
Norway's Plan for a Fleet of Electric Planes - HillaryBriss
http://www.bbc.com/future/story/20180814-norways-plan-for-a-fleet-of-electric-planes
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jillesvangurp
Electric planes still have a few challenges ahead but basically technical
progress seems to make short haul electrical flight feasible within the next
decade.

The reason this is being pursued by so many companies is that electric planes
solve a lot of problems and represent an enormous disruption to the aviation
industry. Modern air planes are very complex and expensive to operate and need
a lot of maintenance. The cost of operating them is completely dominated by
fuel cost, maintenance overhead, and expensive taxes and fees at airports
related to noise and pollution.

With electrical engines, all of this changes. They are light and simple and
tend to have a long operational life with very low maintenance requirements.
Recharging batteries is extremely cheap compared to burning tons of fuel
(literally). Filling up an A321, which takes 24K liters of kerosene, will take
you somewhere between 10 and 15K and gets you a range of around close to 8000
km. Most flights are much shorter than that meaning a lot of their weight and
range is redundant. Also, you burn a lot of fuel on takeoffs and most planes
need to get up high to get to an economical fuel burn rate to cruise. So you
pay a huge price for getting all that weight up on every take off.

Electrical planes don't need to get up that high and can cruise efficiently at
both low and high altitudes. Once cruising, operating them as a glider is
actually feasible as well because you can safely turn the engines off and on
again (unthinkable with a jet).

~~~
montenegrohugo
I understand the advantages of an electrical motor to an ICE, but I have
doubts regarding your third paragraph. The energy density of Li-Ion batteries
best-case scenario is around 1 MJ/kg, whilst Kerosene is 42.8-42.6 MJ/kg.
That's a 40x !!! difference in energy/weight. Of course the electric engine
will have a big efficiency advantage (think 80% vs 40% for ICE), but the gap
in energy density is still enormous.

The other (huge) advantages in flight safety and reduction in noise and
overhead costs still apply, but I don't believe electrical planes will be as
disruptive as portrayed without significant advances in battery technology.

~~~
dogma1138
Jet enegines have a combustion efficiency of 100% at low altitude and 98% at
cruising altitudes. High bypass jet engines will operate 90%+ propulsive
efficiency when you reach cruising speed and altitude.

This can include torbo props.

[https://en.m.wikipedia.org/wiki/Propulsive_efficiency](https://en.m.wikipedia.org/wiki/Propulsive_efficiency)

Fuel has also a very big advantage over batteries and that is that you shed
off weight when you use it while an empty battery will weight as much as a
full one so you’ll end up carrying much more dead weight for the entire
flight.

Fuel cells might be a possibility but I don’t think airplanes with hydrogen
tanks are a good idea.

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peterlk
Out of my depth here. Why are tanks of Kerosene safer than tanks of hydrogen?
Pressure?

~~~
gambiting
Hydrogen leaks out of literally any container it's stored in, if you fill up a
pure lead bottle(a 25kg bottle only holds 1 litre of hydrogen) it will be
empty after 2-3 weeks of doing absolutely nothing - hydrogen molecules are so
small they just permeate through any safe to handle material. Obviously planes
couldn't use tanks made out of lead because of weight, so whatever material
they used would leak even faster - and as hydrogen forms an explosive mixture
with air, that's not a good thing.

~~~
icebraining
Can't you just vent to outside of the plane? It's not like they are usually in
enclosed spaces.

~~~
outworlder
Hangars?

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yason
It it still quite a lot of energy needed from batteries to maintain airspeed
that produces sufficient lift.

For short flights, a crossover between an airship and airplane might be an
interesting idea. Economic and technical arguments might shoot it down but I'm
just contemplating here.

If there was a balloon attached to the body of the plane that would provide
_most of the_ lift the electric motor could just drive the propellers or motor
fans for mostly forward propulsion. The overall speed could be slower because
the wings wouldn't have to convert airspeed to so much lift, saving energy. On
short haul flights the speed wouldn't be a big problem.

The plane wouldn't thus rise up directly like airships: the balloon would only
give most of the lift required for flight. Large but light wings would provide
the remaining bit of lift starting from slow speeds and the plane could thus
basically behave more like a normal plane, taking off and landing as usual
albeit at significantly slower speeds, figuratively as if the plane was
swimming in low gravity or, alternatively, 10x denser air.

A balloon would obviously introduce a lot of aerodynamic drag but since the
balloon would only help in lifting the plane it could be a bit smaller. We
could also build it into an aerodynamic shape instead of a traditional
balloon, and we could integrate parts of the helium filled balloon onto the
plane itself. For example, we could give the small plane huge biplane wings
made out of light-weight steel mesh with helium-filled pods inside.

Edit: Similar idea in
[https://www.youtube.com/watch?time_continue=188&v=oxotOEZCh8...](https://www.youtube.com/watch?time_continue=188&v=oxotOEZCh8g)
where 60% of the lift comes from the helium and 40% from aerodynamic forces.

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davedx
This is really great news. Shipping and aviation are two sectors that
contribute huge amounts of greenhouse gas emissions, but have traditionally
been left out of climate change action plans.

I can't wait to take my first electric flight!

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PopeDotNinja
Real Engineering did a cool video on electric planes a few weeks ago.

[https://youtu.be/VNvzZfsC13o](https://youtu.be/VNvzZfsC13o)

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Jedi72
Has anyone ever considered detachable rockets for aircraft? I'm thinking
SpaceX style boosters on the wings that could return to the airport. My
understanding is that getting up to altitude requires lots of power but
cruising/gliding, not as much. Reusable hydrogen boosters for take off and
electric cruise sounds like an eco (not to mention fun) way to fly

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baybal2
Take a note people - they are not dreaming of electric airlines, but thing
more close to an air taxi with <200km range.

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wpdev_63
I am surprised nobody Larry Page's darling startup in electric planes.

[https://www.youtube.com/watch?v=Jcpq6XYYoY4](https://www.youtube.com/watch?v=Jcpq6XYYoY4)

This is probably the closest thing we have right now and the foreseeable
future.

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IronWolve
Wouldnt electric planes be stuck to propeller drive? So limited to short haul.
Thats why the 2 seater and local turbo prop planes would be the ones replaced.
How can you make an electric Jet engine?

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wefarrell
I've often wondered how much energy would be saved by using some kind of
catapult like the ones on aircraft carriers.

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Markoff
i like how it's there not a single mention what it's financing their electric
car or planes revolution - it's their oil resources - exporting them,
effectively exporting pollution to countries not rich in oil, which can't
afford subsidized switch to electric

if they would be really ecological and not hypocrites they would stop making
money from oil resources

~~~
rdl
Cheap and safe to recover oil (like Saudi, Norway, etc) is way better for the
environment than expensive (tar sands) or dangerous (badly run deep water
operations.). Also, I would sure rather have the government and people of
Norway get money than a lot of the other places selling oil...

~~~
arethuza
Norway's oil isn't nearly as cheap as Saudi oil to extract - ~$21 a barrel for
Norway and ~$9 for Saudi oil. In fact it's roughly the same cost to extract as
US oil.

[https://www.fool.com/investing/2017/03/19/you-wont-
believe-w...](https://www.fool.com/investing/2017/03/19/you-wont-believe-what-
saudi-arabias-oil-production.aspx)

Also, Norway's oil comes from the North Sea - which I'm not sure counts as
"easy".

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rdl
Norway’s oil is inherently difficult compared to Saudi oil, but they already
have a lot of infrastructure and skill and are incredibly competent. It would
be different if we had just discovered the North Sea oil and had to decide
between that and Saudi land based reserves.

