When we last looked at aerospace engine startup H3X, it was still in the perinatal stages, with only renderings and grand plans to create the most powerful engines known to mankind. Since then, it has delivered its first round of engines to customers and signed contracts with major players like the US Air Force and NASA. Fresh off an eight-figure funding round, it’s working to bring bigger, badder megawatt-class machines to market to reduce carbon emissions in the aerospace, marine, and industrial sectors.
More power usually means more weight, either by way of larger or more numerous motors and drive components. It’s a simple, intuitive rule that’s hard to break, but H3X seems to have a pretty effective formula. Its comprehensive strategy to reduce weight, optimize efficiency, and increase power involves using a single additive-manufactured cooling jacket to cool both the motor stator and power electronics, improving the stator winding design, and optimizing its electromagnetics.
Long story short, the H3X manages to pack serious power-to-weight ratio into its compact integrated motors. The current motor range consists of three models that top out at the 200 kW HPDM-250. At 18.7 kg (41.2 lb), the motor is a bit heavier than the 15 kg (33 lb) 250 unit predicted for 2020, largely due to the integrated 6.7:1 gearbox, but it still achieves an impressive 10.7 kW/kg power density. It also manages a better-than-originally-estimated peak system efficiency of 95.4%.
H3X
By comparison, the HPM-400 motor, which UK manufacturer Equipmake believes will be the most power-dense unit in the world by 2023, has a density of 13.3 kW/kg. However, Equipmake calculates this figure using peak power rather than continuous power. If we’re comparing oranges to oranges, the H3X’s HPDM-250 outshines it with a peak power density of 13.4 kW/kg. What makes the HPDM’s impressive figures even greater is that the H3X integrates its inverter into the 18.7 kg motor package, while the Equipmake’s inverter is a separate 10 kg (22 lb) component.
Simply put, the HPDM is a world-class power-density machine, and now the family is getting bigger and significantly more powerful. H3X announced Tuesday that it has closed a $20 million oversubscribed Series A financing round and plans to use the money to develop the next three engines in its lineup: the HPDM-350, 1500, and 2300, which will take its technology into the megawatt class.
“We set out on an ambitious journey to become the world’s leading supplier of advanced electric motors,” said Jason Sylvestre, co-founder and CEO of H3X. “We have proven, with extraordinary speed, that this technology works and plays a key role in enabling sustainable aviation, decarbonizing the marine and industrial sectors, and unlocking the next generation of electric defense technology.”
H3X
H3X has released estimated specifications for the HPDM-1500, estimating it to weigh 125 kg (276 lb). The motor will produce 1,500 kilowatts of continuous power, meaning its power density is planned to exceed the HPDM-250's at 12-kW/kg (continuous).
That figure is remarkable because it is on par with the target benchmark set by the U.S. government’s Advanced Research Projects Agency-Energy (ARPA-E) through its ASCEND program to help develop a net-zero single-aisle electric passenger aircraft comparable in size to the Boeing 737. The agency determined that a power density of 12 kW/kg continuous or greater would be required for such an aircraft to complete a typical five-hour flight.
H3X estimates that current aircraft propulsion systems operate in the 3 to 4 kW/kg range, and also predicts that in some aircraft, range could effectively be doubled by replacing existing propulsion systems with power-dense units. As part of this calculation, the weight saved by using HPDM engines would be allocated to the added battery capacity.
H3X
In addition to electric aircraft and eVTOLs, H3X is developing its next-generation, higher-powered engines for applications such as ferries, tugboats and submarines, industrial equipment and large marine vessels such as electric locomotives. The HPDM line is also positioned for use in hybrid systems as both an engine and a generator. With hollow shafts, the HPDM units are designed for modular stacking, and H3X says up to six 1500 engines can be stacked for a total power of 9 megawatts.
H3X designs, tests and manufactures its engines at its 17,000-square-foot headquarters just outside Denver. In addition to developing its next batch of engines, the company will devote a portion of its $20 million Series A financing to scaling up production and fulfilling existing contracts.
Source: H3X