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Three men in a laboratory look at a computer monitor.

NREL and Raytheon researchers perform system-level testing on the Marine’s Miramar simulated microgrid at NREL's Energy Systems Integration Facility.
Photo by Dennis Schroeder, NREL

Market Demonstration: NREL Helps Transformative Technologies Go Mainstream

NREL bridges scientific discovery and market adoption by helping technologies move from research through development, demonstration, and deployment.

Marine Corps Air Station Miramar (MCAS Miramar) near San Diego, California, is a leader in supplying critical military missions with resilient and renewable power, thanks in part to a partnership with the National Renewable Energy Laboratory (NREL).

And when NREL engineers Robert Butt and Sam Booth went to Miramar in December 2015, they helped validate the functionality of a small microgrid—and further critical resiliency. "The project successfully demonstrated an islanded electrical system that was powered by batteries and solar photovoltaics (PV), without conventional generation," Butt said.

NREL's work is another step toward increased resiliency for the installation following an unexpected occurrence more than five years earlier: the Southwest Blackout of 2011. The event provided an unlikely opportunity for NREL to showcase its deployment expertise.

Around 3:30 p.m. on September 8, 2011, a blackout began to cascade across San Diego. For eight hours, one of the largest power failures in California history paralyzed a large swath of Southern California, including Miramar, about 10 miles north of San Diego.

Fighter jets at the typically busy flight center were grounded. While the power outage disrupted the base and halted the daily operations of the 3rd Marine Aircraft Wing, it proved beneficial in one respect: it provided an opportunity to evaluate the value of developing a microgrid to improve energy resiliency.

Coincidently, technical experts from NREL and the U.S. Navy's Naval Facilities Engineering Command (NAVFAC) were already evaluating options to improve energy resiliency through increased energy efficiency, renewable energy generation, and advanced microgrids.

"We were able to go to Miramar after that outage and sit down with the flight operations and security personnel, and ask them, 'What happened?'" said Booth, a member of NREL's Integrated Applications Center.

The power failure revealed unexpected vulnerabilities: not only were planes grounded, some communication systems didn't function, flight line gates needed to be manned, generators failed, food spoiled, and employees were sent home. "They probably would never have predicted a lot of those things," Booth said.

A goal of this analysis, begun in August 2011, was to help meet the Navy's ambitious energy targets. In particular, NREL began developing a conceptual advanced microgrid design for the 23,000-acre site at Miramar. The microgrid assessment provided a systematic approach to meeting multiple energy goals through a single project that would increase resiliency, utilize renewable energy, and provide cost savings.

A photo of a 200-kilowatt solar carport consisting of solar panels mounted on elevated racks.

This approximately 200-kilowatt solar PV carport provides renewable power to help meet the Navy’s ambitious energy targets and reduce energy costs, as well as providing energy resiliency for Miramar when utilized along with energy storage in a microgrid.
Credit: MCAS Miramar

Building on a Net-Zero Study

The base had already been a key subject of a 2008 joint initiative between the Department of the Defense (DOD) and the U.S. Department of Energy (DOE), which addressed military energy use. Working for DOE, an NREL team had examined the site for net-zero energy potential—that is, the ability to produce as much energy as the based consumed.

NREL, with the work of Booth and others, helped Miramar analyze its energy consumption along with on-site renewable energy. As a result, Miramar has been successfully implementing these measures, reducing building energy intensity by 44% and getting approximately 50% renewable electrical energy. "We learned a lot through our net-zero work," Booth said, including how to use renewable energy, such as photovoltaic energy, when the grid goes down.

After the 2011 blackout, NREL analysts moved ahead with the project, which was designed to provide electrical power to the designated critical loads on base. NREL assisted NAVFAC in planning the microgrid for Miramar—an independent electrical generation and distribution system, which delivers energy that is reliable, economical, and sustainable.

Booth, Butt, and others looked at what went wrong and, in partnership with NAVFAC, came up with a deployable solution. Under the unique plan, the base will construct an Energy Operations Center for the microgrid—along with three control points for the micro-electrical system, including one off base. The microgrid design includes PV, landfill gas, natural gas, and diesel fuel to provide continuous electricity. Further, during times when the external grid is functioning (typically more than 99% of the time), Miramar's energy team can monitor energy usage on the base, helping increase efficiency and savings.

