Solar Power

Denver’s Peña Station gets solar+storage, with unique microgrid approach

Denver International Airport (DEN) is the only major airport to be built in the United States in the last 25 years. The current facility can accommodate 50 million passengers a year. It is the nation’s fifth busiest and the world’s 15th busiest airport.

DEN is taking a step further into the city by partnering with developer and construction company L.C. Fulenwider, Inc. on a new metro stop: Denver’s Peña Station NEXT, which will include hotels, retail and multi-family housing and office space adjacent to the airport. Located on the airport rail line that connects Downtown Denver via Union Station to the airport, the development is within five minutes of Denver International Airport and 20 of downtown Denver.


Peña Station NEXT’s microgrid includes a carport solar array on Denver International Airport carports, a rooftop solar array on Panasonic’s corporate office building and a lithium-ion battery system.

The area is being developed with an an emphasis on sustainability, particularly a solar+storage microgrid. Peña Station NEXT’s microgrid includes a 1.6-MWdc carport solar array on DEN carports, a 259-kWdc rooftop solar array on Panasonic’s corporate office building using its HIT solar modules and a 1-MW/ 2-MWh lithium-ion battery system. The battery system by Younicos with inverter and controls will integrate into the company’s plug-and-play  Y.Cube storage system. Panasonic’s Denver operations hub building, which has an intelligent building energy management system, will serve as the initial anchor load for the microgrid, while the carport system is owned and operated by Xcel Energy under lease with DEN.

This public-private partnership is an interesting aspect of the project, because many microgrids and energy storage systems are deployed for single use cases by single entities, such as a corporation pursuing demand charge reductions or a university campus strengthening energy resilience. While storage can provide a financial return in some markets, utilities and developers are discovering how revenue stacking with multiple value streams can increase storage system value. Battery storage systems can provide a suite of services to multiple entities, such as solar grid integration, ramp control, peak demand reduction and more.

For example, in Ohio the Village of Minster recently completed a solar+storage system with 7 MW / 3 MWh of batteries tied to an adjacent 4.2-MW solar photovoltaic power plant. This project is designed to provide four unique revenue streams: frequency regulation in PJM’s market, transmission and distribution system cost deferral, power quality improvement and demand charge reduction.

The  Peña Station NEXT project is taking a similar approach. The battery energy storage system will deploy five use cases: 1) solar energy grid integration via solar smoothing ramp control and solar time shifting, 2) grid peak demand reduction, 3) energy arbitrage, 4)  frequency regulation, and 5) backup power for Panasonic’s network operations center. This portfolio microgrid aids renewable energy grid integration; strengthens grid resilience through backup power and grid support services and benefits diverse stakeholders and the entire power grid through a multi-use, lithium-ion energy storage battery system.

Each partner has its own interest in the system:

-Xcel Energy is Colorado’s largest investor-owned utility with goals to meet rising in-state renewable energy standards, “As part of Xcel Energy’s Innovative Clean Technologies program in Colorado, we’re eager to demonstrate how energy storage can integrate more solar energy on our system. We’ll also examine how battery systems can become more cost effective by supporting the grid and providing reliability for customers,” said Beth Chacon, director grid storage & emerging technologies, Xcel Energy.

-Panasonic, as the “equity-invested anchor corporate tenant” is the smart and sustainable technologies lead on the project and an invested equity partner in the development

-Younicos is incorporating its large battery energy storage and storage software applications into the project and learning from the system’s stacked use cases. “Multi-resource microgrids that serve different use cases, like the one at Peña Station NEXT, are the types of deployments that will transform the grid on both sides of the meter,” said Jayesh Goyal, Chief Commercial Officer of Younicos. “Our Y.Cube system is ideal for this type of commercial application: fully integrated components with batteries, plug-and-play functionality, and intelligent software to handle various control modes – essentially ‘storage in a box’. We’re proud to be part of this forward-looking project.”

-The city and county of Denver and Denver International Airport are looking to improve the resilience and sustainability of critical DEN assets and better integrate the airport’s loads with the surrounding grid

-Additional partners include sustainability-minded real estate developer L.C. Fulenwider, Xcel Energy’s retail customers in Colorado and Denver’s residents.

The project’s partnership team is referring to this approach as a “portfolio microgrid” with a portfolio of stakeholders, assets and benefits and services. Panasonic, Xcel Energy and Younicos have released a white paper that details this approach and the project.

“We’re so excited about this ‘portfolio’ microgrid—and sharing insights from the project via this white paper—because of how a system such as this can unlock more benefits for more stakeholders,” said Peter Bronski, a coauthor from Panasonic, “and how this public-private partnership approach to the microgrid and the battery system’s stacked use cases can strengthen the overall economics and value propositions.”

The Xcel Energy feeder for Peña Station NEXT already has 20% solar penetration and is expected to have 30% solar penetration by the time the microgrid project is completed in the first half of 2017. The 382-acre transit-oriented development links downtown Denver with DEN and is located adjacent to the Regional Transportation District’s 61st and Peña rail station along the University of Colorado A Line train.

Multi-use battery systems—including the lithium ion battery energy storage system at Peña—are an exciting technology and solution. Despite the opportunities, the relative nascence of storage technology as a stationary grid resource means there are to date limited information and guidance on the analysis, economics, and technological factors of deployment. While Colorado does not currently have open markets for all power grid services that might benefit from battery energy storage, testing at the Peña Station NEXT microgrid will inform Xcel Energy, Panasonic, and Younicos on potential paths forward. Once the microgrid is live in early 2017, Xcel Energy, Panasonic, Younicos, and the other project partners will gather data to review real-world performance and make refinements over time. After completion of the two-year pilot, the project partners will analyze the battery system performance data to determine the optimal settings for the remainder of the battery’s estimated 10-year life span.

This information has been compiled from the project’s recent news release and white paper. 

Solar Power World

Solar Power World