Energy Systems Integration Newsletter: August 2019

Designing a Decentralized Power System; NREL, Eaton partner on Fleet Optimization; NREL Director Martin Keller Speaks at ARPA-E Innovation Summit.

From the Bottom Up: Designing a Decentralized Power System

A far-reaching vision for the future of the electric grid is emerging at NREL.

In the past few years, this vision has grown from a theory on whiteboards to real-power experiments on lab hardware.

It's called "Autonomous Energy Grids" (AEG), an effort to ensure the grid of the future can manage a growing base of intelligent energy devices, variable renewable energy, and advanced controls.

"The future grid will be much more distributed and too complex to control with today's techniques and technologies," said Benjamin Kroposki, director of NREL's Power Systems Engineering Center. "We need a path to get there—to reach the potential of all these new technologies integrating into the power system."

The AEG effort envisions a self-driving power system—a very "aware" network of technologies and distributed controls that work together to efficiently match bi-directional energy supply to energy demand. This is a hard pivot from today's system, in which centralized control is used to manage one-way electricity flows to consumers along power lines that spoke out from central generators.

Instead, AEGs are composed within one another, like a fractalized group of microgrids. Sections, or "cells" of AEG use pervasive communication and controllability to continually pursue their best operating conditions, which adjust to the temperament of customer demand, available generation, and pricing.

Read more about NREL's work in AEGs in this NREL Headlines article.

NREL and Eaton Tap Industry to Optimize Electric Vehicle Fleets

Electric vehicles (EV) are speeding toward the market, but big questions remain about how to optimally incorporate EV fleets. NREL and Eaton are drawing on industry input to understand the economics and energy dynamics of fleets, which will soon be used in sectors such as shipping.

The partnership between Eaton and NREL, which includes a staff-sharing between the organizations, is taking on an extensive analysis of EV fleets, which spans work from equipment testing to cost optimization studies. Their findings will be crucial to an expanding group of fleet stakeholders.

"Our stakeholder advisors include original equipment manufacturers, fleet operators like UPS, Amazon, and Walmart, utility companies from around the country, and also vendors like Eaton," said Santosh Veda, the project's PI and group manager at NREL. "Working with Eaton helps because it's a touchstone to what's happening in the industry."

NREL's Energy Systems Integration Facility (ESIF) is a unique meeting ground for the study—real-power hardware, cyber-physical testing, and in-house techno-economic modeling tools allow partners to understand all angles of the upcoming EV transition. Importantly, NREL and Eaton will learn how these new technologies can be co-optimized with other devices arriving on the grid.

Learn more about NREL and Eaton's fleet optimization studies.

NREL Director Keller Speaks at ARPA-E Innovation Summit

NREL Director Dr. Martin Keller was featured in a panel at the 2019 ARPA-E Innovation Summit in July discussing collaborative energy innovation. Keller highlighted several areas of innovation at NREL, including NREL's work in grid modernization and control, autonomous energy grids, and cybersecurity. He emphasized the need to develop early stage research for the future grid and the importance of collaboration with industry and utilities to scale renewable technologies, especially as the grid changes at an accelerated pace.

"To speed up and work on the problems, I think we have to form a tighter bond between the early stage research and the companies that are starting to scale it and deploy it," said Keller. "Our scientists learn much earlier to see what are the exact problems which we can work on to make an impact for our country."

A video of the full panel discussion is available on the ARPA-E YouTube channel.

Virtual Tools Developed at NREL Create Real-World Savings

Researchers at NREL are working to shorten the path to commercialization and increase overall adoption of renewable energy and energy-efficiency technologies. This is why NREL is creating useful software applications designed to help and highlight potential costs and savings, such as REopt Lite, ResStock, and PRECISE (Preconfiguring and Controlling Inverter Set Points).

