ESIF
2019
﻿ |1|

is implementing between the ESIF and the Flatirons Campus tocentric computing to solve complex energy system challenges. And

create an unprecedented research environment at the +20-MW

we are equally committed to working with smaller partners on theirscale, representing the interface between the distribution andbig ideas. The Shell GameChanger Accelerator™ Powered by NREL

bulk grid power levels. Researchers and partners will be able to(GCxN), is one of our newest venues to help startups accelerate theirleverage capabilities at both sites, including high-performance

path from concept to market.

computing, to explore breakthrough solutions for optimizing
the integration of renewables, buildings, energy storage, andWhat remains constant throughout these exciting changes is what

transportation.

got us here in the first place: NREL’s unwavering commitment to

Resilience and security have a renewed importance across ourwere recognized among the 100 most important inventions of 2019

entire body of grid research. In fact, resilience is the cornerstone of

by R&D Magazine: PREconfiguring and Controlling Inverter SEt-Points

Across the globe, we are witnessing the greatest transformation

autonomous energy grids (AEGs), an NREL research agenda that

(PRECISE™) and ResStock™. Both relied on the ESIF’s capabilities forof our energy systems in history. Since the Energy Systems

has spread from its abstract beginnings in Advanced Research

their development, will help grid modernization keep its momentum,

Integration Facility’s (ESIF’s) creation just over six years ago, theProjects Agency-Energy (ARPA-E) to a practical grid solution thatand were recognized because they show where costs can be saved inresearch and resources dedicated to developing, evaluating,is as effective at controlling wind systems as it is buildings. AEG

our transition to renewable energy.

and reimagining these systems have grown exponentially inalgorithms optimize distributed energy resources autonomously

importance. While the facility continues to be a meeting groundand in real time. AEGs debuted in the real world in 2019 on afor countless partners to explore these concepts, we are looking

rural Colorado grid, following validation at the ESIF. We are also

intently at the future of how these partners will count on the ESIF:

excited to showcase our new cybersecurity visualization capability,

for resilience and security, integrated modeling and simulation,

which will add a new dimension to our grid integration and AEG

and studies at an even greater scale.

research.

again places great responsibility on NREL and the ESIF to drive

That growth in scale has been front and center this past year. Early

A close connection to industry has always driven research at thepartners, we look forward to seeing how the ESIF will continue toin the year, the National Renewable Energy Laboratory (NREL)

ESIF. Nowhere is that more evident than with the high-impact

carry the nation toward a modern power system.

welcomed one of its newest and most powerful research assets,

projects that NREL and the U.S. Department of Energy (DOE)

the Eagle supercomputer. Eagle is a big leap in computational

select each year. Reflecting on last year’s projects, the topics

ability and allows users to simulate technical challenges acrossare as relevant as ever and are already showing their scalability.

the spectrum—from materials to architectures of large-scale

Algorithms from NREL’s collaboration with Holy Cross Energy areautonomous energy systems with millions of devices. Not only

being reapplied to other energy systems, and our stakeholder

does Eagle support innovation, it also demonstrates it: in Fiscal

involvement with Eaton Corporation studying fleet electrification

Year 2019, the data center connected to Eagle won the prestigious

keeps us aligned with concerns of industry. Likewise, the high-DatacenterDynamics (DCD) Data Center Eco-Sustainability Award,

impact projects that began in 2019 reflect growing challenges:

bolstering NREL’s status as a world leader in data center efficiency

understanding how to store energy from the residential to utility

and sustainability.

scale, identifying communications solutions for enhanced grid

Associate Director’s Letterworld-class science and research. This year, two of our innovations

There is no shortage of work ahead, and NREL is uniting sectors
and industries to help define our national direction. DOE’s Grid
Modernization Initiative (GMI) is the nation’s most important resource
for fulfilling the changes our grid needs, and the 2019 GMI lab callinnovation across domains. With expanding capabilities and visionary|2| ﻿visionary step toward expanding capabilities at both the ESIF andIn FY 2019, NREL signed some of the biggest agreements with

NREL’s Flatirons Campus. Research at the ESIF can go up to 2 MW

industry in our history. Energy industry leader ExxonMobil isand 13.2 kV. NREL is developing its Flatirons Campus to allow forinvesting in NREL’s ability to broadly innovate in renewable energy

research at the 20-MW scale with a 115-kV link to the utility. The

technologies. Alongside another industry giant, Hewlett Packard

ARIES initiative will employ a 100-Gbps fiber-optic link that NRELEnterprise, we are developing a vision to apply edge and data-

7 High-Impact Projects
8 Devices & Integrated Systems Testing
14 Sensing & Measurement
20 Systems Controls
28 Design & Planning Tools
32 Energy Security
36 Energy Resilience
38 Institutional Support
40 Advanced Mobility
42 Hydrogen & Renewable Fuel Systems
48 High-Performance Computing
54 ESIF Lab Updates & Advanced Capabilities
58 ESIF Key Performance Indicators

Juan Torres
Associate Laboratory Director for Energy Systems Integration at NREL

59 Partners
60 DOE Program Researchforward operating bases.

Research for Integrated Energy Systems (ARIES) initiative—a

4 Grid Modernization Initiative Overview

Sincerely,

control, and improving microgrid technologies that reliably serve
Eagle will also serve as a critical component of the Advanced

TABLE OF CONTENTS

66 Knowledge Sharing
Martha Symko-Davies
Laboratory Program Manager for the Energy Systems Integration
Facility at NREL

67 Workshops, Conferences, & Events
68 Innovations
72 Publications

﻿ |3|

Grid
Modernization
Initiative
Overview|4| ﻿

The U.S. Department of Energy (DOE) established the Grid
Modernization Initiative (GMI) to develop a coordinatedapproach to grid modernization research across the national
laboratories. GMI is a crosscutting effort that focuses public andprivate partnerships to develop a portfolio of new tools andtechnologies that measure, analyze, predict, protect, and control
the grid of the future.
The development and application of new energy technologies
will introduce both risks and opportunities across the U.S.
economy. The U.S. electric power system must prepare forand adapt to changing conditions and withstand and recoverrapidly from disruptions. In addition, we must understandhow distributed energy resources (DERs) can support both the
distribution and bulk power systems now and in the future. As
a result, the GMI focused on security challenges of the electric
power system in the 2019 lab call and selected portfolio of
projects.

•

Address a fully integrated energy system: The
GMI focuses on a fully integrated vision of energy
systems—from fuel to generation to load, includinginterdependent infrastructures.

•

Strengthen reliability and resilience: The complexityof the electric grid and its interconnection with othercritical systems can accentuate the risk of cascading
failures, so it is paramount that the grid is reliable andresilient against all malicious threats, natural disasters,
and other systemic risks.

The GMI is implementing this vision by investing approximately$80 million through its latest lab call. NREL supports the GMI
through the Grid Modernization Laboratory Consortium(GMLC), a strategic partnership between DOE and the national
laboratories that brings together leading experts, technologies,
and resources to modernize the nation’s electric grid.

To address this continuously changing landscape, DOE
expanded the vision of the GMI to:•

Include more participation across the department: The
GMI reflects a collaborative partnership of five DOE
offices, including the Office of Fossil Energy; the Officeof Nuclear Energy; the Office of Electricity; the Officeof Energy Efficiency and Renewable Energy; and the
Office of Cybersecurity, Energy Security, and Emergency
Response.

Get the full list of projects awarded throughthe 2019 grid modernization lab call at:https://www.energy.gov/2019-gridmodernization-lab-call-awards

﻿ |5|The Next Step in Grid Modernization
In 2019, the GMI announced the 2019 lab call awards, which are
distributed among 23 projects that extend the initiative’s vision to
include more participation across DOE, a focus on fully integrated
energy systems, and increased security and resilience. Of those
23 projects, NREL will contribute to 11 and lead three, displaying
leadership in DER management, institutional assistance, and resources
to integrate energy domains. ESIF, as well as the Flatirons Campus,
will be front and center for these projects, lending essential gridtechnologies and expertise to each collaboration.
Federated Architecture for Secure and Transactive Distributed
Energy Resource Management Solutions (FAST-DERMS)
An architecture that can aggregate and manage a broad range of
DERs—photovoltaics (PV), storage, electric vehicles (EVs), flexible loads,
combined heat and power, and other distributed generators—acrossthe grid for bulk system services.
Clusters of Flexible PV-Wind-Storage Hybrid Generation(FlexPower)
Demonstration of how utility-scale wind and PV generation canbe leveraged as more than simple variable-energy resources totechnologies that provide a full range of reliability services to the bulk
power system.
Water Risk for the Bulk Power System: Asset to Grid Impacts
An analysis platform that advises utilities on short-term operational
and long-term investment decisions related to the impacts and risks ofwater resources.
Development and Calculation of Performance-Based Resilience
Metrics for Defense Critical Infrastructure
Models and metrics for calculating the time-varying performance ofdefense critical infrastructure during long-duration bulk power systemoutages.
HELICS+: From a Facilitator to a Hub
An improvement to the GMLC-created Hierarchical Engine for LargeScale Infrastructure Co-Simulation (HELICS) that will address gaps inin scalable integration with diverse infrastructures and usability forcosimulation complexity.

|6| ﻿Multi-Port Modular Medium-Voltage (M3) Transactive PowerElectronics Energy Hub
Development of smart power electronics hardware and softwareinterfaces for grid applications, including a multiport, medium-voltage
energy hub.
Grid Services, Energy Services Interfaces and Grid Connected Devices
Defining common frameworks that represent grid services andstandardize energy systems integration specifications to simplify DER
integration.
Foundational Assistance to ISO/RTOs under Electricity Market
Transformation
Robust analytic support to address challenges faced by independent
system operators and regional transmission operators in maintaining
reliability, resilience, and affordability.
State Technical Assistance to Public Utility Commissions
Technical assistance to state public utility commissions on topics
that can support their grid modernization or energy infrastructure
initiatives.
Future Electric Utility Regulation
Access to high-quality and impartial analyses, case studies, andsupport tools for decision makers to enlist utilities and customers as
partners in considering alternative regulatory approaches.
Integrated Distribution System Planning: Education, Training, andAssistance
Education, training, and technical assistance to decision makers on
best practices in integrated distribution system planning.
Technical Assistance: Grid-interactive Efficient Buildings
Technical assistance to state energy offices and public utility
commissions to advance buildings that can provide grid services
through demand flexibility using DERs.
Firmware Command and Control
A response capability using baseline firmware and bidirectional
sharing of threats to upstream energy security operations.
Blockchain for Optimized Security and Energy Management(BLOSEM)
Cross-sector guidance, standardized metrics, and testing environments
for advancing blockchain-based concepts for device security, securecommunications, and grid resilience.

High-Impact Projects Overview
Central to the mission of the ESIF is exploration of new areas of research that push the boundaries of conventional thinking. Each
year, NREL issues a Call for High-Impact Projects, seeking partners that demonstrate the use of multiple technologies (such as
storage, wind, solar, hydrogen, and buildings), address the challenges outlined in the Grid Modernization Multiyear Program Plan,and provide lessons that could be implemented across the United States.
As previous work concluded in Fiscal Year (FY) 2019, new high-impact projects began that are set to accelerate innovation anddevelop scalable technologies across industry.

Partners

Project
2018

San Diego Gas & Electric Company

Enhanced visibility of the grid edge with an analytics platform thatvisualizes and interprets distribution-level activity for utilities

Holy Cross Energy

Proving real-time, self-optimizing power systems with highly reliable
and efficient control infrastructure on a rural utility grid

Eaton

Co-optimization of electric vehicle fleets with the grid—charging
dynamics, grid services, and fleet sizing

2019
Salt River Project

Data characterization of customer battery systems—their economics,
performance, and impact on customer power use

Centrica

Hybrid battery energy storage systems that minimize system costs,
maximize use of various battery technologies, and serve the grid with amix of dispatch profiles

Anterix

Dedicated private long-term evolution (LTE) networks for
low-latency, highly reliable device communications

Look for the high-impact project icon throughout the report.

﻿ |7|Project Spotlight

Devices &Integrated
Systems
Testing|8| ﻿

NREL Evaluates
Commercial
Batteries in
High-Fidelity
Energy Storage Study with
Arizona Utility
The potential for energy storage systems to saveenergy costs is exciting to consumers, yet until now
surprisingly little information had been gatheredfrom the field about the economics and energy useof deployed battery energy storage systems (BESS).
NREL has embarked on a three-year study withsupport from Arizona utility Salt River Project (SRP)
to collect and characterize data around customer
BESS, which will provide a reservoir of knowledge forother utilities and BESS vendors about how battery
technologies impact ways that customers use power.
This study centers on how BESS function in practicefor SRP customers and how efficiently thesebatteries coperform with other DER technologies.
SRP provided price-reduced batteries to volunteer
participants in this study, which amounted to several
hundred customers within SRP’s solar energy-richjurisdiction in central Arizona. BESS performance in a
warm climate is specifically relevant to SRP, so NREL

researchers are evaluating how the technologies
will perform in Arizona on days that exceed
temperatures of 100°F.
The batteries offered were among those validated
at the ESIF’s residential battery test bed, where
researchers tested factors related to BESS use.
SRP then collected demographic and geographic
information on the volunteer participants to
supplement data around storage system adoption.
In the past fiscal year, NREL began collecting use
data with SRP’s support. In addition to the collectionof BESS data directly from the devices, inverter
data and advanced metering data across SRP’s
distribution system provide a more complete pictureof customer energy use. The data collected will also
reveal opportunities for renewable energy incentive
programs, such as the one SRP offers its customers.
Data collected throughout the program are being
used to refine models at NREL on customer DER use.
High-performance computing (HPC) resources at the
ESIF will be used to study relationships among thedata and perform large-scale modeling. Ultimately,
these real-world-informed models will allow SRP tounderstand DER growth scenarios on its electric gridand provide utilities across the United States with aclear, high-fidelity vista of customer DER adoption.

﻿ |9|Project Spotlights
Centrica and NREL Pursue a
Resilient and Cost-Effective
Hybrid Battery Energy Storage System
NREL and Centrica are partnering on a high-impact project to explore a hybrid
BESS design that will provide more economic solutions without compromising
grid services. By combining multiple battery technologies into a single hybrid
storage unit, researchers intend to maximize the use of each battery and meetvarious use cases while minimizing overall system costs.
Centrica is providing NREL researchers a hybrid battery storage system basedon sizing guidelines from a system design optimization task led by NREL
under this project. In the ESIF, NREL will integrate the hybrid storage unit andCentrica’s edge controller, an intelligent controller that leverages the strengthsof each battery to mix their dispatch in various ways to meet each use caseand maximize the service life of all the batteries. With Centrica’s input, NREL
developed and filed a software record for an optimal hybrid battery design toolthat can come up with the most economic battery stack designs and dispatch
based on site load, EV charge profile, and PV capacity and generation.
New design guidelines for hybrid energy storage systems can foster a decreasein the price of energy storage for value stacking while increasing theirpenetration. A lower cost BESS immediately unlocks a larger addressable market,
spurring investment and job creation across the entire value chain.

NREL-Led Working Group Signs Off on
Distributed Energy Resource Standard, Sets
the Path for Market Adoption
FY 2019 marked a major milestone for NREL’s leadership in the Institute of Electrical andElectronics Engineers (IEEE) revised 1547 standard, the market-forming standard thatwill guide consumer inverters interfacing with nearly all DERs integrated into the grid.
This year, IEEE P1547.1, the draft test standard for DERs, obtained 97% working group
approval, sending the standard to a public ballot. The working group, led by an NREL
team, is now resolving comments to further improve industry consensus.
Inverter testing related to IEEE 1547 has been ongoing in the ESIF since the ESIF’s
inception and has been informed by partnerships that span private industry, utilities,
and DOE. The future set of inverter functions as prescribed by IEEE 1547 is a result of
hardware testing and simulated systems of many inverters. In the ESIF, researchers haverefined the necessary functions of inverters—from fault responses to control features—
leading to dozens of project insights and progress toward national consensus.
IEEE 1547.1 is expected to be published in 2020, and inverters compliant with thestandard will become available soon after. The nationwide rollout of smart inverters
will enable much higher levels of renewable energy integration while preserving gridstability and reliability.

Hardware-in-the-Loop Simulation Shapes
New Fort Collins Smart Community Design
NREL Hardware-in-the-loop (HIL) simulation and HPC are shaping the design of aunique smart community in Fort Collins, Colorado. Centralized coordination of behindthe-meter DERs and flexible loads will provide energy savings, ensure homeowner
comfort, and minimize grid impacts.
Developed in partnership with Fort Collins Utilities, Thrive Home Builders, A.O. Smith,and technology and hardware providers, the community will feature best-in-class
home energy-efficiency technologies, high-penetration battery storage, and PV
arrays. Within the community’s 498 homes, NREL’s foresee™ software will automate
and coordinate smart devices according to homeowner preferences. A communitylevel aggregator will coordinate individual and aggregate energy resources to adjust
demand in response to real-time grid signals.
ESIF-based simulations and testing will inform decisions related to the sizing ofcommunity solar arrays and battery storage as well as the adoption of additional smart
home technologies. After the project breaks ground in the next year, NREL will validate
actual energy savings and homeowner benefits.

| 10 | ﻿

﻿ | 11 |Project Spotlights

Project Highlights

Electrolyzers on Double Duty, Providing Both Grid
Stability and Hydrogen

Controlling Inverters to Lead—Rather Than Follow—Grid Conditions

Since the project’s inception, in 2014, Southern California Gas Company (SoCalGas) and NREL researchers,with support from DOE’s Office of Energy Efficiency and Renewable Energy (EERE), are studying how to
reduce voltage and frequency disturbances on the electric grid using dispersed electrolyzers that provide
both grid services and usable hydrogen. In FY 2019, the research team found that controlling the dispatchof dispersed electrolyzers helped reduce voltage disturbances on the distribution grid and frequency
disturbances on the transmission grid. The results showed that electrolyzers integrated on a grid with highpenetrations of renewable generation and baseload nuclear generation can reduce voltage disturbances
up to 35% and reduce frequency disturbances by more than 30%. These improvements were validated
using a commercially available 225-kW electrolyzer integrated in the ESIF along with a 1-MW grid simulator.
In the open arena of new vendor technologies, grid-stabilizing support will be a critical asset. This work
elevates the role that electrolyzers could play in future systems. The NREL team is looking into follow-on
work that considers trade-offs among transmission, distribution, and hydrogen production requirements
for economics, fueling demand profiles, and fuel cell electric vehicle (FCEV) applications.

Expansion of ESIF Capabilities for Building- and Vehicleto-Grid Integration
NREL is partnering with midwestern company Commonwealth Edison (ComEd) to help the utility reach
their goal of nearly doubling savings for customers and reducing electricity use in Illinois by 21% in 2030.
To meet this goal, NREL used its network of industry partners, incubators, and conferences to create a listof the most viable energy-efficient technologies applicable to buildings and provide annualized energy
savings for ComEd’s specific territory. This allowed the company to determine the value of each identified
and prioritized technology, several of which are now being validated in the ESIF. In FY 2019, NREL expanded
the ESIF’s capabilities to enable HIL testing for grid-interactive efficient buildings, allowing the NREL-ComEd
team to begin evaluating energy savings for the company and determining how the selected technologies
could offer additional value by providing grid services. The crosscutting, renovated space brings together
commercial building infrastructure, energy storage equipment, and an EV test bed to evaluate how loads
can provide flexibility to the grid and reduce overall consumption while providing comfort to building
occupants.

Watch: Grid-scale electrolyzers could play a significant role in the
integration of hydrogen into the electric grid. Watch this video tolearn more about NREL’s grid-scale electrolyzer work:

As inverter-based resources such as solar increase on the grid, they become more
responsible for maintaining the grid’s stability. DOE’s Solar Energy Technologies Officeis supporting NREL and Oak Ridge National Laboratory through the SunShot National
Laboratory Multiyear Partnership (SuNLaMP) program to stabilize power systems using
well-coordinated, digitally controlled inverters. Most critically, this project is discovering
how inverters can replace traditional inertial (mechanical) means of regulating
frequency. The solution will accommodate both newer and existing inverters, ensuringthat devices can be seamlessly integrated into electric power systems with service
functions enabled.
In FY 2019, the interlaboratory team developed a programmable smart frequency
control that uses machine learning-based predictions of frequency conditions.
Evaluating the inverter controls, the team found that their technique could save
50% on PV headroom—the power reserved to provide frequency control. In future
work, researchers will consider a model for grids with extremely high PV penetrationand perform hardware validations and field tests to evaluate the range of operating
conditions.

NREL Creates Transmission-Level Control with Ternary Pumped Storage
Hydropower
One option for the United States to expand its sizable hydropower capacity is througha technique called ternary pumped storage hydropower (T-PSH), which can provide
grid services while pumping water as storage for later use. NREL was awarded funding
by DOE’s Water Power Technologies Office to develop detailed dynamic and economic
models of T-PSH plants with the goal of analyzing their technical feasibility andquantifying their ability to provide frequency-related ancillary services to the grid.
The NREL team evaluated advanced pumped storage on the Western Interconnection
under different penetration levels of renewable energy and assessed the value of these
services under different market structures. For example, a vendor-neutral dynamic
model of T-PSH was created at the ESIF to simulate the seamless transition among threeoperation modes: generation mode, pumping mode, and hydraulic short-circuit mode.
Comparing conventional pumped storage hydropower (PSH) and T-PSH, researchers
found that T-PSH can provide frequency support to the grid while pumping water.
The range of operation provided by T-PSH could offer increased flexibility in managing
diverse energy resources integrated into the U.S. electric grid. This work puts essential
techno-economic results into the hands of PSH stakeholders, informing industry andgovernment of possibilities for developments in this sector.

(https://bit.ly/35HnSOB).
| 12 | ﻿

﻿ | 13 |Project SpotlightSensing &Measurement

Home Data

NREL Extends
Grid Visibility
for Utilities with
Down-to-the-In FY 2019, NREL and SDG&E brought the grid edge
into utility control rooms through a data analytics,
management, and visualization platform.
Utilities across the country have invested more than $5
billion in deploying advanced metering, infrastructure(AMI), or an integrated system of smart meters. Whilemost utilities use AMI for billing or metering the NRELSDG&E partnership has transformed such data into a
tool for grid monitoring and control. With the ESIF’s
capacity for large-scale data analytics, management,
and visualization capabilities, NREL created an analytics
platform for AMI data that reveals and interprets behindthe-meter activity for utilities. This transformation
is essential for utilities to manage the integration ofbehind-the-meter assets, such as PV and EVs.
AMI picks up where traditional grid monitoring ends: atthe secondary/behind-the-meter level, which focuseson phase and power information from homes at thegrid edge. Using SDG&E’s feeder model and billionsof data points, researchers first generated synthetic| 14 | ﻿

measurements that resemble the AMI deployed on
SDG&E’s system. The researchers then used HPC
resources at the ESIF to transform large data sets into
actionable, salient features that are useful for verifying
grid planning models. The team’s result included 2-D
and 3-D visualization tools for real-time secondary
system awareness and a derivation of customer phase
information based on AMI data. This tool includes
insights into predicting locations on the feeder thatmight witness voltage exceedances, especially in thepresence of high penetrations of PV.
This work will empower utilities across the nation that
require more informed grid operations and controls
as increasing numbers of DERs come online. The AMI
analytics and tools developed between SDG&E and NREL
can assist in directing policy, contingency planning,and general real-time awareness at the grid edge, andthey can greatly improve the process for planningmodel remediation. This technology has the potential tosignificantly reduce the costs for supporting high levelsof DERs while enhancing the flexibility, affordability,
reliability, and robustness of grid operations.
Looking ahead, NREL is searching for opportunities that
operationalize the phase information and distribution
system data, possibly through real-time DER control.
SDG&E plans to deploy tools from this project to validate
results against planning models.

