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December 2013

Energy Systems Integration eNewsletter

Welcome to another issue of the Energy Systems Integration eNewsletter, the quarterly—and soon to be monthly—eNewsletter for energy systems integration (ESI) at the National Renewable Energy Laboratory (NREL). In the coming months, you'll begin to hear from us more frequently, but in smaller doses as we retool our newsletter and accompanying website to better represent the scope of work being done in the area of ESI, both at NREL and globally. Each month, we will bring you updates from NREL and our partners on the latest ESI developments worldwide. Plus, we'll highlight new ESI-related opportunities emerging in the fields of technology, science, policy, and markets.

Have an item for the next issue of the ESI eNewsletter? Email us at

In this Issue

ESIF Garners a LEED Platinum Designation

Photo of the exterior of the NREL Energy Systems Integration Facility at sunrise.

It's official—the ESIF is a LEED Platinum facility.
Photo by Dennis Schroeder, NREL

The ESIF was dedicated as the newest DOE user facility by Energy Secretary Ernest Moniz in September—and it recently earned a new distinction: the Platinum rating for new construction from the U.S. Green Buildings Council's Leadership in Energy and Environmental Design (LEED®) Green Building program. The ESIF earned all 56 LEED points applied for—well above the 52 points required to earn the Platinum designation, the highest available under the LEED rating system. The facility is 40% more energy efficient than the baseline building performance rating under U.S. and international building standards—and a 720-kilowatt solar array located on campus boosts that percentage to 46.2%.

The ESIF achieved its high energy efficiency through a whole-building, integrated design that includes such approaches as natural daylighting, with 15-foot-long skylights and large expanses of clerestory windows that allow lights to be shut off for about four hours at mid-day. Operable windows enable natural cooling and ventilation throughout the building, and solar-powered fans help extract heat from offices. In addition, the ESIF's high performance computing (HPC) data center is not only highly efficient, but it helps to heat the building. Contributing to the LEED Platinum designation was the use of recycled materials for 27% of the facility, while 78% of ESIF construction waste was recycled or reused. See the NREL press release for more information.

And the Award Goes to…the ESIF's HPC Data Center

Photo of the wires inside the computer racks in a data center.

The liquid-cooled computer racks in the ESIF's HPC data center earned it a top award for green computing.
Photo by Dennis Schroeder, NREL

After making its debut earlier this year, the ESIF's state-of-the-art HPC data center has now earned a top industry accolade. Supercomputing news resource HPCwire recently honored NREL, along with industry partners Asetek and Aspen Systems, with its 2013 Editor's Choice Award for the Best Application of Green Computing in HPC for the liquid-cooling data center retrofit in the ESIF.

Aspen Systems installed an Asetek liquid-cooling system as an energy-efficiency retrofit to an existing air-cooled Aspen HPC cluster already installed in the ESIF data center. Liquid-cooling technology takes advantage of the fact that liquid has approximately 1,000 times the cooling capacity of air, and that pumps circulating liquid cooling are much more efficient than fans circulating air—all of which will help the ESIF data center achieve an ultra-efficient annualized average power usage effectiveness (PUE) rating of 1.06 or better. See the NREL High Performance Computing website to learn more about the ESIF's HPC data center.

NREL Demonstrates the ESIF's Power Hardware-in-the-Loop Capability

Photo of two men in a laboratory looking at various computer screens showing testing results.

NREL successfully demonstrated the ESIF's utility-scale PHIL capability with Advanced Energy's 500-kilowatt inverter.
Still from DOE video

Leveraging the ESIF's megawatt-scale power capacity to take ESI research to the next level, NREL researchers and operations staff have successfully demonstrated the power hardware-in-the-loop (PHIL) testing capability in the ESIF. PHIL allows simulated electrical grids to be connected to physical devices such as photovoltaic (PV) inverters to test advanced device controls and functionality at full power—and determine whether their integration changes the landscape of the grid. The PHIL testing capability is made possible by key infrastructure in the ESIF, which includes a programmable 1-megawatt AC grid simulator, a 1-megawatt PV simulator, and a 1-megawatt load bank connected through the ESIF's Research Electrical Distribution Bus (REDB).

Earlier this year, NREL researchers worked with industry partner Advanced Energy (AE) to complete evaluation of an AE 500-kilowatt PV inverter's advanced grid support features. NREL researchers are now working on testing this same inverter when connected to a simulated real-world electric distribution system using PHIL techniques. This will allow for evaluation of the inverter's advanced grid support features and their impact on an electric distribution system prior to field deployment on an actual distribution system.

This November, a first step towards this goal was completed when the 500-kilowatt inverter was connected to a simulation of a simplified distribution system, allowing testing of the inverter's response to a simulated grid islanding event. NREL researchers will continue working with AE to complete this full PHIL evaluation using a real-world distribution system model in 2014. This testing capability allows electric utilities and manufacturers to partner together and "bring their own circuit" to NREL to demonstrate and test new, potentially game-changing innovations in a controlled laboratory environment—revealing the effects of these technologies on the distribution system while posing no risk to the utilities or their customers. See the ESI website to learn more about how partners can leverage the ESIF's capabilities.

Fueling Robot Automates Hydrogen Hose Reliability Testing in the ESIF

Photo of a large yellow and red robot in a laboratory.