REopt Lite takes NREL's internal REopt software to the public, offering a free way for consumers to analyze the cost-effectiveness of deploying renewable generation on commercial properties. It's as simple as entering an address, selecting the utility rate from a drop-down menu, and choosing the type of building. REopt Lite then provides a recommended system size and dispatch strategy to minimize the cost of energy.

While REopt Lite is for commercial properties, ResStock is designed to provide the same information for entire neighborhoods or communities. The tool also scales to states, utilities, regions, and even the entire country.

PRECISE gives utilities greater control over residential inverters, allowing them to maximize the cost-effective use of the panels. Utilities can also identify the best and safest operating conditions for new solar energy systems before they are deployed.

Learn more about these cost-saving tools in this NREL Headlines article.

Exploring Tomorrow's Energy Solutions, Together – NREL's Annual Partner Forum

On August 12-13, 2019, 200 participants from the private sector, government entities, academia, and more gathered at NREL's South Table Mountain Campus in Golden, Colorado for NREL's 2019 Partner Forum. These entities with diverse backgrounds came together to address the very real energy-related challenges they face in the years and decades ahead.

"When we look at the problems we have, our science is good … that's the first step," NREL Director Keller said from the stage while discussing, with ExxonMobil Vice President of Research and Development Vijay Swarup, the organizations' new $100 million partnership. "But how do we shorten the time to get ideas to the market to make an impact? We team up at an early stage with partners to accelerate time to market."

Speakers covered a variety of challenges, including coordinating efforts, meeting renewable energy targets, security and resiliency, storage, electrons to molecules, and scale. While there are plenty more challenges to face in the future, President of Xcel Energy Colorado Alice Jackson stressed the importance of industry, government, and academia working together.

"The answer is not in this room yet," Jackson said. "The thing that's going to solve all this is probably stuck in some middle schooler's head."

For more about the NREL Partner Forum and approaches to solving the energy challenges of tomorrow, read this article from NREL Headlines.

NREL, Commonwealth Edison Collaborate on Evaluating Highly Efficient Technologies for Building Energy Savings

A recent partnership between NREL and midwestern utility company Commonwealth Edison (ComEd) aims to reduce energy consumption by more than 20% in the Illinois area by promoting more energy-efficient technologies for buildings.

While the first few approved technologies have already begun evaluations, ComEd and NREL will evaluate other technologies at the ESIF. Space at the ESIF has recently been enhanced to fast-track scalable solutions with energy use, generation, storage among buildings, vehicles, and the larger electric grid.

"We plan to leverage the ESIF's unique capability as a flight simulator for commercial buildings to evaluate energy savings for ComEd and grid services for DOE," said NREL researcher Grant Wheeler. "This type of collaboration is a great step for the renovated space as it illustrates to other utilities and DOE how to use this new capability to answer their urgent needs."

A recent NREL Headlines article has more on the partnership between NREL and ComEd.

Commissioning of Bioreactor System Signals Storage Opportunity with Power-to-Gas

This past month, NREL and its partners celebrated the commissioning of the United States' first scalable biomethanation reactor system at NREL. The event, coincident with NREL's annual Partner Forum, highlighted the partnership between NREL, Southern California Gas Company (SoCalGas), and Electrochaea to convert excess renewable energy into pipeline quality methane.

"With SoCalGas and NREL demonstrating the scalability of this technology we can soon realize safe and reliable storage of renewable energy well beyond the capacity of batteries," said Mich Hein, CEO of Electrochaea. "A simultaneous benefit will be lowering the overall carbon intensity of the natural gas grid, as we have already accomplished with parts of the electrical power grid."

The natural gas pipeline infrastructure can store excess renewable energy for use months later; it could be critical to smoothing the intermittency of variable renewables such as wind and solar.

With the reactor in place and research underway, the next steps for the partnership will focus on improving the power-to-gas process. Researchers will improve the efficiency of the process, identify locations where grid-scale energy storage would be most beneficial, and study how to reduce capital costs and automate plant operations.

