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Carderock Holds Demonstration of SOFC Hybrid Power System

By Daniel Daglis, NSWC Carderock Division Public Affairs | February 14, 2017


Naval Surface Warfare Center, Carderock Division is playing a significant role in the Office of Naval Research (ONR) Renewable Sustainable Expeditionary Power (RSEP) initiative.

Carderock's Advanced Power and Energy Branch (Code 636) hosted the demonstration and test kickoff of the first logistics fuel (JP-8) compatible renewable-hybrid Solid Oxide Fuel Cell (SOFC) system Jan. 26 in West Bethesda, Maryland. The SOFC was developed under an ONR Future Naval Capability (FNC).

Evan Rule, a mechanical engineer in Code 636, served as the test lead on the project. Rule came to Carderock as the result of an internship he completed at the command while attending York College in Pennsylvania.

"At Carderock, we've been testing hybrid-power systems for the past four or five years for the Marine Corps," Rule said. "We were brought into the RSEP program as subject matter experts on traditional hybrid technologies. These systems are typically powered by diesel generators and renewables such as photovoltaics, which are hybridized with energy storage."

According to Rule, the SOFC technology developed under this FNC addresses the challenge of processing high-sulfur content logistics fuels such as JP-8 so it can be safely reformed and consumed by the fuel cell. During the demonstration, the system was able to support three different simulated load profiles and show the system's ability to replace a traditional diesel generator while providing the added benefits of fuel savings, silent operation, and reduced maintenance. Fuel cells have to heat up to function, and as the first hybrid fuel cell which uses military fuels; it can rely on solar power and lithium-ion batteries while the heating takes place in the field.

"The goal of this particular effort was to make efficiency gains over traditional hybrid power systems by using a fuel cell -- which has a higher efficiency throughout its operating range -- but the technical challenge was that they needed to use a military logistics fuel; in this case it was F-24 or JP-8," Rule said. "Reforming F-24 and JP-8, because of its high sulfur content is difficult, so there are a lot of complex processes going on within the system."

Rule said currently the military just uses diesel generators which range in size from three kilowatts up to 100 kW wherever they need power. Military personnel currently have to make frequent fuel convoy deliveries, which are not always safe and can put the warfighter at risk, added Rule.

"The idea is that we can reduce that logistics burden with hybrid power systems," Rule continued. "The initial step was hybrid power systems with generators -- which is currently in the acquisition process for the Marine Corps -- and now ONR is looking at technologies of the future. The RSEP effort looked at many alternative power sources, but due to the high level of power assurance required by the Marines, the RSEP program chose to hybridize a fuel cell with less reliable sources such as photovoltaics."

When it comes to Carderock's role as subject matter experts with the hybrid power systems, Rule said they are also aiming to help the industry improve their knowledge base on what the military's needs are because sometimes it can be a challenge for industry to understand what the military actually needs and wants, and it is not always something that can be conveyed through performance specifications.

Further testing will be conducted at Carderock to verify the system's compliance with all Technology Transition Agreement requirements.


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