Boosted by Ampaire’s selection of its Epic energy storage system to convert the Cessna Grand Caravan turboprop aircraft to hybrid-electric propulsion, Electric Power Systems (EP Systems) is stepping up plans to secure a larger stake in the growing electric aviation sector. During this week’s JetBlue Ventures Sustainable Travel Summit in San Francisco, the U.S. company’s founder and CEO, Nathan Millecam, said that he expects the Epic battery packs to be installed on as many as 14 aircraft models in 2023.
Earlier this month, Ampaire confirmed that it will use the Epic system for its EcoCaravan program, for which it is developing a hybrid-electric propulsion system. According to EP Systems, its battery pack will deliver an energy density of over 200 Wh/kg and will be able to support 2,000 fast-charge cycles before needing to be replaced. It says that a full recharge takes 20 minutes for each pack.
Ampaire has been evaluating the Epic system during extensive flight trials of its Electric EEL technology demonstrator aircraft, which is itself a conversion of the Cessna Skymaster. In July, the company announced the selection of Red Aircraft’s AO3 engine to provide the combustion component of the hybrid-electric powertrain.
EP Systems has already supplied battery systems for several new and existing aircraft, including Diamond Aircraft’s eDA-40 electrified version of its DA-40 trainer, NASA’s X-57 technology demonstrator, Boeing’s Cargo Air Vehicle, the Aurora Flight Sciences Pegasus uncrewed air vehicle, and Embraer’s Ipanema. The company says its cells have been or will be used by new eVTOL aircraft developers, including Archer, Supernal, and Elroy Air, as well as by other aircraft manufacturers such as Bell, Bye Aerospace, Aura Aero, and VoltAero.
According to Millecam, EP Systems has purposely started to supply the Epic system for small aircraft with up to four passenger seats, before scaling up the technology to larger models. He told the JetBlue summit that the system can support flight cost savings of around 46 percent on aircraft such as flight trainers, compared with the cost of existing types burning fossil fuels.
In 2019, EP Systems received funding from Boeing’s Horizon X venture capital division and also from aircraft engine maker Safran. Millecam said that the company is now seeking fresh funding as it prepares to scale up to produce higher volumes of battery cells.
“One of the key challenges we face is how you scale up [manufacturing of] aviation propulsion batteries,” Millecam acknowledged. He pointed to the complex manufacturing technologies that are needed to meet airworthiness requirements for aviation applications of the technology.
EP Systems seeks to achieve certification of the Epic packs in 2023 and is currently working with the FAA on a technical standard order to support this effort. “The most advanced [electric propulsion] projects are actually in Europe right now, so we’re working with our European customers to get supplemental type certificates [for aircraft conversions] as well as new type certificates,” Millecam stated.
According to Millecam, flight training and utility aircraft will be the most successful early adopters of electric propulsion, followed by new applications such as eVTOL air taxis. “With bigger aircraft [such as larger airliners], the assumption is that now you’re getting into hybrid [electric] architectures,” he concluded. “These need very big batteries and there are other types of integration that need to happen at the propulsion powertrain. This level of complexity hasn’t been developed or flown yet so that is a huge step forward for the industry to get that level of complexity.”
