Energy Systems Integration Newsletter: July 2020

In this edition, NREL's OptGrid software optimizes renewable energy technologies at the grid edge, a power upgrade expands grid integration research, and we're helping power systems industries improve grid resilience and reliability.

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NREL-Developed Software Available for Distributed Energy System Optimization

NREL has developed and licensed a new technology to manage a modern energy system characterized by distributed and renewable energy resources. OptGrid is an engine for the real-time control of distributed assets, and it is equally functional for a city or a community. With OptGrid management, users can optimize grid-edge devices—such as electric vehicles, battery energy storage systems, and solar panels—to achieve increased resilience against outages and more energy-efficient savings.

NREL's Flatirons Campus Receives Power Boost To Expand Grid Integration Research

NREL's Flatirons Campus completed its Power Generation Upgrade Project, which doubled the power, from 10 megawatts to 19.9 megawatts, to boost the site's Integrated Energy Systems at Scale research mission. The project—completed in partnership with Xcel Energy, the U.S. Fish and Wildlife Service, and the Department of Energy's Golden Field Office—increases and enhances research capabilities that allow for studying real-world effects of multiple technologies on an electric grid rather than relying solely on computer simulations. The upgrade also promises to unlock further insights into how the real-time control and optimization of distributed energy resources interact with the larger grid.

Watch this short video to learn more about the improved research capabilities at NREL's Flatirons Campus.

Q&A: Fei Ding

Since beginning her career in NREL's Power Systems Engineering Center in 2015, Electrical Engineering Researcher Fei Ding has co-authored 59 publications on integrating renewable energy into the electric grid.

So far this year, she has published research on grid resilience during extreme weather events and other disruptions, dynamic restoration strategies for distribution strategies, a hierarchical control framework to manage behind-the-meter distributed energy resources for grid regulation, and an evaluation of a distributed energy resource management system through hardware-in-the-loop simulation.

In this Q&A, Ding took some time to talk with us about her work in grid resilience and reliability.

NREL Method Boosts Resolution of Solar and Wind Forecasts with Adversarial Learning

The state of the art in climate forecasting is analogous to a blurry image—the big picture is discernible, but if you zoom into the details, you find that data are missing. In the case of solar and wind resource forecasting, NREL researchers recently achieved a 50-times resolution improvement over past methods: For every original pixel, the NREL team managed to add 2,500 pixels. Their method was described in a publication from the Proceedings of the National Academy of Sciences.

With higher resolution forecasts, policymakers and the renewable energy industry can accurately evaluate renewable resources available at a local scale. The key to the team's success was adversarial training, in which two networks compete at producing more accurate data. High-resolution data from NREL, including the Wind Integration National Dataset (WIND) Toolkit and the National Solar Radiation Database, were used to help train the model. The authors conclude the paper with an application of their method to climate scenario data from the United Nations.

New Research on Distributed Energy Storage System Models Improves Optimization Speed and Scale

New research published in IEEE Transactions on Smart Grid provides model improvements for grid-tied battery systems. A primary challenge of connecting renewable energy resources with the power system is predicting and planning for the variability of wind and solar power. Distributed energy storage systems connected to the electric grid can address forecasting errors from energy fluctuations, yet traditional optimal power flow models are computationally complex and challenging to use.

In this journal article, NREL researchers Kyri Baker (joint faculty at the University of Colorado) and Dane Christensen, along with co-authors, develop and analyze a relaxed convex dynamic energy storage systems model that can generate dependable power flow prediction. This approach simplifies the mathematical formulation for dispatching grid-tied batteries under a wide range of grid conditions, resulting in an approximate 30-times reduction in computation time and cost.

This work is expected to be broadly applicable as distributed energy resources and loads begin to participate in power system operation and markets.

Report Details Standardized Device Models for Advanced Grid

An interlaboratory report has been published that presents models and an evaluation of common distributed energy resources. The three-part report, titled Development and Evaluation of Distributed Energy Resource Device Models, describes the results from three national laboratories—Argonne, NREL, and Oak Ridge—studying models of electric vehicles, electric water heaters, and commercial refrigeration systems, respectively.

In each of the three technology areas, research teams built mathematical models to characterize the physics and operation of the devices. Rather than building custom models for each device class, however, the interlaboratory team demonstrated standardized models that can be easily incorporated into grid planning. The report then considers the experimental results of simulations using the device models.

The research covered in this report is in support of Grid Modernization Laboratory Consortium Project 1.4.2, which focuses on modeling devices in a standardized battery-equivalent format, such that device fleets are generically able to provide grid services and dispatch for the modern electric grid. 

