New Microgrid Testbed for Maritime and Coastal Energy Technologies

A new microgrid testbed for energy technology development and testing is now online at the Pacific Northwest National Laboratory (PNNL) Sequim campus (PNNL-Sequim). 

The testbed infrastructure streamlines the lengthy process for in-water testing of new marine energy and ocean technologies—potentially saving developers months and thousands of dollars per project—and by enabling research on the use of microgrids to support maritime businesses and coastal energy resilience. 

"This is the first testbed in the United States to enable simultaneous testing of connected energy generation, electricity storage, and sensors and control software to track load, while including precommercial market marine energy generation technologies," said Rob Cavagnaro, PNNL mechanical engineer and marine energy research lead.

The new testbed brings together multiple research efforts and projects funded by different state and federal agencies into an interconnected system. The system enables real-world performance evaluations of new energy technologies and how these technologies interact on a controlled microgrid. 

These capabilities support PNNL-Sequim’s ongoing research into new technologies intended to increase energy affordability and resilience along U.S. coasts, where many communities and businesses face grid reliability challenges related to remote locations, storms, and flooding. 

Laying the foundation for the microgrid 

At the center of the new testbed is a microgrid funded by the Washington State Department of Commerce. Designed to study how different energy generation technologies can support flexibility, the microgrid allows researchers to monitor patterns of electricity use and evaluate the costs and benefits of different energy sources. 

Integrated controllers allow researchers to evaluate the performance of new energy technologies connected to the microgrid and their potential for powering maritime and shoreline businesses and communities. The microgrid also includes onshore energy storage, funded through the Department of Energy’s Office of Electricity,

“The information we get from this microgrid will inform how to effectively design microgrids in other coastal locations that may be struggling with power outages or unreliable grids,” said Simon Geerlofs, PNNL advisor and project lead. 

Expanding on the microgrid to test marine energy technologies

PNNL researchers are already leveraging the new microgrid to provide greater insight into new marine energy technologies, including tidal turbines. 

Connected to the microgrid is the Department of Energy's Hydropower and Hydrokinetic Office-funded Cabled Research Array for the Blue Economy and Energy (CRABEE)—a subsea node on the seafloor of Sequim Bay that acts as an underwater power strip for testing marine energy systems and technologies. Cables connected to CRABEE run from onshore laboratory facilities out into Sequim Bay, where they can be connected to tidal turbines, environmental monitoring systems, and other technologies. In the future, the U.S. Department of War, Office of Naval Research, will fund the effort to extend cables further into the bay to support testing in deeper waters. The cables will be used to support accelerating maritime autonomy technology.

New marine energy devices can plug into CRABEE and be monitored at onshore facilities to evaluate their performance under real ocean conditions. This infrastructure streamlines many steps in the multiyear process of deploying and testing new energy technologies in the ocean, de-risking technology development for industry through time and cost savings, and helping to advance new marine energy technologies to commercial markets. 

“CRABEE is a key part of conducting in-water testing of marine energy devices at PNNL-Sequim,” said Cavagnaro. “By connecting CRABEE to the microgrid, now we can test how these new technologies perform in real ocean conditions and how they might interact with the grid and other energy sources as part of an integrated system.”

The microgrid has also been used to evaluate solar photovoltaics for energy generation—work funded by the Washington State Department of Commerce—two EV charging stations, and a charging station designed to support the hybrid research vessel Resilience. As PNNL-Sequim continues to grow in the future, the microgrid can be expanded to connect to more energy generation sources and balance fluctuating loads. 

“We are also evaluating the potential to power the PNNL-Sequim campus in the future using locally-generated energy for increased energy independence and security,” said Geerlofs. 

To learn more about the microgrid testbed capabilities at PNNL-Sequim, reach out to Simon Geerlofs and Rob Cavagnaro.