﻿ | 15 |NREL Improves High-Solar-Power Systems with New
Method for Finding Faults

Project Spotlights

With funding from DOE’s Solar Energy Technologies Office, NREL is studying a method to detect andcharacterize faults associated with systems containing significant penetrations of PV.

NREL Targets Efficient Buildings with SiteSpecific Weather Forecasts

Inverter-based systems, such as those with PV, could interfere with the grid’s traditional electricalprotection system to identify and remediate faults. The potential dangers span both high-penetration
solar and microgrid systems, possibly hindering their future growth. NREL’s exploration of travelingwave-based fault protection could unlock the techniques needed to secure future power systems.

Buildings are large energy consumers, and their energy use depends acutely
on the conditions outdoors. With expertise in weather forecasting, multisystemsimulations, and automated control, NREL has begun a three-year study on
developing site-specific weather forecasts for individual buildings and advanced
building control techniques based on local weather conditions and using
information learned from the ESIF’s building assets. The project is funded by
DOE’s Building Technologies Office and extends the work of two NREL-led GMLC
projects in the domains of sensor development and multiscale control systems.

This past year, NREL researchers launched an initial study analyzing how traveling wave-based
schemes could operate on a distribution grid. For system simulations, researchers identified powerline models and considered inaccuracies that needed to be corrected. On the hardware side,
researchers leveraged the ESIF’s Medium-Voltage Outdoor Test Area, which supports systems up to
13.2 kV and can simulate two utility distribution feeders. Researchers performed preliminary analysesof traveling wave techniques on this system and determined how to process resulting data for thenovel protection scheme.

In its first year, the NREL team showed that building site-specific weather
conditions could be reliably derived from distributed weather data andsensors. Advanced machine learning methods were developed to learn thespatiotemporal correlations between weather conditions at the nearby weather
stations and the individual building site. Conditions such as temperature, solar
irradiance, relative humidity, and wind speed variously impact building loads.
The NREL team then performed sensitivity analyses to evaluate the impactof local weather conditions on building energy consumption under different
climate zones and for different prototype buildings.

Looking ahead, NREL is connecting with partners to scale up this research. With a suitable outdoor
test facility, NREL can improve the fidelity of traveling wave-based protection experiments andreliably evaluate how this protection technique could perform on real systems.

Future work is planned for improving forecasts, unifying building controls withenergy-use predictions, and characterizing the impact of such controls. The
team’s effort is taking advantage of historical meteorology and building energy
consumption data collected by sensors at the ESIF to validate the developed
technologies in this project. The final product will include a platform to makebuildings responsive to their local environment, which is the most significant
variable affecting their energy use.

| 16 | ﻿

﻿ | 17 |Project Spotlight
LTE Communications Shown
to Support Grid ThroughCritical Events
NREL and Anterix, the largest holder of licensed spectrum in the 900-MHz band,successfully piloted private LTE networks in utility control applications. Anterix,alongside an advisory board largely comprising utility representatives, sought
to understand how advanced distribution management systems (ADMS), with
their increasing communications dependence, would perform using private LTE
networks. With a low-latency, high-capacity, and highly reliable communications
platform, utilities can overcome control issues associated with poor signal
strength and avoid the congestion of thousands of grid-edge devices, which
could otherwise become a showstopper if not prioritized.
NREL tested a critical protection function that demands low latency over private
LTE communications. Leveraging ESIF assets and portions of the ADMS test
bed, NREL showed that the wireless network successfully communicated criticalprotection-related signals, even under congested and weak-signal scenarios.
Future work will consider other ADMS use cases that apply private LTE as thecommunications backbone to grid-edge equipment.

| 18 | ﻿

﻿ | 19 |Project Spotlight
Breakthroughs in Control
and Optimization Leadto Vision of Autonomous
Energy Grids

SystemControls| 20 | ﻿

NREL’s work with autonomous energy grids (AEGs)
draws on all assets and connects all facets of themodern energy transformation. It is a vision madefor grid management at every scale, inclusive of
every technology, and as economically compellingas it is operationally. AEGs are a pivot away fromtraditional systems to decentralized rather thancentralized control, and they are resilient rather
than vulnerable to system-wide blackouts. The
vision for AEGs is that we can wield widespread datacollection, machine learning methods, and a suiteof new power flow algorithms to optimally match
supply and demand across energy systems.
FY 2019 was a landmark for the broad portfolioof work included in AEGs. NREL was granted new
funding from DOE’s Office of Electricity Advanced
Modeling Grid Research Program, Building
Technologies Office, Wind Energy Technologies
Office, as well as an ARPA-E program that helped
develop the core control functions behind AEGs for
program-specific applications. NREL used laboratorydirected research and development (LDRD) funds
to explore the foundational science behind AEGs
at the intersection of energy systems. NREL also
hosted several conferences that connected industry
and research circles that formalized AEG initiatives
and released dozens of AEG-related publications
and presentations. NREL continues to construct thetheoretical underpinnings of AEGs, which include
groundbreaking work at the intersection of control
theory and optimization.

The AEG body of work is ramping up and creating
new opportunities for energy innovation. In
the laboratory, AEGs have been successful insimulations that cross energy domains. On thegrid, AEG applications are currently operational on
two real-world systems for NREL industry partners.
Meanwhile, the AEG research team participatedin a DOE technology acceleration program that
positioned AEGs for broader market adoption.
As automated control guides the moment-tomoment dynamics of the grid, researchers are asking
how energy markets can participate in transactive
control and how communications can be secured
from cyber threats.

.

Building off NREL’s foundational workin AEGs, researchers are now evaluating
how to expand the functionality of
autonomous algorithms into lesspredictable events, such as cascading
failures. A new LDRD project, named
Autonomous Grids—Identification,
Learning, and Estimation, kicked off in
FY 2019 and seeks to overcome current
issues in autonomous grid control,
including barriers to computational
scalability and oversimplified system
dynamics, to accurately assess stability
and decisions for device control.

﻿ | 21 |Project Spotlights
From Theory to Lab to Live: NODES
Algorithms Transform Grid Control for
Modern Energy Systems
During the past three years, NREL’s work under the ARPA-E Network Optimized
Distributed Energy Systems (NODES) program achieved the ideal outcome for
DOE’s ARPA-E research portfolio: bold, creative, transformational solutions.
NODES began with the unique concept to leverage existing grid flexibility tofundamentally change the way parts of the grid are operated and increase
reliability. In FY 2019, the final year of ARPA-E funding for the NREL NODES
team, researchers demonstrated how the work evolved from theory andsimulation, to laboratory demonstration at the ESIF, and finally to real-world field
deployment—providing a proven foundation for new avenues in grid control.
The NREL-developed NODES algorithms coordinate autonomous decisions
across thousands of connected distributed resources and loads to improve local
operating conditions while providing coordinated control of these resources
as a single virtual power plant that can provide strength to the grid. Having
achieved an in-laboratory hardware simulation of real-time DER optimization
with a record number of interconnected power devices and control hardware
by leveraging devices at the ESIF, the NODES architects are now proving theirproject on small-scale grids, including a microgrid at a vineyard in California anda net-zero energy district in Basalt, Colorado.
For the NODES team, ARPA-E support provided the opportunity to take a leap offaith, landing with the algorithms that are now at the center of NREL’s growing
research portfolio in AEGs. This project inspired momentum in many others
that employ real-time grid control, and it will serve as a foundation for NREL
researchers to continue to bridge early-stage research with industry innovation.

Think Big, Start Small: A Colorado
Utility Tests NREL Innovations in Grid
Modernization
Through a collaborative research-and-development (R&D) agreement between DOE and NREL, Holy
Cross Energy has modernized its system operations in pursuit of fast-tracked renewable energy
goals. The Colorado cooperative, which oversees power in such diverse districts as Aspen Snowmass
and rural ranching communities, is leveraging NREL’s accomplishments in AEGs and ADMS todemonstrate intelligent control on its distribution grid. Such capabilities allow the utility to achieveadvanced visibility into their power system as more DERs are engaged.
ADMS research at NREL has allowed Holy Cross to simulate its grid in a realistic management
environment under various renewable scenarios using a common protocol for device
communications, MultiSpeak, from the National Rural Electric Cooperative Association (NRECA) anda Survalent ADMS controller. Beyond planning for increasing renewable penetrations, NREL’s ADMS
test bed at the ESIF also helped Holy Cross achieve more tangible outcomes. In FY 2019, Holy Cross
applied NREL’s breakthrough control algorithms—developed under the ARPA-E NODES program—toa zero energy neighborhood, collecting first-ever data around energy devices and their complex
control and optimization. The algorithms, which serve as the foundations for AEGs, were piloted ona four-home—soon to be 27-home—neighborhood managed by Holy Cross. The algorithms were
programmed onto controllers manufactured by partner Heila Technologies that are now locatedwithin the homes.
This demonstration is allowing Holy Cross to transition toward renewables with resilience in mind.
Grid resilience is especially important to Holy Cross because its service territory includes some of thenation’s most wildfire- and avalanche-prone terrain.
The results of NREL and Holy Cross Energy’s grid modernization partnership will be watched byother rural utilities and cooperatives around the United States and is being sponsored by NRECA.
The partnership also marks the real system debut of NODES and a novel application of ADMS. It is an
opportunity for these technologies to start small and scale up to systems around the United States.

Watch: Learn more about the NREL-Holy Cross Energy
partnership that’s taking NREL algorithms for AEGs to
a net-zero energy development in Basalt, Colorado:(https://bit.ly/3amdPCo).

| 22 | ﻿

﻿ | 23 |Advanced Distribution Management System Evaluation
Targets Partner Needs with Case Studies

NREL and Eaton Mobilize Industry to Unite,
Plan for EV Fleet Growth

The ADMS test bed at the ESIF is central to one partner’s labeling of the facility as a “distribution system
in a box.” The focus of the test bed is on helping utilities modernize operations and safely test options for
managing an upsurge in customer-sited energy devices.

The electrification of vehicle fleets presents unique challenges for utility companies and fleet
owners. At the same time, it presents a synergistic opportunity for stakeholders to consider fleet
electrification within the bigger context of DER integration. During the last two years, NREL andon-site partner Eaton have continuously engaged stakeholders from across industry to develop a
co-optimization platform and techno-economic analyses for how DER technologies can operate inconcert with EV fleets.

NREL asked its partners how to best use the test bed’s capabilities. The results were two case studies
addressing one of the industry’s most urgent needs facing an ADMS rollout and one of its most keen interests
for future applications.
The first case study considers the impact that model quality will have on ADMS performance. Researchers useda feeder from Colorado’s Xcel Energy utility and simulated how an ADMS application responded at different
levels of model quality.
The second case study simulated a feeder from rural utility partner Holy Cross Energy to study a future highDER scenario and enhanced ADMS data collection that extends observability and controllability behind themeter. The study revealed that by using NREL’s real-time control algorithms (see NODES and AEGs) and modelpredictive control framework to control DERs, overvoltage events are completely prevented, and the flexibilityof DERs to provide active and reactive power support is well leveraged to optimize distribution grid operation.
With support from DOE’s Office of Electricity, the ADMS test bed continues to be built around partner
needs, and with the recent integration of the ESIF’s most advanced capabilities—from cosimulation tocommunications—the ADMS test bed is a national resource that can be leveraged to modernize our grid.

Making the Most of Data for Grid Optimization
Two NREL projects are part of the Enabling Extreme Real-Time Grid Integration of Solar Energy (ENERGISE)
program, an initiative from DOE’s Solar Energy Technologies Office to innovate fast-acting grid control thatpulls out all the stops, including widespread data collection, machine-learned forecasting, and controllable
energy devices. NREL’s projects are cornerstones of this task: researchers are building frameworks aroundefficient grid forecasting and centralized control for a decentralized grid.
One project, Grid Optimization with Solar (GO-Solar), is learning how to use the fewest measurements andthe fewest control points to optimize the grid. With diverse sensor data, the GO-Solar platform will estimate
and forecast the state of the grid and then efficiently direct its behavior. The entire island of Oahu, Hawaii, will
be simulated and used to validate GO-Solar and test cyberattacks on the platform using the GMLC-funded
cosimulation software HELICS. Large-scale HIL demonstration will also be performed in the ESIF.
The other project, Enhanced Control and Optimization of Integrated Distributed Energy Applications (ECOIDEA), is creating an architecture to control the grid hierarchically from the perspective of a utility. This projectis using an ADMS for real-time operation of DERs. This past fiscal year, researchers modeled the control
architecture on NREL’s ADMS test bed and initiated a field validation of the controls on Xcel’s grid in Colorado.

| 24 | ﻿

EV fleet use is an important constraint in determining battery sizing, availability, and charging rates—
these considerations can make or break the decision to electrify a fleet and could make a differencein many millions of dollars annually for corporations and utilities. Additional concerns, such as impact
on battery life and charging infrastructure needs, make the optimization of EVs with DERs very
complex, especially at the scale of deployment expected in the coming years. The NREL-Eaton teamhas developed a framework to co-optimize these technologies.
The ESIF—with its capacity for high-performance testing on real and simulated DERs as well as its
suite of techno-economic analysis resources—offers a unique destination for this project. In FY 2019,
the ESIF’s HPC and power hardware-in-the-loop (PHIL) capabilities were used to elevate the fidelity of
testing. NREL’s in-house tools—including Renewable Energy Integration and Optimization (REopt™),
Electric Vehicle Infrastructure Projection (EVI-Pro), and Battery Life Assessment and Simulation(BLAST)—have been central to optimizing the economics of EV fleets. Additionally, NREL leveraged
Eaton’s Power Xpert controller to understand the coordinated control of diverse energy devices. This
NREL-Eaton partnership represents a significant collaboration with regular on-site work; an industry
advisory board; and highly visible, consensus-driven research.
The growth in EV fleets has the potential for impact that will be felt across the grid, and this project
evaluates how systems can be co-optimized with other technologies and with consideration oflocation. Questions that have been asked and that will influence the future of electrification include:
How can we co-optimize other grid resources when electrifying fleets to make the most economic
sense? How can we optimally size EV fleets? And how can these assets be coordinated to provide therequired grid flexibility to enable an electrified future?

Watch: See how NREL and Eaton are drawing on industry input tounderstand the economics and energy dynamics of fleets:(https://bit.ly/304tcuo).

﻿ | 25 |Award-Winning Software Safely Puts
New Solar on the Grid, Cuts Cost on
Infrastructure
As hardware costs drop, ratepayers are rushing toward solar; however, some
utilities are overwhelmed by their responsibility to safely program each new solar
inverter. An NREL-developed software, PREconfiguring and Controlling Inverter
SEt-Points (PRECISE™), offers a solution to speed up inverter registrations while
optimizing inverters’ reliability and energy savings. In FY 2019, PRECISE wasdeployed on a real grid, recognized as one of the year’s most important inventions
by receiving an R&D 100 award, and prepared for application worldwide.
NREL’s partner in the development of PRECISE, the Sacramento Municipal Utility
District (SMUD), helped motivate this software. SMUD’s distribution system
contains some of the fastest growth in residential solar, but customer solar
applications were being delayed by the critical and time-consuming process ofreviewing inverter settings. SMUD and NREL collaborated to automate the process,resulting in SMUD’s adoption of the new technology. An inverter application used
to take more than a week to review, but now PRECISE optimizes inverter settings ina matter of seconds.
PRECISE was developed at the ESIF by combining newly built grid optimization
techniques with the latest standards for inverter settings. PRECISE’s ability to
optimize inverter settings across a multitude of variables was accomplishedthrough large-scale system simulation using NREL’s PHIL.
The success of PRECISE could soon save solar-rich grids from hefty investments.
An outcome of the software is that grids will no longer need multimillion-dollar
command and control infrastructure updates to optimize inverter performancein real time; instead, PRECISE places operational windows on each inverter thatwill last throughout the device’s lifetime. It is an efficient optimization scheme formillions of new devices that requires minimal investment from utilities.
For the next steps, NREL is seeking to support grids that are undergoing a shift tohigh-penetration solar by adapting PRECISE to their grids. PRECISE will optimize
power systems with any type of technical requirements, whether they containlegacy or advanced inverters or have inverter control infrastructure.

Watch: PRECISE helps utilities identify optimal inverter
modes and settings for distributed PV, cutting costs
and delays for rooftop PV. Learn more by watching thisvideo: (https://bit.ly/306jnfn).

| 26 | ﻿

Algorithms for Building Controls
Balance Comfort and Efficiency
A building’s energy use can be forecasted, and a new project isshowing that smart controls can benefit from those forecasts.
The project is funded by DOE’s Building Technologies Officeand connects NREL and the University of Colorado Boulder withcompanies that are also pushing the frontier in buildings science.
In collaboration with QCoefficient, a company that integrates
heating, ventilating, and air-conditioning operations with thegrid, and Heila Technologies, which creates hardware solutions
for microgrid control, NREL is learning the optimal control ofbuildings that will balance grid services, resilience, and occupantcomfort. The approach could provide enormous energy savings
by integrating two sectors that have historically operated
independently.
This partnership is applying ESIF assets to learn building behavior
and how buildings will respond to NREL’s control algorithms.
HPC will be used to first learn—through reinforcement-learningtechniques—how building energy behavior correlates withbuilding occupancy, and later how that behavior responds to
NREL’s algorithms. The ESIF’s simulation capabilities will allow
researchers to validate numerous approaches to building control.
The team’s embrace of model-free learning will be a uniqueoutcome of this project—an approach that will reduce theexpense and labor of producing building-specific models andextend the results of this project to generic buildings withminimal customization. This project will also allow buildings
to participate in resilience services by automatically supplying
critical assets in disaster or severe weather events.

Finding Common Ground
Between Control Systems
Mirroring changes to the grid, energy management is about
to become much more complex. In the cross-laboratory GMLC
project “Multi-Scale Integration of Control Systems,” NREL andpartners are synthesizing control for energy management
systems (EMS), distribution management systems (DMS), andbuilding management systems (BMS) into an open framework.

Laboratory have virtually linked their DMS and EMS, respectively,
through the Energy Sciences Network, an intersite data link. NREL
researchers have also successfully defined and demonstrated ause case that uses distribution system assets to support voltages
in transmission systems.
Coordination among the control systems will smoothmanagement for system operators in an increasingly connected
grid. While each management system evolves, NREL and partner
laboratories are helping to find common ground related to data
integration, decision support, and risk-based operations.

Improving Grid Resilience withDistributed Device Controls
The spread of grid devices means, metaphorically, a lot moreeyes on the grid and a new level of grid intelligence. These
two attributes are being channeled in the collaborative GMLC
project “Increasing Distribution Resiliency Using Flexible DER andMicrogrid Assets Enabled by OpenFMB” to protect distribution
systems from faults and service outages and step up system
resilience with fast communications and controls.
The approach to resilience involves an algorithm created bypartner General Electric, which NREL tailored for testing on a realworld feeder, as identified by another partner, Duke Energy. This
past year, NREL worked with project partners to install the ADMS
and complete remote connection testing between NREL, Oak
Ridge National Laboratory, and the University of North CarolinaCharlotte with digital and analog simulation capability.
This project is representative of the GMLC Resilient Distribution
Systems portfolio as a technology that can overcome a cyberincident in an early stage, specifically by focusing on fault
location, isolation, and system recovery. Also in line with theportfolio, this year marked a field validation on a distribution
system. Next steps will use the secure cross-laboratory link aswell as a decentralized form of the algorithms created at the
Pacific Northwest National Laboratory to further understand how
distribution system management and grid intelligence can cometogether for system resilience. The team’s developments will bescalable, fast, and widely relevant to power system operators
within the open-source messaging protocol OpenFMB.

The past year has recorded important steps toward integrating
the control frameworks. NREL and Pacific Northwest National
﻿ | 27 |Project Spotlight

Design &Planning
Tools

Simulation Engine HELICS
Continues to Drive LargeScale Studies at the ESIFAt the heart of the ESIF’s large-scale power
simulations environment is HELICS. By providing
interfaces between modeling tools, HELICS enables
highly scalable cosimulation links among multiple
interconnected energy systems, including the powersystem, communications and controls systems,
and more. The platform enables unprecedented
integrated physical-market-controller simulations
that include hundreds to tens of thousands ofindividual software models running across multiple
HPC nodes through NREL’s super computer Eagle.
In FY 2019, HELICS served as the foundation
for some of the ESIF’s most impactful research,
including city-scale simulations to support NREL’s| 28 | ﻿

work in AEGs. Researchers used HELICS to develop
grid control simulations for a new high-penetration
solar control scheme and to help manage millionsof devices on Hawaii’s grid. HIL simulations reliedon HELICS to coordinate interactions amongslower timescale models and faster real-timetransient simulations that directly interact withhardware on NREL’s ADMS test bed. Additionally,
researchers began using HELICS for resilient energy
systems analysis—from developing cybersecurity
assessment plans for novel control schemes tosupporting the multi-lab continental-scale North
American Energy Resilience Model (NAERM).
HELICS has been developed as part of a GMLC
initiative and in collaboration with Lawrence
Livermore National Laboratory, Pacific Northwest
National Laboratory, and Argonne National
Laboratory. In FY 2019, HELICS was recognized as a
finalist for an R&D 100 award.

﻿ | 29 |Project Highlights
Cooperation Across Countries Informs Transcontinental
Power System Modeling
Renewable energy is transforming power systems in each North Americancountry, leading researchers to ask how the continent’s grid could look if
its transmission systems were coordinated. The North American Renewable
Integration Study (NARIS) pulls together NREL modeling resources
and supercomputer simulation capacity to assess the challenges andopportunities of coordinating power system planning and operations acrossCanada, Mexico, and the United States through the year 2050.
NARIS will inform grid planners, operators, and regulators around thepossibilities of interregional and international cooperation while delivering
scenarios, methods, and data sets to enable future studies. NREL tools formodeling resource planning, production costs, power flow, and reliability
have been expanded through NARIS using the ESIF’s HPC and NREL’s
continent-wide wind data sets.
Using NREL’s open-source tools and upcoming results from NARIS simulations,stakeholders will be able to perform deeper analyses into topics such as
power system stability and resilience in the transition to a modern electric
power system.

Realistic-But-Not-Real Data Sets Offer Work-Around for Grid ResearchWith a final year of funding from ARPA-E, researchers further developed the Synthetic Models for
Advanced Realistic Testing of Distribution systems and Scenarios (SMART-DS) repository of synthetic
power system data sets. SMART-DS creates power system models with consideration of real geography,
line characteristics, and typical utility practices. The models are compared against thousands of utility
feeders to ensure that the structure and operation of the SMART-DS data sets are representativeof realistic electrical networks. The development of synthetic power system data sets is a boon forresearchers who in the past were limited to trialing their grid advancements on small feeder models.
Not only are all SMART-DS models freely available online, but the models also contain numerous
customizable scenarios, including EV penetrations, solar and battery deployments, outage scenarios, anddemand response, to name a few. SMART-DS was developed in collaboration with the Comillas Institutefor Research in Technology, Massachusetts Institute of Technology, CYME International, and Electrical
Distribution Design.

Solar Planning Tool Links Economics and Operation
NREL partnered with the Electric Power Research Institute (EPRI); University of Tennessee, Knoxville;
and Southern Methodist University to create a resource for understanding the interplay of economicscheduling and power system response. The project is named the Multi-timescale Integrated Dynamics
and Scheduling for Solar (MIDAS-Solar). MIDAS-Solar will provide an essential planning tool for system
operators. The modeling tool will accurately assess system reliability, including all forms of reliability
services currently provided by modern PV power plants. It will also simulate grid scenarios between dayahead (economic scheduling) and subsecond (system response analysis) timescales.
In its first year, this project, which was funded by DOE’s Solar Energy Technologies Office, was applied to
California’s goal for extremely high renewable energy deployment. The team successfully modeled an
integrated power system within its multitimescale operation framework, showing how deployments ofmany renewable energy systems can be represented in the MIDAS-Solar modeling scheme.
Upcoming work will consider reserve scheduling under critical contingency conditions and will study
interactions of reliability services at all timescales.

| 30 | ﻿

﻿ | 31 |Project Spotlight
Exploring Dynamic Cyber
Solutions on a Virtual
Utility Grid

EnergySecurity

Evaluating cybersecurity for an evolving electric grid
requires a special kind of validation space—one that
goes beyond our physical world.
With continued LDRD support to increase thesecurity and resilience of the electric grid, NREL
researchers have built an emulation environment forthe safe evaluation of vulnerabilities within complex
cyber-energy systems. This novel emulation platform
allows NREL to clone thousands of virtual griddevices working with physical grid devices—solar
inverters, wind turbine control systems, batteries,
and EV chargers—throughout NREL’s ESIF and
Flatirons Campus.

