{"id":3006,"date":"2020-02-06T11:23:15","date_gmt":"2020-02-06T16:23:15","guid":{"rendered":"https:\/\/blogs.sw.siemens.com\/thought-leadership\/?p=3006"},"modified":"2026-03-26T12:03:36","modified_gmt":"2026-03-26T16:03:36","slug":"transitioning-aircraft-propulsion-from-carbon-to-electrons","status":"publish","type":"post","link":"https:\/\/blogs.sw.siemens.com\/thought-leadership\/transitioning-aircraft-propulsion-from-carbon-to-electrons\/","title":{"rendered":"Transitioning aircraft propulsion from carbon to electrons"},"content":{"rendered":"\n

Where today meets tomorrow: how the electric propulsion system may fundamentally change aircraft design<\/strong><\/p>\n\n\n\n

\u201cEvery American should have reliable, affordable, and\nefficient transportation, and the electrification of aviation systems has the\npotential to transform the way aircraft consume and use energy,\u201d said U.S.\nSecretary of Energy Dan Brouillette.<\/p>\n\n\n\n

In December 2019, the U.S.\nDepartment of Energy<\/a> announced up to $55 million in funding for two\nprograms supporting the development of low-cost electric aviation engine\ntechnology and powertrain systems.<\/p>\n\n\n\n

Currently, there are more than 200 start-ups working on\nbuilding a variety of electric aircraft and there are several trainers and\nother small aircraft with limited range in service. With so many companies\ndeveloping this technology and increased investment from both the public and\nprivate sector, electric commercial aircraft are moving toward reality. For\ninstance,  Scandinavian\nAirlines and Airbus<\/a> recently announced a partnership to develop an\nelectric-hybrid propulsion system.<\/p>\n\n\n\n

It\u2019s clear that electrically propelled aircraft have a future. The question is, which companies will participate in that future? What is the fate of the aircraft companies that don\u2019t seek to invest in electric aviation via advanced technologies and software?<\/p>\n\n\n\n

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The eFusion Aircraft’s first flight<\/figcaption><\/figure><\/div>\n\n\n\n

Building the electric\npropulsion system<\/strong><\/h2>\n\n\n\n

If\nyou think about the propulsion unit of an aircraft whether it\u2019s a turbine like\na jet engine or a piston-driven design, it\u2019s a complex machine, and yet, a\nrelatively simple concept. With electric propulsion, it\u2019s even simpler \u2014 there\u2019s\nno combustion cycle, just a motor controlled by a throttle turning a prop\nfaster or slower.<\/p>\n\n\n\n

The\nswitch from carbon-based aviation fuel to electricity isn\u2019t that big of a change\nin terms of the overall function of the aircraft \u2014 there are still blades\nspinning and ducting air to achieve flight. However, the move toward electric\npropulsion requires exploration of new design trade-offs to fully extract the\npotential this technology offers.  <\/p>\n\n\n\n

Trade\nstudies in the use of electric motors to propel aircraft must consider\nimportant differences in the flight profiles of these new aircraft \u2013\nlightweight sport planes have different requirements than commercial\naircraft.   These differences guide the\ntrajectory of technology development that will mark the evolution of electric\naviation.  Bridging the gap from\nyesterday\u2019s aircraft to tomorrow\u2019s will depend on what makes sense for each type\nof aircraft. <\/p>\n\n\n\n

For\nexample, might an aircraft be all electric or a hybrid of gas turbine and electric?   In the\nhybrid case, will the gas turbine both propel the aircraft and generate\nelectricity for motors, or will they be separate systems?  Might it also charge batteries on board so\nthat electrical systems are used for a portion of the flight and the gas\nturbines are used for other portions?  In\nthe case of small electrical planes flying today, batteries and a highly\nefficient motor are sufficient to support the flight profile.  Bye Aerospace<\/a>, for example, has developed\nan all-electric trainer that showcases what can be achieved by pursuing a\nsolely electric, battery powered approach.<\/p>\n\n\n\n

Motor technology is an extremely important factor.\u00a0 \u00a0The ability to generate the most thrust from the lightest weight motor possible is key to advancing electric flight.\u00a0 The Bye Aerospace eFlyer 2 uses a Siemens SP70D motor powered by the aircraft\u2019s batteries.\u00a0 The SP70D has a power to weight ratio, a key metric for aircraft propulsion, of 5.22 kW\/kg.\u00a0 Achieving 5 to 10 kW\/kg in motor design is the threshold for practical aircraft operation.\u00a0 Current designs are in this range and new developments continue to push the state of the art forward. <\/p>\n\n\n\n

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