Energy Systems Integration Newsletter: April 2020

In this edition, a new video shows how NREL and Anterix are providing relief for utility operations and communications congestion, an NREL test bed is helping stakeholders maximize the value of residential battery systems, researchers aim to put a value on energy resilience, and more.

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Only at the ESIF: Video Shows NREL-Anterix Collaboration for Critical Communications

Wireless networks are a busy space—so busy that they risk crowding out important communications and control of energy devices across distribution systems. To ensure that the most critical grid communications also have the highest priority, NREL and industry partner Anterix have validated fast control over a 900-MHz private LTE network. For utilities managing major growth in distributed energy resources, the results of the NREL-Anterix partnership show promise for some relief for utility operations and for communications congestion.

Automated Test Bed Offers Remote Access To Help Battery Stakeholders Make Sense of Residential Systems

For an industry that is expected to empower renewable energy and grid stability, battery energy storage systems are not yet operating at full capacity. Following a research partnership on residential battery systems, an NREL team identified an opportunity to connect stakeholder priorities and maximize the value of battery systems. The result is NREL's new residential battery test best—an automated, fully remote research space for any stakeholder. Read more about the energy storage capability at the Energy Systems Integration Facility.

Nature Energy Article Sets Reference for Valuing Resilience

How much would you pay for power during an outage? An extra $20 per day? Would you pay more to ensure that your community stays powered? That premium for resilient power is the subject of "When the Lights Go Out," a recent Nature Energy news article written by NREL Research Manager Kate Anderson.

In the article, Anderson summarizes a 2020 study that asks hundreds of customers to value access to power during an outage, specifically a 10-day winter outage. The authors take a direct approach to the question of how to quantify resilience—there is broad value to introducing resilient infrastructure, but how do customers see that value?

Anderson reports that commercial and industrial customers tend to place a higher value on resilience than residential customers. Residential respondents in the study indicated that they are willing to pay U.S. $1.70 to U.S. $2.30 per kilowatt hour, or U.S. $43–$52 per day, and U.S. $19–$29 per day to support their communities.

The study highlighted by Anderson sets a reference dollar value for measuring resilience. Anderson emphasizes, however, that the willingness of customers to pay involves deeper decision making—how long the outage is, where the outage is located, and the knowledge the customer has about the outage impact. These are topics that Anderson suggests for follow-on studies.

Story in WIRED Reviews Real-World Application of NREL Algorithms for Grid Automation

A recent article in WIRED highlights how NREL's real-time optimal power flow algorithms are being used to help a small community in Basalt, Colorado, transition to a self-optimizing, zero energy neighborhood.

Developed under funding from the Department of Energy (DOE) Advanced Research Projects Agency-Energy, NREL created the algorithms to "optimize electricity distribution both at the level of individual homes and at the level of the entire grid," according to NREL Senior Scientist Andrey Bernstein, who was interviewed by WIRED.

NREL then partnered with Holy Cross Energy to help the utility apply NREL's algorithms to homes in the Basalt Vista community, where they are used to manage distributed energy resources and allow them to function autonomously.

Until recently, the algorithms had been tested only in an NREL lab, where they were successfully demonstrated on more than 100 real devices. Deploying the algorithms in Basalt Vista has helped prove that they can also function in a real-world scenario. More specifically, WIRED reports that NREL's real-time optimal power flow algorithms have "helped utilities and their customers save money, increase the amount of renewable energy systems on the grid, and bolster the resiliency of local power networks."

Read the full article "The Power Plant of the Future Is Right in Your Home" on WIRED.

Learn more about NREL's real-time optimal power algorithms.

Q&A with Jerry Davis: Local Microgrids for the U.S. Military, Cutting-Edge Research, and Ultramarathons

Jerry Davis works with the U.S. Department of Defense to develop renewable energy technologies for military operations and installations. A graduate of the U.S. Naval Academy, Davis joined NREL in 2010, where he is a laboratory program manager in NREL's Innovation, Partnering, and Outreach directorate. Davis sat down with us to talk about his work on bringing advanced microgrid technologies and cybersecurity measures to support the Department of Defense and mission readiness.

Check out our Q&A with Davis.

Earth Day 2020: NREL Articles Celebrate History and Buildings Research

To celebrate the 50th anniversary of Earth Day, two NREL articles highlight our close ties to the event and research that is exemplary of our commitment to environmental stewardship.

The first article features NREL's close history with Earth Day. NREL's second laboratory director, Denis Hayes, was instrumental in the creation of the inaugural event in 1970, closely coordinating the event with founder and U.S. Senator Gaylord Nelson from Wisconsin. Hayes also founded the Earth Day Network, whose mission is to build the world's largest environmental movement to drive transformative change for people and the planet. The article details the evolution of the event and the celebrations around the 50th anniversary, which included a DOE-hosted haiku contest and celebratory video.

The second article takes a look at how NREL has applied its buildings research to its South Table Mountain Campus, where NREL showed the world that zero energy at scale was possible and that energy use reduction and energy-efficiency technologies had a prominent place in the design and construction of buildings.

"Earth Day is about looking at how we use energy and how we can increase sustainability by reducing our negative impact on Earth," said Roderick Jackson, laboratory program manager of Buildings Research. "Our goal is a clean energy future."

Letting Solar Speak with Hybrid Designs for Communications

Although our current power system is not necessarily prepared for the immense growth in communications from grid-edge devices, NREL researchers are looking at how to make the most with what we have.

A recent NREL report titled Opportunistic Hybrid Communications Systems for Distributed PV Coordination presents three years of research demonstrating how the efficient use of in-place communications infrastructure—including power line communications, low-power wireless, and standard Ethernet cabling—can improve the speed and spread of grid-edge communications.