With the increase in DERs and growing potentialof cyber threats, the attack surface across the
distribution grid is expanding. New cybervulnerabilities accompany distributed grid devices,calling for advanced cyber solutions that can protect
such assets. By emulating a virtualized utility grid,
NREL can safely evaluate the impact of these trends,
implement intrinsic security in the system designphase, and position the distributed grid as a much
more challenging target for malicious attacks.

The platform leverages Sandia National
Laboratories’ SCEPTRE, a tool that provides theability to emulate multiple infrastructures (electric,
water, gas, and transportation) and communications
networks. Looking ahead, the team plans tointegrate the multilaboratory HELICS cosimulation
framework into the platform, enabling even more
dynamic emulation and visualization for advanced
threat analysis.

| 32 | ﻿

﻿ | 33 |Project Highlights
Advancing Encryption for Distributed Energy Resources
with Module-OT
During the past two years, NREL has worked with Sandia National Laboratories,
the Public Service Company of New Mexico, and Yaskawa-Solectria Solar todevelop Module-OT, a low-cost, modular device that provides optimized
encryption for DERs and their operational networks. The device software iscompatible with a variety of operating systems and is compliant with the threemajor communications protocols used in DER systems: Modbus, Distributed
Network Protocol 3, and Smart Energy Profile 2.0.
In FY 2019, advancements to the technology focused on improving data
privacy for user applications through encryption, authentication, authorization,
certificate management, and user access control. Researchers evaluated andverified the performance of the module with emulated distribution system
devices and data. The device was then physically validated both in the laboratory
at the ESIF and in the field at a 500-kW solar-plus-storage site in New Mexico thatis owned and operated by the Public Service Company of New Mexico.
This technology will help protect command-and-control messages overcommunications channels, allowing distributed systems to operate smoothly
without disruption from malicious adversaries.

The Distributed Energy Resources Cybersecurity Framework
With support from DOE’s Federal Energy Management Program, NREL
researchers developed the Distributed Energy Resources Cybersecurity
Framework (DERCF) to help federal agencies across the country mitigate
gaps in cybersecurity for distributed energy. This framework expands on
DOE’s Cybersecurity Capability Maturity Model (C2M2), the nation’s current
framework for cybersecurity evaluation, placing increased focus on DERs
as well as physical security and technical management. NREL developed awritten version of the DERCF, detailing best practices and security controls for
DERs, in addition to a Web application for cybersecurity assessments. The Web
application guides account owners through a series of questions about thecontrols and practices that pertain to their DER use and application, including
PV generation, wind turbine generation, EVs and charging stations, andelectrical battery storage.

Watch: Learn more about what NREL is doing to
mitigate threats to today’s energy infrastructure
and provide a pathway to a more secure andresilient energy future: (https://bit.ly/2FyN7Z9).

| 34 | ﻿

﻿ | 35 |Project Spotlight
From Sea to Sea, DOE Eyes
National Resilience Solution
with NREL Insight

EnergyResilience| 36 | ﻿Resilience has become a key focus area acrossmodern grid studies, and one DOE project is taking
the largest look yet at how to improve the resilienceof the North American power system. NAERM is abroadly useful platform for planning, situationalawareness, and recovery from emerging challenges
to the grid. The NAERM effort has counted on
NREL leadership—as well as seven other national
laboratories—throughout FY 2019, which included
several accomplishments toward the project’s
national vision.

With HPC at the ESIF, NREL modeled disasters andunexpected outages on the North American grid
system. In one use case, NREL simulated multiday,
long-duration events, such as a polar vortex. NREL
modeled the combined impact on the electric gas
infrastructure from an unexpected outage; dual-fuelfiring generator limitations; and wind turbine cold
temperature and icing cutoffs that affected all bulk
system loads, transmission, and renewable resources.
In another study that NREL leads, researchers arecharacterizing the impact of DERs in resilience
scenarios. Their studies this past year simulated DER
response in the event of delayed voltage recovery
from a fault. Results from such studies help utilities
develop best practices for resilience planning acrossall grid scales.

In mid-2019, DOE released the NAERM congressional
report, which NREL helped author. The report
includes NREL input into strategic planning, industry
engagement, and technical development. It alsodetails modeling efforts performed at NREL on the
Eagle supercomputer and leveraging past DOEfunded projects at NREL, including the National Solar
Radiation Database, the Wind Integration National
Dataset (WIND) Toolkit, and the North American
Renewable Integration Study.

NREL’s support of NAERM also extended to
stakeholder engagement. NREL created visualizations
that enable modeling analysts and executive
management to understand grid operations
and impacts. Also, the NREL-developed Resilient
Operations Model will empower stakeholders to
support nationwide resilience. With the continued
development of NAERM, NREL will lend its expertisein exploring critical “what if” questions regarding ourenergy infrastructure and the challenges it will face.

﻿ | 37 |Project Highlight
NREL and the National Park Service Visualize Improved Resilienceat Coastal Parks
Researchers at NREL partnered with the National Park Service (NPS) to examine
the risk of coastal park infrastructure to natural hazards with the intent toimprove operational resilience. Through prior work, the NPS determined thatrising sea levels coupled with storm events endanger natural and cultural
resources and park-built assets. A new visualization platform is helping
researchers develop a planning guide for improved resilience for the NPS as
well as other land management agencies and entities facing similar threats.
An initial site assessment entailed a resilience analysis of infrastructure related
to energy, transportation assets, fuel delivery, communications, cybersecurity,
and water systems. Using the ESIF’s unique 3-D visualization capabilities,
researchers developed a spatial augmented reality platform that combines
site data with a physical 3-D model of the study area. This platform allows
researchers to physically demonstrate the impact of various natural hazards on
infrastructure and assets.
The new spatial augmented reality framework is a first-of-its-kind tool thatcombines measured and modeled data with a physical 3-D model, providing
the unique capability to demonstrate the impact of climate hazards on
infrastructure and assets. This tool provides an economic and transportable
method to communicate complicated data sets in a visually compelling andstraightforward manner.

| 38 | ﻿

﻿ | 39 |Project Spotlight

Institutional
SupportRenewable Energy Tools
Increase Resilience for
Storm-Struck Puerto Ricoand Virgin Islands
In the wake of several high-intensity Caribbean
storms, NREL expanded resilience tools to U.S.
territories Puerto Rico and the Virgin Islands.
Collaboration between NREL and the islands will
prepare both territories to make renewable energy
investments and decisions that strengthen theirinfrastructure against future events.
NREL first extended its National Solar Radiation
Database to the two islands. These data, as wellas Puerto Rico grid models developed in the ESIF,
helped NREL produce an extension of the System
Advisor Model (SAM) that is specific to Puerto Rico,enabling stakeholders to perform production cost

| 40 | ﻿modeling and cost-benefit analysis of renewableenergy systems. NREL then trained decision makers
in Puerto Rico on how to use the tools as well as on
best practices around emerging energy resources.
During two workshops in March 2019, stakeholders
shared their energy planning needs and learned
about tools from NREL and other national
laboratories to support energy planning in PuertoRico. NREL also organized a webinar series forparticipating laboratories to provide stakeholders
access to tools, resources, and modeling results.
The NREL planning tools are now nationally inclusiveand contain models for Puerto Rico’s exceptionallyvulnerable grid. Comprehensive resilience planning
is a national priority, and this project provides
support to the DOE-led NAERM initiative.

﻿ | 41 |Advanced
Mobility| 42 | ﻿

Project Highlight
Improving Grid Resilience with Vehicle-toGrid Characterization
NREL researchers are comparing the degradation of two Chrysler Pacifica
plug-in hybrid electric vehicle (PHEV) battery packs for DOE and EPRI. In the
ESIF, researchers are evaluating one pack that would undergo a normal PHEV
profile, modeling a scenario where a car drives to work and charges at home.
In comparison, researchers are evaluating a second pack subjected to a PHEV
profile where, after arriving home, the car battery would contribute to powering
grid activities. In the coming year, researchers will cycle these batteries throughthe equivalent of two years’ worth of vehicle use while evaluating capacity
degradation and power loss as the battery packs age. Results of this study are
anticipated to shed light on whether PHEV batteries can supplement the energy
demands of a home and provide increased grid resilience.

﻿ | 43 |Hydrogen &Renewable
Fuel Systems

Project Highlight
H2@Scale Brings New Partners
to Advance Station Design andOperating Strategies
Through DOE’s H2@Scale initiative, NREL continues to work withindustry partners to advance the large-scale production, transport,
storage, and use of hydrogen across multiple sectors of the economy.
Power generators, technology developers, and automakers areleveraging NREL expertise and ESIF capabilities through cooperative
H2@Scale research projects to address early-stage R&D challenges inhydrogen infrastructure, low-temperature electrolysis, energy storage,
and renewables-to-grid integration. In FY 2019, NREL kicked off a
new project with Shell, Air Liquide, Toyota, and Honda to researchinnovative hydrogen station designs and operating strategies. The
team will address challenges related to component reliability at highthroughput fueling stations and develop high-flow-rate systems for
new applications such as medium- and heavy-duty truck fueling.

| 44 | ﻿

﻿ | 45 |Project Highlights
Improving Alkaline Membrane Fuel Cell Performance
Alkaline membranes are a promising technology at a low level of technology readiness with significant potential
for decreasing costs and precious metal use in energy conversion devices. NREL is developing high-performance
alkaline fuel cell membranes and electrodes to improve the commercial viability of this technology. In FY 2019,
NREL, with partners Georgia Institute of Technology and the University of South Carolina, demonstrated forthe first time alkaline membrane fuel cell power density at more than 3 W/cm2 using advanced membranes,
electrodes, and cell testing. This level of performance is more than double the highest reported performance in2017 and is near parity with the proton-conducting systems that are available today.

Converting Waste Carbon Dioxide and Hydrogen to Fuels and Chemicals
NREL is leading a multilaboratory collaboration to develop an industrially scalable electrochemical process for
reducing waste carbon dioxide (CO2) to useful chemicals and fuels. This “electrons-to-molecules” approach uses
a waste product as the backbone to store inexpensive renewable electricity as hydrogen and carbon bonds inthe form of high-density liquid fuels and valuable chemicals. NREL leveraged its experience in hydrogen fuelcell and electrolyzer test stand construction and operation to develop test stands for CO2 electrolysis. These newcapabilities provide critical electrochemical diagnostics information about CO2 electrolyzers and establish NREL asa facility for benchmarking CO2 reduction devices and electrocatalyst performance.

Bioreactor Begins Producing Renewable Natural Gas from Renewable Hydrogenand Carbon Dioxide
NREL, SoCalGas, and Electrochaea are developing a flexible biomethanation process to upgrade biogas waste
streams to produce pipeline quality renewable natural gas using a pressurized 700-L bioreactor designed
and built by SoCalGas. The biomethanation process converts CO2 and hydrogen gases using the biocatalyst
Methanothermobacter thermautotrophicus (methanogen) to produce methane, water, and heat. This process is a
way to store low-cost renewable electricity in the expansive natural gas grid and to recycle CO2 using renewablehydrogen. In FY 2019, NREL commissioned the bioreactor and began operations with the methanogen, which wascelebrated with a ribbon-cutting ceremony at NREL’s Partner Forum in August. The first methane production fromthe bioreactor was confirmed with the onboard gas chromatograph within six hours of starting gas flows. As the
microorganism population grew, the reactor pressure was increased gradually, and methane production reached
90% after about 40 hours. Moving forward, the hydrogen and CO2 flow rates as well as the bioreactor pressure
will be increased to achieve the operating target of 18-bar pressure and gas composition of greater than 97%
renewable methane.

Enabling High-Volume Manufacturing of Fuel Cell Membranes
NREL completed a multiyear project with W.L. Gore & Associates to develop methods for characterizing the fullproduction-roll quality of fuel cell membranes as they are being manufactured. Using ESIF roll-to-roll processing
equipment and laboratory-developed optical inspection techniques and apparatus, the team provided full-width,full-length, high-resolution imaging of 14 production and experimental rolls of GORE-SELECT Membrane, totaling
more than 1.6 km of membrane mapped. Researchers also used NREL-developed automated algorithms to detectand classify membrane defects in each roll.
| 46 | ﻿

﻿ | 47 |Project Spotlight

HighPerformance
ComputingHigh-Performance
Computing Powers Detailed
Study of Future Energy
Pathways for Los Angeles
The City of Los Angeles could take many routes toreach its goal of 100% renewable energy by 2045. In
a study of unprecedented detail for the Los Angeles
Department of Water and Power, NREL is performing
hundreds of thousands of simulations to understandthe options and trade-offs among the various
investments Los Angeles could make.

possible net macroeconomic impacts in addition
to an analysis of all capacity needs and bulk power
operations.
As more cities adopt near-term renewable energy
goals, this project could empower stakeholders withan example of objective, high-fidelity power systems
analysis for informed planning and decision making.

NREL’s supercomputer Eagle has been programmed
to simulate factors in Los Angeles’s energy transition,
including EV adoption, building electrification, andenergy-efficiency improvements. The simulations
depend on an integrated suite of sophisticated
NREL energy modeling tools, and results will reveal

Watch: See how NREL’s new supercomputer Eagle is helping NREL researchers
find the answers to smart, bold questions about transforming our energy
system: (https://bit.ly/2T3VKTo).

| 48 | ﻿

﻿ | 49 |Improving Load Predictions to Better Understand Offshore Wind
Systems Physics

Project Highlights

NREL is working on an international research project focused on validating themodeling tools used to design offshore wind systems with HPC. The goal is toimprove load predictions from engineering-level models through comparison
to measurement data and higher fidelity simulations using computational fluid
dynamics (CFD). In FY 2019, NREL performed simulations with the system in a
fixed condition for multiple regular wave scenarios. The system was also forced tooscillate in the surge direction for different frequencies and amplitudes. This simpler
structure was used as a starting point to understand the methodology and needs
when performing CFD simulations of offshore wind structures.

Eagle: NREL’s Newest Supercomputer Dedicated to Energy Efficiency
and Renewable Energy Research
As a replacement for NREL’s prior supercomputer, Peregrine, Eagle was put into
production use in January 2019. Like Peregrine, Eagle was designed and built
by Hewlett Packard Enterprise and has an innovative warm-water liquid-coolingsystem that allows waste heat to be captured for reuse. The system is a Linuxcluster that uses a fast InfiniBand network. It comprises 2,114 interconnectedcompute nodes with 4,228 Intel Skylake processors and 76,104 total cores—
along with 14 petabytes of high-speed data storage. The peak performanceof Eagle is approximately 8 petaflops, or 8 million billion floating point(mathematical) operations per second.

Developing a Next-Generation Capability for Simulating Modern
Wind Turbines

NREL Garners Top Sustainability Honor at Data Center
Dynamics Awards
In December 2018, NREL won the prestigious Data Center Dynamics (DCD) Data
Center Eco-Sustainability Award, bolstering the laboratory’s status as a world
leader in data center efficiency and sustainability. Referred to as the Oscars of thedata center industry, the annual DCD Global Awards recognize the industry’s top
data center projects and people. An independent panel of data center experts
selected finalists from hundreds of entries from organizations around the world.
This award recognizes innovative and pioneering approaches to sustainability
through the design or major retrofit of a data center facility. The win solidifies
NREL’s claim to the most energy-efficient data center in the world, which NREL
designed in partnership with SmithGroup LLC and Johnson Controls Inc.

ResStock™ Building Analysis Tool Improves Energy Efficiency forStates, Municipalities, Utilities, and Manufacturers
NREL received a 2019 R&D 100 Award in the Software Services category for
ResStock™, a highly granular energy simulation tool that leverages the ESIF’s HPC
for a new approach to large-scale residential energy analysis. Using the Eagle
supercomputer, ResStock combines large data sources, statistical sampling,
and detailed subhourly building simulations to model hundreds of thousandsof buildings and identify cost-effective efficiency upgrades. Drawing fromreal-world characteristics and physics-based models, it has identified potential
upgrades worth $49 billion in annual savings across the United States. In FY
2019, the ResStock team released a resource for communities planning their own
building stock analysis, and the technology was a key component of a first-of-itskind 100% renewable energy study for the City of Los Angeles.

| 50 | ﻿

NREL’s HPC Data Center, supercomputing
systems, and visualization facilities support
cross-cutting research to tackle energy
challenges that cannot be addressed
through traditional experimentation
alone. NREL’s HPC resources are criticalin transforming large AMI data sets into
actionable, distribution-level planningfor SDG&E; developing advanced model
scenarios for the multi-lab NAERM project;and helping the City of Los Angeles
reach its ambitious renewable energy
targets through hundreds of thousands ofsimulations.

NREL is developing Nalu-Wind, a next-generation wind power plant fluid flow solver,with funding from both DOE’s Water Power Technologies Office and the Office of
Science’s Exascale Computing Project. In FY 2019, NREL and partners created a
new blade-resolved model of a large modern wind turbine, enabling scientists andengineers to begin understanding the complex flow physics in multiturbine wind
power plants that will take advantage of future exascale modeling and simulation
capability. When validated by targeted experiments, these and other predictive
physics-based high-fidelity computational models—and the new knowledge
derived from their solutions—provide an effective path to optimizing wind power
plants. With a code that can run at exascale, researchers will be able to simulate
wind power plant cases at unprecedented resolutions and domain extents, allowing
for new scientific discoveries about wind power plant physics. Likewise, futuresmaller HPC systems will borrow technology from these systems.

Evaluating the Impact of Water Availability on Grid Configurations
The U.S. electric power sector relies heavily on cooling water and hydroelectric
power for reliable and consistent operation. The impacts of water scarcity on power
sector operations can be quantified using a variety of metrics, including total systemproduction costs, regional energy generation, and regional energy prices, among
others. Using a power systems model and HPC to evaluate the impact of water
availability and grid configurations, NREL is considering region-wide impacts aswell as subregional responses to capture regional capacity differences and realistic
grid connectivity dynamics. In FY 2019, NREL researchers used Eagle to capture
multiple climate-forced water availability scenarios across a range of historicaland future years. Researchers believe this work represents the largest set of powersystem simulations under climate-forced water constraints to date. With traditional
computing, run time for this type of simulation could take two months. HPC iscritical for this project, allowing each of the 700 individual-year simulations torequire only about two days.
﻿ | 51 |Analyzing Costs, Benefits of Distributed Photovoltaic Generators to Help
Evaluate Solutions for Distributed Photovoltaic Systems
To help utilities, solar developers, and DER aggregators evaluate different solutions tointegrate distributed photovoltaics (DPV) onto the grid, NREL is evaluating the costs
and benefits of DPV generators to distribution systems as a function of penetrationlevel. Researchers use a bottom-up methodology that combines power flow
modeling and hosting capacity analysis with techno-economic analysis. In FY 2019,
NREL incorporated innovative quasi-static time-series simulations to capture timedependent impacts of PV as well as consider a broader set of advanced technology
options for grid integration, including distributed energy management systems andflexible interconnection approaches. With access to Eagle, researchers can conduct
this analysis for a much larger number of DPV penetration levels to elucidate the key
drivers of costs. Additionally, the HPC allows for rapid prototype development of new
algorithms and tools for distribution grid integration.

Demonstrating Power, Utility of High-Fidelity Computation Methods toModel Meaningful Catalytic Systems
Affordable energy storage is of paramount importance if renewables are to become adominant contribution to the U.S. energy supply. One approach is to store the energy
in the form of a liquid fuel, using either a photo-electrochemical cell or an electrolyzer
hooked into an electrical source. In FY 2019, NREL used a promising catalyst as amodel to demonstrate how the implementation of high-fidelity computational
methods can scale to large system sizes, extend this framework to systems involving
solvent screening, and incorporate additional energetic terms. Results demonstrated
the power and utility of techniques to model physically meaningful catalytic systems
at realistic operating conditions using high-fidelity computational methods.

Assessing the Relationship Between Energy Efficiency and Demand
Response in Future Power Systems
NREL is using HPC to provide a realistic and detailed understanding of the relativevalue of and interaction between the energy-efficiency and demand characteristics
of building technologies in terms of power systems’ time-varying costs and emissions.
In FY 2019, researchers launched the first phase of this project, which was built on
past work to tackle grid reliability challenges; researched occupant requirements
and preferences; and analyzed the value of energy efficiency and demand response
in at least three regions, leveraging several NREL models. The outcome will be an
analysis platform that can assess trade-offs and cobenefits between energy efficiency
and demand response in a variety of power system futures. Having access to HPC
resources allows NREL to work unconstrained in terms of geospatial extent andresolution of the analysis.

| 52 | ﻿

﻿ | 53 |Top Operations Updates

ESIF Lab Updates& Advanced
Capabilities| 54 | ﻿•Commissioned an outdoor bioreactor system designed to operate
in hazardous locations (Class 1, Division 2). Currently operating tobiologically convert hydrogen and CO2 to pure methane (natural gas)•

Upgraded overhead medium-voltage research distribution line in theMedium-Voltage Outdoor Test Area to triple its length, add platforms
for equipment mounting, and include connection points for advanced
data acquisitions and easy equipment hookup•

Built out ADMS test bed functionality by deploying commercial ADMS
platforms with advanced applications and prototype control systems,
integrating HELICS, and including input from industry advisory partners•

Built and commissioned a 30-kWe, 60-kW thermal natural gas
combined heat and power system in the Power Systems Integration
Laboratory•

Expanded electrolyzer fuel cell test capabilities in the Energy Sciences
Laboratories•

Reconfigured 25% of office space, doubling occupancy in that area•

Reconfigured common spaces, adding meeting spaces and huddle
rooms for additional staff•

Reconfigured Eaton laboratory space in the Energy Storage Laboratory
as well as office space per proprietary user agreement•

Completed audit. The International Organization for Standardization(ISO) commended the ESIF, finding no opportunities for improvement
and no items of noncompliance. The ESIF was further recognized for
four system strengths: one in quality and three in health and safety.

﻿ | 55 |Optimization and Control Laboratory
Converted to Include New Capabilities
ESIF Operations converted more than 5,000 ft² of high-bay laboratory space into
integrated capabilities for commercial buildings infrastructure and completed
research electric distribution bus and thermal capability extensions in this space. The
new commercial building infrastructure capabilities combine building automation
technology with both thermal and electric power optimization. Researchers in thespace can also leverage new capabilities in advanced behind-the-meter energy storage
integration, such as ice storage, refrigeration, and combined heat and power.

ESIF Operations Expanded Power Hardwarein-the-Loop Capabilities
The ESIF’s PHIL capabilities were completed to offer the set of all pertinent HIL
platforms. The ESIF specified and acquired the Typhoon HIL platforms and added the
NovaCore RTDS Simulator and Opal-RT systems. The RTDS and Opal-RT systems werealso expanded to meet future project needs. ESIF Operations plans to blend thesecapabilities by linking them across remote sites (the Flatirons Campus to the ESIF)
and increasing functionality in thermal systems-in-the-loop and network-in-the-loop
capabilities.

New Facility-Wide Data Acquisition Network
ESIF Operations built a versatile, cost-effective data platform serving multiple protocol
translation and streaming data for real-time monitoring. Included is a web-based
visualization tool that allows quick and easy visualization of data setups and project
views for demonstration, offering a huge set of viewable data tags from across thefacility. The end points of the OPC Unified Architecture-based data stream are low costand quickly configurable for high-speed data on voltage, current, and temperature. It
also includes local processing for power and energy calculations.

