“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.
Still, power flow is continuous, while measurements are not; and smart homes and photovoltaic inverters aren’t supercomputers that can solve complex optimization problems.
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.
Only a few early adopters currently trialing the technology. But it’s building toward a very concrete future.
That’s because the NREL team started by building a solid foundation: the theory behind AEG.
Filling Gaps in the Literature
AEG follows from an ongoing project for DOE’s vanguard energy agency, the Advanced Research Projects Agency-Energy (ARPA-E). A cohort of NREL scientists working within ARPA-E’s Network Optimized Distributed Energy Systems (NODES) program concentrated on developing real-time optimization and control methods for power systems.
NREL researchers Annabelle Pratt, Chin-Yao Chang, Bri-Mathias Hodge, and Benjamin Kroposki collaborate in the Power Systems Energy Center in the Energy Systems Integration Facility (ESIF) at NREL.
“I would say for us, it all started with NODES,” said Senior Researcher and AEG Technical Lead Andrey Bernstein. “In terms of algorithms and framework, NODES covers just one cell—one bounded community. Then Ben had this idea of having cells that communicate with each other to form a hierarchical system that could cover the entire grid. That’s how it went to the multicell perspective.“
With the launch of NODES in 2015, Bernstein and fellow NREL Researcher Emiliano Dall’Anese set their sights on new algorithms for a distributed grid. These algorithms use the limited computation of many customer devices (e.g., inverters) to functionally run the grid.
“Our main algorithms are coming from optimization and control theory,” said Bernstein. “If you go to the literature, there’s a gap between the two: Optimization finds solutions (but ignores real-world conditions) while control algorithms work to stabilize in not-ideal conditions. We’re bridging the two domains.”
Bernstein and Dall’Anese have been prolific in their publishing on this topic, building the theoretic scaffolding for this new discipline paper by paper PDF. The successive challenges they face are predominated by a few rigid facts. For example, power flow is continuous, while measurements are not; and smart homes and photovoltaic inverters aren’t supercomputers that can solve complex optimization problems.
“What’s novel in our solution is that we address a two-part problem,” said Kroposki. “First, because of the large number of devices, we cannot use central control, but must instead distribute the optimization problem. The other problem is that we have time-varying conditions, therefore the optimization is changing every second and must be solved in real time.”
NREL’s legacy in this domain has been helpful in seeing a pathway to real-world implementation. In California and Hawaii—two states that would benefit from AEGs—NREL has helped troubleshoot a dozen problems related to customer-sited inverters, advancing their state of the art along the way. What happens, for example, when the rotating generators that balance frequency at 60 (or 50) Hz are decommissioned? Methods developed for Hawaii and later used in California PDF helped answer this question by adding smart-grid functionality to the inverters to enhance stability.
Other challenges remain, such as identifying the complete set of inverter functions required PDF to help stabilize the grid, as well as the necessary incentives.
At a theoretical level, AEG stitches these developments together—along with NREL expertise in control technology development, microgrid and distribution system controls, and cybersecurity—into a larger, more complete theory. The expanding AEG community, which convened in April during a workshop at NREL, is focusing on understanding all the parts of the puzzle and solving for gaps. But while the AEG algorithms are still in the shop, the team is pulling in partners across industry and energy sectors to see how AEG looks in application.
Like the grid that the team is optimizing, distributed “cells” of support are appearing for AEG. Within the laboratory, a circle of AEG contributors is expanding thanks to NREL-directed funding for exploratory research projects. As the project’s principal investigator, Kroposki wants to keep the ball rolling in other energy domains while the theorists continue to piece together the program’s skeleton.
One of these domains is wind energy, in which an AEG-future also presumes an autonomous wind farm. Jennifer King is a researcher at NREL who has spent the past year constructing the wind slice of AEG.
“It’s one of my favorite projects by far,” said King. “It’s a nice mix of applied research, but we still get to work at the fundamental, technical level.”
King’s work is helping to build the foundation of AEG—crafting optimization problems to self-regulate cells the size of wind farms. But her research also concerns optimally integrating the variable supply of wind energy.
“The techniques and the communication across technologies just don’t exist today,” said King. “One thought is that buildings can shift their load to try and match (the variable output of wind), so we’re working with the buildings team to understand how.”
