[HN Gopher] United Airlines is aiming to have electric planes fl...
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       United Airlines is aiming to have electric planes flying by 2030
        
       Author : mfiguiere
       Score  : 14 points
       Date   : 2022-10-06 20:14 UTC (2 hours ago)
        
 (HTM) web link (www.cnbc.com)
 (TXT) w3m dump (www.cnbc.com)
        
       | O__________O wrote:
       | Anyone able to comment on if this is even possibly with current
       | technology, and if not, in order of degree of difficulty & being
       | critical to executing this, what needs to be created for it to be
       | realistically feasible?
        
         | whateveracct wrote:
         | There's a recent Sabine video about this very topic, actually.
         | It didn't sound promising.
        
           | O__________O wrote:
           | Thanks, assuming you mean Sabine Hossenfelder and this video:
           | 
           | What's the Best Way to Make Air Travel Climate Friendly?
           | 
           | https://youtube.com/watch?v=RVaVMyd0lI0
           | 
           | Part on electric planes starts at 2:30 and only last a 3-4
           | mins.
        
         | aftbit wrote:
         | The fundamental problem with electric aviation is the terrible
         | specific energy & energy density of existing battery
         | technology. Just for a very rough order-of-magnitude
         | comparison, the most energy-dense batteries in common use today
         | (lithium polymer cells) hold somewhere around 0.2-1 MJ/kg and
         | 1-3 MJ/L [1]. Jet-A (kerosene) on the other hand holds
         | somewhere around 40 MJ/kg [2]. Some of that might be recovered
         | by using efficient electric motors instead of combustion
         | engines, which are typically pretty inefficient, but even then
         | we're still looking at a >4x decrease in fuel range.
         | 
         | Notably though, these guys have pretty modest goals:
         | 
         | >The 30-passenger planes will be driven by electric motors with
         | battery-derived energy, allowing the planes to have a fully
         | electric range of 200 kilometers (124 miles). The planes will
         | also include a reserve-hybrid engine powered by sustainable
         | aviation fuel, allowing it to have an extended range of up to
         | 400 kilometers with a full flight.
         | 
         | Energy lost to drag goes up with the cube of velocity, so
         | flying slow, light planes over short hops might be doable with
         | fully electric engines and modern batteries.
         | 
         | As a side note, it's especially telling that they'll fly with a
         | reserve engine that uses hydrocarbon fuel. This might be done
         | for safety, but I would suspect it's more about making them
         | economically viable while allowing them to be painted as a
         | green alternative. Most routes will likely require at least
         | some fuel consumption.
         | 
         | 1: https://en.wikipedia.org/wiki/Lithium_polymer_battery
         | 
         | 2: https://en.wikipedia.org/wiki/Kerosene
        
           | O__________O wrote:
           | Yes, it was my understanding that battery capacity was the
           | major barrier. To bad it's not easy to just safely hot swap
           | batteries in flight, which would likely solve the problem.
        
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       (page generated 2022-10-06 23:02 UTC)