The ESIF was verified through internationally recognized ISO and Occupational Healthand Safety Assessment Series certifications, including ISO 9001 standard for quality
management, ISO 14001 standard for environmental health and safety, and OHSAS
18001 standard for proper and effective management of health and safety in theworkplace.

Improved Safety Evaluation for Next-Generation
Lithium-Ion Batteries
Researchers have devised a new strategy for testing the limits of next-generation lithium-ion
batteries, including evaluating and ensuring that the batteries meet the highest safety standards
before sending them to market. The new capability fills a crucial gap between the laboratory’s
world-class computational models and thermal evaluation of advanced battery chemistries. The
ESIF provides a space to integrate comprehensive, real-time, multiscale, multidomain models withmodern experimental characterization capabilities that stretch batteries under abuse conditions.
This capability combines NREL’s HPC capabilities with sophisticated characterization tools tofacilitate studies of multiple simultaneous failure modes.

Benchmarking Study Showed Excellent Electrolyzer
Performance and Durability
NREL developed anion exchange membrane and proton exchange membrane electrolysis
test stations to perform state-of-the-art performance and durability experiments with highreproducibility and repeatability. This research supports the HydroGEN Advanced Water SplittingMaterials consortium and other DOE Fuel Cell Technologies Office projects. In a publishedbenchmarking study, NREL’s experimental data showed excellent agreement with those of highly
acknowledged international institutions. These results establish NREL as a leading institution forvalidating the performance and durability of electrolyzer technologies. NREL currently operates
seven proton exchange membrane test stations and is expanding its anion exchange membrane
test station capacity to three test stations.

Improved Reliability of Hydrogen Dispenser Nozzles
for Hydrogen Fueling
To allow for fast fueling, hydrogen is cooled to subzero temperatures (-40°C) before it is dispensed
into FCEVs. These cold temperatures can cause moisture in the air to condense and frost over on
nozzle and receptacle components and in some cases to freeze-lock the nozzle onto the vehicle
for up to several minutes. NREL designed and built a climate-controlled test stand to evaluatehydrogen nozzle freeze-lock and the ideal conditions under which freeze-lock occurs. Results
will be used to help nozzle manufacturers and station providers supply more robust and reliable
nozzles in various climate conditions.

The verifications validate the ESIF’s best-in-class facility mission, demonstrating its
commitment to implementing continuous improvement.

| 56 | ﻿

﻿ | 57 |PARTNERSAir Liquide

Leviton Manufacturing

ToyotaAnterix

Lynntech Inc.

University of California at Irvine

BREK Electronics

Mainstream Engineering

California GO-Biz

Michigan Economic
Development Corporation

University of Colorado at
Boulder

Centrica
The Chemours Company
Commonwealth Edison
Company

ESIF Key Performance
Indicators
ESIF Laboratories

Eaton Corporation
Electric Power ResearchInstitute

Xcel Energy

National Park Service

Yasakawa Solectria Solar

Nel Hydrogen
Ocean Renewable Power
Company
OverDrive
Pacific Gas & Electric Company
Peroxygen Systems

Emerson Electric

pH Matter

Energy Web Foundation

Port of Long Beach

Exelon Corporation

Powerfield Energy

Ford

Power Innovations

Frontier Energy

Proton OnSite
Public Service Company of
New Mexico

155 users•

95% lab availability

Garmor Tech•

83% lab utilization.

General Motors
Giner Inc.
GVD Corporation
Hawaiian Electric Companies•

361 users•

90% lab availability

Holy Cross Energy

80% utilization.

Honda

•

NanoSonic

Element One•

HPC Data Center| 58 | ﻿Daimler AG

Hewlett Packard Enterprise

WalmartRIX Industries
Salt River Project
San Diego Gas & ElectricCompany
Shell
SolarReserve

HyET Hydrogen

Southern California Gas
Company

Hyperlight Energy

Southern Company

Hyundai

SunvaporKWJ Engineering

Tatsuno Corporation

Partnerships are key to NREL’s successand mission. In 2019, two NREL projects
were recognized by R&D World magazine
as one of the nation’s 100 mostinnovative technologies in the past year, both of whichleveraged the ESIF’s unique capabilities and were builtwith industry partners in mind.
The NREL-developed software PRECISE was built withpartner Sacramento Municipal Utility District as a
response to challenges in the solar industry. PRECISE,
validated at the ESIF, offers a solution to speed up
inverter registrations while optimizing inverter reliability
and energy savings.
Also recognized, the building analysis tool ResStockallows states, municipalities, utilities, and manufacturers
to identify which home improvements save themost energy and money. With access to NREL’s Eagle
supercomputer, ResStock has run more than 20 million
simulations using a statistical model of housing stock
characteristics. With these data, researchers haveuncovered $49 billion in potential annual utility billsavings through cost-effective energy efficiency
improvements.
﻿ | 59 |DOE PROGRAMRESEARCH

GMLC Category 1 Projects:
DER Siting and Optimization Tool for California

Grid Modernization

ARPA-E
Network Optimized Distributed Energy Systems (NODES)••

Real-Time Optimization and Control of Next-Generation Distribution 		
Infrastructure (RONIN)
A Robust Distributed Framework for Flexible Power Grids: Enabling the 		
Grid of the Future (ROBUST)

Generating Realistic Information for the Development of Distribution and Transmission
Algorithms (GRID DATA)•

Synthetic Models for Advanced, Realistic Testing: Distribution Systems andScenarios (SMART-DS)

Creating Innovative and Reliable Circuits Using Inventive Topologies andSemiconductors (CIRCUITS)•

A High-Voltage, High-Reliability Scalable Architecture for Electric Vehicle
Power Electronics

Saving Energy Nationwide in Structures with Occupancy Recognition (SENSOR)•

Battery-Free RFID Sensor Network with Spatiotemporal Pattern Network
Based Data Fusion System for Human Presence Sensing

Buildings
GMLC Category 1 Projects:
Advanced Sensor Development
Grid Sensing and Measurement Strategy
Interoperability| 60 | ﻿Fuel Cell Technologies Office

GMLC Category 1 Projects:

1.4.15 Development of Integrated Transmission,
Distribution, and Communication Models
1.4.17 Extreme Event Modeling1.4.18 Computational Science for Grid 		
Management
1.4.25 Distribution System Decision Support Tools

1.1 Foundational Metrics Analysis

1.4.26 Development and Deployment of MultiScale Production Cost Models

1.2.1 Grid Architecture

1.4.29 Future Electricity Utility Regulation

1.2.2 Interoperability
1.2.3 Grid Modernization Laboratory Consortium
Testing Network
1.2.4 Grid Services and Technologies
Valuation Framework
1.2.5 Grid Sensing and Measurement Strategy
1.3.05 DER Siting and Optimization Tool
for California
1.3.10 Vermont Regional Partnership Enabling theUse of DER
1.3.21 Alaska Microgrid Partnership1.3.29 Grid Frequency Support from Distributed
Inverter-Based Resources in Hawaii

GMLC Category 2 Projects:
GM0061 Virtual Battery-Based 			Characterization and Control of Flexible Building
Loads Using VOLTTRON
GM0062 Vehicle to Building Integration Pathway
GM0063 Development of an Open-Source
Platform for Advanced Distribution
Management Systems
GM0085 Systems Research Supporting Standards
and Interoperability
GM0086 Modeling and Control Software Tools to
Support V2G Integration

1.3.33 Midwest Interconnection Seams Study

GM0094 Measurement-Based Hierarchical
Framework for Time-Varying Stochastic Load
Modeling

1.4.01 Standards and Test Procedures for 		
Interconnection and Interoperability

GM0163 Diagnostic Security Modules for Electric
Vehicle to Building Integration

1.4.02 Definitions, Standards and Test Proceduresfor Grid Services

GM0172 VOLTTRON Message Bus Protocol
Adapter

1.4.04 Advanced Sensor Development

GM0187 Community Control of Distributed
Resources for Wide Area Reserve Provision

Integrated Multi-Scale Data Analytics and Machine Learning for the Grid

1.4.09 Integrated Multi Scale Data Analytics andMachine Learning for the Grid

Distribution System Decision Support Tools

1.4.10 Control Theory

GM0229 Integrated Systems Modeling of theInteractions between Stationary Hydrogen,
Vehicle and Grid Resources

1.4.11 Multi-Scale Integration of Control Systems(EMS/DMS/BMS)

GM0237 Advanced Distribution Management
System Testbed Development

﻿ | 61 |GM0252 Optimal Stationary Fuel Cell Integration and Control(DG-BEAT)
SI-1545 Rapid QSTS Simulations for High-Resolution 		Comprehensive Assessment of Distributed PV Impacts
SI-1583 Stabilizing the Power System in 2035 and Beyond: 		
Evolving from Grid-Following to Grid-Forming Distributed Inverter
Controllers
SI-1586 Opportunistic Hybrid Communications Systems for 		Distributed PV Coordination

1.2.2 Interoperability
1.2.3 Grid Modernization Laboratory Consortium Testing Network
1.2.4 Grid Services and Technologies Valuation Framework
1.2.5 Grid Sensing and Measurement Strategy
1.3.05 DER Siting and Optimization Tool for California
1.3.10 Vermont Regional Partnership Enabling the Use of DER

SI-1631 Assessing the Value of Concentrating Solar Power in a
SunShot Future

1.3.21 Alaska Microgrid Partnership

SI-1639 System Advisor Model

1.3.29 Grid Frequency Support from Distributed Inverter-Based
Resources in Hawaii

SI-1689 Additively Manufactured PV Inverter

1.3.33 Midwest Interconnection Seams Study

SI-1695 Accelerating Systems Integration Codes and Standards

1.4.02 Definitions, Standards and Test Procedures for Grid Services

SI-1728 Solar Resource Calibration, Measurement
and Dissemination

1.4.04 Advanced Sensor Development

WGRID-04 Providing Ramping Service with Wind to Enhance 		Power System Operational Flexibility

1.4.10 Control Theory
1.4.11 Multi-Scale Integration of Control Systems (EMS/DMS/BMS)WGRID-05 Power System Reliable Integration Support to Achieve
Large Amounts of Wind Power (PRISALA)

1.4.15 Development of Integrated Transmission, Distribution andCommunication (TDC) Models

WGRID-35 Market and Reliability Opportunities for Wind on the
Bulk Power System

1.4.17 Extreme Event Modeling

WGRID-38 North American Renewable Integration Study (NARIS)WGRID-49 Understanding the Role of Short-term Energy Storageand Large Motor Loads for Active Power Controls by Wind PowerWGRID-59 WindView: An Open Platform for Wind Energy
Forecast Visualization
GMLC Resilient Distribution Systems Projects:

1.4.18 Computational Science for Grid Management
1.4.25 Distribution System Decision Support Tools
1.4.26 Development and Deployment of Multi-Scale Production
Cost Models
1.4.29 Future Electricity Utility Regulation
GMLC Category 2 Projects:

Increasing Distribution Resiliency using Flexible DER and 		Microgrid Assets Enabled by OpenFMB (Decentralized FLISR)

GM0061 Virtual Battery-based Characterization and 		Control of Flexible Building Loads Using VOLTTRON

Laboratory Value Analysis Team

GM0062 Vehicle to Building Integration Pathway

Office of Electricity Delivery and Energy Reliability
GMLC Category 1 Projects:
1.1 Foundational Metrics Analysis| 62 | ﻿

1.2.1 Grid Architecture

GM0063 Development of an Open-Source Platform for Advanced
Distribution Management Systems

GM0086 Modeling and Control Software Tools to Support
V2G Integration
GM0094 Measurement-Based Hierarchical Framework for TimeVarying Stochastic Load Modeling
GM0163 Diagnostic Security Modules for Electric Vehicle to 		
Building Integration
GM0172 VOLTTRON Message Bus Protocol Adapter
GM0187 Community Control of Distributed Resources for WideArea Reserve Provision
GM0229 Integrated Systems Modeling of the Interactions 		
between Stationary Hydrogen, Vehicle and Grid Resources
GM0237 Advanced Distribution Management System
Testbed Development
GM0252 Optimal Stationary Fuel Cell Integration and Control(DG-BEAT)
GMLC Resilient Distribution Systems Projects:

SuNLaMP Subrecipient Projects (NREL as subrecipient)
Oak Ridge National Laboratory Prime: Frequency Response ofThree Major U.S. Power Grids
Sandia National Laboratories Prime: Distribution System Modeling
Argonne National Laboratory Prime: An Integrated Tool for 		
Improving Grid Reliability
GMLC Category 1 Projects:
1.1 Foundational Metrics Analysis
1.2.1 Grid Architecture
1.3.21 Alaska Microgrid Partnership
1.4.01 Standards and Test Procedures for Interconnection andInteroperability
1.4.15 Development of Integrated Transmission, Distribution andCommunication Models
1.4.25 Distribution System Decision Support Tools

Increasing Distribution Resiliency using Flexible DER and 		Microgrid Assets Enabled by OpenFMB (Decentralized FLISR)

1.4.29 Future Electricity Utility Regulation

Laboratory Value Analysis Team1.3.29 Grid Frequency Support from Distributed Inverter-Based
Resources in Hawaii

Solar Energy Technologies Office
SuNLaMP Prime Projects (GMLC Category 2)
Additively Manufactured PV Inverter
Solar Resource Calibration, Measurement and Dissemination
System Advisor Model
Assessing the Value and Impact of Dispatchable Concentrated
Solar Power
Opportunistic Hybrid Communications Systems for Distributed PV
Coordination
Accelerating Systems Integration Standards (ACCEL)

1.4.04 Advanced Sensor Development
Other Direct Projects
U.S. Representation for the International Energy Agency 		
Photovoltaic Power Systems (IEA PVPS) Task 14
Demonstration of Ancillary Services by Large PV Plant in California
North American Renewables Integration Study (NARIS)PV Plant and Battery Energy Storage Integration
Solar Technology Cost Modeling and Competitive Analysis
Eclipse PeakNorth American Energy Resiliency Model (NAERM)

Stabilizing the Power System in 2035 and Beyond: Evolving from
Grid-Following to Grid-Forming Distributed Inverter Controllers

GM0085 Systems Research Supporting Standards and 		
Interoperability

﻿ | 63 |FY 2019 Solar Energy Technologies Office Lab Call Projects
Solar Radiation Research Laboratory (SRRL)The National Solar Radiation Data Base (NSRDB)Interconnection & Interoperability Standards Accelerating 		Systems Integration Standards (ACCEL II)
Multi-timescale Integrated Dynamic and Scheduling for Solar(MIDAS-Solar)
Artificial-Intelligence-Driven Smart Community Control for 		
Accelerating PV Adoption and Enhancing Grid Resilience
Innovative Protection Systems for High-Pen PV Grids
FY21-End-Lab Call sub, DER Cyber Security Standards 		
Development (Sandia National Laboratories Prime)
Multi-Lab Grid Modeling Support for Puerto Rico Phase IIINTEGRATE Projects (Collaborative)
Southern California Gas Company

ENERGISE Projects
NREL Primes:
Grid Optimization with Solar (GO-Solar)
Enhanced Control, Optimization, and Integration of Distributed
Energy Applications (Eco-Idea)
NREL Subs:

NREL Subs:

GMLC Category 2 Projects:

Coordinated Ramping Product and Regulation Reserve 		
Procurements in California Independent System Operator andMidcontinent Independent System Operator Using Multi-Scale
Probabilistic Solar Power Forecasts

WGRID-04 Providing Ramping Service with Wind to
Enhance Power System Operational Flexibility

Advancing the Weather Research and Forecasting Solar Model to
Improve Solar Irradiance Forecast in Cloudy Environments

WGRID-35 Market and Reliability Opportunities for Windon the Bulk Power System

Advanced Systems Integration for Solar Technologies
NREL Subs:
Enhancing Grid Reliability and Resilience through Novel 		Distributed Energy Resource Control, Total Situational Awareness,
and Integrated Distribution-Transmission Representation (Lead:
Arizona State University)
Enabling Cybersecurity, Situational Awareness and Resilience inDistribution Grids with High Penetration of Photovoltaics (Lead:
Kansas State University)
Modeling and Control of Solar Photovoltaics for Large Grid 		Disturbances and Weak Grids (Lead: University of South Florida)
Protection and Restoration Solutions to Reliable and Resilient
Integration of Grid-Connected Photovoltaic Installations and 		Distributed Energy Resources: Design, Testbed, Proof of Work, andImpact Studies (Lead: University of Oklahoma)
Solar Critical Infrastructure Energization System (Lead: ElectricPower Research Institute)
Autonomous and Resilient Operation of Energy Systems withRenewables (Lead: Siemens Corp.)

Scalable/Secure Cooperative Algorithms and Framework for 		
Extremely-high Penetration Solar Integration (SolarExPert)

Vehicle Technologies OfficeElectric Access System Enhancement (EASE)

GMLC Category 1 Projects:

WGRID-05 Power System Reliable Integration Support toAchieve Large Amounts of Wind Power (PRISALA)WGRID-38 North American Renewable Integration
Study (NARIS)WGRID-49 Understanding the Role of Short-term Energy
Storage and Large Motor Loads for Active Power Controls
by Wind PowerWGRID-59 WindView: An Open Platform for Wind Energy
Forecast Visualization

Wind Power Technologies OfficeWind Grid Projects – FY 2019 Start:
Continental-Scale Transmission Modeling Methods for
Grid Integration Analysis
Atmosphere to Electrons to Grid (A2e2g)
Wind Grid Integration Stakeholder Engagement
Wind Power as Virtual Synchronous Generation (WindVSG)
Advanced Modeling, Dynamic Stability Analysis, andMitigation of Control Interactions in Wind Power Plants

Water Power Technologies Office
North American Grid Integration Study (NARIS)

Solar Forecasting II Projects

1.3.33 Midwest Interconnection Seams Study

Pumped Storage and Hydropower Value
Consortium (HVC)

NREL Primes:

1.4.11 Multi-Scale Integration of Control Systems (EMS/DMS/BMS)

Ternary PSH Design and Evaluation

1.4.26 Development and Deployment of Multi-Scale Production
Cost Models

Obermeyer PSH Valuation

Probabilistic Cloud Optimized Day-Ahead Forecasting System
Based on Weather Research and Forecasting Solar System
Solar Uncertainty Management and Mitigation for Exceptional
Reliability in Grid Operations (SUMMER-GO)

FY2017 Small Business Voucher – Natel
DehlsenIntegrated Hydropower
Ocean Renewable Power Company| 64 | ﻿

﻿ | 65 |KNOWLEDGE
SHARING
Expanding Awareness of Tomorrow’s Gridthrough Outreach, Tours, and Mentorship
Educational outreach is vital to the advancement of R&D at the ESIF. NREL
embraces its role in educating the next generation of power systems
engineers, visitors from industry and Washington, D.C., and our neighbors
here in Golden, Colorado. In honoring this commitment, the ESIF hosted
more than 330 tours and more than 4,500 visitors in FY 2019, providing
the opportunity for many to witness the state-of-the-art research being
conducted at the facility.
NREL is also fostering the future of energy systems integration researchthrough its continued support of internship opportunities. In FY 2019,
the ESIF offered more than 50 internships to graduate and undergraduate
students. Internships at the ESIF offer students exposure to a multitude of
topics in energy systems integration, from hydrogen fuel cell development
to the evaluation of cyber anomalies in a virtual grid environment. These
opportunities propel the future research community in energy systems
integration to build long-term relationships with our experts throughout
the facility. Several types of internships are available to students who have avariety of backgrounds in science and technology.

| 66 | ﻿

WORKSHOPS, CONFERENCES,& EVENTS
The following table includes a snapshot of the workshops, conferences, and events held in the ESIF in FY 2019.

Title

Date

Networked Microgrids

October 17–18, 2018

Artificial Intelligence at NREL Technical Meeting

January 11, 2019

Survalent ADMS Training

January 14–18, 2019

NREL Mobility Industry Advisory Board Workshop

March 13, 2019

Innovative Optimization and Control Methods for Highly Distributed Autonomous Systems

April 11–12, 2019

Exascale Computing Project’s Stochastic Grid Dynamics Project, ExaSGD, Technical Meeting

July 8–9, 2019

NREL Data-Driven Forecasting and Prediction for Energy Systems Workshop

July 10–11, 2019

﻿ | 67 |INNOVATIONSThe ESIF delivered 352 technical outputs, including journal articles, records of invention, software, and conference papers.

Title

Primary NREL Center

NREL Number

Scientific Perceptual Loss Networks

2C00 - Computational Sciences

ROI-19-75

Distributed Reinforcement Learning forControl of Large-Scale Energy Systems

2C00 - Computational Sciences

ROI-19-77

Title

Primary NREL Center

NREL Number

Hydrogen Fueling Analyzer

5B00 - Energy Systems Integration Facility

SWR-17-41

Gray-box Model Identification of Inverter Nonlinear Control Dynamics

5D00 - Power Systems Engineering

ROI-19-04

Carbon Free Data Center Control andAssessment

2C00 - Computational Sciences

ROI-20-03

Configuration of Advanced Inverter Functions
using IEC 61850 AMPVI_ICD

5B00 - Energy Systems Integration Facility

SWR-18-09

SOLARUN (Solar Resource Uncertainty
Application)

5D00 - Power Systems Engineering

SWR-19-41

Advanced control strategy to generate fault
initiated current signatures for distribution-pole mounted PV micro-inverters

5D00 - Power Systems Engineering

ROI-19-10

ProgressiveHedging.jl

2C00 - Computational Sciences

SWR-19-42

SWR-19-43

2C00 - Computational Sciences

SWR-19-05

IGMS-HELICS (or IGMS v3) Integrated Grid
Modeling System

5D00 - Power Systems Engineering

ACES-CoSim (Advanced Computational
Energy Systems - Co-Simulation)

Module OT - Software

5R00 - Energy Security and Resilience

SWR-19-44

Bokeh-streaming

5D00 - Power Systems Engineering

SWR-19-08
SWR-19-48

2C00 - Computational Sciences

SWR-19-10

MAFRIT (Multi-Area Frequency Response
Integration Tool)

5D00 - Power Systems Engineering

CKAN Data Tools for EMN Data Hubs

Hybrid Intrusion Detector for Energy System

5R00 - Energy Security and Resilience

ROI-19-128

System and Method for using AMI measurements for Phase identification

5D00 - Power Systems Engineering

ROI-19-20

5R00 - Energy Security and Resilience

ROI-19-131

Hierarchical Distributed Voltage Regulation in
Networked Autonomous Grids

5D00 - Power Systems Engineering

HERMES: A Cyber-Physical Visualization andResearch Platform

5R00 - Energy Security and Resilience

SWR-19-53

Bewley Lattice Visualization (BL-Vis)

5D00 - Power Systems Engineering

HERMES: A Cyber-Physical Visualization andResearch Platform HERMES

5B00 - Energy Systems Integration Facility

ROI-19-140

ROI-19-23

SWR-19-17

TC4E (Transactive Control for Energy)

7A40 - Integrated Applications

SWR-19-18

Hydrogen Mass/Ratio Control and Passive
Membrane Water Management

ROI-19-144

5D00 - Power Systems Engineering

SWR-19-27

SHARP-Net: Platform for Self-Healing andAttack Resilient PMU Networks

5R00 - Energy Security and Resilience

OpenSMEMS (Open source Sequential
Multi-timescales Electricity Market Simulation
Tool)

5D00 - Power Systems Engineering

SWR-19-62; SWR 19-61

Joint Optimization of Electricity Generationand Use

5D00 - Power Systems Engineering

Electric Power and Gas System
Co-Simulation Platform
Python Electromagnetic Transients PyEMT

2C00 - Computational Sciences

SWR-19-63

Fidelity-Weighted Neural Network Training(FWNNT)

2C00 - Computational Sciences

5R00 - Energy Security and Resilience

SWR-19-64

GPU Implementation of Thickness Mapping
and Quality Control For Films Moving ThroughA Web-Line System

2C00 - Computational Sciences

Platform for Self-Healing and Attack
Resilient PMU Networks SHARP-Net| 68 | ﻿

ROI-19-68

SWR-19-34

SWR-19-35; ROI-16-96

﻿ | 69 || 70 | ﻿Patent Filings

Title

Primary NREL Center

NREL Number

HIDES (Hybrid Intrusion Detection for Energy
Systems)

5R00 - Energy Security and Resilience

SWR-19-65; ROI-19-128

Title

Primary NREL Center

NREL Number

Loss Informed Dispatcher for Battery Systems(LIDBS)

5D00 - Power Systems Engineering

SWR-19-68

Heterogenous Network Topology Management
and Control

5D00 - Power Systems Engineering

17-95

Battery Ensemble ANN Modeler (BEAM)

5D00 - Power Systems Engineering

SWR-19-69

Low-Observability Matrix Completion

5D00 - Power Systems Engineering

18-26

Grid-Edge Resource Controller to EnhanceDistribution Grid Resilience

5D00 - Power Systems Engineering

SWR-19-70

Low-Observability Matrix Completion

5D00 - Power Systems Engineering

PCT/18-26

Network Load Forecasting (NLF)

5D00 - Power Systems Engineering

SWR-19-72

Image-Based Solar Estimates

5D00 - Power Systems Engineering

PROV/18-56A

Station Data Analyzer

2C00 - Computational Sciences

SWR-20-04

Modular Scalable Power Conversion

5D00 - Power Systems Engineering

PROV/17-74B

Heavy-duty Hydrogen Vehicle Simulator

5B00 - Energy Systems Integration Facility

SWR-20-05

Coordinated Net-Load Management

5D00 - Power Systems Engineering

18-59

Dynamic Electrolyzer Control

5B00 - Energy Systems Integration Facility

SWR-20-06

Modular Scalable Power Conversion

5D00 - Power Systems Engineering

17-74

Integrated Synchronization Control of Grid-Forming Inverters

5D00 - Power Systems Engineering

PROV/18-134

Distribution Network Phase Identification

5D00 - Power Systems Engineering

PROV/19-20

Hierarchical Distributed Voltage Regulation

5D00 - Power Systems Engineering

PROV/19-23

Renewable Power to Renewable Natural Gas
Using Biological Methane Production

5B00 - Energy Systems Integration Facility

PCT/18-48

Real Time Voltage Regulation Through Gather
and Broadcast Techniques

5D00 - Power Systems Engineering

16-35

Decentralized Oscillator-Based Converter
Control

5D00 - Power Systems Engineering17-64

﻿ | 71 |PUBLICATIONS
Conference Papers (Preprints)

Most Downloaded
Publications
The following were the most downloaded FY 2019 ESIF
publications on NREL.gov:
1.