NREL's fueling robot makes hydrogen hose reliability testing as simple as pushing a button.
Photo by Devonie McCamey, NREL

With at least three major auto manufacturers expected to roll out fuel cell electric vehicles in the 2015 to 2017 timeframe, the need for a reliable U.S. hydrogen fueling infrastructure is greater than ever. That's why NREL is using a robot in the ESIF Power Systems Integration Laboratory to assess the durability of hydrogen fueling hoses, a largely untested—and currently costly—component of hydrogen fueling stations.

Only one manufacturer in the world currently makes certified hydrogen fueling hoses—so not only are prices high with the current lack of competition and demand, but not much has been done to test the hoses' durability over time in a real-world environment. That's where NREL's robot comes into play. The automated machine mimics the repetitive stress of a human bending and twisting the hose to refuel a vehicle—all under the high pressure and low temperature required to deliver hydrogen to a fuel cell vehicle's onboard storage tank.

The sole German-based hydrogen hose manufacturer is highly interested in this testing and has provided hoses and extra hose material to NREL free of charge. The test plan for the hose reliability project is not only to test the repetitive fueling motion under high-pressure and low-temperature conditions, but also to perform analysis of the hose material itself to see how it degrades over time. To learn more about the hose reliability project and see the robot in action, watch the YouTube video.

NREL Launches New Grid Interface Test System for Wind Turbines

Photo of the metal interiors of the hardware components of a controlled grid interface system.

NREL's CGI (hardware components shown here) provides system engineers with a better understanding of how wind turbines react to grid disturbances.
Photo by Dennis Schroeder, NREL

The acronym might call to mind computer graphics, but NREL's "CGI" is a whole different animal—one that could prove key to integrating more wind power on the electric grid. CGI stands for the new Controllable Grid Interface test system NREL has developed to examine how multi-megawatt wind turbines, solar inverters, energy storage systems, and other electrical equipment interact with the power grid. Located at NREL's National Wind Technology Center, the CGI is a combination of hardware and real-time control software for simulating these interactions while also testing and quantifying the performance of renewable generation during grid disturbances. For wind technologies in particular, the CGI can examine wind turbine performance while riding through voltage faults or unbalanced voltage conditions, while responding to under- and over-frequency events, and in various grid support functions.

NREL's CGI is rated for 7 MVA and is the only system in the world that is fully integrated with two dynamometers—and it has the capacity to extend that integration to turbines in the field as well as to a matrix of electronic and mechanical storage devices, all of which are located within close proximity on the same site. The CGI tests wind turbines off-line from the grid, verifies compliance with standards, and provides grid operators with the performance information they need for a fraction of the time and cost it would take to test the turbines in the field.

Toyota Partners with NREL to Advance Plug-In Electric Vehicle Integration

Photo of two fuel cell hybrid electric vehicles with two men looking at a computer screen nearby.

NREL engineers Mike Simpson (left) and Tony Markel run tests on PHEVs at the ESIF's MVOTA.
Photo by Dennis Schroeder, NREL

Plug-in electric vehicles are already on the market—but NREL is now collaborating with Toyota Motor Engineering & Manufacturing to find new and better ways to integrate them into the power grid. Scientists and engineers at the ESIF and NREL's Vehicle Testing and Integration Facility are using 20 Toyota Prius plug-in hybrid electric vehicles (PHEVs) to develop and explore ways to prepare grid operators and energy infrastructure to accommodate the growing U.S. electric vehicle fleet. Toyota has relocated the PHEVs to the ESIF's Medium Voltage Outdoor Test Area (MVOTA), which provides easy interconnection and testing alternatives for grid integration hardware. The project will provide confirmation on the levels at which vehicle loads become significant to distribution grid power quality challenges and will lead to foundational strategies for monitoring and control throughout the grid.

The MVOTA is a distribution-level electrical laboratory that allows utilities and researchers to evaluate equipment at the medium voltage range (4 kilovolts to 34 kilovolts is the "typical" range for medium voltage, while the MVOTA is 13.2 kilovolts). The MVOTA is arranged with reclosing breakers to simulate two utility distribution feeders, and it has ties to both the local utility and the ESIF's Research Electrical Distribution Bus (REDB), allowing tremendous flexibility in testing utility-scale equipment at megawatt levels. Future equipment will include long-length simulators, which will allow researchers to create circuits that appear as miles in length electrically without installing miles of wire.

Who's Who on the ESIF Visitor List

The Energy Systems Integration Facility continues to attract high-profile visitors. Recent visitors include:

  • University of Michigan
  • Federal Utility Partnerships
  • Toshiba
  • Ron Loveland, Energy Advisor to the Welsh Government
  • Karla Olsen, Deputy Communications Director, DOE
  • House Energy and Water Appropriations Staff
  • Assistant Secretary Pat Hoffman, OE-1, DOE
  • San Diego Gas & Electric
  • Asetek
  • DOE Advanced Scientific Computing Research (ASCAR)
  • Barry MacColl, GM of Research, Testing and Development, Sustainability Division, Eskom
  • Sandia National Laboratories

Partner With Us

Interested in partnering with NREL at the ESIF? The first step is to complete a detailed summary of your project using the Project Summary Form as a guide. The Project Summary Form requests information on your projects, including goals, expected outcomes, scope, schedule, and required resources. Learn more about working with the ESIF or contact