from the airline-spelled-backwards-is-enalpria dept.
[...] Assuming these electric aircraft could be built, would they actually lower emissions? At present, no. Given the average emissions involved with powering the US grid, the emissions involved with powering an electric aircraft (including losses during transmission) would be about 20 percent higher than those generated by a modern, efficient jet engine. That doesn't mean they'd be entirely useless from a climate perspective, though. Once the additional warming effects of aircraft are taken into consideration, the electric aircraft comes out ahead by about 30 percent.
Future considerations complicate things pretty quickly, though. The price of renewable energy is expected to keep dropping, which will make renewables a larger part of the grid, lowering the emissions. The authors estimate that the vast majority of charging will take place during daylight hours—the peak of solar production—as well. Assuming future solar production leads to a discount on electric use during the day, it could help the economics of electric aircraft; currently, they only make sense economically with fuel at about $100/barrel.
How all of this would affect air travel is very sensitive to the capacity of future batteries. The authors estimate that an effective range of about 1,100 kilometers would allow electric aircraft to cover 15 percent of the total air miles (and corresponding fuel use) and nearly half the total flights. That would raise the total electricity demand by about one percent globally, although most of that would affect industrialized nations. Upping the range to 2,200 kilometers would allow 80 percent of the global flight total to be handled by electric aircraft.
Zeppelins still don't seem to figure into the answer.
(Score: 0) by Anonymous Coward on Saturday December 15 2018, @08:18AM (1 child)
If a tunnel or bridge can almost be justified, but not quite, then we often end up with a ferry. Electric airplanes can replace the ferries.
The big determining factor is likely to be FAA rules. If the equivalent to an engine overhaul is cheaper or faster, the electric planes get a huge advantage. Noise regulations could play a role.
(Score: 1) by khallow on Saturday December 15 2018, @04:20PM
How many cars can an electric plane carry?
(Score: 2, Informative) by Anonymous Coward on Saturday December 15 2018, @09:04AM (2 children)
The submission below is infinitely more interesting than this no-content rambling.
https://soylentnews.org/submit.pl?op=viewsub&subid=30636¬e=&title=First+ever+plane+with+no+moving+parts+takes+flight+ [soylentnews.org]
(Score: 0) by Anonymous Coward on Saturday December 15 2018, @02:16PM
Two things about that "plane" with no moving parts:
1) I want my planes to go further than 60 meters.
2) I want moving parts on my plane, including (but not limited to) a rudder, some flaps and landing gear.
(Score: 2) by FatPhil on Sunday December 16 2018, @10:26PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 4, Informative) by Anonymous Coward on Saturday December 15 2018, @09:04AM (5 children)
Two engines = 220,000 hp or 161.4 MW. 1100 km is about 2 hours in the air, probably more but at a low throttle. That makes 322 MWh. Account the fact that cruise is not takeoff and divide by 3. We need now 100 MWh.
Tesla is proud of a lighter 75 kWh battery in Model 3. To get to 100 MWh we need only 1333 such batteries. Each weighs 275 lbs or 125 kg. Together they will weigh 166 tonnes. Wolfram-Alpha conveniently mentions that it's 1.7 x cargo mass of a Boeing 747-200F. A smaller a/c will be correspondingly less powerful. It will not take off even empty. At the same time kerosene is light and contains a lot of energy. A Boeing 747 will need 22-25 tons of fuel for the same trip, but this a/c is very inefficient for short flights.
I just wanted to show how far away we are from electric aircraft. There are no chargers in the air - and an electric car cannot yet cover 1,100 km on a single charge. Aviation is very energy-intensive. Per passenger-mile it's not much, though, but visible in ticket price. We should hope that one day electric airplanes will fly in the skies - but at the same time we'd get our flying cars (same battery technology is needed for both.) And flying car is a symbol of unreachable, pretty much like controlled nuclear fusion.
(Score: 1) by NateMich on Saturday December 15 2018, @09:13AM (4 children)
Thank you. I wanted to post that the entire idea is idiotic, but I don't think I need to.
I would like to mention however that recharging planes would be a serious problem, but that isn't even the real issue here.
(Score: 3, Interesting) by Runaway1956 on Saturday December 15 2018, @10:55AM (3 children)
Regarding charging planes - it seems obvious to me that they would need to change batteries, rather than wait for the chargers to do their job. No airline wants their planes sitting on the tarmac for half of eternity while the batteries charge! Somehow, though, I can't see the authorities approving of pulling tons of batteries out of the aircraft, then slapping a bunch of new ones in place. For efficiency, you would almost have to redesign the air frame, so that a very large forklift drives up to the belly of the plane, the batteries are disconnected as a unit, then unlatched from the aircraft, and the whole power unit hauled away as a unit.