Phase I Microgrid Cost Study: Data Collection and Analysis of
Microgrid Costs in the United States

2.

“ESIF 2018 Annual Report”

3.

“Cost-Competitive Electrolysis-Based Hydrogen Under
Current U.S. Electric Utility Rates”

4.

Advanced Inverter Voltage Controls: Simulation and Field Pilot
Findings

5.

A New Approach for Short-Term Solar Radiation Forecasting
Using the Estimation of Cloud Fraction and Cloud Albedo

6.

“Capacity Market Model Considering Flexible Resource
Requirements: Preprint”

7.

Certification Procedures for Data and Communications
Security of Distributed Energy Resources

8.

“Cost-Effectiveness of Grid Energy Storage Technologies in
Current and Future U.S. Power Systems”

9.

Baja California Sur Renewable Integration Study

10. “NREL + Holy Cross Energy”

Abraham, S.A., K. McKenna, and A. Nagarajan. 2019. “Development
and Clustering of Rate-Oriented Load Metrics for Customer Price-Plan
Analysis: Preprint” (NREL/CP-5D00-72655). Presented at the IEEE
Power and Energy Society General Meeting (IEEE PES GM), Atlanta,
Georgia, August 4–8, 2019.
Aworo, O.J., and B. Mather. 2019. “Experimental Determination of PV
Inverter Response to Grid Phase Shift Events: Preprint (NREL/CP5D00-70496).” Presented at the 2018 IEEE Power and Energy Society
General Meeting (IEEE PES GM), Portland, Oregon, August 5–9, 2018.
Bernstein, A., and E. Dall’Anese. 2019. “Asynchronous and Distributed
Tracking of Time-Varying Fixed Points: Preprint (NREL/CP5D00-73422).” Presented at the 2018 IEEE Conference on Decision andControl (IEEE CDC), Miami Beach, Florida, December 17–19, 2018.
Biswas, R.S., J. Tan, H. Jain, V. Gevorgian, and Y.C. Zhang. 2019.
“Equivalent Test Bed in PSCAD and PSLF for Studying Advanced Power
Systems Controller Performance: Preprint” (NREL/CP-5D00-73106).
Presented at the 2019 IEEE Conference on Innovative Smart Grid
Technologies (IEEE ISGT), Washington, D.C., February 17–20, 2019.
Chartan, E., and H. Obermeyer. 2019. “Grid Integration and Market
Analysis of Adjustable-Speed Pumped Storage Hydropower: Preprint”(NREL/CP-5D00-74282). Presented at HydroVision International 2019,
Portland, Oregon, July 23–25, 2019.
Chartan, E., J. Wright, and G. Landwehr. 2019. “Comparing the Valueof Improved Variable Renewable Energy Forecasting Accuracy inSouth African and United States Power Systems: Preprint” (NREL/
CP-5D00-72593). Presented at WindAc 2018, Cape Town, South Africa,
November 5–6, 2018.
Chen, Y., and Y. Lin. 2019. “Hierarchical Management of Distributed Energy
Resources Using Chance-Constrained OPF and Extremum Seeking
Control: Preprint” (NREL/CP-5D00-73404). Presented at the American
Control Conference, Philadelphia, Pennsylvania, July 10–12, 2019.
Ding, F., H.V. Padullaparti, M. Baggu, S. Veda, and S. Meor Danial. 2019.
“Data Enhanced Hierarchical Control to Improve Distribution Voltage
with Extremely High PV Penetration: Preprint” (NREL/CP-5D00-72755).
Presented at the 2019 IEEE Power & Energy Society General Meeting(IEEE PES GM), Atlanta, Georgia, August 4–8, 2019.

| 72 | ﻿Ding, F., K. Horowitz, B. Mather, and B. Palmintier. 2019. “Sequential
Mitigation Solutions to Enable Distributed PV Grid Integration: Preprint”(NREL/CP-5D00-70411). Presented at the 2018 IEEE Power and Energy
Society General Meeting (IEEE PES GM), Portland, Oregon, August
5–10, 2018.
Dutta, S., R. Mallik, B. Majmunovic, S. Mukherjee, G.-S. Seo, D.
Maksimovic, and B. Johnson. 2019. “Decentralized Carrier Interleavingin Cascaded Multilevel DC-AC Converters: Preprint” (NREL/CP5D00-74846). Presented at the 2019 IEEE Workshop on Control andModeling for Power Electronics (IEEE COMPEL), Toronto, Canada, June
17–20, 2019.
Fang, X., B.-M. Hodge, and F. Li. 2018. “Capacity Market Model
Considering Flexible Resource Requirements: Preprint (NREL/CP5D00-70162)” 2019. Presented at the IEEE Power and Energy Society
General Meeting (IEEE PES GM), Portland, Oregon, August 5–10, 2018.
Fang, X., B.-M. Hodge, V. Krishnan, and F. Li. 2018. “Potential of Wind
Power to Provide Flexible Ramping Products and Operating Reserve:
Preprint (NREL/CP-5D00-70161).” Presented at the IEEE Power andEnergy Society General Meeting (IEEE PES GM), Portland, Oregon
August 5–10, 2018.
Fang, X., M.T. Craig, and B.-M. Hodge. 2019. “Linear Approximation
Line Pack Model for Integrated Electricity and Natural Gas Systems
OPF: Preprint” (NREL/CP-5D00-73763). Presented at the IEEE Powerand Energy Society General Meeting (IEEE PES GM), Atlanta, Georgia,
August 4–8, 2019.
Faqiry, M., L. Wang, H. Wu, D. Krishnamurthy, and B. Palmintier. 2019.
“ADP-Based Home Energy Management System: A Case Study Using
Dynamo: Preprint” (NREL/CP-5D00-70422). Presented at the Powerand Energy Society General Meeting (IEEE PES GM), Portland, Oregon,August 5–10, 2018.
Gevorgian, V. 2019. “Highly Accurate Method for Real-Time Active
Power Reserve Estimation for Utility-Scale PV Power Plants: Preprint”(NREL/CP-5D00-72419). Presented at the Solar Integration Workshop,
Stockholm, Sweden, October 16-17, 2018.
Gevorgian, V., M. Baggu, and D. Ton. 2019. “Interconnection
Requirements for Renewable Generation and Energy Storage in Island
Systems: Puerto Rico Example: Preprint” (NREL/CP-5D00-73848).
Presented at the 4th International Hybrid Power Systems Workshop,
Crete, Greece, May 22–23, 2019.

﻿ | 73 |Guo, L., C. Zhao, and S.H. Low. 2019. “Graph Laplacian Spectrum andPrimary Frequency Regulation: Preprint” (NREL/CP-5D00-71124).
Presented at the IEEE Conference on Decision and Control Miami,
Florida, December 17–19, 2018.
Jain, A.K., K. Horowitz, F. Ding, N. Gensollen, B. Mather, and B. Palmintier.
2019. “Quasi-Static Times Series PV Hosting Capacity Methodology
and Metrics: Preprint” (NREL/CP-5D00-72284). Presented at the 2019
IEEE Conference on Innovative Smart Grid Technologies (IEEE ISGT),
Washington, D.C., February 17–20, 2019.
Jain, H., B. Palmintier, D. Krishnamurthy, I. Krad, and E. Hale. 2019.
“Evaluating the Impact of Price-Responsive Load on Power Systems
Using Integrated T&D Simulation: Preprint” (NREL/CP-5D00-70197).
Presented at the 2019 IEEE Conference on Innovative Smart Grid
Technologies (IEEE ISGT), Washington, D.C., February 17–20, 2019.
Janine F., G.T. Klise, A. Walker, and O. Lavrova. 2018. “Evaluating Energy
Impacts and Costs from PV Component Failures: Preprint” (NREL/CP6A20-72212. Presented at the World Conference on Photovoltaic Energy
Conversion (WCPEC-7), Waikoloa, Hawaii, June 10–15, 2018.
Jhala, K., V. Krishnan, B. Natarajan, and Y.C. Zhang. 2019. “Data-Driven
Preemptive Voltage Monitoring and Control Using Probabilistic Voltage
Sensitivities: Preprint” (NREL/CP-5D00-72661). Presented at the 2019
IEEE Power and Energy Society General Meeting (IEEE PES GM),
Atlanta, Georgia, August 4–8, 2019.
Lin, Y., D. McLarty, A. Pratt, B. Ball, G. Henze, and G. Saur. 2018. “Optimal
Dispatch Controller for Fuel Cell-Integrated Building: Preprint” (NREL/
CP-5D00-71423). Presented at the High Performance Buildings
Conference, West Lafayette, Indiana, July 9–12, 2018.
Liu, Z., Z. Zhang, and Y. Lin. 2019. “Impact of Inverter-Interfaced
Renewable Generation on Transient Stability at Varying Levels of
Penetration: Preprint” (NREL/CP-5D00-70489). Presented at the IEEE
Annual Conference of the IEEE Industrial Electronics Society (IEEEIECON), Washington, D.C., October 21–23, 2018.
Lu, M., G.-S. Seo, M. Sinha, F. Rodriguez, S. Dhople, and B. Johnson. 2019.
“Adaptation of Commercial Current-Controlled Inverters for Operation
with Virtual Oscillator Control: Preprint” (NREL/CP-5D00-72318).
Presented at the 2019 IEEE Applied Power Electronics Conferences(IEEE PELS), Anaheim, California, March 17–21, 2019.
Mahmud, R., and A. Nejadpak. 2019. “Distributed Cooperative Control ofHybrid AC/DC Microgrid: Preprint” (NREL/CP-5D00-73879). Presented
at the 46th IEEE Photovoltaic Specialists Conference (IEEE PVSC 46),
Chicago, Illinois, June 16–21, 2019.

| 74 | ﻿Mallik, R., B. Majmunovic, S. Mukherjee, S. Dutta, G.-S. Seo, D.
Maksimovic, and B. Johnson. 2019. “Equivalent Circuit Models of
Voltage-Controlled Dual Active Bridge Converters: Preprint” (NREL/
CP-5D00-74061). Presented at the 2019 IEEE Workshop on Control andModeling for Power Electronics (IEEE COMPEL), Toronto, Canada, June
17–20, 2019.
Mukherjee, S., Y. Gao, R. Ramos, V. Sankaranarayanan, B. Majmunovic,
R. Mallik, S. Dutta, G.-S. Seo, B. Johnson, and D. Maksimovic. 2019. “ACResistance Reduction Using Orthogonal Air Gaps in High-Frequency
Inductors: Preprint” (NREL/CP-5D00-74060). Presented at the 2019
IEEE Workshop on Control and Modeling for Power Electronics (IEEE
COMPEL), Toronto, Canada, June 17–20, 2019.
Nazir, M.S., I.A. Hiskens, A. Bernstein, and E. Dall’Anese. 2019. “Inner
Approximation of Minkowski Sums: A Union-Based Approach andApplications to Aggregated Energy Resources: Preprint” (NREL/CP5D00-73423). Presented at the 2018 IEEE Conference on Decision andControl (IEEE CDC), Miami Beach, Florida, December 17–19, 2018.
Netto, M., V. Krishnan, L. Mili, Y. Susuki, and Y.C. Zhang. 2019. “A Hybrid
Framework Combining Model-Based and Data-Driven Methods for
Hierarchical Decentralized Robust Dynamic State Estimation: Preprint”(NREL/CP-5D00-72685). Presented at the 2019 IEEE Power andEnergy Society General Meeting (IEEE PES GM), Atlanta, Georgia,
August 4–8, 2019.
Padullaparti, H., S. Veda, S. Dhulipala, M. Baggu, T. Bialek, and M. SymkoDavies. 2019. “Considerations for AMI-Based Operations for Distribution
Feeders: Preprint” (NREL/CP-5D00-72773). Presented at the 2019
IEEE Power & Energy Society General Meeting (IEEE PES GM), Atlanta,
Georgia, August 4–8, 2019.
Paret, P., G. Moreno, B. Kekelia, R. Kotecha, X. Feng, K. Bennion, B.
Mather, A. Zakutayev, S. Narumanchi, S. Kim, and S. Graham. 2019.
“Thermal and Thermomechanical Modeling to Design a Gallium
Oxide Power Electronics Package: Preprint” (NREL/CP-5400-72291).
Presented at the 6th IEEE Workshop on Wide Bandgap Power
Devices and Applications (WiPDA 2018), Atlanta, Georgia, October 31–
November 2, 2018.
Pierre, B.J., H.N. Villegas Pico, R.T. Elliott, J. Flicker, Y. Lin, B.B. Johnson,
J.H. Eto, R.H. Lasseter, and A. Ellis. 2019. “Bulk Power System Dynamics
with Varying Levels of Synchronous Generators and Grid-Forming
Power Inverters: Preprint” (NREL/CP-5D00-74107). Presented at the
46th IEEE Photovoltaic Specialists Conference (IEEE PVSC 46), Chicago,
Illinois, June 16–21, 2019.

Pratt, K. A., D. Krishnamurthy, and A. Maitra. 2019. “Hardware-inthe-Loop Test Bed and Test Methodology for Microgrid Controller
Evaluation: Preprint” (NREL/CP-5D00-73627). Presented at the 2018
IEEE PES Transmission and Distribution Conference and Exposition(T&D), Denver, Colorado, April 16–19, 2018.

Seo, G.-S., M. Colombino, I. Subotic, B. Johnson, D. Gross, and F. Dorfler.
2019. “Dispatchable Virtual Oscillator Control for Decentralized InverterDominated Power Systems: Analysis and Experiments: Preprint” (NREL/
CP-5D00-72774). Presented at the 2019 IEEE Applied Power Electronics
Conferences (IEEE PELS), Anaheim, California, March 17–21, 2019.

Prabakar, K., A. Singh, and C. Tombari. 2019. “IEEE 1547-2018 Based
Interoperable PV Inverter with Advanced Grid-Support Functions:
Preprint” (NREL/CP-5D00-73131). Presented at the 46th IEEE
Photovoltaic Specialists Conference (IEEE PVSC 46), Chicago, Illinois,
June 16–21, 2019.

Shah, S., P. Koralwicz, R. Wallen, and V. Gevorgian. 2019. “Impedance
Characterization of Utility-Scale Renewable Energy and Storage
Systems: Preprint” (NREL/CP-5D00-73173). Presented at the 2019
Energy Conversion Congress and Exposition (IEEE ECCE), Baltimore,
Maryland, September 29–October 3, 2019.

Prabakar, K., M. Shirazi, A. Singh, and S. Chakraborty. “Advanced
Photovoltaic Inverter Control Development and Validation in aController-Hardware-in-the-Loop Test Bed: Preprint (NREL/CP5D00-68511)” Presented at the IEEE Energy Conversion Congress andExposition (IEEE ECCE), Cincinnati, Ohio, October 1–5, 2017.

Shah, S., V. Gevorgian, and H. Liu. 2019. “Impedance-Based Predictionof SSR-Generated Harmonics in Doubly-Fed Induction Generators:
Preprint (NREL/CP-5D00-72559).” Presented at the 2019 IEEE Powerand Energy Society General Meeting (IEEE PES GM), Atlanta, Georgia,
August 4–8, 2019.

Pratt, A., M. Baggu, F. Ding, S. Veda, I. Mendoza, and E. Lightner. 2019. “A
Test Bed to Evaluate Advanced Distribution Management Systems forModern Power Systems: Preprint” (NREL/CP-5D00-73705). Presented
at the 2019 IEEE EUROCON, Novi Sad, Serbia, July 1–4, 2019.

Singh, A., and K. Prabakar. 2019. “Controller-Hardware-in-the-Loop Test
Bed for Fast-Switching SiC-Based 50-kW PV Inverter: Preprint” (NREL/
CP-5D00-71544). Presented at the 44th Annual Conference of the IEEE
Industrial Electronics Society (IEEE IECON), Washington, D.C., October
21–23, 2018.

Ren, H., V. Krishnan, Y. C. Zhang, and N. N. Schulz. 2019. “Online Static
Load Model Estimation in Distribution Systems: Preprint” (NREL/
CP-5D00-73228). Presented at the 2019 IEEE 28th International
Symposium on Industrial Electronics (IEEE ISIE), Vancouver, Canada,
June 12–14, 2019.
Roy, J., G.-S. Seo, and A. Singh. 2019. “Highly Reliable Multi-Port Smart
Inverter Modules for PV-Based Energy Systems: Preprint” (NREL/
CP-5D00-73857). Presented at the 46th IEEE Photovoltaic Specialists
Conference (IEEE PVSC 46), Chicago, Illinois, June 16–21, 2019.
Sengupta, M., A. Habte, and J. M. Freeman. 2019. “The Case for Custom
TMYs: Examples Using the NSRDB: Preprint” (NREL/CP-5D00-74063).
Presented at the 46th IEEE Photovoltaic Specialists Conference (IEEE
PVSC 46), Chicago, Illinois, June 16–21, 2019.
Sengupta, M., A. Habte, Y. Xie, A. Lopez, and C. A. Gueymard. 2019.
“The National Solar Radiation Database (NSRDB) for CSP Applications:
Preprint” (NREL/CP-5D00-72310). Presented at the 2018 Solar Powerand Chemical Energy Systems Conference (SolarPACES), Casablanca,
Morocco, October 2–5, 2018.
Sengupta, M., A. Lopez, A. Habte, and Y. Xie. 2019. “Improving the
Accuracy of the National Solar Radiation Database (1998-2016):
Preprint” (NREL/CP-5D00-72410). Presented at the 2018 European PV
Solar Energy Conference and Exhibition (EU PVSEC), Brussels, Belgium,
September 24–28, 2018.

Singh, A., M. Chinthavali, S. Sudhoff, K. Bennion, K. Prabakar, X. Feng,
Z. Wang, and S. Campbell. 2018. “Development and Validation of a
SiC Based 50 kW Grid-Connected PV Inverter: Preprint” (NREL/CP5D00-70872). Presented at the 2018 IEEE Energy Conversion Congress
and Exposition (IEEE ECCE), Portland, Oregon, September 23–27, 2018.
Singh, A., S. Reese, and S. Akar. 2019. “Performance and TechnoEconomic Evaluation of a Three-Phase, 50-kW SiC-Based PV Inverter:
Preprint” (NREL/CP-5D00-73124). Presented at the 46th IEEE
Photovoltaic Specialists Conference (IEEE PVSC 46), Chicago, Illinois,
June 16–21, 2019.
Tan, S. Y., H. Saha, A. Florita, G.P. Henze, and S. Sarkar. 2019. “A Flexible
Framework for Building Occupancy Detection Using Spatiotemporal
Pattern Networks: Preprint” (NREL/CP-5D00-73359). Presented at theIEEE American Control Conference, Philadelphia, Pennsylvania, July
10–12, 2019.
Thiagarajan, R., A. Nagarajan, P. Hacke, and I. Repins. 2019. “Effectof Reactive Power on Photovoltaic Inverter Reliability and Lifetime:
Preprint” (NREL/CP-5D00-73648). Presented at the 46th IEEE
Photovoltaic Specialists Conference (IEEE PVSC 46), Chicago, Illinois,
June 16–21, 2019.

﻿ | 75 |Thiagarajan, R., P. Gotseff, A. Hoke, and E. Ifuku. 2019. “Inverter Testingfor Verification of Hawaiian Electric Rule 14H: Preprint (NREL/CP5D00-73647).” Presented at the 46th IEEE Photovoltaic Specialists
Conference (IEEE PVSC 46), Chicago, Illinois, June 16–21, 2019.
Veda, S., M. Baggu, and A. Pratt. 2019. “ADMS Test Bed: Defining a Use
Case for Data Improvement for ADMS Deployment: Preprint” (NREL/
CP-5D00-72404). Presented at the 2019 IEEE Innovative Smart Grid
Technologies Conference (IEEE ISGT), Washington, D.C., February
18–21, 2019.
Vignola, F., J. Peterson, F. Mavromatakis, S. Wilbert, A. Forstinger, M.
Dooraghi, and M. Sengupta. 2019. “Removing Biases from Rotating
Shadowband Radiometers: Preprint” (NREL/CP-5D00-72278 ).
Presented at the 2018 Solar Power and Chemical Energy Systems
Conference (SolarPACES), Casablanca, Morocco, October 2–5, 2018.
Vignola, F., J. Peterson, R. Kessler, V. Sandhu, M. Sengupta, and A. Habte.
2019. “Improved Field Evaluation of Reference Cell Using Spectral
Measurements: Preprint” (NREL/CP-5D00-74037). Presented at the
46th IEEE Photovoltaic Specialists Conference (IEEE PVSC 46), Chicago,
Illinois, June 16–21, 2019.
Yujie T., E. Dall’Anese, A. Bernstein, and S.H. Low. 2019. “A FeedbackBased Regularized Primal-Dual Gradient Method for Time-Varying
Nonconvex Optimization: Preprint” (NREL/CP-5D00-73424). Presented
at the 2018 IEEE Conference on Decision and Control (IEEE CDC), Miami
Beach, Florida, December 17–19, 2018.
Zhang, Y., A. Bernstein, A. Schmitt, and R. Yang. 2019. “State Estimationin Low-Observable Distribution Systems Using Matrix Completion:
Preprint” (NREL/CP-5D00-73540). Presented at the HawaiiInternational Conference on System Sciences, Maui, Hawaii, January
8–11, 2019.
Zhou, X., Z. Liu, W. Wang, C. Zhao, F. Ding, and L. Chen. 2019.
“Hierarchical Distributed Voltage Regulation in Networked
Autonomous Grids: Preprint (NREL/CP-5D00-73345).” Presented at
the IEEE American Control Conference Philadelphia, Pennsylvania July
10–12, 2019.

