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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.

March 2017

Read the latest ESI news from NREL.

Photo of the iUNIT, a LEED Silver, 380 sq ft volume metric modular apartment unit being tested at scale in the ESIF at NREL.

iUnit Brings 380-Square-Foot Modular Apartment to the ESIF to Evaluate Advanced, Multifamily Construction

Roughly 38 million people in the United States live in buildings that contain five or more units, totaling almost 18.5 million households. Increasing energy efficiency in America's multifamily apartment buildings, however, faces a number of challenges. Such challenges are largely due to immediate bottom-line approaches for multifamily construction, limitations to large photovoltaic (PV) systems, and a lack of access to data for residents, appraisers, and investors.

Recognizing this, Denver developer iUnit is working with NREL researchers at the Energy Systems Integration Facility (ESIF) to employ the lab's apartment-in-the-loop research capabilities and energy modeling tools for enhanced energy efficiency while creating a modular apartment technology development platform for construction. The team aims to understand how a reduction in apartment-scale energy loads combined with energy storage can be scaled up to whole-building energy management. Researchers are also investigating energy storage opportunities that may be available to optimize PV integration at a whole-building scale.

Modular construction is considerably faster than building from the ground up because developers and contractors can assemble fully furnished units and ship them to the site, ready to install. Such processes can significantly cut time for construction, enabling a faster return on investment for property owners and making energy and cost savings data more readily available through deployment. Additionally, efficiency strategies can be more carefully installed where such expertise is concentrated. With an increasing demand for urban areas to accommodate growth in U.S. cities, modular apartment factories across the country may also benefit by revitalizing a niche manufacturing base and recruiting skilled workers for advanced, net zero, multifamily construction.

Startup Company Draws on Support from Incubator to Test its Inverter at the ESIF

Go Electric—a startup company developing an uninterruptible power supply that instantly synchs to the grid—has started testing its device in the Energy Systems Integration Facility's (ESIF's) Energy Storage Laboratory. Go Electric's technology, called LYNC DR, integrates patented microgrid power transfer technology with battery energy storage and Open Automated Demand Response communication capability to provide continuous power and automatic demand response functionality to a commercial building. The device is built around a synchronous inverter and a lithium-ion battery and is able to switch between the two sources without interrupting power to its loads. Renewable energy systems can also be integrated into the system.

The company is receiving support from NREL as part of its participation in the Wells Fargo Innovation Incubator (IN2) program. IN2 is a nine-year, $30 million program designed to facilitate early-stage technologies that provide scalable solutions to reduce the energy impact of commercial buildings. IN2 is funded by the Wells Fargo Foundation and co-administered by NREL. Awardees such as Go Electric receive up to $250,000 in technical assistance and project-related support from NREL. In addition to receiving funding, they have access to NREL's world-class facilities, such as the ESIF, and they spend a period of time testing, validating, and incubating their technologies at NREL to help them meet key validation milestones on their path to commercialization.

The inclusion of the battery system will allow the LYNC DR to intentionally disconnect from the grid and rely on battery power during times when the utility grid is under stress. As part of its support from IN2, NREL researchers, in collaboration with Go Electric, will evaluate this functional capability as well as demand response functionality and other value propositions of the technology. The testing should conclude by midsummer.

NREL Assists Hawaiian Electric Companies with Key Standards Document, Boosting Deployment of Grid-Supportive Inverters

NREL helped Hawaiian Electric Companies (HECO) develop a Source Requirements Document (SRD)—a key technical standards document for Underwriters Laboratories 1741—that will allow photovoltaic (PV) inverter manufacturers to move toward certifying "grid-supportive" inverters by September 7, 2017. HECO will be requiring that inverters connected to their electric distribution system be certified to a new standard that tests grid support functions of inverters, including fixed power factor, voltage ride-through, frequency ride-through, ramp-rate control, soft-start reconnection, and voltage-watt control. A select set of inverters were recently modeled and evaluated at NREL for these advanced functionalities.

"Building the critical mass of 'grid-supportive' inverters will enable the Hawaiian Electric Companies to meet its goal to double the amount of rooftop solar PV in the next 5 years," said HECO Technology Implementation Director Earle Ifuku.