I also question how fast these things can be. Jets are fast - faster than just about anything other than rockets. With batteries, you're moving backward to propellors, or at best, turbines. How fast can you make those? Jets pretty much took over aviation by reason of their speed.
For battery powered craft, we need a whole lot of tech breakthroughs, and probably a more leisurely approach to air travel. I don't see either of those happening real soon.
(Score: 2) by Dr Spin on Saturday December 15 2018, @11:48AM
Jets pretty much took over aviation by reason of their speed.
Having taken over, people were able to realise that fuel economy and reliability were also important. And no one has any plans to produce a piston engine that competes with high bypass turbojets.
You could reasonably expect fare paying passenger planes with the battery life of a sub $100 drone, Above that, you have unreasonable expectations.
Warning: Opening your mouth may invalidate your brain!
(Score: 2, Interesting) by khallow on Saturday December 15 2018, @04:14PM
Most jets are turbines, let us note. Turbines can go a little into the supersonic regime. The key is to slow incoming supersonic air to subsonic speeds (expansion and heating) for the turbine to grip, and then eject at supersonic speed (reverse of the initial process). Certainly, they'd be able to function at the normal high subsonic speeds that passenger jets currently travel at.
The big problem is the battery mass.
(Score: 4, Interesting) by subs on Saturday December 15 2018, @05:14PM
A few little details:
- Modern turbofan engines derive around 85 - 90% of their thrust from the bypass fan.
- A bypass fan is little more than a glorified high-speed fixed pitch propeller.
- If you replace the turbine engine core with an electric motor, in principle there's nothing preventing you from building an electric fan engine that would achieve the same speeds that a turbofan could (M0.75 - M0.84).
- "or at best, turbines" - this makes no sense from an engineering perspective. All aviation jet engines ARE turbine engines.
If you look at things such as propfans [wikipedia.org] or unducted fans / ultra high-bypass turbofans, the differences between a turbofan and turboprop engine get blurred until there's basically no distinction left.
In short, the propulsor / engine tech isn't really what's holding electric aircraft back. That's pretty much a solve engineering problem and we have all the tech needed for it available today (in fact we've probably had for the last half century). What kills it is the battery energy density.
(Score: 3, Insightful) by MichaelDavidCrawford on Saturday December 15 2018, @09:37AM (2 children)
A long time ago I read that the transport one passenger at 60 MPG.
This was before the first graphite epoxy 787. Doubtlessly many planes will be composite someday.
It's likely you contribute to increased fuel efficiency when you change planes at a hub rather than flying nonstop as the former generally has more occupied seats.
Yes I Have No Bananas. [gofundme.com]
(Score: 2) by suburbanitemediocrity on Saturday December 15 2018, @07:27PM (1 child)
This is true...provided the plane is more than half loaded.
(Score: 3, Informative) by toddestan on Sunday December 16 2018, @01:19AM
And you're also assuming the car has a single occupant. Most any car will hit 60 MPG per passenger if there's two people in the car. A truck or van will do the same with 3-4 people in it.
(Score: 5, Insightful) by Lester on Saturday December 15 2018, @10:17AM (15 children)
People talk about electric cars, with batteries or hydrogen cells or compressed air etc. The question is that there are not mines of hydrogen or whatever you want. They only store energy. In fact, there are only a few sources of energy: Sun, geothermic and nuclear. Fossils fuels is just a battery that was recharged millions years ago, and that instead of releasing energy in form of electricity releases it in form heat.
Most electricity comes from fossil fuels. So we are exchanging
(fuel -> heat -> mechanic energy)
for
(fuel -> heat -> mechanic energy [turbine] -> electricity -> transportation by wires -> mechanic energy [car engine])
And in each step you waste energy. So, electric cars don't look a great idea from the energy or pollution point of view.
Nevertheless there are other points. We already have the technology to move from any energy from/to electricity. Electricity is a very portable format, it is the Esperanto of energies. ;-). So, when we run out of fossil fuels (2030-2050) [wikipedia.org]. We will have most of our machines running with electricity. We won't face two problems, replacing fuels and replacing all our engines. At least we have several years to replace fuel engines by electric engines and improve this technolgy.
Most electricity comes from fossil fuels, and if we were to replace all current combustion cars with electric cars we would have ten fold (or one hundred) the production of electricity. How? Now with nuclear and fossil fuels, but we will run out of both. It looks like renewable energies will not be able to replace completely fossil fuels and fusion seems to be far. So it looks that we will have to live with less energy.