Conference Papers (Published Proceedings)
Aworo, O.J., and B. Mather. 2018. “Experimental Determination of PV
Inverter Response to Grid Phase Shift Events” (NREL/CP-5D00-74635).
In Proceedings of the 2018 IEEE Power & Energy Society
General Meeting (IEEE PES GM). Piscataway, NJ: Institute of Electricaland Electronics Engineers.

| 76 | ﻿

Baker, K., and A. Bernstein. 2019. “Joint Chance Constraints Reduction
Through Learning in Active Distribution Networks” (NREL/CP5D00-73633). Proceedings of the 2018 IEEE Global Conferenceon Signal and Information Processing (GlobalSIP). Piscataway,
NJ: Institute of Electrical and Electronics Engineers.

Ding, F., K. Horowitz, B. Mather, and B. Palmintier. 2018. “Sequential
Mitigation Solutions to Enable Distributed PV Grid Integration” (NREL/
CP-5D00-73327). In Proceedings of the 2018 IEEE Power &Energy Society General Meeting (IEEE PES GM). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.

Bernstein, A., and E. Dall’Anese. 2019. “Asynchronous and Distributed
Tracking of Time-Varying Fixed Points” (NREL/CP-5D00-73480). In
Proceedings of the 2018 IEEE Conference on Decision andControl (CDC). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.

Dutta, S., R. Mallik, B. Majmunovic, S. Mukherjee, G.-S. Seo, D.
Maksimovic, and B. Johnson. 2019. “Decentralized Carrier Interleavingin Cascaded Multilevel DC-AC Converters” (NREL/CP-5D00-74062).
In Proceedings of the 2019 20th Workshop on Control andModeling for Power Electronics (COMPEL). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.

Biswas, R.S., J. Tan, H. Jain, V. Gevorgian, and Y.C. Zhang. 2019.
“Equivalent Test Bed in PSCAD and PSLF for Studying Advanced
Power Systems Controller Performance” (NREL/CP-5D00-74607).
In Proceedings of the 2019 IEEE Power & Energy Society
Innovative Smart Grid Technologies Conference (ISGT).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Fang, X., B.-M. Hodge, and F. Li. 2018. “Capacity Market Model
Considering Flexible Resource Requirements” (NREL/CP-5D00-73328).
In Proceedings of the 2018 IEEE Power & Energy Society
General Meeting (IEEE PES GM). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.

Brouillon, J.-S., M. Colombino, D. Gross, and F. Dorfler. 2018. “The Effectof Transmission-Line Dynamics on a Globally Synchronizing Controller
for Power Inverters” (NREL/CP-5D00-73225). In Proceedings ofthe 2018 European Control Conference (ECC). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.

Faqiry, M.N., L. Wang, H. Wu, D. Krishnamurthy, and B. Palmintier. 2018.
“ADP-Based Home Energy Management System: A Case Study Using
DYNAMO” (NREL/CP-5D00-73329). In Proceedings of the 2018
IEEE Power & Energy Society General Meeting (IEEE PES
GM). Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Cammardella, N.J., R.W. Moye, Y. Chen, and S.P. Meyn. 2019. “An Energy
Storage Cost Comparison: Li-Ion Batteries vs Distributed Load Control”(NREL/CP-5D00-73834). In Proceedings of the 2018 Clemson
University Power Systems Conference (PSC). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.

Freeman, J. M., G. T. Klise, A. Walker, and O. Lavrova. 2019. “Evaluating
Energy Impacts and Costs from PV Component Failures” (NREL/
CP-6A20-73690). In Proceedings of the 2018 IEEE 7th World
Conference on Photovoltaic Energy Conversion (WCPEC).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Chen, X., C. Zhao, and N. Li. 2018. “Distributed Automatic LoadFrequency Control with Optimality in Power Systems” (NREL/CP5D00-72928). In Proceedings of the 2018 IEEE Conference onControl Technology and Applications (CCTA). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.

Ghosh, S., F. Ding, J. Simpson, T. Harris, M. Baggu, H. G. Aghamolki, and
W. Ren. 2019. “Techno-Economic Analysis for Grid Edge Intelligence:
A Preliminary Study on Smart Voltage Regulator Controls” (NREL/CP5D00-72386). In Proceedings of the 2019 IEEE Power & Energy
Society Innovative Smart Grid Technologies Conference(ISGT). Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Chen, Y., and Y. Lin. 2019. “Hierarchical Management of Distributed
Energy Resources Using Chance-Constrained OPF and Extremum
Seeking Control” (NREL/CP-5D00-75053). In Proceedings of the2019 American Control Conference (ACC).
Das, R., G.-S. Seo, D. Maksimovic, and H.-P. Le. 2019. “An 80-W
94.6%-Efficient Multi-Phase Multi-Inductor Hybrid Converter” (NREL/
CP-5D00-74261). In Proceedings of the 2019 IEEE AppliedPower Electronics Conference and Exposition (APEC).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Gotseff, P., N. Wunder, A. Hoke, E. Ifuku, and R. Ueda. 2018. “Residential
Advanced Photovoltaic Inverter Pilot Study Results for SelectDistribution Secondaries in Hawai’I” (NREL/CP-5D00-73699). In
Proceedings of the 2018 IEEE 7th World Conference on
Photovoltaic Energy Conversion (WCPEC). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.
Guo, L., C. Zhao, and S. H. Low. 2019. “Graph Laplacian Spectrum
and Primary Frequency Regulation” (NREL/CP-5D00-73482). In
Proceedings of the 2018 IEEE Conference on Decision andControl (CDC). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.

Habte, A., M. Sengupta, A. Andreas, R. Narasappa, T. Thomas, A. Wolf,
and C.A. Gueymard. “Characterization of a Low-Cost Multi-Parameter
Sensor for Solar Resource Applications” (NREL/CP-5D00-73701).
In Proceedings of the 2018 IEEE 7th World Conference on
Photovoltaic Energy Conversion (WCPEC). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.
Habte, A., M. Sengupta, A. Lopez, Y. Xie, and G. Maclaurin. 2018.
“Assessment of the National Solar Radiation Database (NSRDB 19982016)” (NREL/CP-5D00-73702). In Proceedings of the 2018 IEEE
7th World Conference on Photovoltaic Energy Conversion(WCPEC). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.
Hasandka, A., J. Zhang, A. S. M. Shafiul, A. R. Florita, and B.-M. Hodge.
2018. “Simulation-Based Parameter Optimization Framework for LargeScale Hybrid Smart Grid Communications Systems Design” (NREL/
CP-5D00-71734). In Proceedings of the 2018 IEEE International
Conference on Communications, Control, and Computing
Technologies for Smart Grids (SmartGridComm). Piscataway,
NJ: Institute of Electrical and Electronics Engineers.
Hayter, S. J., and S. Stout. 2019. “The Role of Building Codes andControls in Enhancing Community Resilience” (NREL/CP-5C00-74930).
In Proceedings of the E3S Web of Conferences. EDP Sciences.
Jacobs, N., S. Hossain-McKenzie, D. Jose, D. Saleem, C. Lai, P. Cordeiro,
A. Hasandka, M. Martin, and C. Howerter. 2019. “Analysis of System andInteroperability Impact from Securing Communications for Distributed
Energy Resources” (NREL/CP-5R00-73177). In Proceedings of the2019 IEEE Power and Energy Conference at Illinois (PECI).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Jager-Waldau, A., C. Bucher, K. H. B. Frederiksen, R. Guerro-Lemus, G.
Mason, B. Mather, C. Mayr, D. Moneta, J. Nikoletatos, and M. B. Roberts.
2018. “Self-Consumption of Electricity Produced from PV Systems
in Apartment Buildings - Comparison of the Situation in Australia,
Austria, Denmark, Germany, Greece, Italy, Spain, Switzerland and theUSA” (NREL/CP-5D00-73713). In Proceedings of the 2018 IEEE
7th World Conference on Photovoltaic Energy Conversion(WCPEC). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.
Jain, A. K., K. Horowitz, F. Ding, N. Gensollen, B. Mather, and B.
Palmintier. 2019. “Quasi-Static Time-Series PV Hosting Capacity
Methodology and Metrics” (NREL/CP-5D00-74935). In Proceedingsof the 2019 IEEE Power & Energy Society Innovative Smart
Grid Technologies Conference (ISGT). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.

﻿ | 77 |Jain, H., B. Palmintier, D. Krishnamurthy, I. Krad, and E. Hale. 2019.
“Evaluating the Impact of Price-Responsive Load on Power Systems
Using Integrated T&D Simulation” (NREL/CP-5D00-74936). In
Proceedings of the 2019 IEEE Power & Energy Society
Innovative Smart Grid Technologies Conference (ISGT).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Lundstrom, B., S. Patel, S. Attree, and M.V. Salapaka. 2018. “FastPrimary Frequency Response using Coordinated DER and Flexible
Loads: Framework and Residential-scale Demonstration” (NREL/CP5D00-73334). In Proceedings of the 2018 IEEE Power & Energy
Society General Meeting (IEEE PES GM). Piscataway, NJ: Instituteof Electrical and Electronics Engineers.

Pierre, B. J., M. E. Elkhatib, and A. Hoke. 2018. “PV Inverter Fault
Response Including Momentary Cessation, Frequency-Watt, and Virtual
Inertia” (NREL/CP-5D00-73729). In Proceedings of the 2018 IEEE
7th World Conference on Photovoltaic Energy Conversion(WCPEC). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.

Kenyon, R. W., and B. Mather. 2019. “Quantifying Transmission Fault
Voltage Influence and its Potential Impact on Distributed Energy
Resources” (NREL/CP-5D00-72453). In Proceedings of the 2018
IEEE Electronic Power Grid (eGrid). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.

Mahmud, R., A. Hoke, and D. Narang. 2018. “Validating the Test
Procedures Described in UL 1741 SA and IEEE P1547.1” (NREL/CP5D00-73724). In Proceedings of the 2018 IEEE 7th World
Conference on Photovoltaic Energy Conversion (WCPEC).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Ren, H., N. N. Schulz, V. Krishnan, and Y. C. Zhang. 2019. “Online
Static Load Model Estimation in Distribution Systems” (NREL/
CP-5D00-74634). In Proceedings of the 2019 IEEE 28th
International Symposium on Industrial Electronics (ISIE).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Khan, M. M. S., Y. Lin, B. Johnson, M. Sinha, and S. Dhople. 2018.
Stability Assessment of a System Comprising a Single Machine and a
Virtual Oscillator Controlled Inverter with Scalable Ratings” (NREL/
CP-5D00-71634) In Proceedings of IECON 2018 - 44th Annual
Conference of the IEEE Industrial Electronics Society.
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Lai, C., P. Cordeiro, A. Hasandka, N. Jacobs, S. Hossain-McKenzie, D. Jose, D.
Saleem, and M. Martin. 2019. “Cryptography Considerations for Distributed
Energy Resource Systems” (NREL/CP-5R00-73178). In Proceedings ofthe 2019 IEEE Power and Energy Conference at Illinois (PECI).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Latif, A., and A. Nagarajan. 2019. “Field Validated Utility-Scale Battery
Storage Control Models for Quasi-Static Analyses” (NREL/CP5D00-71931). In Proceedings of the 2019 IEEE Power & Energy
Society Innovative Smart Grid Technologies Conference(ISGT). Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Liu, B., H. Wu, A. Pahwa, F. Ding, E. Ibrahim, and T. Liu. 2018. “Hidden
Moving Target Defense against False Data Injection in Distribution
Network Reconfiguration” (NREL/CP-5D00-73331). In Proceedingsof the 2018 IEEE Power & Energy Society General Meeting(IEEE PES GM). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.

| 78 | ﻿Mallik, R., B. Majmunovic, S. Mukherjee, S. Dutta, G.-S. Seo, D.
Maksimovic, and B. Johnson. 2019. “Equivalent Circuit Models of
Voltage-Controlled Dual Active Bridge Converters” (NREL/CP5D00-74630). In Proceedings of the 2019 20th Workshop on
Control and Modeling for Power Electronics (COMPEL).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Mather, B. 2018. “Fast Determination of Distribution-Connected
PV Impacts Using a Variable-Time-Step Quasi-Static Time-Series
Approach” (NREL/CP-5D00-73964). In Proceedings of the 2017
IEEE 44th Photovoltaic Specialist Conference (PVSC).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Mather, B., A. Oluwafemi, R. Bravo, and D. Piper. 2018. “Laboratory
Testing of a Utility-Scale PV Inverter’s Operational Response to Grid
Disturbances” (NREL/CP-5D00-70495). In Proceedings of the 2018
IEEE Power & Energy Society General Meeting (IEEE PES
GM). Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Mukherjee, S., Y. Gao, R. Ramos, V. Sankaranarayanan, B. Majmunovic,
R. Mallik, S. Dutta, G.-S. Seo, B. Johnson, and D. Maksimovic. 2019. “ACResistance Reduction Using Orthogonal Air Gaps in High Frequency
Inductors” (NREL/CP-5D00-74631). In Proceedings of the2019 20th Workshop on Control and Modeling for PowerElectronics (COMPEL). Piscataway, NJ: Institute of Electrical andElectronics Engineers.

Liu, Z., Z. Zhang, and Y. Lin. 2018. “Impact of Inverter-Interfaced
Renewable Generation on Transient Stability at Varying Levels of
Penetration” (NREL/CP-5D00-73463). In Proceedings of IECON
2018 - 44th Annual Conference of the IEEE Industrial
Electronics Society. Piscataway, NJ: Institute of Electrical andElectronics Engineers.

Paret, P., G. Moreno, B. Kekelia, R. Kotecha, X. Feng, K. Bennion, B.
Mather, A. Zakutayev, S. Narumanchi, S. Kim, and S. Graham. 2018.
“Thermal and Thermomechanical Modeling to Design a Gallium Oxide
Power Electronics Package” (NREL/CP-5400-73254). In Proceedingsof the 2018 IEEE 6th Workshop on Wide Bandgap Power
Devices and Applications (WiPDA). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.

Lu, M., G.-S. Seo, M. Sinha, F. Rodriguez, S. Dhople, and B. Johnson.
2019. “Adaptation of Commercial Current-Controlled Inverters forOperation with Virtual Oscillator Control” (NREL/CP-5D00-72775).
In Proceedings of the 2019 IEEE Applied Power Electronics
Conference and Exposition (APEC). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.

Pattabiraman, D., J. Tan, V., Gevorgian, A. Hoke, C. Antonio, and D.
Arakawa. 2018. “Impact of Frequency-Watt Control on the Dynamics
of a High DER Penetration Power System” (NREL/CP-5D00-70476).
In Proceedings of the 2018 IEEE Power & Energy Society
General Meeting (IEEE PES GM). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.

Reno, M. J., J. A. Azzolini, and B. Mather. 2018. “Variable Time-Step
Implementation for Rapid Quasi-Static Time-Series (QSTS) Simulationsof Distributed PV” (NREL/CP-5D00-73731). In Proceedings of the2018 IEEE 7th World Conference on Photovoltaic Energy
Conversion (WCPEC). Piscataway, NJ: Institute of Electrical andElectronics Engineers.

Singh, A., and K. Prabakar. 2018. “Controller-Hardware-in-the-Loop
Testbed for Fast-Switching SiC-Based 50-kW PV Inverter” (NREL/
CP-5D00-73466). In Proceedings of IECON 2018 - 44th Annual
Conference of the IEEE Industrial Electronics Society.
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Singh, S., S. Veda, S. P. Singh, and M. Baggu. 2019. “Maximizing the
Benefits of Volt/VAR Optimization in the Presence of Community
Energy Storage” (NREL/CP-5D00-71658). In Proceedings of the2018 IEEE International Conference on Power Electronics,
Drives and Energy Systems (PEDES). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.
Sparn, B., D. Krishnamurthy, A. Pratt, M. Ruth, and H. Wu. 2018.
“Hardware-in-the-Loop (HIL) Simulations for Smart Grid Impact
Studies” (NREL/CP-5500-73339). In Proceedings of the 2018 IEEE
Power & Energy Society General Meeting (PESGM). Piscataway,
NJ: Institute of Electrical and Electronics Engineers.

Roy, J., and B. Mather. 2019. “Study of Voltage-Dependent Harmonic
Characteristics of Residential Appliances” (NREL/CP-5D00-72817).
In Proceedings of the 2019 IEEE Texas Power and Energy
Conference (TPEC). Piscataway, NJ: Institute of Electrical andElectronics Engineers.

Tan, J., Y. C. Zhang, S. You, Y. Liu, and Y. Liu. 2018. “Frequency Response
Study of a U.S. Western Interconnection Under Extra-High Photovoltaic
Generation Penetrations” (NREL/CP-5D00-73341). In Proceedingsof the 2018 IEEE Power & Energy Society General Meeting(PESGM). Piscataway, NJ: Institute of Electrical and Electronics
Engineers.

Sengupta, M., A. Habte, Y. Xie, A. Lopez, and C. A. Gueymard. 2019.
“The National Solar Radiation Database (NSRDB) for CSP Applications”(NREL/CP-5D00-74706). In Proceedings of SolarPACES 2018:
International Conference on Concentrating Solar Power andChemical Energy Systems. AIP Publishing.

Tan, S. Y., H. Saha, A. R. Florita, G. P. Henze, and S. Sarkar. 2019.
“A Flexible Framework for Building Occupancy Detection Using
Spatiotemporal Pattern Networks” (NREL/CP-5D0075055). In
Proceedings of the 2019 American Control Conference(ACC).

Seo, G.-S., M. Colombino, I. Subotic, B. Johnson, D. Gross, and F. Dorfler.
2019. “Dispatchable Virtual Oscillator Control for Decentralized Inverterdominated Power Systems: Analysis and Experiments” (NREL/CP5D00-74307). In Proceedings of the 2019 IEEE Applied PowerElectronics Conference and Exposition (APEC). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.

Veda, S., M. Baggu, and A. Pratt. 2019. “Defining a Use Case for ADMS
Testbed: Data Quality Requirements for ADMS Deployment” (NREL/CP5D00-74947). In Proceedings of the 2019 IEEE Power & Energy
Society Innovative Smart Grid Technologies Conference(ISGT). Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Seo, S., J. Kim, E. Muljadi, S. Meor-Danial, M. Worthington, and R. Wills.
2019. “Flicker Mitigation for a Grid-Connected Tidal and River Power
Generator Using the BESS” (NREL/CP-5D00-74944). In Proceedingsof the 2019 10th International Conference on PowerElectronics and ECCE Asia (ICPE 2019 - ECCE Asia).
Shah, S., P. Koralewicz, V. Gevorgian, and R. Wallen. 2018. “Large-Signal
Impedance Modeling of Three-Phase Voltage Source Converters”(NREL/CP-5D00-73465). In Proceedings of IECON 2018 - 44th
Annual Conference of the IEEE Industrial Electronics Society.
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

Vignola, F., J. Peterson, F. Mavromatakis, S. Wilbert, A. Forstinger,
M. Dooraghi, and M. Sengupta. 2019. Removing Biases from
Rotating Shadowband Radiometers” (NREL/CP-5D00-74708). In
Proceedings of SolarPACES 2018: International Conference
on Concentrating Solar Power and Chemical Energy Systems.
AIP Publishing.
Vignola, F., J. Peterson, R. Kessler, M. Dooraghi, M. Sengupta, and F.
Mavromatakis. 2018. “Evaluation of Photodiode-Based Pyranometers
and Reference Solar Cells on a Two-Axis Tracking System” (NREL/
CP-5D00-73754). In Proceedings of the 2018 IEEE 7th World
Conference on Photovoltaic Energy Conversion (WCPEC).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.

﻿ | 79 |Villegas Pico, H.N., B. Mather, and G.-S. Seo. 2019. “Model Identificationof Inverter Nonlinear Control Dynamics” (NREL/CP-5D00-72503). In
Proceedings of the 2018 IEEE Electronic Power Grid (eGrid).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Wang, J., A. Pratt, and M. Baggu. 2018. “Design of a Microgrid Transition
Controller II: System Recovery Under Abnormal Conditions” (NREL/CP5D00-73342). In Proceedings of the 2018 IEEE Power & Energy
Society General Meeting (PESGM). Piscataway, NJ: Institute ofElectrical and Electronics Engineers.
Wang, J., B. Miller, A. Pratt, J. Fossum, T. Bialek, S. Manson, and M.
Symko-Davies. 2018. “Diesel Generator Controller Evaluation via
Controller-Hardware-in-the-Loop for Various Microgrid Operation
Modes” (NREL/CP-5D00-72350). In Proceedings of the 2019 IEEE
Power & Energy Society Innovative Smart Grid Technologies
Conference (ISGT). Piscataway, NJ: Institute of Electrical andElectronics Engineers.
Xie, T., R. Das, G.-S. Seo, D. Maksimovic, and H.P. Le. 2019. “Multiphase
Control for Robust and Complete Soft-Charging Operation of Dual
Inductor Hybrid Converter” (NREL/CP-5D00-74311). In Proceedingsof the 2019 IEEE Applied Power Electronics Conference
and Exposition (APEC). Piscataway, NJ: Institute of Electrical andElectronics Engineers.
Xie, Y., and M. Sengupta. 2018. “Assessing the Performance of theFast All-Sky Radiation Model for Solar Applications with Narrowband
Irradiances on Tilted Surfaces (FARMS-NIT)” (NREL/CP-5D00-73756)
In Proceedings of the 2018 IEEE 7th World Conference on
Photovoltaic Energy Conversion (WCPEC). Piscataway, NJ:
Institute of Electrical and Electronics Engineers.
Xie, Y., M. Sengupta, and C. Deline. 2018. “Recent Advancementsin the Numerical Simulation of Surface Irradiance for Solar Energy
Applications” (NREL/CP-5D00-74015). In Proceedings of the2017 IEEE 44th Photovoltaic Specialist Conference (PVSC).
Piscataway, NJ: Institute of Electrical and Electronics Engineers.
Zhang, J., A. Hasandka, S.M. Shafiul Alam, T. Elgindy, A.R. Florita, andB.-M. Hodge. 2019. “Analysis of Hybrid Smart Grid Communication
Network Designs for Distributed Energy Resources Coordination”(NREL/CP-5D00-74975). In Proceedings of the 2019 IEEE
Power & Energy Society Innovative Smart Grid Technologies
Conference (ISGT). Piscataway, NJ: Institute of Electrical andElectronics Engineers.
Zhou, X., Z. Liu, W. Wang, C. Zhao, F. Ding, and L. Chen. 2018.
“Hierarchical Distributed Voltage Regulation in Networked Autonomous
Grids” (NREL/CP-5D00-75056). In Proceedings of the 2019
American Control Conference (ACC).
| 80 | ﻿Zhu, X., and B. Mather. 2018. “DWT-Based Aggregated Load Modelingand Evaluation for Quasi-Static Time-Series Simulation on Distribution
Feeders” (NREL/CP-5D00-73343). In Proceedings of the 2018 IEEE
Power & Energy Society General Meeting (PESGM). Piscataway,
NJ: Institute of Electrical and Electronics Engineers.
Zhu, X., and Y.C. Zhang. 2018. “Coordinative Voltage Control
Strategy with Multiple Resources for Distribution Systems of HighPV Penetration” (NREL/CP-5D00-73757). In Proceedings of the2018 IEEE 7th World Conference on Photovoltaic Energy
Conversion (WCPEC).

