "Undersea Microbes Provide Path to Energy Storage."

Learn more in a recent Greentech Media article.

Q&A with Dick DeBlasio—38 Years of Engineering at NREL

When Dick DeBlasio started at NREL (then the Solar Energy Research Institute) in 1978, it took him a week to ditch his tie and dress shoes. "Having come out of the Air Force and a career in Washington, I was very disciplined," he said.

During his time at NREL, DeBlasio held various senior positions at NREL before retiring as the lab’s chief engineer for renewable electricity and end-use system research and applications. Today, he supports NREL as a research fellow emeritus. Learn more about DeBlasio’s time at NREL, including his role in getting the ESIF built, in this Q&A.

NREL Workshop Convenes Industry Experts on Cybersecurity and an Evolving Grid

On October 9–10, NREL’s Cyber-Physical Systems Security and Resilience Center hosted its second annual workshop at the Denver Marriott West in Golden, Colorado. Attendees hailed from utilities, vendors, and other national laboratories to attend the workshop on best practices for distributed energy resource (DER) security.

Exploring the states of cybersecurity and the electric grid today, a number of common concerns and opportunities were shared throughout the event. Presenters covered topics ranging from the convergence of information technology and operations technology to mitigating the dangers of electromagnetic pulse, security implications of connecting microgrids to the macrogrid, and the research needed to mitigate the challenges that exist in DER security.

Learn more about the workshop.

Video: Cybersecurity & Resilience Research at NREL

Also, check out our latest video on NREL’s cybersecurity and resilience research, featuring the lab’s Cyber-Physical Systems Security and Resilience Center Director Erfan Ibrahim. The video presents Ibrahim’s perspective on the current state of affairs for cybersecurity as it relates to the grid—as well as NREL’s role as a vendor-agnostic resource to help identify cyber vulnerabilities in emerging grid technologies and encourage collaborative work in the field.

NREL Demonstrates and Advances the Benefits of Hydrogen Technology

For decades, advancements in technology and cost reductions have been dramatically changing the potential to use hydrogen in our energy systems and to enhance the future flexibility of the grid. The U.S. Department of Energy (DOE) H2@Scale initiative is exploring the potential for wide-scale hydrogen production and use in the United States. Bringing together the Fuel Cell Technologies Office and 14 national laboratories, including NREL, H2@Scale is looking to expand the focus of hydrogen technologies beyond power generation and transportation, to grid services and industrial processes.

Read the recent R&D Magazine article to learn more about H2@Scale

Partner Week at NREL Explores the Future

Partner Week at NREL explored disruption, an approaching world including net zero energy districts, exascale computing, more efficient photovoltaics, and next-generation wind turbine blades, to name a few. Although the vision was futuristic, the focus was on NREL's current collaboration with more than 700 partners.

Read the full feature story on

NREL Hosts ESIF High Impact Project Review

Representatives from DOE’s Office of Energy Efficiency and Renewable Energy traveled to Golden, Colorado to attend the ESIF High Impact Project Review. The September 21 meeting included research results, status updates, and highlights from the eight designated high impact project for 2017. High Impact Projects are chosen and vetted based on specific criteria, including whether they utilize multiple technologies, address the challenges identified by DOE in the Grid Modernization Multi Year Program Plan, and their potential to impact the electric grid on a national scale. The agenda also included a tour of the newly installed bioreactor, a live demonstration of ESIF’s remote connection capabilities, and discussions with NREL researchers and the partner organizations that attended the event. Hawaiian Electric Companies' Colton Ching commented on the importance of their partnership with NREL saying,  "This work is integral to HECO’s distributed solar and storage adoption. Results of this work are incorporated—in real time—into Hawaiian Electric's PUC filings for its DER tariff."