Energy Systems Integration Newsletter: December 2019

In this edition: Holy Cross Energy Sets Renewable Electricity Example Using NREL Algorithms; Two Workshops Highlight a Unique NREL Capability; Q&A with Senior Research Engineer Julieta Giraldez-Miner; and more!

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NREL Partnership with Holy Cross Energy Sets a National Example for Grid Control

Nearly every major U.S. city has set renewable energy goals that will require converting vast urban centers to using new power systems in 10, 20, or even 50 years.

At NREL, that future is much closer: in-lab simulations have validated how these new energy systems could look. But NREL testing and a city the size of New York are at very different scales, so what works for 100 in-lab devices might not translate to a real system of 100 million devices.

The solution might lie somewhere between the two in the rural town of Basalt, Colorado—population 4,170. Within a neighborhood in Basalt's rugged foothills, NREL is testing one of its most novel grid operation solutions with the members of local electric cooperative Holy Cross Energy.

The partnership's "think big, start small" approach could help other cities adapt the same techniques with even greater reach.

Learn more about how Holy Cross Energy is bringing NREL algorithms out of the lab and into homes.

Workshops Highlight Unique NREL Capability

In November, two workshops demonstrated how NREL’s novel advanced distribution management system (ADMS) test bed can help utilities modernize their distribution system. The project established a national, vendor-neutral test bed to accelerate industry development and adoption of ADMS capabilities for the next decade and beyond. The workshops disseminated results of the project from the past year.

Sponsored by DOE's Office of Electricity's Advanced Grid Research Program and DOE's Solar Energy Technologies Office, the workshop welcomed more than 40 attendees to NREL’s Energy Systems Integration Facility, including electric utilities, ADMS and utility control equipment vendors, and consultants. Participants heard about the latest ADMS research and saw live demonstrations of the test bed.

“The test bed enables utility partners, vendors, and researchers to evaluate existing and future ADMS use cases in a test setting that provides a realistic combination of multiple utility management systems and field equipment” said Murali Baggu, Laboratory Program Manager of Grid Integration at NREL.

By combining a multi-timescale simulation environment with power- and controller-hardware-in-the-loop to simulate a utility distribution system, and an advanced visualization capability, the test bed is helping utilities evaluate the performance of ADMS applications to monitor and coordinate renewable energy assets. With its ability to mirror a utility’s unique circumstances, the test bed can help optimize the value of a specific ADMS application for a more efficient and secure grid.

 “The ADMS test bed will speed industry adoption of ADMS,” said Annabelle Pratt, principal engineer in NREL’s Power Systems Engineering Center. “It allows a utility to evaluate the impact of ADMS applications on their current and future system at lower cost and no risk to customers.”

The workshops presented three case studies, including two joint projects with Xcel Energy and Schneider Electric. The first of these addressed the question of how accurate the data provided to the ADMS needs to be to ensure good voltage management. The second assessed coordinated control of legacy equipment, smart photovoltaic inverters, and high-speed switched capacitors. The third case study, a joint project with Holy Cross Energy and Survalent, is evaluating coordinated operation of ADMS and a prototype distributed energy resource management system for voltage and peak load management.

Watch this video to learn more about NREL’s ADMS test bed.

Providing Innovative Integration Options: Q&A with Julieta Giraldez-Miner

As a senior research engineer in NREL's Power Systems Engineering Center, Julieta Giraldez-Miner assists utilities with managing distributed energy resources. Now in her ninth year at NREL, Giraldez-Miner leads projects on microgrids, smart grids, and grid integration. We sat down with Giraldez-Miner to find out more about her field of study and the opportunities and challenges she is excited to tackle.

Read our Q&A with Julieta Giraldez-Miner.

Happy Holidays — NREL Year in Review

As another year comes to an end, we are looking back at the many achievements across the spectrum of energy-efficiency and renewable energy technologies in 2019. Watch this video for a special holiday message from NREL and check out our top stories of the year.

We look forward to another productive year at NREL and wish you a year of successful endeavors as we continue our efforts to transform energy.

While Vehicles and Buildings Drive Electrification, Control of Technologies Creates Opportunities, NREL Study Finds

The demand for electricity is expected to surge through the next 30 years—at the upper end of estimates, electricity consumption will increase 85% by 2050. This transition is being driven mostly by two sectors: transportation and buildings. A recent NREL report, titled "Potential Impacts of Transportation and Building Electrification on the Grid," finds that optimized control of new technologies as well as integration with renewable resources and storage will help to incorporate more electricity and do so efficiently.

The report, published in Current Sustainable/Renewable Energy Reports, explains electrification in the context of how systems will accommodate the growth in demand. The specific effects of electric vehicles and space heating are reviewed across subject areas such as peak demand changes, voltage regulation, integrated resource planning, and upgrades to distribution systems.