Journal Articles
Achanta, P.K., B.B. Johnson, G.-S. Seo, and D. Maksimovic. 2019. “AMultilevel DC to Three-Phase AC Architecture for Photovoltaic Power
Plants.” IEEE Transactions on Energy Conversion 34 (1): 181–190.
Ahangharnejhad, R.H., A.B. Phillips, K. Ghimire, P. Koirala, Z. Song,
H.M. Barudi, A. Habte, M. Sengupta, R.J. Ellingson, Y. Yan, R.W. Collins,
N.J. Podraza, and M.J. Heben. 2019. “Irradiance and Temperature
Considerations in the Design and Deployment of High Annual Energy
Yield Perovskite CIGS Tandems.” Sustainable Energy & Fuels 7:
1,841–1,851.
Anderson, T., C.-Y. Chang, and S. Martinez. 2019. “Distributed
Approximate Newton Algorithms and Weight Design for Constrained
Optimization.” Automatica 109.
Baker, K., and A. Bernstein. 2019. “Joint Chance Constraints in AC
Optimal Power Flow: Improving Bounds Through Learning.” IEEE
Transactions on Energy Conversion 10 (6): 6,376–6,385.
Bernstein, A., and E. Dall’Anese. 2019. “Real-Time Feedback-Based
Optimization of Distribution Grids: A Unified Approach.” IEEE
Transactions on Control of Network Systems 6 (3): 1,197–1,209.
Bernstein, A., E. Dall’Anese, and A. Simonetto. 2019. “Online PrimalDual Methods with Measurement Feedback for Time-Varying Convex
Optimization.” IEEE Transactions on Signal Processing 67 (8):1,978–1,991.
Bugbee, B., B. W. Bush, K. Gruchalla, K. Potter, N. Brunhart-Lupo, and
V. Krishnan. 2019. “Enabling Immersive Engagement in Energy System
Models with Deep Learning.” Statistical Analysis & Data Mining:
The ASA Data Science Journal 12 (4): 325–337.
Cavraro, G., A. Bernstein, V. Kekatos, and Y.C. Zhang. 2019. “Real-Time
Identifiability of Power Distribution Network Topologies with Limited
Monitoring.” IEEE Control Systems Letters 4 (2): 325–330.

Cerrai, D., D. W. Wanik, M. A. E. Bhuiyan, X. Zhang, J. Yang, M. E. B.
Frediani, E.N. Anagnostou. 2019. “Predicting Storm Outages Through
New Representations of Weather and Vegetation.” IEEE Access.
Christensen, D., M. Martin, E. Gantumur, and B. Mendrick. 2019. “Risk
Assessment at the Edge: Applying NERC CIP to Aggregated Grid-Edge
Resources.” Electricity Journal 32 (2): 50–57.
Colombino, M., E. Dall’Anese, and A. Bernstein. 2019. “Online
Optimization as a Feedback Controller: Stability and Tracking.” IEEE
Transactions on Control of Network Systems.
Craig, M., J. Zhao, G. Schneider, A. Schneider, S. Watson, and G.
Stark. 2019. “Net Revenue and Downstream Flow Impact Trade-Offs
for a Network of Small-Scale Hydropower Facilities in California.”
Environmental Research Communications.
Craig, M.T., I. Losada Carreno, M. Rossol, B.-M. Hodge, and C. Brancucci.
2019. “Effects on Power System Operations of Potential Changes
in Wind and Solar Generation Potential under Climate Change.”
Environmental Research Letters 14 (3).
Cruickshank, R., G. Henze, R. Balaji, B.-M. Hodge, and A. Florita. 2019.
“Quantifying the Opportunity Limits of Automatic Residential Electric
Load Shaping.” Energies 12 (17).
Cui, M., J. Wang, A. Florita, and Y. C. Zhang. 2019. “Generalized Graph
Laplacian Based Anomaly Detection for Spatiotemporal MicroPMU
Data.” IEEE Transactions on Power Systems 34 (5): 3,960–3,963.
Dall’Anese, E., A. Simonetto, and A. Bernstein. 2019. “On theConvergence of the Inexact Running Krasnosel’skii-Mann Method.” IEEE
Control Systems Letters 3 (3): 613–618.
Devine, M.T., S. Nolan, M.A. Lynch, and M. O’Malley. 2019. “The Effect ofDemand Response and Wind Generation on Electricity Investment andOperation.” Sustainable Energy, Grids and Networks 17.
Dong, Z., J. Tan, A. St-Hilaire, E. Muljadi, D. Corbus, R. Nelms, andM. Jacobson. 2019. “Modeling and Simulation of Ternary Pumped
Storage Hydropower for Power System Studies.” IET Generation,
Transmission and Distribution 13 (19): 4382.
Doubleday, K., A. Parker, F. Hafiz, B. Irwin, S. Hancock, S. Pless, andB.-M. Hodge. 2019. “Toward a Subhourly Net Zero Energy District
Design Through Integrated Building and Distribution System Modeling.”
Journal of Renewable and Sustainable Energy.

Doubleday, K., F. Hafiz, A. Parker, T. Elgindy, A. Florita, G. Henze, G.
Salvalai, S. Pless, and B.-M. Hodge. 2019. “Integrated Distribution System
and Urban District Planning With High Renewable Penetrations.”
WIRES Energy and Environment.
Emmanuel, M., and J. Giraldez. 2019. “Net Electricity Clustering at
Different Temporal Resolutions Using a SAX-Based Method forIntegrated Distribution System Planning.” IEEE Access 7.
Fang, X., B.-M. Hodge, E. Du, C. Kang, and F. Li. 2019. “Introducing
Uncertainty Components in Locational Marginal Prices for Pricing
Wind Power and Load Uncertainties.” IEEE Transactions on Power
Systems 34 (3): 2,013–2,024.
Fang, X., B.-M. Hodge, F. Li, E. Du, and C. Kang. 2019. “Adjustable
and Distributionally Robust Chance-Constrained Economic Dispatch
Considering Wind Power Uncertainty.” Journal of Modern Power
Systems and Clean Energy 7 (3): 658–664.
Fang, X., B.-M. Hodge, H. Jiang, and Y. C. Zhang. 2019. “Decentralized
Wind Uncertainty Management: Alternating Direction Method ofMultipliers Based Distributionally-Robust Chance Constrained Optimal
Power Flow.” Applied Energy 239: 938–947.
Fang, X., H. Cui, H. Yuan, J. Tan, and T. Jiang. 2019. “DistributionallyRobust Chance Constrained and Interval Optimization for Integrated
Electricity and Natural Gas Systems Optimal Power Flow with Wind
Uncertainties.” Applied Energy 252: 113420.
Feng, C., D. Yang, B.-M. Hodge, and J. Zhang. 2019. “OpenSolar:
Promoting the Openness and Accessibility of Diverse Public Solar
Datasets.” Solar Energy 188: 1369–1379.
Gensollen, N., K. Horowitz, B. Palmintier, F. Ding, and B. Mather. 2019.
Beyond Hosting Capacity: Using Shortest-Path Methods to Minimize
Upgrade Cost Pathways.” IEEE Journal of Photovoltaics 9 (4):1051–1056.
Guerra, O. J., J. Eichman, J. Kurtz, and B.-M. Hodge. 2019. “CostCompetitiveness of Electrolytic Hydrogen.” Joule 3 (10): 2,445–2,443.
Gueymard, C. A., A. Habte, and M. Sengupta. 2019. “Reducing
Uncertainties in Large-Scale Solar Resource Data: The Impact ofAerosols.” IEEE Journal of Photovoltaics 8 (6): 1,731–1,737.
Gueymard, C. A., J. M. Bright, D. Lingfors, A. Habte, and M. Sengupta.
2019. “A Posteriori Clear-Sky Identification Methods in Solar IrradianceTime Series: Review and Preliminary Validation Using Sky Imagers.”
Renewable & Sustainable Energy Reviews 109: 412–427.

﻿ | 81 |Gueymard, C. A., V. Lara-Lanego, M. Sengupta, and Y. Xie. 2019. “Surface
Albedo and Reflectance: Review of Definitions, Angular and Spectral
Effects, and Intercomparison of Major Data Sources in Support ofAdvanced Solar Irradiance Modeling over the Americas.” Solar Energy
182: 194–212.
Habte, A., M. Sengupta, C. A. Gueymard, R. Narasappa, O. Rosseler, andD.M. Burns. 2019. “Estimating Ultraviolet Radiation from Global Horizontal
Irradiance.” IEEE Journal of Photovoltaics 9 (1): 139–146.
Haegel, N. M, H. Atwater Jr., T. Barnes, C. Breyer, A. Burrell, Y.-M. Chiang,
S. De Wolf, B. Dimmler, D. Feldman, S. Glunz, J.C. Goldschmidt, D.
Hochschild, R. Inzunza, I. Kaizuka, B. Kroposki, S. Kurtz, S. Leu, R. Margolis,
K. Matsubara, A. Metz, W. K. Metzger, W. Tumas, J. van de Lagemaat, E.
Warren, M. Werner et al. 2019. “Terawatt-Scale Photovoltaics: Transform
Global Energy.” 2019. Science.
Hanrieder, N., A. Ghennioui, A. A. Merrouni, S. Wilbert, F., Wiesinger, M.
Sengupta, L. Zarzalejo, and A. Schade. 2019. “Atmospheric Transmittance
Model Validation for CSP Tower Plants.” Remote Sensing 11 (9): 1083.
Hasan, I., T. Husain, Y. Sozer, I. Husain, and E. Muljadi. 2019. “Mechanical
Performance of Transverse Flux Machines.” IEEE Transactions on
Industry Applications 55 (4): 3,716–3,724.
Helisto, N., J. Kiviluoma, H. Holttinen, J. D. Lara, and B.-M. Hodge. 2019.
“Including Operational Aspects in the Planning of Power Systems
with Large Amounts of Variable Generation: A Review of ModelingApproaches.” WIRES Energy and Environment.
Hoke, A., J. Giraldez, B. Palmintier, E. Ifuku, M. Asano, R. Ueda, and M.
Symko-Davies. 2019. “Setting the Smart Solar Standard: Collaborations
Between Hawaiian Electric and the National Renewable Energy
Laboratory.” IEEE Power & Energy Magazine 16 (6): 18–29.
Kim, C., E. Muljadi, and C. C. Chung. 2019. “Coordinated Control ofWind Turbine and Energy Storage System for Reducing Wind Power
Fluctuation.” Energies 11 (1): 52.
Kim, J., E. Muljadi, V. Gevorgian, A. F. Hoke. 2019. “Dynamic Capabilities
of an Energy Storage-Embedded DFIG System.” IEEE Transactions on
Industry Applications 55 (4): 4,124–4,134.
Kim, J., E. Muljadi, V. Gevorgian, M. Mohanpurkar, Y. Luo, R. Hovsapian,and V. Koritarov. 2019. “Capability-Coordinated Frequency Control
Scheme of a Virtual Power Plant with Renewable Energy Sources.” IET
Generation, Transmission and Distribution 13 (16): 3642.

| 82 | ﻿Kim, J., V. Gevorgian, Y. Luo, M. Mohanpurkar, V. Koritarov, R. Hovsapian,and E. Muljadi. 2019. “Supercapacitor to Provide Ancillary Services With
Control Coordination.” IEEE Transactions on Industry Applications
55 (5): 5,119–5,127.
Kotecha, R., W. Metzger, B. Mather, S. Narumanchi, and A. Zakutayev.
2019. “Modeling and Analysis of Gallium Oxide Vertical Transistors.” ECS
Journal of Solid State Science and Technology 8 (7): Q3202–
Q3205.
Kumler, A., I. Losada Carreno, M. Craig, B.-M. Hodge, W. Cole, and C.
Brancucci. 2019. “Inter-Annual Variability of Wind and Solar Electricity
Generation and Capacity Values in Texas.” Environmental Research
Letters.
Kumler, A., Y. Xie, and Y. C. Zhang. 2019. “A Physics-Based Smart
Persistence Model for Intra-Hour Forecasting of Solar Radiation (PSPI)
Using GHI Measurements and a Cloud Retrieval Technique.” Solar
Energy 177: 494–500.
Mather, B., and G. Yuan. 2019. “Going to the Next Level: The Growth ofDistributed Energy Resources [Guest Editorial].” IEEE Power & Energy
Magazine.
O’Malley, M. 2019. “Guest Editorial.” IEEE Transactions on Smart Grid
10 (1): 1,089–1,090.
Ostrometzky, J., A. Bernstein, and G. Zussman. 2019. “Irradiance Field
Reconstruction from Partial Observability of Solar Radiation.” IEEE
Geoscience and Remote Sensing Letters: 1–5.
Purba, V., B. B. Johnson, M. Rodriguez, S. Jafarpour, F. Bullo, and S. V.
Dhople. 2019. “Reduced-Order Aggregate Model for Parallel-Connected
Single-Phase Inverters.” IEEE Transactions on Energy Conversion
34 (2): 824–837.
Saha, H., A.R. Florita, G. P. Henze, and S. Sarkar. 2019. “Occupancy
Sensing in Buildings: A Review of Data Analytics Approaches.” Energy
and Buildings 188–189: 278–285.
Sajadi, A., S. Zhao, K. Clark, and K. A. Loparo. 2019. “Small-Signal Stability
Analysis of Large-Scale Power Systems in Response to Variability of
Offshore Wind Power Plants.” IEEE Systems Journal.
Saleem, D., A. Sundararajan, A. Sanghvi, J. Rivera, A. I. Sarwat, and B.
Kroposki. 2019. “A Multidimensional Holistic Framework for the Securityof Distributed Energy and Control Systems.” IEEE Systems Journal.

Schneider, K. P., S. Laval, J. Hansen, R. B. Melton, L. Ponder, L. Fox, J.
Hart, J. Hambrick, M. Buckner, M. Baggu, K. Prabakar, M. Manjrekar,
S. Essakiappan, L. M. Tolbert, Y. Liu, J. Dong, L. Zhu, A. Smallwood, A.
Jayantilal, C. Irwin, and G. Yuan. 2019. “A Distributed Power System
Control Architecture for Improved Distribution System Resiliency.”
IEEE Access 7: 9,957–9,970.
Sedzro, K. S. A., X. Shi, A. J. Lamadrid, and L. F. Zuluaga. 2019. “A Heuristic
Approach to the Post-Disturbance and Stochastic Pre-DisturbanceMicrogrid Formation Problem.” IEEE Transactions on Smart Grid 10(5): 5,574–5,586.
Seo, G.-S., and H. P. Le. 2019. “S-Hybrid Step-Down DC-DC ConverterAnalysis of Operation and Design Considerations.” IEEE Transactions
on Industrial Electronics 67 (1): 265–275.
Seo, G.-S., R. Das, and H. P. Le. 2019. “Dual Inductor Hybrid Converter
for Point-of-Load Voltage Regulator Modules.” IEEE Transactions on
Industry Applications.
Shah, S., and L. Parsa. 2019. “Impedance-Based Prediction of Distortions
Generated by Resonance in Grid-Connected Converters.” IEEE
Transactions on Energy Conversion 34 (3): 1,264–1,275.
Shah, S., P. Koralewicz, V. Gevorgian, R. Wallen, K. Jha, D. Mashtare,
R. K. Burra, and L. Parsa. 2019. “Large-Signal Impedance-Based Modelingand Mitigation of Resonance of Converter-Grid Systems.” IEEE
Transactions on Sustainable Energy 10 (3): 1439–1449.
Sun, M., C. Feng, E. K. Chartan, B.-M. Hodge, and J. Zhang. 2019. “A TwoStep Short-Term Probabilistic Wind Forecasting Methodology Based on
Predictive Distribution Optimization.” Applied Energy 238: 1,497–1,505.
Vartanian, C., R. Bauer, L. Casey, C. Loutan, D. Narang, and V. Patel. 2019.
“Ensuring System Reliability: Distributed Energy Resources and Bulk
Power System Considerations.” IEEE Power & Energy Magazine 16(6): 52–63.
Villegas Pico, H. N., and B. B. Johnson. 2019. “Transient Stability
Assessment of Multi-Machine Multi-Converter Power Systems.” IEEE
Transactions on Power Systems 34 (5): 3,504–3,514.
Weitenberg, E., Y. Jiang, C. Zhao, E. Mallada, C. De Persis, and F. Dorfler.
2019. “Robust Decentralized Secondary Frequency Control in Power
Systems: Merits and Trade-Offs.” IEEE Transactions on AutomaticControl 64 (10): 3,967–3,982.

Wright, J., G. Landwehr, and E. Chartan. 2019. “Assessing the Value of
Improved Variable Renewable Energy Forecasting Accuracy in the South
African Power System.” Journal of Energy in Southern Africa 30 (2).
Wu, C., H. Jiang, I. Kalra, X. Wang, M. Cano, P. C. Maness, J. Yu, and W.
Xiong. 2019. “A Generalized Computational Framework to Streamline
Thermodynamics and Kinetics Analysis of Metabolic Pathways.”
Metabolic Engineering.
Wu, D., A. M. Aldaoudeyeh, M. Javadi, F. Ma, J. Tan, J. N. Jiang. 2019. “A
Method to Identify Weak Points of Interconnection of Renewable Energy
Resources.” International Journal of Electrical Power & Energy
Systems 111: 72–82.
Xie, Y., M. Sengupta, and C. Wang. 2019. “A Fast All-Sky Radiation Modelfor Solar Applications with Narrowband Irradiances on Tilted Surfaces(FARMS-NIT): Part II. The Cloudy-Sky Model.” Solar Energy 188:
799–812.
Zhang, W., W. Kleiber, A. R. Florita, B.-M. Hodge, and B. Mather. 2019.
“Modeling and Simulation of High-Frequency Solar Irradiance.” IEEE
Journal of Photovoltaics 9 (1): 124–131.
Zhang, W., W. Kleiber, A. R. Florita, B.-M. Hodge, and B. Mather. 2019. “A
Stochastic Downscaling Approach for Generating High-Frequency Solar
Irradiance Scenarios.” Solar Energy 176: 370–379.

Posters
Bryce, R. 2019. “Utility-Scale Vanadium Redox Flow Battery forDistribution Grid Support: System Dynamics and Efficiencies” (NREL/
PO-5D00-74248). Presented at the 12th Annual Beyond Lithium-Ion
Symposium, Golden, Colorado, June 25–27, 2019.
Fang, X., M. T. Craig, and B.-M. Hodge. 2019. “Linear Approximation Line
Pack Model for Integrated Electricity and Natural Gas Systems OPF”
(NREL/PO-5D00-74363). Presented at the IEEE Power and Energy
Society General Meeting (PESGM), Atlanta, Georgia, August 4–8, 2019.
Ghosh, S., F. Ding, J. Simpson, T. Harris, M. Baggu, H. G. Aghamolki, and
W. Ren. 2019. “Techno-Economic Analysis for Grid Edge Intelligence: A
Preliminary Study on Smart Voltage Regulator Controls” (NREL/PO5D00-73305). Presented at IEEE Innovative Smart Grid Technologies(ISGT) Conference, Washington, D.C., February 17–20, 2019.
Habte, A., and M. Sengupta. 2019. “ASTM Solar Resource Standards for
Solar Energy Industry” (NREL/PO-5D00-74138). Presented at the Solar
Power International 2019 Conference, Salt Lake City, Utah, September
23–26, 2019.

﻿ | 83 |Habte, A., M. Sengupta, A. Andreas, R. Narasappa, T. Thomas, A. Wolf,
and C. Gueymard. 2018. “Low-Cost Multiparameter Sensor for Solar
Resource Applications” (NREL/PO-5D00-72430). Presented at the Solar
Power International 2018 Conference, Anaheim, California, September
24–27, 2018.

Netto, M., V. Krishnan, L. Mili, Y. Susuki, and Y. Zhang. 2019. “Applicationof the Koopman Operator-Theoretic Framework to Power System
Dynamic State Estimation” (NREL/PO-5D00-73236). Presented at the
IPAM Operator Theoretic Methods in Dynamic Data Analysis and Control
Workshop, Los Angeles, California, February 11–15, 2019.

Habte, A., M. Sengupta, A. Andreas, and Y. Xie. 2019. “Data Quality
Assessment Using SERI-QC” (NREL/PO-5D00-74202). Presented at
the 6th International Conference of Energy and Meteorology, Technical
University of Denmark, June 24–27, 2019.

Sen Biswas, R., J. Tan, H. Jain, V. Gevorgian, Vahan, and Y. Zhang. 2019.
“Equivalent Test Bed in PSCAD and PSLF for Studying Advanced Power
Systems Controller Performance” (NREL/PO-5D00-73289). Presented atIEEE Innovative Smart Grid Technologies (ISGT) Conference, Washington,
D.C., February 17–20, 2019.

Habte, A., M. Sengupta, C.A. Gueymard, R. Narasappa, O. Rosseler, andD.M. Burns. 2018. “Estimating Ultraviolet Radiation from Total Radiation”(NREL/PO-5D00-72429). Presented at the Solar Power International
2018 Conference, Anaheim, California, September 24–27, 2018.
Jain, A. K., K. Horowitz, F. Ding, N. Gensollen, B. Mather, and B. Palmintier.
2019. “Quasi-Static Time-Series Photovoltaic Hosting Capacity
Methodology and Metrics” (NREL/PO-5D00-73304). Presented at IEEE
Innovative Smart Grid Technologies (ISGT) Conference, Washington, D.C.,
February 17–20, 2019.
Jain, H., B. Palmintier, D. Krishnamurthy, I. Krad, and E. Hale. 2019.
“Evaluating the Impact of Price-Responsive Load on Power Systems
Using Integrated T&D Simulation” (NREL/PO-5D00-73296). Presented atIEEE Innovative Smart Grid Technologies (ISGT) Conference, Washington,
D.C., February 17–20, 2019.
Kenyon, R. W., B. Mather, and B.-M. Hodge. 2019. “Assessment of IEEE
1547 Low-Voltage Ride-Through Criteria Impact on Bulk Power System
Dynamics Following Transmission Path Fault” (NREL/PO-5D00-74432).
Presented at the IEEE Power and Energy Society General Meeting(PESGM), Atlanta, Georgia, August 4–8, 2019.
Kutchenreiter, M., A. Habte, A. Andreas, and M. Sengupta. 2019.
“Ventilator Improvements for Reducing Radiometer Frost, Snow, and Ice
Accumulation” (NREL/PO-5D00-74105). Presented at the 2019 ARM/ASR
PI Meeting, Bethesda, Maryland, June 10–14, 2019.
Latif, A., and A. Nagarajan. 2019. “Field Validated Utility-Scale Battery
Storage Control Models for Quasi-Static Analyses” (NREL/PO5D00-73302). Presented at IEEE Innovative Smart Grid Technologies(ISGT) Conference, Washington, D.C., February 17–20, 2019.
Latif, A., R. Bryce, and A. Nagarajan. 2019. “Novel Technique forDeveloping Linearized Convex System Models from Experimentally
Derived Data” (NREL/PO-5D00-74510). Presented at the IEEE Powerand Energy Society General Meeting (PESGM), Atlanta, Georgia, August
4–8, 2019.

| 84 | ﻿

Sengupta, M. and A. Habte. 2019. “Standards and Best Practices for Solar
Measurements” (NREL/PO-5D00-73909). Presented at the 2019 PV
Systems Symposium, Albuquerque, New Mexico, May 14–16, 2019.
Sengupta, M., A. Habte, Y. Xie, M. Rossol, and G. Buster. 2019. “Evolutionof NREL’s National Solar Radiation Database (NSRDB)” (NREL/
PO-5D00-74137). Presented at the Solar Power International 2019
Conference, Salt Lake City, Utah, September 23–26, 2019.
Singh, S., S. P. Singh, S. Veda, and M. Baggu. 2018. “Smart Grid-Enabled
CVR: An Advanced Application for Distribution Management Systems”(NREL/PO-5D00-71946). Presented at the IEEE Power and Energy
Society General Meeting (PEGSM), Portland, Oregon, August 5–9, 2018.
Thiagarajan, R., A. Nagarajan, P. Hacke, and I. Repins. 2019. “Effects ofReactive Power on Photovoltaic Inverter Reliability and Lifetime” (NREL/
PO-5D00-74155). Presented at the 46th IEEE Photovoltaic Specialists
Conference (PVSC 46), Chicago, Illinois, June 6–21, 2019.
Velaga, Y.N., K. Prabakar, A. Singh, P. K. Sen, and B. Kroposki. 2019.
“Advanced Distribution Protection for High Penetration of Distributed
Energy Resources (DER)” (NREL/PO-5D00-74384). Presented at theIEEE Power and Energy Society General Meeting (PESGM), Atlanta,
Georgia, August 4–8, 2019.
Wang, J., B. Miller, A. Pratt, J. Fossum, T. Bialek, S. Manson, and M. SymkoDavies. 2019. “Diesel Generator Controller Evaluation via ControllerHardware-in-the-Loop for Various Microgrid Operation Models” (NREL/
PO-5D00-73290). Presented at IEEE Innovative Smart Grid Technologies(ISGT) Conference, Washington, D.C., February 17–20, 2019.
Yang, J., M. Sengupta, Y. Xie, P. A. Jimenez, and J.-H. Kim. 2019. “Adjoint
Sensitivity Analysis of FARMS for Forecasting Variables of WRF-Solar”(NREL/PO-5D00-74092). Presented at the 2019 Joint WRF/MPAS User’s
Workshop, Boulder, Colorado, June 10–14, 2019.