Pre-AEG trends are already underway in the buildings domain, too. DOE recently awarded grants for the automated control of buildings. Additional funding for autonomous wind energy systems coming from DOE’s Office of Energy Efficiency and Renewable Energy aims to improve wind farm operations with the AEG concept. The effort also recently received support through DOE’s Technology Commercialization Fund.
By incorporating these complex systems, AEG is guiding their respective progress toward a unified solution for the grid. But in doing so, AEG is also opening a Pandora’s box of technical challenges. “The more we dig in, the more topics we find that need to be addressed,” said Kroposki.
Among them is scale. The team is currently simulating AEGs with a few hundred nodes on the high-performance computer housed at NREL’s Energy Systems Integration Facility. But regions such as the Bay Area have more than 20 million control points. How would an AEG perform if deployed there? And what market incentives will it take to get there?
Trying to decide the fate of a million things on a second-by-second basis is where the challenge comes in.”
—Jennifer King, NREL researcher
From Foundations to Functional
Put succinctly by King, “Algorithm solve times are needed every one second. Trying to decide the fate of a million things on a second-by-second basis is where the challenge comes in.”
Furthermore, stepping out of the theoretical world, real power systems pose real problems. Communications are delayed, grid devices come from many vendors, and data isn’t always available where it’s needed. This is a special challenge for Bernstein and team, whose algorithms must be robust despite not-so-ideal conditions.
“Let’s say we produce very nice algorithms,” said Bernstein. “They still depend on physics—the topology of the lines and models of the devices. If you’re in a building and you want to choose what to turn on or off, you need to have an accurate model of that building, which can be difficult to find.”
To overcome peculiarities such as device models, Bernstein is wielding big data and tools from machine learning.
“Sometimes, defining the model is harder than learning how to be optimal from data and measurements,” said Bernstein. “Instead of building the models, we’re using data to learn the optimal behavior directly.”
Still other conditions are limiting AEG; there are hanging questions about how to arrange the communications infrastructure, and critically, how to secure that future infrastructure from cyberthreats. Such practical questions will be the focus as AEG takes a real-world form.
The Road to Market Endorsement
While Kroposki predicts a 10-year effort, an AEG market arrival may come sooner. There’s already progress toward commercialization of AEG algorithms. The theory that Bernstein and Dall’Anese constructed to power AEG was selected by DOE’s I-Corps program for advancement to market. The IP Group also picked AEG as a candidate for its tech-acceleration portfolio.
Industry is stepping behind the vision, too. Siemens is partnering with NREL to develop distributed control techniques with support from DOE’s Solar Energy Technologies Office. Likewise, NREL’s collaborative work with Eaton is drawing from the AEG effort for autonomous, electrified mobility solutions.
Of all places, the first real-world test of AEG algorithms is happening at a Sonoma vineyard. The Stone Edge Farm Estate’s microgrid was programmed for distributed control using the theory originally developed by Bernstein and Dall’Anese.
NREL has also explored how to sustain a distributed energy market using blockchainPDF—an option for so-called transactive energy markets. Kroposki expects that “you’ll probably see AEG appear from the bottom up; starting with hospitals, campuses, and communities.”
Indeed, a small cooperative utility in Colorado, Holy Cross Energy, is already deploying control techniques from the ARPA-E NODES workPDF.
As the theory progresses—from foundations, to simulation, to small-scale application—Kroposki hopes that participation will grow, too.
“There are many people out there working on tiny aspects of this… we see this as a broad vision. If you’re interested in this work, please get ahold of us.“
Learn more about NREL’s Grid Modernization work. RESEARCH AREAS
- Integrated Devices and Systems
- Sensing, Measurement, and Forecasting
- Power Systems Operations and Controls
- Power Systems Design and Studies
- Security and Resilience
- Institutional Support
NREL grid research is led by the Power Systems Engineering Center under the direction of Ben Kroposki. The center is part of the Energy Systems Integration directorate, led by Associate Laboratory Director Juan Torres. NREL’s grid research is aligned with the U.S. Department of Energy’s Grid Modernization Initiative as part of the Grid Modernization Laboratory Consortium.
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.
