After years of planning, engineering and collaboration, Firefly is officially on the water.
Lyman-Morse launched the 49-foot solar-electric catamaran from Thomaston, Maine, on August 3, 2026. Upstream Alliance will soon bring Firefly to the Delaware River, where the vessel will serve as a floating classroom, science laboratory and research platform.
Watch the Firefly launch video
Read the Lyman-Morse launch announcement
24 Batteries. 201 kWh. One Electric Vessel.
At the heart of Firefly sits one of the largest custom marine battery systems Lithionics has helped bring to life.
Twenty-four Lithionics 51V 165Ah lithium iron phosphate battery modules power the vessel’s propulsion system and deliver more than 201 kWh of onboard energy storage. Eight battery management systems provide control and redundancy, while two additional 24V Lithionics batteries support house power, including lighting, navigation and pumps.
The system also integrates 24 bifacial solar panels, 16 chargers and shore power, bringing solar generation, lithium battery storage and electric propulsion together in one complete marine power system.
Explore the 51V 165Ah Lithionics battery module
Built for More Than Transportation
Firefly goes beyond electric propulsion.
Upstream Alliance created the vessel to give students hands-on opportunities to study water quality, conduct research and explore the Delaware River ecosystem. Each trip can welcome up to 32 students, turning the vessel into a floating classroom for environmental science, sustainability and STEM education.
The technology powering Firefly becomes part of that experience. Students won’t just learn about clean energy in a classroom. They’ll experience it firsthand on a vessel powered by solar generation and high-capacity lithium battery storage.
Follow Firefly’s delivery journey with Upstream Alliance
Engineering for the Mission
Firefly brings energy storage, electric propulsion, solar charging, onboard power and safety together in one integrated system designed to meet U.S. Coast Guard Subchapter T requirements.
The project brought together Upstream Alliance, Lyman-Morse, Gerr Marine, OceanPlanet Energy, Lithionics Battery and other technology partners to turn the concept into a working vessel.
Firefly demonstrates what high-capacity lithium battery systems can deliver when engineers build around the demands of a real-world marine application.
49 feet. 24 Lithionics batteries. More than 201 kWh of stored energy. And one very different kind of classroom.
Explore the Lithionics Firefly Battery System