Read this NREL Headlines article for more on the ceremony and NREL's partnership with SoCalGas and Electrochaea.

NREL Releases First-of-its-Kind Certification Procedure for Distributed Energy Resource Security

In collaboration with members of the SunSpec Alliance Working Group for Distributed Energy Resource (DER) Cybersecurity, NREL recently published a first-of-its-kind report that outlines a certification procedure for DER cybersecurity. The report, Certification Procedures for Data and Communications Security of Distributed Energy Resources, details 11 test cases that can be used to verify authentication, authorization, confidentiality, and data integrity for data and communications for DERs.

Since April 2016, NREL has been working with the National Electrical Manufacturers Association (NEMA) to develop a secure Internet of Things protocol that can be applied to DER systems. With the growing need to securely integrate DER assets as they are interconnected with the electric grid, NEMA sought NREL's expertise to help demonstrate security specifications for the DER portion of the International Electrotechnical Commission (IEC) standard 61850, specifically for substation automation. With continued support from NEMA and DOE's Solar Energy Technologies Office, NREL proposed a series of certification procedures that would allow vendors of different DER technology standards to ensure consistent security specifications.

The certification procedures outlined in the report are designed to prevent DERs from common cyberattack and vulnerabilities, such as eavesdropping, spoofing through security certificates, replay attacks, and man-in-the-middle attacks. The test cases are applicable to all communications flowing from DERs to the grid over Transmission Control Protocol/Internet Protocol networks, and aim to help vendors, utilities, certification laboratories, and government organizations improve the health of their cybersecurity.

NREL Study Shows that Hydrogen is Cost Competitive

Hydrogen energy systems are no longer a technology of the future, says a recent paper published in Joule. The NREL authors behind the study revealed that costs to implement a hydrogen-based system can be cost-competitive with gasoline in the U.S. and could be driven lower if more dynamic tariffs are used.

The authors studied more than 7,000 industrial and commercial U.S. retail electric utility rates. By dynamically simulating electrolyzer operations under the different rate structures, the authors found that electrolysis units can already provide cost-competitive fuel in 20 states operating under 81 retail electricity rates.

This research demonstrates a lower cost to implement hydrogen-based systems than what previous studies have reported. As a flexible energy carrier, hydrogen could help accommodate high shares of wind and solar energy, and integrate disparate energy sectors such as electricity and transportation. Learn more about hydrogen energy research at NREL.

Three Pubs in ESI: Real-time grid operation and validating new PV designs

Generalized Graph Laplacian Based Anomaly Detection for Spatiotemporal MicroPMU Data—Diverse sensing technologies are appearing across grids. Phasor measurement units (PMUs) are among the most used of these technologies for gathering voltage and current information. This paper, published in IEEE Transactions on Power Systems, considers PMU data from distribution-level systems, and how those data analytics can be visualized. Specifically, the researchers develop a method to visualize spatiotemporal relationships among the PMUs, which will help in real-time electric grid operations.

Real-Time Identifiability of Power Distribution Network Topologies With Limited Monitoring—From another study aimed at understanding our grid in real-time, this letter in IEEE Control Systems Letters suggests a strategy for best placement of metering technology that reduces the number of installations and recovers the grid's true topology. This strategy offers distribution system operators access to monitoring of switch statuses to track reconfiguration, with only limited metering.  

Irradiance and Temperature Considerations in the Design and Deployment of High Annual Energy Yield Perovskite CIGS Tandems—ESI researchers Manajit Sengupta and Aron Habte contributed to a cross-institution project to study high energy yield tandem photovoltaics (PV) with a chemical composition named CIGS. The NREL duo helped study efficiency of these PV technologies with consideration of irradiance and temperature, and the annual energy yields of the PV over the course of a year. The study, published in Royal Society of Chemistry, Sustainable Energy & Fuels, concludes that by using several different tandem device designs, the maximum possible annual energy yield can be just almost achieved.