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Energy Systems Integration News

Photo of several men looking through a large window at a laboratory in the Energy Systems Integration Facility.

A recent tour of the Energy Systems integration Facility. Photo by Dennis Schroeder, NREL

June 2015

Welcome to Energy Systems Integration News, NREL's monthly newsletter designed to keep industry partners, stakeholders, associations, and educational institutes up to date on the latest energy systems integration (ESI) developments at NREL and worldwide.

Have an item for the next issue of Energy Systems Integration News? Email us at

In This Issue


NREL's Work with SolarCity and Hawaiian Electric Featured in New Video and SOLAR TODAY

NREL has released a new video highlighting NREL's work with SolarCity to study how to better integrate solar onto the grid. The work includes collaboration with the Hawaiian Electric Companies (HECO) to analyze high-penetration solar scenarios using advanced modeling and inverter testing at the Energy Systems Integration Facility (ESIF). The video features SolarCity's Ryan Hanley and NREL's Dr. Bryan Hannegan and Dr. Martha Symko-Davies discussing this unique partnership.

In a recent feature story for SOLAR TODAY, NREL's Don Gwinner explains the project, discussing how the rigorous testing at the ESIF has helped to allay Hawaiian Electric's concerns about potential system-level disturbances such as transient overvoltage and anti-islanding with high amounts of distributed photovoltaics. Read the full articlefromSOLAR TODAY.

Featured Partnership: NREL + Google

$1 million will go to the team that does the best job of creating a smaller, less expensive solar power inverter in Google's Little Box Challenge. Testing at the Energy Systems Integration Facility (ESIF) will help Google and IEEE determine the winner.

Download the project fact sheet and learn about how to partner with NREL on energy systems integration research.

Closing a Gap of 500 Miles in 28 Milliseconds: INL and NREL Demonstrate Power Grid Simulation at a Distance

NREL and Idaho National Laboratory (INL) have successfully connected grid simulations at their two labs for real-time interaction via the Internet. With this connection, real-time digital simulator racks at INL can be interfaced to NREL's grid simulator, making it possible to simulate complex power systems.

Read the press release for more information.

EPRI and NREL Develop Standard Messaging That Allows Distributed Energy Resources to Talk to Grid Operations

NREL and the Electric Power Research Institute (EPRI) have developed and tested a standard messaging platform for distributed energy resourcessolar panels, wind turbines, microgrids, and battery storagethat use smart inverters to connect to the grid.

This new system provides a common language that will provide grid operators access to information about demand, supply, and use of electricity.

Learn more about the system.

ESI Researchers Receive NREL Innovation and Technology Transfer Awards

Several NREL ESI researchers have been honored by NREL for projects that highlight the lab's culture of innovation.

Afshin Andreas and Ibrahim Reda from NREL's Resource Assessment and Forecasting group were honored for their work in developing an algorithm to predict the position of the sun with a high degree of accuracy. Solar tracking company Device Logic will incorporate the algorithm into tracking systems for utility-scale solar plants.

Mari Shirazi, Blake Lundstrom, and Sudipta Chakraborty from NREL's Distributed Energy Systems Integration group received an award for the copyright of the new PV Inverter Maximum Power Point Tracking and IEEE 1547 Standard Compliance Control Code. Although this software was first developed in 2012, the copyright was approved just last year. The software implements algorithms to achieve both MPPT and IEEE 1547 Standard compliance for a single-phase photovoltaic (PV) inverter, and can be adapted for single-stage (DC-AC converter only) or two-stage (DC-DC plus DC-AC converters with DC link). The algorithms contain functions whose inputs and outputs provide the hooks into the customer low-level control code and that can be called inside the customer low-level C-code according to desired execution rate. US Hybrid licensed the code in 2014 for use in inverters.

Read more about the awards.