The team's research, funded by the DOE Solar Energy Technologies Office, shows how utilities and grid system operators can reduce the computational and security-related challenges of managing millions of devices—instead of expensive infrastructure buildouts, the team introduces an approach for estimating grid conditions at any scale, in real time.

Three objectives guided the team's research effort:

  1. Create a "hybrid" communications system that takes advantage of various communications infrastructures
  2. Use the hybrid communications to estimate the grid's state
  3. Validate both in the laboratory.

For the final objective, the team simulated hybrid communications and state estimation in the Energy Systems Integration Facility by connecting real photovoltaics (PV) in-the-loop within a Hierarchical Engine for Large-scale Infrastructure Co-Simulation (HELICS) co-simulation environment. Results from the validation allowed the team to compare the relative trade-offs in reliability of different network designs and the functionality of the team's distributed approach to estimating the state of the grid.

Among other findings of the study, the team invented solutions for optimally placing data aggregators for distribution system communications, a distributed and adaptive architecture for defense against cybersecurity, and algorithms for distributed state estimation at multiple scales.

Future work is imagined for testing the cyber defenses of the proposed communications architecture and for more widely validating the state estimation and distributed control created in this study. In particular, lessons learned from this research are being incorporated into the recently started Situational Awareness of Grid Anomalies project.

Learn more about dynamic measurement and state estimation at the grid edge.

NREL Engineer Rachel Romero Announced as One of the 20 To Watch: Women in HVAC by Engineered Systems

NREL Engineer Rachel Romero was recently named as one of the winners in Engineered Systems magazine's second annual "20 To Watch: Women in HVAC" competition. The contest, designed to honor the women of engineering, received more than 100 nominations.

In her profile for the award, Romero discussed the day-to-day of her job, her history in engineering, and the unique challenges that women face in the industry. She mentioned being recognized by ASHRAE with a distinguished service award in 2019 as the proudest moment in her career.

"The organization recognized my hard work of encouraging young engineers to stay in an aging industry," Romero said.

Romero also leads the DOE Solar Decathlon Design Challenge in which teams of students compete to design zero energy-ready buildings.

Revised IEEE 1547 Standard To Integrate DERs with the Grid: NREL's Clause-by-Clause Technical Report

The Institute of Electrical and Electronics Engineers (IEEE) has revised its foundational 1547 standard to help operators of distributed energy resources (DERs) and utilities to effectively integrate these systems, such as solar photovoltaics and energy storage, into the grid. The revised standard, IEEE 1547-2018, has been updated significantly since it was first developed in 2003 and now enables the use of modern DER devices to support the distribution and transmission system under normal and abnormal grid conditions. NREL researchers published a technical report summarizing these updates in Clause-by-Clause Summary of Requirements in IEEE Standard 1547-2018.

NREL principal engineer and lead author of the report David Narang is also the working group chair of the IEEE 1547 Revision Working Group. The technical report summarizes the 11 chapters, or clauses, specifying the details and requirements that apply to different aspects of DERs as they connect with the electric power system. Researchers also identify key stakeholders and their various roles, which include utilities; solar and other DER developers, integrators, and installers; and state regulators and policymakers.

This clause-by-clause summary of the standard is one of several educational resources that will be featured on an NREL website dedicated to providing readings, presentations, and other educational materials on the revised DER interconnection requirements. This effort is part of a project funded by the DOE Solar Energy Technologies Office. The new website will be available in May.

Publications Roundup

Unsupervised Clustering-Based Short-Term Solar Forecasting

Predicting the weather to optimize solar PV performance is always challenging for grid operators; however, a new forecasting method shows a 20% increase in reliably predicting changing weather conditions compared to other models. In a new article published in IEEE Transactions on Sustainable Energy, researchers developed the Optimized Cross-Validated ClUsteRing (OCCUR) method, which integrates solar data clustering, pattern recognition, and machine-learning capabilities to measure the sun's energy on horizontal surfaces, taking moving clouds and weather into account. Because OCCUR can make predictions just one hour ahead of current weather conditions, this method has significantly improved forecasting accuracy, which can help grid operators plan for PV penetrations more effectively and increase the grid's reliability.

Iquitos Solar Energy Integration Study

Could a remote power system in the Amazon Rainforest incorporate solar PV resources to decrease its energy costs? Iquitos, Peru, has an islanded electric grid and high energy costs because of its isolated location in northeastern Peru and because of its use of heavy fuel oil delivered by ships on the Amazon River. An NREL technical report demonstrates that integrating PV into Iquitos's energy system would not only be feasible but also could reduce fuel generation costs by $2.1 million annually. Researchers found that a PV panel located in this part of the Amazon Rainforest would have an average capacity factor of 16% and that up to 15 MW of PV capacity could be safely generated with instantaneous, systemwide PV penetration of 30%. Researchers also showed how PV penetration at various levels would offset heavy fuel oil generation and benefit the economy according to the number of solar panels installed.

Optimal Placement of Data Concentrators for Expansion of the Smart Grid Communications Network

As distributed solar PV increasingly support the grid, advanced metering infrastructure (AMI) for these resources is a critical communications component for utility operators to monitor and control power flow reliably and efficiently. To avoid information congestion along these networks that can cause connectivity bottlenecks and islanding, communication hardware should be optimally placed within AMI networks, which will help ensure a reliable connection between smart meters and electrical control centers.

An article in the IET Smart Grid journal proposes three different approaches for placing communication hardware, or data concentrators, within AMI networks. Researchers conclude that two of these models provide useful solutions for optimal placement, minimize residual buffer capacity, and can address resilience concerns as PV and utility integrations continue to expand.


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