A new video from NREL highlights the partnership between Eaton and NREL, which includes a staff-sharing between the organizations. The partnership 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 PDF.
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.”
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. (below)
Kate Anderson (left), Sakshi Mishra, Kathleen Krah, Emma Elgqvist, and Xiang Li developed the REopt Lite energy modeling tool. Photo by Dennis Schroeder/NREL
Josh Schaidle wants an answer from college chemistry and engineering students when he visits their classrooms: How much does a catalyst cost?
“That’s the first question, and you don’t get a lot of answers initially,” said Schaidle, a chemical engineer in the National Bioenergy Center at the U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL) and director of the NREL-led Chemical Catalysis for Bioenergy Consortium(ChemCatBio).
But considering the price tag of a chemical catalyst manufacturing process, or the cost of deploying solar panels, or even the savings energy efficient buildings can generate are increasingly important functions of NREL research.
That’s why Schaidle and his NREL colleagues are creating useful software applications designed to help highlight potential costs and savings. In doing so, they hope to shorten the path to commercialization and increase overall adoption of renewable energy and energy-efficiency technologies.
Here are a few recent examples of this effort.
In collaboration with Pacific Northwest National Laboratory through ChemCatBio, Schaidle and his team developed a free program called CatCost, designed to estimate the costs associated with manufacturing different types of catalysts. “This is not a money-making opportunity,” Schaidle said. “We’re sharing knowledge broadly with the catalysis community and enabling them to accelerate their research.”
The idea behind CatCost was sparked about four years ago by the realization that virtually no public information was available for estimating the costs of pre-commercial catalysts. Schaidle said he and his colleagues were trying to develop a better, cheaper way to convert biomass into liquid transportation fuels. That required choosing the right catalyst.
“We were looking at all these different catalytic materials,” Schaidle said. “Some we knew were pretty expensive, like platinum. Others used less-expensive metals but were being synthesized using fairly exotic methods. We sat there and we said, “We’re starting to assess the performance of these catalysts, we’re putting them in a reactor, we’re studying them, but we have no knowledge of how much these materials are going to cost.”
Not only does CatCost draw from a continually updated database of the price of raw materials, it also considers the cost to manufacture a catalyst. It’s not enough to say that platinum is an expensive raw material or that nickel isn’t. “In reality, sometimes the synthesis steps—the actual processing steps—can contribute a reasonable amount to the overall costs of the catalysts,” Schaidle said.
CatCost also features a spent catalyst reclamation module. “If you’re using platinum as a catalyst and you finish running the catalyst in a reactor and it’s basically spent, are you going to toss it? Of course not,” Schaidle added. “You’re going to put a lot of time and effort into recovering that platinum. The tool takes that into account. It uses decision logic to evaluate when you should recover valuable metals from a spent catalyst, including how to do that and the costs associated with that.”
CatCost offers users the choice of a web-based application or a spreadsheet. Both have the same functionality, although the online version comes with interactive visualizations.
Schaidle said CatCost has been widely used since its release, and he’s fielded calls from companies large and small. “A few larger corporations have said this tool has specifically improved their research efficiency,” he reported.
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NREL’s REopt software analyzes the cost-effectiveness of deploying solar panels on commercial properties, and has been used to assess energy optimization opportunities for more than 10,000 sites. But it’s an internal tool that only “10–15 people at NREL know how to use it,” said Kate Anderson, program manager for the REopt Lite development team. “It’s primarily used to provide analysis services to our partners.”
Enter REopt Lite, which emerged from beta testing last fall. “The Lite version includes about 10% of what’s in REopt,” Anderson said. “We chose the most-used features, the most tried and true, so we felt confident making them available in a public version. By making REopt Lite open, accessible, and free to the public, we’re hoping to increase the impact of it, which to us means increasing deployment of clean-energy projects. So far we have about 8,000 users and over a million hits to the application program interface.”
REopt Lite relies on a series of default data sets. Users have the choice of 76 inputs—but only need three for a preliminary analysis. It’s as simple as entering an address, selecting the utility rate from a drop-down menu, and choosing the type of building. Based on this information, REopt Lite provides a recommended system size and dispatch strategy to minimize the building’s cost of energy. The tool also estimates how long the recommended system can sustain the site’s critical load in the event of a grid outage.