NREL ESI Researchers Contribute to IEEE PES GM "Best Papers"

NREL ESI researchers contributed to two papers that were named as 2015 IEEE Power and Energy Society (PES) General Meeting (GM) Best Conference Papers in the area of Power System Modeling and Simulation:

  • " A GridLAB-D Communication Interface for Smart Distribution Grid Simulations" (Timothy Hansen, Siddharth Suryanarayanan, Anthony Maciejewski, Howard Jay Siegel, Colorado State University; Bryan Palmintier, NREL)
  • "An Assessment of the Impact of Stochastic Day-Ahead SCUC on Economic and Reliability Metrics at Multiple Timescales" (Hongyu Wu, Erik Ela, Ibrahim Krad, Anthony Florita, Jie Zhang, Bri-Mathias Hodge, Eduardo Ibanez, NREL; Wenzhong Gao, University of Denver)

The researchers will participate in the "Best Conference Papers on Power System Modeling and Simulation" session at the IEEE PES General Meeting in Denver, Colorado, from 15 p.m. on July 27, 2015.

Hear from NREL's Energy System Integration Experts at Upcoming Events

Attending the 2015 Municipal Smart Grid Summit, Grid Edge Live, or the IEEE Power and Energy Society General Meeting? Don't miss presentations from NREL's ESI program, including Dr. Martha Symko-Davies and Dr. Erfan Ibrahim.

See the full list of upcoming NREL ESI events.

NREL Releases Electricity Market Modeling Package

After several months of public beta testing, NREL's Transmission and Grid Integration group has released the first stable version of rplexos, an R package used to analyze results from PLEXOS, a simulation software tool for the electricity market.

rplexos is a free, open-source tool that is optimized for large data sets. Since its release on April 22, rplexos has been downloaded thousands of times worldwide, and is already being used by U.S. utilities and system operators.

Learn more about NREL's transmission grid integration research.

NREL ESI in the News

Check out the latest stories in the media surrounding ESI at NREL: NREL President Dan Arvizu talks grid modernization in Transmission & Distribution World, Executive Gov covers the NREL-INL Grid Simulation link, and North American Windpower highlights a study by NREL and General Electric that could usher more renewables onto the grid in the western U.S. states.

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ESI in the U.S. and Around the World

NREL Partners With CSIRO to Establish PV Testing Capability in Australia

NREL has had international reach in its work with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to establish a new facility to study the way photovoltaic (PV) panels respond to changes in solar conditions.

In addition to the design and construction of the new testing facility, CSIRO and partnersNREL, Desert Knowledge Australia Solar Centre, and Lend Leasedeveloped software tools and used them to analyze data from 59 PV modules from 17 different manufacturers, including 12 different PV technology types. The project partners demonstrated that, with the right measurements, PV system output can be mathematically corrected back to the same standard reference conditions used to nameplate the modules in the factory.

Read more about the project.

iiESI March Workshop Summary Available

On March 3031, the International Institute for Energy Systems Integration (iiESI) held a workshop at Imperial College in London on research challenges in energy systems integration. Read the workshop summary to learn what was discussed at the meeting.

iiESI is a community of scholars and practitioners from around the world engaged in developing an efficient global energy system. The institute will serve as a platform to facilitate information exchange and set research priorities, and will serve as a liaison among industry, policymakers, and researchers.

Stay tuned: a summary of the May 1822 workshop held at the University of Leuven in Belgium will be posted shortly at Watch for upcoming issues of Energy Systems Integration News for more iiESI updates.

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Who's Who at the ESIF

See Who Visited the ESIF in April and May

Recent visitors to the Energy Systems Integration Facility (ESIF) include:

  • Aquahydrex
  • BMNT Partners
  • Cummins
  • Denver International Airport
  • Electric Power Research Institute (EPRI)
  • Export-Import Bank of the United States
  • Florida Power & Light
  • LG
  • Mexican Secretary of Foreign Affairs, Jose Antonio Meade Kuribrena, and Undersecretary for North America, M. Alcocer Martinez de Castro
  • Netherlands Enterprise Agency (RVO)
  • Poudre Valley Rural Electric Association
  • San Diego Gas and Electric (SDG&E)
  • SolarCity
  • SRI International
  • SunEdison
  • Toyota
  • United States Maritime Administration (MARAD)
  • United States Navy
  • University of Texas at San Antonio
  • Xcel Energy

Want to know what the buzz is about? Schedule an ESIF visit today.

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