The NREL team provided technical assistance getting the design ready for bid. The $18 million project, funded by the DOD, is expected to be built in the next few years and will increase the resiliency of the installation by providing approximately 100 buildings with more reliable power from the microgrid. "There are a lot of lessons the Air Force, Army, Navy, and others looking to do this can learn as they expand more broadly to a whole portfolio of microgrids," Booth said.

The NREL team was able to leverage innovative ideas for the larger microgrid from the smaller microgrid project that was commissioned in December 2015. To reduce risks and cost, in December 2014, the team utilized NREL's Energy System Integration Facility (ESIF) to conduct hardware-in-the loop testing of Raytheon's microgrid power and control system that closely mirrored the planned building-scale installation at MCAS Miramar's Public Works building. "Seeing a complete renewable energy system perform as envisioned felt like history in the making," said Mick Wasco, Miramar's installation energy manager.

NREL engineers assisted Raytheon during this effort by reviewing test plans and procedures, acquiring data during demonstration and follow-on analyses, and contributing to the final report.

As energy storage technologies are improved and costs decrease, Butt noted, hybrid systems that can provide grid-connected benefits as well as standby functionality are expected to be more common for building-scale microgrids.

The engagements at Miramar are one example of how NREL bridges scientific discovery and market adoption by helping complete the energy innovation cycle—as technology moves from research through development, demonstration, and deployment. And Miramar isn't alone. The laboratory has provided such assistance for a range of entities in both the private and public sectors.

NREL Teams Up to Spur Hawaii's Energy Progress

Statistics from 2014 show that about 68% of Hawaii’s electricity generation is from imported oil, with coal and renewables making up the remaining 32% of the fuel mix. NREL provided technical assistance to deploy renewable energy to military bases across the Atlantic and Pacific regions. For example, the Navy and a local utility announced in October 2015 that they would develop solar generating facilities for 117 megawatts at airfields used by two bases on Florida's Panhandle. By December 2015, the Navy completed their 1-gigawatt goal.

Yet, as vital as such installations in California and Florida are to national security, bases on islands have greater vulnerability because of the need to import fuel, as well as their reliance on smaller electrical grids. And the vulnerability extends beyond the military to commercial and residential applications.

About 90% of Hawaii's electricity is generated from imported petroleum. To relieve oil dependence, in 2008 the State of Hawaii and DOE launched the Hawaii Clean Energy Initiative (HCEI), made up of business leaders, policy makers, and concerned citizens committed to lead Hawaii to energy independence. HCEI set a goal of 70% clean energy by 2030, which the State of Hawaii recently updated to 100% by 2045.

NREL's foundational efforts in Hawaii have provided a textbook example of applying a fully integrated approach to renewable energy and energy efficiency deployment. This approach included aspects of target setting, stakeholder outreach, policy and legislation, and technology and economic analysis. In one instance, NREL helped the Department of Hawaiian Home Lands create a new net-zero community for low-income families.

Senior Engineer Ken Kelly, who succeeded two NREL team members stationed on the island, worked as a project manager on behalf of DOE with the State of Hawaii. The partners sought to determine how Hawaii could reach a statewide 40% renewable energy portfolio standard, along with a 30% energy efficiency standard, as well as transportation modifications and renewable fuels usage.

"One of our roles was convening the local stakeholders to define pathways and address barriers," Kelly said, including the Hawaiian Electric Companies (HECO), the Hawaii State Energy Office, The University of Hawaii System, and members of the private sector.

 "We contributed to some of the backbone analysis, such as high-penetration island grid studies," he said, adding that the engagement "was absolutely a partnership, and showed the importance of that partnership" in furthering clean energy technologies. One tangible result in the quest for what Kelly termed "a very daunting transportation energy goal" was to accelerate the adoption of electric vehicles on the Hawaiian Islands.

Senior Project Leader Mike Callahan, who currently is based in Hawaii and concentrates on Navy efforts, has continued the tradition of building on NREL's clean energy efforts on the island—which now boasts the highest per-capita solar energy penetration of any state.

Callahan, who also supports the Navy's renewable energy project development in Guam and other parts of the Pacific, is helping implement NREL successes. In one case, NREL and NAVFAC implemented advanced control systems on existing rooftop air-conditioning units on Joint Base Pearl Harbor-Hickham. During the demonstration, the retrofits reduced overall energy by roughly 15%.

Even as DOD projects like that were showing gains, NREL was instrumental in pursuing even bigger improvements. NREL collaborated with SolarCity and HECO, using ESIF testing to assess challenges of interconnecting high penetrations of distributed photovoltaics with the electric power system. They analyzed high-penetration solar scenarios using advanced modeling and testing, power electronic devices (inverters) capable of converting the direct current produced by photovoltaic panels into alternating current, the type of electricity used by household appliances.