Initially, the software only considered the cost-effectiveness of solar and energy storage for a site, but updates added the possibility of drawing power from wind turbines and designing systems for resilience.
“We’re continuing to add new capabilities to it,” Anderson said. “We get a lot of input from users, as well as our advisory board, for additional capabilities or ways to improve it.”
Upcoming changes include the addition of combined heat and power systems and making REopt Lite open source. According to Anderson, “Open sourcing it will allow software developers to integrate the code into their tools and programs, hopefully increasing the impact of it.”
The REopt™ Lite web tool helps commercial building managers:
- Evaluate the economic viability of grid-connected PV, wind, and battery storage at a site
- Identify system sizes and battery dispatch strategies to minimize energy costs
- Estimate how long a system can sustain critical load during a grid outage.
REopt Lite offers a no-cost subset of features from NREL’s more comprehensive REopt model. REopt Lite also offers an application programming interface (API). Send questions and tool feedback to REopt@nrel.gov.
Step 1: Choose Your Focus. Do you want to optimize for financial savings or energy resilience?
Step 2: Enter Your Data. Enter information about your site and adjust the default values as needed to see your results. Site and Utility (required) m Site location, Electricity rate Use custom electricity rate, Net metering system size limit (kW) Enter 0 if net metering is not available. Wholesale rate ($/kWh)Site nameAdvanced inputs. Reset to default values Load Profile (required) Financial
While REopt Lite is for commercial properties, ResStock is designed to provide information applicable to entire neighborhoods or communities. The energy analysis tool also scales to states, utilities, regions, and the entire country.
“We’ve seen a lot of excitement from basically everybody we talk to,” said Eric Wilson, a senior research engineer at NREL. “Every couple of weeks I have conversations with states or cities or manufacturers who are interested in using it in some way or another.”
ResStock builds on decades of NREL building-efficiency research. More than a dozen different data sources power ResStock’s ability to analyze how changing one parameter could increase energy efficiency and thus bring down costs. It considers inputs from individual homes including the era when it was built, how much insulation is in its attic and walls, square feet, what type of heating and cooling systems are used, and how efficient those systems are. The application has enough data to analyze communities across the United States, save for Alaska and Hawaii where the sample sizes are too small.
The types of ResStock users vary. A manufacturer, for example, might find it useful to determine whether to develop a new type of water heater or air conditioner. “It’s part of market research,” Wilson said. “It can help companies understand the total potential revenue.”
Likewise, cities are finding ResStock useful in determining how the potential for energy-efficiency opportunities and related costs. They could ask, for example, “What upgrades to the building stock are cost-effective without incentives—and which upgrades may need some incentives to spur people to make changes? Cities are also really interested in making sure any action they take on their energy or climate goals benefit low-income households,” Wilson explained.
The ResStock and ComStock analysis tools are helping states, municipalities, utilities, and manufacturers identify which building stock improvements save the most energy and money. Learn more.
Data Visualization. Explore existing analysis results on ResStock’s interactive website. State-level results can be filtered to identify the savings potential in various segments of the housing stock, whether that is homes of a certain vintage, homes with a specific heating fuel type, or homes with a certain type of wall construction type.Data Viewer
State Fact Sheets. State audiences can benefit from the series of fact sheets developed for the 48 contiguous U.S. states. Each fact sheet presents the potential for economic energy and utility bill savings for the state. The top ten energy savings home improvements are highlighted. State Fact Sheets https://resstock.nrel.gov/factsheets/CO
Analyze Your Scenario. Use the free and open-source software yourself (or partner with NREL or a third-party consultant). Analyze the scenarios of interest to you, whether you wish to evaluate the potential of a specific technology, define your own cost-effectiveness equations, or plug in hyperlocal data to get a high-granularity picture of the potential in a city or utility service territory. Analysis results can be privately uploaded to the ResStock website for visualization.Read the Documentation
Gain insights on the methodology and view national- and state-level results in the NREL Technical Report, Energy Efficiency Potential in the U.S. Single-Family Housing Stock .