Presentations
Baggu, M. 2019. “A Test Bed to Evaluate Advanced Distribution Management
Systems for Modern Power Systems” (NREL/PR-5D00-74262). Presented atIEEE Eurocon 2019, Novi Sad, Serbia, July 1–4, 2019.
Bernstein, A. 2019. “Asynchronous and Distributed Tracking of TimeVarying Fixed Points” (NREL/PR-5D00-74796). Presented at theInnovative Optimization and Control Methods for Highly Distributed
Autonomous Systems Workshop, Golden, Colorado, April 11–12, 2019.
Chartan, E. 2019. “Grid Integration and Market Analysis of Adjustable-Speed
Pumped Storage Hydropower” (NREL/PR-5D00-74348). Presented at
HydroVision International 2019, Portland, Oregon, July 25, 2019.
Columbino, M., J. W. Simpson-Porco, and A. Bernstein. 2019. “Toward
Robustness Guarantees for Feedback-Based Optimization” (NREL/
PR-5D00-74797). Presented at the Innovative Optimization and Control
Methods for Highly Distributed Autonomous Systems Workshop, Golden,
Colorado, April 11–12, 2019.
Ding, F. 2019. “Distributed Energy Resource Management Solutions to
Enable Reliable and Resilient Distribution Grids” (NREL/PR-5D00-74511).
Presented at the IEEE Power and Energy Society General Meeting,Atlanta, Georgia, August 4–9, 2019.
Ding, F. 2018. “Grid Modernization of Cooperatives and Municipal Utilities
via Breakthrough System Monitoring, Control and Optimization” (NREL/
PR-5D00-72745). Presented at the ADMS Testbed Workshop, Golden,
Colorado, September 26, 2018.
DiOrio, N., N. Blair, J. Freeman, A. Habte, E. Elgqvist, M., Deceglie, D.C.
Jordan, A. Nag, A. Shinn, and C. Deline. 2018. “Solar System Modeling at
NREL” (NREL/PR-6A20-72547). Presented at Solar Power International
2018, Anaheim, California, September 24, 2018.
Gevorgian, V. 2018. “Grid Integration of Variable Renewable Generation:
Reliability Challenges and Solutions” (NREL/PR-5D00-72615). Presented
at the ICEF 5th Annual Meeting, Tokyo, Japan, October 10, 2018.
Gevorgian, V. 2018. “NREL Controllable Grid Interface (CGI): Overview
of Progress and Projects” (NREL/PR-5D00-72886). Presented at the
5th Annual International Workshop on Grid Simulator Testing of Energy
Systems and Wind Turbine Powertrains, Tallahassee, Florida, November
15–16, 2018.
Giraldez, J. 2017. “Voltage Regulation with Customer-Sited Resources”(NREL/PR-5D00-70562). Presented at the EUCI Hawaii Power Summit
2017, Honolulu, Hawaii, December 1, 2017.

Graf, P., J. Annoni, C. Bay, D. Sigler, D. Biagioni, M. Lunacek, A. Bernstein,and W. Jones. 2019. “Distributed Reinforcement Learning with ADMM-RL”(NREL/PR-2C00-74798). Presented at the Innovative Optimization andControl Methods for Highly Distributed Autonomous Systems Workshop,
Golden, Colorado, April 11–12, 2019.
Guerra, O., J. Eichman, B.-M. Hodge, and J. Kurtz. 2018. “Cost-Competitive
Electrolysis-Based Hydrogen Under Current U.S. Electric Utility Rates”(NREL/PR-5D00-72710). Presented at the 2018 AIChE Annual Meeting,Pittsburgh, Pennsylvania, October 30, 2018.
Guerra, O., J. Eichman, B.-M. Hodge, and J. Kurtz. 2018. “CostEffectiveness of Grid Energy Storage Technologies in Current and Future
U.S. Power Systems” (NREL/PR-5D00-72709). Presented at the 2018
AIChE Annual Meeting, Pittsburgh, Pennsylvania, November 1, 2018.
Hoke, A. 2019. “DER Testing and Verification – Overview of IEEEP1547.1” (NREL/PR-5D00-74497). Presented at the PJM Technical
Workshop on DER Integration, July 30, 2019. Valley Forge,
Pennsylvania, July 30–31, 2019.
Hoke, A. 2019. “Smart Inverter Utility Experience in Hawaii” (NREL/PR5D00-74091). Presented at the IEEE Power and Energy Society General
Meeting, Atlanta, Georgia, August 4–9, 2019.
Hoke, A., P. Gotseff, M. Emmanuel, N. Wunder, and J. Giraldez. 2019.
“Estimating Customer Impact of Volt Watt Using Only Smart Meter
Voltage Data” (NREL/PR-5D00-74146). Presented at the Distributed
Energy Resource Stakeholder Meeting, Honolulu, Hawaii, May 9, 2019.
Ingraham, M. 2019. “Hydropower Value and Opportunities in Future Grid
States” (NREL/PR-5D00-73309). Presented at the CEATI Hydropower
Conference, Tucson, Arizona, March 19–20, 2019.
Jain, A. K., R. Bryce, S. Ghosh, A. Latif, M. Emmanuel, A. Nagarajan,
D. Palchak, and J. Cochran. 2019. “Distribution Systems Planning andAnalysis Framework for Indian Feeders – Partnership with BSES/
BRPL” (NREL/PR-5D00-74626). Presented at the Second International
Conference on Large-Scale Grid Integration of Renewable Energy inIndia, New Delhi, India, September 6, 2019.
Koralewicz, P., R. Wallen, and V. Gevorgian. 2018. “Overview of CGI/DYNOS/PHIL Platform” (NREL/PR-5000-72923). Presented at the 5th
Annual International Workshop on Grid Simulator Testing of Energy
Systems and Wind Turbine Powertrains, Tallahassee, Florida, November
16, 2018.

﻿ | 85 |Krishnan, V., B. Hobbs, Q. Xu, E. Spyrou, P. Edwards, H. Sky, H. Hamann,
R. Zhang, J. Zhang, B. Li, A. Motley, C. Loutan, R. Web, B. Borissov, and
S. Rose. 2019. “Coordinated Ramping Product and Regulation Reserve
Procurements Using Probabilistic Solar Power Forecasts” (NREL/
PR-5D00-73568). Presented at the ESIF Spring Technical Workshop,
Albuquerque, New Mexico, March 19, 2019.
Kroposki, B. 2019. “Summarizing the Technical Challenges of High Levelsof Inverter-based Resources in Power Grids” (NREL/PR-5D00-73869).
Presented at the Grid-forming Inverters for Low-inertia Power Systems
Workshop, Seattle, Washington, April 20–22, 2019.

Pratt, A. and T. Bialek. 2019. “Borrego Springs Community Microgrid”(NREL/PR-5D00-74477). Presented at the International Microgrid
Symposium, Fort Collins, Colorado, August 9–12, 2019.’
Sekulic, W., and P. McNutt. 2019. “Evaluating the Incident Energy ofArcs in Photovoltaic DC Systems: Comparison Between Calculated andExperimental Data” (NREL/PR-5K00-73213). Presented at the IEEE IAS
Electrical Safety Workshop, Jacksonville, Florida, March 4–8, 2019.
Sengupta, M. 2019. “Data Quality Assessment Using SERI-QC” (NREL/PR5D00-74203). Presented at the 6th International Conference on Energy &Meteorology (ICEM), Copenhagen, Denmark, June 24–27, 2019.

Lundstrom, B. 2018. “Multi-PCC Electric Distribution System Power
Hardware-in-the-Loop” (NREL/PR-5D00-72907). Presented at the 5th
Annual International Workshop on Grid Simulator Testing of Energy
Systems and Wind Turbine Powertrains, Tallahassee, Florida, November
15–16, 2018.

Sengupta, M., A. Habte, and J. Freeman. 2019. “The Case for Custom
TMYs: Examples Using the NSRDB” (NREL/PR-5D00-74201). Presented
at the 46th IEEE Photovoltaic Specialist Conference, Chicago, Illinois, June
16–21, 2019.

Moreno, G., K. Bennion, B. Kekelia, R. Kotecha, B. Mather, S. Narumanchi,
P. Paret, B. Tellekamp, A. Zakutayev, S. Graham, and S. Kim. 2019. “Ga2O3
Packaging and Thermal Management Challenges and Opportunities”(NREL/PR-5400-73902). Presented at the Third Ultrawide-Bandgap
Workshop, Adelphi, Maryland, May 14–16, 2019.

Sengupta, M., A. Habte, Y. Xie, and G. Maclaurin. 2019. “Spectral andBroadband Data Sets from The National Solar Radiation Database(NSRDB)” (NREL/PR-5D00-74218). Presented at the 6th International
Conference on Energy & Meteorology (ICEM), Copenhagen, Denmark,June 24–27, 2019.

Palmintier, B. 2019. “Advanced Inverters: (1547) Capabilities, Experiences,and Interaction with Hosting Capacity” (NREL/PR-5D00-73449).
Presented at the NRCan Canada-USA-Mexico Workshop on Hosting
Capacity with Advanced Inverter Functions, Montreal, Quebec, Canada,
February 19, 2019.

Shah, S., P. Koralewicz, and V. Gevorgian. 2018. “CGI for Impedance
Characterization of Inverter-Coupled Generation” (NREL/PR5D00-72899). Presented at the 5th Annual International Workshop on
Grid Simulator Testing of Energy Systems and Wind Turbine Powertrains,
Tallahassee, Florida, November 15–16, 2018.

Palmintier, B. 2019. “HELICS for Integrated Transmission, Distribution,
Communication, & Control (TDC+C) Modeling” (NREL/PR-5D00-73977).
Presented at the SETO Workshop on Challenges for Distribution,
Washington, D.C., May 17, 2019.

Torres, J., and N. Laws. 2018. “Energy Resilience Through Grid
Modernization and Renewables Integration” (NREL/PR-7A40-72884).
Presented at the Critical Infrastructure Resilience Workshop, Washington,
D.C., December 7, 2018.

Palmintier, B., and Y. Zhang. 2019. “Grid Optimization with Solar (GOSolar) Experiences With: Data-Driven and Machine Learning Approaches
for High-Pen PV Grids” (NREL/PR-5D00-73976). Washington, D.C., May
16–17, 2019.

Veda, S. 2019. “Impact of Solar Eclipse 2017 on Grid Operations Panel
Session: Impact of Climatic Events on the Operation and Planning”(NREL/PR-5D00-74544). Presented at the IEEE Power and Energy
Society General Meeting, Atlanta, Georgia, August 4–9, 2019.

Pratt, A., B. Amundson, and S. Veda. 2019. “Addressing ADMS Adoption
Challenges Using NREL’s ADMS Testbed” (NREL/PR-5D00-73255).
Presented at Distributech Conference and Exhibition 2019, New Orleans,Louisiana, February 5–7, 2019.

Veda, S., and S. Ghosh. 2018. “Model Improvement for ADMS
Deployment” (NREL/PR-5D00-72746). Presented at the ADMS Testbed
Workshop, Golden, Colorado, September 25–26, 2018.

Pratt, A., and M. Baggu. 2019. “ADMS Testbed” (NREL/PR-5D00-73277).
Presented at the IEEE Innovative Smart Grid Technologies (ISGT)
Conference, Washington, D.C., February 17–20, 2019.

| 86 | ﻿

Woodhouse, M., A. Walker, R. Fu, D. Jordan, and S. Kurtz. 2019. “The Roleof Reliability and Durability in Photovoltaic System Economics” (NREL/
PR-6A20-73751). Golden, Colorado, February 11, 2019.

Subcontract Reports
Kempton, W. 2019. Final Report: Open V2X at ESIF: June
2015–February 2017 (NREL/SR-5B00-70279). Golden, CO: National
Renewable Energy Laboratory.
Smarter Grid Solutions, Inc. 2019. Smarter Grid Solutions |National Renewable Energy Laboratory: Active Management
Integration: June 2015–November 2016 (NREL/SR-5B00-70278).
Golden, CO: National Renewable Energy Laboratory.

Technical Reports
Beiter, P., P. Spitsen, K. Nunemaker, T. Tian, W. Musial, E. Lantz, and
V. Gevorgian. 2018. 2017 Offshore Wind Technologies Market
Update Executive Summary (NREL/TP-6A20-72464). Golden, CO:
National Renewable Energy Laboratory.
Binz, R., R. Bracho, A. Anderson, M. Coddington, E. Hale, M. Ingram, M.
Martin, et al. 2019. A Report on the Implementation of Smart
Grids in Mexico (NREL/TP-7A40-72699). Golden, CO: National
Renewable Energy Laboratory.
Brancucci, C., R. Bracho, G. Brinkman, and B.-M. Hodge. 2018. Baja
California Sur Renewable Integration Study (NREL/TP5D00-72598). Golden, CO: National Renewable Energy Laboratory.
Chernyakhovskiy, I., S. Koebrich, V. Gevorgian, and J. Cochran. 2019. GridFriendly Renewable Energy: Solar and Wind Participation in
Automatic Generation Control Systems (NREL/TP-6A20-73866).
Golden, CO: National Renewable Energy Laboratory.
Christensen, D., X. Jin, B. Sparn, S. Isley, et al. 2018. Final Report: TIP337 Home Battery System for Cybersecure Energy Efficiency
and Demand Response (NREL/TP-5500-72184). Golden, CO: National
Renewable Energy Laboratory.
Dooraghi, M., A. Andreas, M. Kutchenreiter, I. Reda, M. Stoddard, M.
Sengupta, and A. Habte. 2018. Broadband Outdoor Radiometer
Calibration (BORCAL) Process for the Atmospheric Radiation
Measurement (ARM) Program: Second Edition (NREL/TP5D00-71476). Golden, CO: National Renewable Energy Laboratory.
Gevorgian, V. 2019. Highly Accurate Method for Real-Time Active
Power Reserve Estimation for Utility-Scale PV Power Plants(NREL/TP-5D00-73207). Golden, CO: National Renewable Energy
Laboratory.

Gevorgian, V., P. Koralewicz, H. Villegas, S. Shah, R. Wallen, D. Corbus, J.
Keller, R. Hovsapian, M. Mohanpurkar, R. Kadavi, M. Pnawar, J. Leonard, M.
Richwine, N. Miller, D. Gao, W. Yan, and W. Gao. 2019. WGRID-49 GMLC
Project Report: Understanding the Role of Short-Term Energy
Storage and Large Motor Loads for Active Power Controls byWind Power (NREL/TP-5D00-72888). Grid Modernization Laboratory
Consortium. Golden, CO: National Renewable Energy Laboratory.
Giraldez, J., A. Hoke, P. Gotseff, N. Wunder, M. Blonsky, M. Emmanuel,A. Latif, E. Ifuku, M. Asano, T. Aukai, and R. Sasaki. 2018. Advanced
Inverter Voltage Controls: Simulation and Field Pilot Findings(NREL/TP-5D00-72298). Golden, CO: National Renewable Energy
Laboratory.
Giraldez, J., F. Flores-Espino, S. MacAlpine, and P. Asmus. 2018. Phase
I Microgrid Cost Study: Data Collection and Analysis of
Microgrid Costs in the United States (NREL/TP-5D00-67821).
Golden, CO: National Renewable Energy Laboratory.
Habte, A., A. Andreas, M. Sengupta, R. Narasappa, A. Hoke, P. Gotseff,
R. Thiagarajan, A. Wolf, L. Carranza, and D. Wattsirst. 2019. Low-Cost
Multiparamenter Device for Solar Resource Applications(NREL/TP-5D00-73104). Golden, CO: National Renewable Energy
Laboratory.
Habte, A., M. Sengupta, Y. Xie, M. Dooraghi, I. Reda, A. Driesse, C.
Gueymard, S. Wilbert, and F. Vignola. 2018. Developing a Framework
for Reference Cell Standards for PV Resource Applications(NREL/TP-5D00-72599). Golden, CO: National Renewable Energy
Laboratory.
Hodge, C., K. Hauck, S. Gupta, and J. Bennett. 2019. Vehicle
Cybersecurity Threats and Mitigation Approaches (NREL/TP5400-74247). Golden, CO: National Renewable Energy Laboratory.
Holmberg, D., M. Burns, S. Bushby, A. Gopstein, T. McDermott, Y. Tang,
Q. Huang, A. Pratt, M. Ruth, F. Ding, Y. Bichpuriya, N. Rajagopal, M. Ilic, R.
Jaddivada, and H. Neema. 2019. NIST Transactive Energy Modelingand Simulation Challenge Phase II Final Report (NIST Special
Publication 1900-603). National Institute of Standards and Technology.
Horowitz, K., Z. Peterson, M. Coddington, F. Ding, B. Sigrin, D. Saleem, S.E.
Baldwin, et al. 2019. An Overview of Distributed Energy Resource(DER) Interconnection: Current Practices and Emerging
Solutions (NREL/TP-6A20-72102). Golden, CO: National Renewable
Energy Laboratory.

﻿ | 87 |Ibrahim, R., M. Dooraghi, A. Andreas, and A. Habte. 2018. NREL
Pyrheliometer Comparisons: September 24 – October 5, 2018
(NPC-2018) (NREL/TP-1900-72607). Golden, CO: National Renewable
Energy Laboratory.
Ibrahim, R., M. Dooraghi, A. Andreas, J. Gröbner, and C. Thomann. 2018.
Comparison Between Absolute Cavity Pyrgeometers andPyrgeometers Traceable to World Infrared Standard Groupand the InfraRed Integrating Sphere (NREL/TP-1900-72633).
Golden, CO: National Renewable Energy Laboratory.
Kumler, A., Y. Xie, and Y. Zhang. 2018. A New Approach for ShortTerm Solar Radiation Forecasting Using the Estimation of
Cloud Fraction and Cloud Albedo (NREL/TP-5D00-72290). Golden,
CO: National Renewable Energy Laboratory.
Lundquist, J. K., A. Clifton, S. Dana, A. Huskey, P. Moriarty, J. van Dam,and T. Herges. 2019. Wind Energy Instrumentation Atlas (NREL/TP5000-68986). Golden, CO: National Renewable Energy Laboratory.
Mayyas, A., M. Ruth, B. Pivovar, G. Bender, and K. Wipke. 2018.
Manufacturing Cost Analysis for Proton Exchange Membrane
Water Electrolyzers (NREL/TP-6A20-72740). Golden, CO: National
Renewable Energy Laboratory.
McAllister, R., D. Manning, L. Bird, M. Coddington, and C. Volpi.
2019. New Approaches to Distributed PV Interconnection:
Implementation Considerations for Addressing Emerging
Issues (NREL/TP-6A20-72038). Golden, CO: National Renewable Energy
Laboratory.
Saleem, D., and C. Carter. 2019. Certification Procedures for
Data and Communications Security of Distributed Energy
Resources (NREL/TP-5R00-73628). Golden, CO: National Renewable
Energy Laboratory.
Sengupta, M., A. Habte, Y. Xie, A. Lopez, M. Dooraghi, M. Kutchenreiter, A.
Andreas, I. Reda, M.J. Foster, and C. Gueymard. 2019. Solar Resource
Calibration, Measurement, and Dissemination: Final Report
FY 2016–FY 2018 (NREL/TP-5D00-73667). Golden, CO: National
Renewable Energy Laboratory.
Xie, Y., M. Sengupta, M. Dooraghi, and A. Habte. 2019. Reducing PV
Performance Uncertainty by Accurately Quantifying the PV
Resource (NREL/TP-5D00-73377). Golden, CO: National Renewable
Energy Laboratory.

| 88 | ﻿

Miscellaneous
Brochures“Cybersecurity for the Future Electric Grid.” NREL/BR-5R00-73906.
“ESIF User Guide: Energy Systems Integration Facility.” NREL/BR5C00-72391.

Fact Sheets“NREL + Holy Cross Energy.” NREL/FS-5B00-72335.
“NREL + Verizon Wireless.” NREL/FS-5B00-71598.
“NREL and San Diego Gas & Electric Company.” NREL/FS-5B00-72334.
Cover (front), photo from iStock, 990107158; page 3, photo from iStock, 159022053;
page 4-5, photo from iStock, 150379782; page 6, photo from iStock, 150379782;
page 8-9, photo by Dennis Schroeder, NREL 60130; page 10, photo from iStock,
1029087644; page 10-11, photo from iStock, 1177095707; page 12-13, photo by Dennis
Schroeder, NREL 60025; page 13, photo from iStock, 1029087644; page 14-15, photoby Dennis Schroeder, NREL 60133; page 16-17, photo by Dennis Schroeder, NREL
60438; page 17, photo by Dennis Schroeder, NREL 60440; page 18-19, photo by
Dennis Schroeder, NREL 60289; page 20-21, photo from iStock, 1131102682; page
22-23, photo by Dennis Schroeder, NREL 60069; page 23, photo by Joshua Bauer,
NREL; page 24-25, photo by Dennis Schroeder, NREL 60107; page 26, photo by
Joshua Bauer, NREL 54939; page 28-29, photo from iStock, 1029087644; page 30,
photo from iStock, 1166423076; page 32-33, photo from iStock, 669178062; page33, photo by Dennis Schroeder, NREL 56394; page 34, photo by Shamia HossainMcKenzie, Sandia National Laboratories; page 34-35, photo from iStock, 184914325;
page 35, photo from iStock, 873055760; page 36-37, photo from iStock, 1130140918;
page 38-39, photo by Dennis Schroeder, NREL 60168; page 40-41, photo from
iStock, 453305585; page 42-43, photo from iStock, 488178053; page 44-45, photoby Dennis Schroeder, NREL 60024; page 46-47, photo by Dennis Schroeder, NREL
59012; page 48-49, photo by Dennis Schroeder, NREL 53840; page 49, photo from
iStock, 1042067682; page 50, photo from iStock, 1029093688; page 50-51, photoby Dennis Schroeder, NREL 45440; page 52-53, photo from iStock, 599497714;
page 54-55, photo by Werner Slocum, NREL 60946; page 56-57, photo by Dennis
Schroeder, NREL 60019; page 58, photo by Dennis Schroeder, NREL 54878; page60, photo by Dennis Schroeder, NREL 56397; page 65, photo by Dennis Schroeder,
NREL 54986; page 66, photo by Dennis Schroeder, NREL 57974; page 66-67, photoby Dennis Schroeder, NREL 58760; page 70-71, photo by Dennis Schroeder, NREL
54236; page 72, photo by Dennis Schroeder, NREL 60653; page 89, illustration by
Anthony Castellano, NREL; cover (back), photo by Joshua Bauer, NREL 59215.

﻿ | 89 |National Renewable Energy Laboratory
15013 Denver West Parkway, Golden, CO 80401
303-275-3000 • www.nrel.gov
Printed on paper that contains recycled content.

| 90 | ﻿

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
NREL/BR-5C00-75862 • January 2020