Sakshi Mishra Talks AI Research and Women in STEM on the Society of Women Engineers Diverse Podcast

As a guest on the recent Society of Women Engineers Diverse podcast, NREL's Sakshi Mishra discussed her research in artificial intelligence (AI) and advocacy for women and girls interested in careers in science, technology, engineering, and math (STEM). 

A power systems engineer by education and energy systems researcher by profession, Mishra talked to Society of Women Engineers host Roberta Rincon about using advanced machine learning algorithms for large-scale integration of clean energy resources, behind-the-meter deployment of distributed energy resources on the grid, and AI to generate increased situational awareness and insights for more efficient grid operations.

During the interview, Mishra also discussed gender challenges she faced in pursuing an advanced education in STEM as well as the need for mentorship and outreach from female researchers. "That's what I'm trying to do, inject this message now into the [educational] system, so we see the results in five years." Mishra also had useful advice for frontline engineers who want to transition into research.

Hear more from Sakshi Mishra on the Society of Women Engineers Diverse podcast.

Virtual Registration for Energy Exchange 2020 Is Open

With a global pandemic testing our nation's resilience, energy security, and the ability of federal agencies to execute their missions under adverse conditions, it is more important than ever to provide the energy management community with the right training and resources to succeed. In keeping with social-distancing protocols, the Federal Energy Management Program is holding this year's Energy Exchange virtually August 10–14, 2020.

The comprehensive five-day training and trade show will help agencies ensure that their facility operations and energy management practices are resilient, efficient, and secure. The event will feature 40 training sessions in 6 focus areas where resource planners and managers can earn continuing education units, explore technically validated solutions, and engage with agency leadership and the private sector. The event will also include a virtual technology pavilion and trade show showcasing exhibitors' cutting-edge technologies across the energy and water sectors, and participants will have the opportunity to connect with Federal Energy Management Program staff in the virtual hub.

Join this year's Energy Exchange wherever you are—register today!

NREL Director Shares Vision, Plan for the Future

In a recent blog post, NREL Director Martin Keller outlined NREL's 10-year plan to address some of the most critical global energy challenges. The plan focuses on three key research areas:

  • Integrated energy pathways: examining the future grid and how we can incorporate more renewables, energy storage, smart loads, and other devices working together as a coordinated system

  • Electrons to molecules: exploring the use of renewable, affordable electricity as the driving force for the conversion of low-energy molecules to generate higher value, higher energy chemicals, fuels, and materials

  • Circular economy for energy materials: exploring new concepts, approaches, and understanding for recover and recycle, materials substitution, device and system design, and advanced manufacturing processes.

"NREL's vision lays the foundation for scientific research and technological innovation to shape a highly efficient and resilient energy future," Keller says.

Publication Roundup

Model of Operation-and-Maintenance Costs for Photovoltaic Systems
Because many photovoltaic (PV) plants have been operational for only a short time, significant data are lacking to properly determine the operation and maintenance (O&M) cost of a particular project. This NREL technical report presents a method for calculating costs associated with the O&M of PV systems of different sizes, applications (residential, commercial, or utility), and under different environmental conditions. The PV O&M cost model has the ability to calculate annual O&M costs for better budget planning, examine net present value to help inform life cost decisions, and determine the required reserve amount or line of credit that should be kept to cover timely repairs of unplanned failures. The authors' method was prepared with input from a working group sponsored by the Department of Energy's Solar Energy Technologies Office and is currently available in an online implementation.

NREL Creates Grid Modernization Framework for India Utilities
India is soon expected to integrate substantially more distributed energy resources, such as solar PV, battery energy storage systems, and electric vehicles—a result of government policies supporting cleaner air and reduced emissions. The push for sustainability will put new pressure on utilities, which are not necessarily prepared to face overhauls in planning and operational practices. In a partnership with the U.S. Agency for International Development (USAID) and the Government of India, NREL developed a replicable framework to help utilities accommodate emerging technologies and the potential opportunities they might introduce.

The authors of the framework recently published their method and results in a report titled Preparing Distribution Utilities for Utility-Scale Storage and Electric Vehicles. The report introduces grid-readiness metrics to quantifiably assess the impacts of different integration scenarios. The scenarios were studied for real distribution feeders in India, in close partnership with local utility, BSES Reliance Private Limited, and helped determine realistic infrastructure costs for utilities to accommodate new technologies.

Using NREL's Eagle supercomputer, the authors completed more than 500 hours of simulations and studied representative distribution networks in India's power system at a 10-year time horizon. The results show the impact on grid operations from expanded electric vehicle charging and how battery energy storage systems can help mitigate such impacts. The authors also present economic analyses in terms of cost models for installing battery energy storage systems in India, which will guide policymakers through critical long-term decision-making processes.

Learn more about USAID-NREL work in India and around the world.


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