Results of the study suggest that one of the most important opportunities exists in grid controllers, which can have a very large impact on the demand profile of electrification technologies. Those technologies, when not controlled, are the largest contributors to increased peak demand. The study also finds that electrification technologies, renewables, and storage could be used together, especially at the distribution level, because the systems are growing concurrently and are demonstrated to work well together.

Future work is suggested for resource planning, forecasting peak demand, and projecting the growth of electrification to a higher certainty. Read more about NREL's research on electrification.

USAID-NREL Partnership Supports Mini-Grid Deployment in Haiti

In collaboration with the Government of Haiti and via a partnership with the U.S. Agency for International Development (USAID) and the World Bank, NREL assisted with developing a request for proposals for new mini-grid projects in Haiti. The USAID-NREL partnership supported this initiative with trainings and technical assistance to enable private-sector partnerships and accelerate the deployment of advanced energy technologies. USAID and NREL also developed a Renewable Energy (RE) Data Explorer customized for Haiti and the Dominican Republic. The RE Data Explorer is a geospatial analysis tool used to analyze and visualize renewable energy potential and inform prospecting and planning for renewable energy project development.

Visit the USAID-NREL partnership's Haiti project page to learn more about this project and how the USAID-NREL partnership is assisting with sustainable economic growth in Haiti.

NREL Publication Offers Guidance for DER Security, Setting the Path Toward New Standards

For every new solar inverter, electric vehicle charger, energy storage system, or any other network-connected energy device, a top priority is mitigating cyber vulnerabilities in the form of data exchange, communications, and controls. NREL researchers are targeting such vulnerabilities to improve the cybersecurity of distributed energy resources (DERs), and a recent publication has summarized the functionalities that industry can adopt to secure the grid's many new devices.

The paper, titled "Recommended Functionalities for Improving Cybersecurity of Distributed Energy Resources," contains recommendations that came out of working groups that convened on the topic of DER security. The first section reviews the new expectations of a modern distribution system—high integration of renewables, unpredictable load patterns, bidirectional power flow, etc.—and follows with specific DER functionalities that can have a cyber-physical impact.

DER functionalities are drawn from the current standard for DER interconnection and interoperability, IEEE 1547-2018. Specific suggestions from the paper concern power modes of devices and how those power modes could be manipulated. This is followed by a discussion of how malicious actors could target such modes and which best practices industry can adopt for security.

This publication was presented at the Resilience Week Conference 2019 in San Antonio, Texas. Research into DER security is expected to influence future drafts of interconnection standards, which currently lack cybersecurity recommendations.

Learn more about NREL's research in DER cybersecurity.

NREL Secures 21 Awards to for Further CSP and PV Research

On November 6, 2019, DOE's Solar Energy Technologies Office awarded $128 million to 75 new projects that will advance solar technologies in five major areas. NREL was awarded a major portion of this funding: the projected value of all the projects in which NREL is involved totals nearly $20 million. Each innovative project will strive to improve the growing solar market in five areas: photovoltaics (PV), concentrating solar power (CSP), balance-of-systems soft cost reduction, innovations in manufacturing, and advanced solar power system integration technologies. The funding from these 21 awards NREL is participating in will enable NREL to continue to push the limits of solar technology research.

Publications Roundup—Grid Control, Hybrid Power Plants, and Energy Security

"Online Stochastic Optimization of Networked Distributed Energy Resources"
Recent publications have developed the theory behind distributed control and optimization of energy systems. But these studies have mostly overlooked an implication of distributed control: that network operators do not necessarily have access to devices to control and that devices are customer-owned and their control by network operators first needs to be properly incentivized. This paper, published in IEEE Transactions on Automatic Control, optimizes economic and operational objectives for customers and utilities while ensuring that the voltages are within prescribed limits. The method presented loops customers into the grid control space, a first for dynamic grid control algorithms. This paper also breaks new ground in how discrete variables are represented in the optimization.

"Validating Performance Models for Hybrid Power Plant Control Assessment"
This work concerns hybrid power plants (HPPs) that variously combine sources such as photovoltaic (PV) plants, battery energy storage systems, and wind turbine generators. Controls for HPPs require simplified models that can minimize the complexity and computation of simulating such systems. This paper, published in a special issue of Energies, presents such models and validates them through field measurements taken from PV and wind generation as well as battery energy storage at NREL's Flatirons Campus. Results indicate that the model is successful in estimating power generation variability from fluctuations in wind speed and solar irradiance and that the proposed models are useful for HPP control design in all model-based design stages.

"Renewable Energy to Support Energy Security"
This quick read, published as part of the U.S. Agency for International Development-NREL partnership, gives an overview of the support that renewable energy systems can provide for power system security. It summarizes the variety of threats facing energy systems and offers guidance on approaches to overcome such threats. In its conclusion, this quick read also introduces the Resilient Energy Platform, which provides a set of global resources for nations that are planning and developing resilient systems.


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