NREL engineer Andy Hoke worked with HECO and the Smart Inverter Technical Working Group, HECO's forum of inverter industry stakeholders, to develop the SRD document with the goal to harmonize requirements with the ongoing revision of IEEE Standard 1547. The IEEE standard, which Hoke and others at NREL and throughout the country are helping to develop, is in draft form and will soon define new rules for the use of distributed energy resources such as PV rooftop systems. Such advancements in standardization requirements for grid-supportive inverters will enable greater deployment of renewable energy resources for HECO as well as other markets throughout the United States.

NREL Researchers Lend Their DER Integration Expertise to IEEE Power & Energy Magazine's March/April Issue

The worldwide growth of distributed energy resources (DERs) shows no signs of slowing down. And that's got everyone asking: how do you minimize the challenges and take advantage of the opportunities of more distributed energy on the grid? The March/April issue of IEEE Power & Energy Magazine features new ideas and solutions as well as case studies and lessons learned from those on the front lines. NREL's Barry Mather served as guest editor for this issue.

Don't miss these articles by NREL staff:

Change in Brooklyn and Queens: How New York's Reforming the Energy Vision Program and Con Edison Are Reshaping Electric Distribution Planning, by Michael Coddington, Damian Sciano, and Jason Fuller

Achieving a 100% Renewable Grid: Operating Electric Power Systems with Extremely High Levels of Variable Renewable Energy, by Benjamin Kroposki, Brian Johnson, Yingchen Zhang, Vahan Gevorgian, Paul Denholm, Bri-Mathias Hodge, and Bryan Hannegan

Read the whole issue here.

NREL Contributes to NERC Report on Maintaining Grid Reliability with High Penetrations of DER

With an ever-increasing number of photovoltaic systems interconnecting to distribution systems and potentially impacting the reliability of bulk power systems, the North American Electric Reliability Corporation (NERC) initiated the Distributed Energy Resource (DER) Task Force (DERTF) in 2016 to consider such impacts and plan a path forward for the continued reliable and resilient operation of the electric grid. The DERTF consisted of a wide cross section of power system experts, including participation by NREL's DER interconnection and modeling experts. NREL contributed details on the bulk system impacts of DERs with funding from the U.S. Department of Energy's Grid Modernization Laboratory Consortium.

The DERTF has recently released its report, which outlines the potential impact of DERs on the bulk system, provides recommendations for modeling guidelines for the treatment of DERs in bulk system dynamic studies, and examines which existing NERC standards may need to be revised as DERs comprise a larger share of overall generation in the future.

NERC's board of directors has already recommended further work along the lines of that in the DERTF's report, such as providing guidelines for improving existing modeling practices for DERs in bulk-system dynamic studies, providing better accounting of DERs currently not visible to bulk system operators, and further coordinating bulk system requirements with existing and developing DER standards such as IEEE P1547. NREL's work, in collaboration with other industry experts represented in the DERTF, will ensure that DERs can continue to be integrated at increasingly higher levels while maintaining, or improving, bulk system reliability.

Webcast: Using Machine Learning & Mathematics for Advanced Cyber Threat Detection

Join our next Smart Grid Educational Series webinar titled “An Industrial Immune System: Using Machine Learning for Next-Generation ICS Security” on April 7, 2017 at 10 a.m. MDT. The session, led by Jeffrey S. Cornelius of Industrial Control and Critical Infrastructure Solutions, will address how new machine learning and mathematics are automating advanced threat detection—and why some of the world’s leading energy and manufacturing companies are using these technologies to detect early indicators of cyber-attacks or vulnerabilities.

Register to attend.

NREL Receives EPRI's Interoperability Leadership Award for Work on Smart Devices

NREL, Austin Energy, Southern Company, and the Tennessee Valley Authority were recognized by the Electric Power Research Institute (EPRI) in February 2017 for their work on products and standards that enable power systems and customer devices to share and use information. NREL received the award for work it conducted with EPRI to demonstrate the grid benefits of connected consumer devices. The joint project showed how electrical devices commonly found in the home—such as water heaters, pool pumps, and thermostats—could be collectively used to regulate power levels on the grid. By using open-standard communications, different types of devices can communicate with each other and grid operators while minimizing customer inconvenience.