View webinar slides and recording from a Building America webinar presented on March 29. 2017 Publications
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Utilities are the intended users for another NREL-developed tool, called PRECISE. The acronym stands for Preconfiguring and Controlling Inverter Set-Points. Developed with the Sacramento Municipal Utility District, PRECISE allows utilities greater control over residential inverters (which change the direct current output of solar panels to alternating current for use by household appliances), allowing them to maximize the cost-effective use of the panels.
With PRECISE, utilities can also identify the best and safest operating conditions for new solar energy systems. The automated software eliminates guesswork, and can even help utilities determine how to customize inverter settings to provide a balance between grid stability and customer savings.
For example, when a customer asks for approval to install solar panels on the roof of their house, the utility can use PRECISE to input the location and size of the requested system and find out the optimal settings for the system’s inverter. “You can set it and forget it,” said Adarsh Nagarajan, an NREL engineer and principal investigator on the project. “With the optimal setting, a solar panel that comes close to topping the utility’s safe voltage limits can be automatically triggered to produce less power.”
Now in use in parts of California, the open-source tool will soon be tried out in India. “Any utility can use this,” Nagarajan said. “PRECISE will reduce interconnection time by 50%. It’s going to be time-efficient—cost-efficient for sure.”
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.
The National Renewable Energy Laboratory (NREL) recently partnered with the midwestern utility company Commonwealth Edison (ComEd) on a project that will help the utility reach their goal of nearly doubling savings for customers and reducing electricity use in Illinois by 21% by 2030. This new collaboration with NREL will help ComEd reach their goal through more energy-efficient technologies for buildings.
This partnership was initiated by Bill Livingood, manager of NREL’s Commercial Buildings Research Group. Staff from NREL’s Commercial Buildings Research Group and Building Energy Science Group are leveraging their core skills of simulation and laboratory experimentation to help ComEd address its energy reduction goals.
In order to meet this goal, the NREL team is utilizing its vast network of industry partners, incubators, and conferences to create a list of the most viable energy-efficient technologies applicable to buildings. NREL researchers will provide annualized energy savings for ComEd’s specific territory, allowing them to determine the value proposition of each identified and prioritized technology. ComEd can then take these top-selected technologies and incorporate them into their next cycle of energy efficiency incentive program design.
An initial list of technologies met the criteria that ComEd established for their emerging technology program, and from those identified, NREL researchers ranked the technologies and narrowed their suggested selections to proceed with the next step of experimentation.
The next step in the process is to develop detailed experimentation plans for each individual technology and then carry out R&D evaluations. Fortunately, several of the technologies selected build on existing research conducted by NREL.
“The beauty of the selected technologies is that we are already leveraging the prior research knowledge that we have accumulated at NREL, and then applying it to a different application for this particular utility. We’re going to minimize the cost of those technology evaluations by tapping into the previous intel and knowledge that we’ve gathered,” said Ramin Faramarzi, NREL’s principal investigator for the ComEd partnership project.
The Department of Energy (DOE) is also very interested in the work NREL is doing with ComEd and has joined the collaboration with a unique focus on load flexibility in commercial buildings. DOE is especially interested in working with ComEd to determine how the selected technologies could offer further value by providing grid services such as load flexibility.
Although the first few approved technologies have already begun evaluations, there is an opportunity for the other technologies to be evaluated at NREL’s Energy Systems Integration Facility. The space in the ESIF has recently been renovated to fast-track scalable solutions with energy use, generation, storage among buildings, vehicles, and the larger electric grid. Ultimately, the ESIF will explore integrated energy pathways.
“We’re supporting the ComEd partnership by making sure the ESIF is ready to evaluate any ComEd technologies using hardware-in-the-loop capabilities. 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. This type of collaboration is a great step for the renovated ESIF as it illustrates to other utilities and DOE how to use this new capability to answer their urgent needs,” said Grant Wheeler, principal investigator for a portion of the ESIF.
The dedicated space in the ESIF is still in its early stages of use; the commercial buildings side of the lab only opened on June 28. But the potential research and future projects to be conducted in the space, such as the ComEd partnership project, are expected to have far-reaching impacts.
“We are hoping that through the course of this project, we will pave the path for a much more expansive and long-term relationship beyond this contract that we currently have with ComEd. We would like to continue the role of an unbiased and impartial energy adviser in support of ComEd’s energy efficiency program,” said Faramarzi.
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 ResourcesPDF, 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.