NREL provided the test results to the utility, and the utility then increased their PV penetration levels from 120% to 250%, enabling all island community members to reduce the amount of imported oil. Further, the test results helped the utility clear out a backlog of requests for distributed solar.

"NREL was able to test advanced inverters at the ESIF and demonstrate how they would perform, thus reducing risk to the utility and community," Callahan said.

The benefits don't end there. Callahan said that such a deployment—where lab research into clean technologies, policy analysis, and testing all get deployed in the field—help inform new research as he reaches back to NREL. "It's a virtuous cycle of what we see in the marketplace influencing the solutions we develop in the lab," he said.

NREL Helps Iconic Park Brighten Up

While there are many examples of NREL's work helping spread clean energy technology, the laboratory's role in transforming the iconic island of Alcatraz in San Francisco Bay is a highlight. The former prison is host to is 959 solar panels, reducing the amount of diesel fuel that was ferried across the bay for 75 years. The island's solar panels produced more than 325,000 kilowatt-hours of electricity in 2013.

The panels are part of an effort by the National Park Service (NPS), in partnership with DOE and NREL, to bring clean energy to national parks and landmarks—but it rests on a foundation of research and development as solid as "The Rock," as the former prison is known.

NREL and DOE's Federal Energy Management Program (FEMP) work began when Andy Walker, Ph.D., installed instruments to measure loads and solar resources on the island and conducted a feasibility study. "I worked until the end of the day installing data loggers, and from the roof of the cellblock I could see the last ferry back to San Francisco about to pull out," he recalled.

After 14 months of data collection and modeling the energy and financial performance of a system, results indicated that a PV system with batteries would be cost-effective. NREL continued to support the project and NREL's Mary Werner facilitated a performance contract to finance and install the system. That installation, however, was suspended due to financier concerns about historic preservation contingencies, and the project stalled until the park received appropriations through the American Recovery and Reinvestment Act (ARRA) in 2009.

NREL was also supported by ARRA in providing a design charrette, system design input and analysis, updated load measurement, and assistance in the preparation of the schematic design report included in the request for proposal. NREL provided photo-realistic renderings of what the system would look like from the mainland to assuage concerns related to historic preservation.

"There are two approaches to doing solar projects on historic buildings," Walker explained. "One is to hide it so that it can't be seen, and the other is to make it appear different so that there is no confusion about what is historic fabric and what is not. This project takes the first approach by keeping the PV array low on the cellblock roof behind a parapet wall."

A 307-kilowatt PV array now sits on the roof of the main cell house building, attached to two battery strings of 240 cells each, which add up to 1,920 kilowatt-hours. A modular inverter plant converts the DC power from the PV array, and to and from the batteries to AC power compatible with the island grid.

The array eliminates about 337,000 kilograms of carbon dioxide emissions per year while reducing the time the diesel generator runs from 100% to 40%, and saving about 40% of the fuel consumption. As a result of NREL analysis, the NPS also made some energy efficiency changes, such as better light bulbs and changes in operation to reduce energy consumption. But subsequent NREL analysis of the actual performance indicates there are more improvements that can be made.

"In the current effort with NPS with funding from FEMP, we are reviewing more than two years of the system operation data to see if additional fuel savings might be achievable through improved control strategies," said Senior Engineer Dan Olis. Principal Engineer Otto Van Geet conducted a site visit to the installed system and met with park staff. Preliminary data shows the potential to reduce total fuel consumption by about 25% more per year, or by about 14,000 gallons per year. The most recent NREL report by Olis makes "low-cost, no-cost" control setting recommendations to improve the battery charging scheme and reduce the amount of PV generation that is curtailed, to bring the energy savings up to the 60% efficiency potential.

Clearly, NREL is making an impact—in areas as varied as military bases, residential communities, and public spaces, to name a few—but the influence don't end there. "Our job is to remove roadblocks to get renewables and energy efficient technologies more quickly and efficiently into the marketplace," said Kelly.

And being on the ground in unique island locations such as Alcatraz, Hawaii, and Guam, among others, is one way to leverage the laboratory's reach.

Learn about NREL's technology deployment activities.

Beyond R&D: Market Impact

Spring 2016 / Issue 9

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Editorial Team

  • Kim Adams | Managing Editor
  • Bill Gillies | Creative Director
  • Dennis Schroeder | Photographer
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