EPRI's Interoperability Leadership Award is awarded annually to companies and organizations that develop and deploy technologies that improve grid interoperability.

Baggu Shines at India Smart Grid Forum

Attendees at the India Smart Grid Forum—held in New Delhi, India, on March 7–10—had plenty of opportunities to gain insights from NREL's Murali Baggu. On Tuesday, March 7, Baggu contributed to two tutorials: "Leading Transformation with Smart Energy: A 360° Perspective on Energy Efficiency, DER (Distributed Energy Resources), and Transactive Energy" and "Power System Flexibility: Demand Response, Energy Storage, and Microgrids; Innovative Business Models & Benefits." On Thursday, March 9, Baggu was one of four people representing the United States in a panel discussion on the "State of Smart Grid Technology—U.S. and Indian." He capped off the week on Friday with a keynote address for a session on "RE (Renewable Energy) Integration, Energy Storage, & Microgrids."

Chad Blake Named as ESI Research Operations Director

NREL announced the selection of Chad Blake as its new Energy Systems Integration (ESI) Research Operations Director, effective March 1, 2017. In this new and expanded role, Blake joins NREL's ESI leadership team to provide strategic vision and lead the execution of the science and technology operations for the Energy Systems Integration Facility (ESIF) while supporting the safe, efficient, and effective conduct of research in grid modernization and ESI.

Since joining NREL in 2007, Blake has worked in the ESIF as a senior research project leader, and he has served as the ESIF operations manager since 2012. His selection as ESI research operations director is based on his deep understanding of the ESIF, his technical and operational experience, and his forward-thinking vision for the ESIF's next phase of growth.

Get an Update on the ESIF in its 2016 Annual Report

Want a sense of everything that went on in NREL's Energy Systems Integration Facility (ESIF) last year? Modernizing Our Grid and Energy System: ESIF 2016 contains highlights of major projects, information on ESIF partners and ongoing research projects, and a list of the inventions and publications coming out of the facility. If you're interested in using the ESIF's capabilities as a user facility, be sure to check out the user facility updates on page 59. Download the report from

Register for DOE's Grid Modernization Initiative Peer Review

The U.S. Department of Energy will hold a peer review of their Grid Modernization Initiative projects on April 18–20, 2017, in Arlington, Virginia. More than 80 projects among 13 programs will be reviewed, including many that NREL researchers are leading. The event is open to the public and a great opportunity to learn about the current state of technology and network with peers. Register to attend.

NREL's Work in Grid Modernization Is Pushing Boundaries

Safely integrating clean, reliable, affordable energy into the electric grid at a pace and scale that matters is what we're working on at the Energy Systems Integration Facility. From leading efforts to revise interconnection standards, to inventing new technologies, to solving real-world challenges in partnership with industry, we're engaged in pioneering research that is transforming our energy system.

Now you can find the latest grid modernization projects we are working on all in one place. Visit for project descriptions as well as wind, solar, and renewable resource data sets and modeling tools.

NREL Releases First-of-its-Kind Report Demonstrating Utility-Scale PV Can Contribute to System-Wide Reliability

NREL released "Demonstration of Essential Reliability Services by a 300-MW Solar Photovoltaic Power Plant," which details research NREL performed in collaboration with California Independent System Operator and First Solar.

The project team developed a pioneering demonstration concept and test plan to show how various active and reactive power controls can increase the value of photovoltaic (PV) generation by taking it from being a simple variable energy resource to a resource that provides a wide range of ancillary services, including:

  • Plant participation in automatic generation control (AGC)
  • Primary frequency control
  • Active power ramp-rate control
  • Voltage regulation and reactive power control.

For AGC participation in particular, test results showed that regulation accuracy by the PV plant was 24–30 points better than fast gas turbine technologies.

To learn more about this project, register for a webinar hosted by the research team on April 27.