Anyone who believes in indefinite growth in anything physical,
on a physically finite planet, is either mad or an economist
There is not sustainable growth, only sustainable equilibrium.
The later we be aware of this fact, the lower will be the standard of living when we reach the equilibrium
(Score: 1, Interesting) by Anonymous Coward on Saturday December 15 2018, @11:21AM (5 children)
We will never run out if fossil fuels. It's just their price will rise so much that they would be too expensive to burn. Note that the industry needs both coal (metallurgy, chemistry) and oil (chemistry.) Transition of chemistry away from oil and gas is likely impossible, as we make nearly all plastics from them. Transition of industry is possible, but we need more nuclear power plants and a stronger grid, probably with 230/380V routed into houses. (The current 120V standard was already obsolete in 1960-s, as it limits power use and consumes precious copper.) Any government official will tell you that we need 100 years for that upgrade.
Electric cars will improve ecology for several reasons. First, they do not pollute where people live. Second, millions of exhausts of individual cars cannot be efficiently cleaned; but central power plants can be. Third, efficiency of high power turbines is higher than an ICE of a car. Fourth, there are non-polluting sources of electric power. Due to range/cost issues, a hybrid is a good transitional choice. (I have a hybrid for more than a decade.)
(Score: 3, Disagree) by Dr Spin on Saturday December 15 2018, @12:03PM (1 child)
Most of the world already has 230V to houses. Its just that America is chronically backward.
We have already reached the state where most pollution from recent cars is from the tyres and brakes. Not everyone is driving 1970's clunkers.
Unfortunately electric cars weigh a lot more than the alternatives, and as a result, pollution from brakes and tyres is higher.
Of course, actual research into actual pollution levels and its causes in real life is hard to come by.
The efficiency of a high power turbine is indeed higher than that found in a car. However, the distribution losses here in the relatively tiny UK are 30%.
They would be higher in almost any other country. You would be far better off having a truck engine drive a generator at the end of your street, and
then using the waste heat for home heating instead of throwing it away. We have piped gas to every home, so this could burn nice clean gas
(as sold by a Russian mafiosi near you) or hydrogen - ideal for convenient explosions.
There is still a massive opportunity for something better. We research scientists need more grants! (Please give generously).
Warning: Opening your mouth may invalidate your brain!
(Score: 2) by suburbanitemediocrity on Saturday December 15 2018, @06:58PM
The US is 240v to the house (10 better than 230).
(Score: 3, Interesting) by Lester on Saturday December 15 2018, @12:23PM (2 children)
Yes, that is the peak of oil that I linked. But from a practical point of view, if driving from home to work cost 100$, you don't have gas for car.
And medicine. Many drugs use chemicals components from crude. That is why shortage of oil it will be nightmare, and it is stupid just burning it. But as long as there is champage on the ice, let's party, toast and drink.
Nuclear power is expensive [wikipedia.org]It is a huge investment, that you may recover in years, that means financial costs. It costs to manage the waste. it costs to dismantle it. No private company wants to build a nuclear power plant, and those have done it, have swindled the government (o the citizens), many of the hidden costs are assumed by the government (waste, financial, assurance, security for years after dismantlement).
Now there are about 450 nuclear plants in the world. You need 7 years to build one. Are we going to build 4,000 before 2050? I don't think so. Second. Uranium is as limited as fossil fuel. According with this [wikipedia.org]at the current rate we will run out of Uranium in 135 years, if you build 4,000 nuclear plants it will last 13,5 years.
Nuclear plants are not profitable.
Well I'm in Spain, we have 220V. Since 1960, I think.
I' not very optimistic about transition. None wants to give up conveniences. Problems look far and politicians are not going to promise sacrifices today, for a better tomorrow. And if they do, we will not vote them.
(Score: 2) by suburbanitemediocrity on Saturday December 15 2018, @06:55PM
Most of the US is 240 also, but split phase ( https://en.wikipedia.org/wiki/Split-phase_electric_power [wikipedia.org] ). High energy devices like whole house central AC/heat pumps, water heaters, dryers. 120v is for 2.5kw devices.
(Score: 0) by Anonymous Coward on Saturday December 15 2018, @10:17PM
4,000 nuclear plants will not appear overnight. We have at least 30-50 years to transition to fusion plants. We have no time left to drag the feet. Gather physicists, explain the problem to them, task them, finance them. There is no other way - we need remaining oil for chemical works, we will run out of Uranium soon, and solar/wind cannot power huge demands of steel furnaces and aluminum plants (the power must be delivered non-stop, otherwise metals solidify forever.)
(Score: 1, Insightful) by Anonymous Coward on Saturday December 15 2018, @11:42AM
Solar/wind needs better storage tech, but thats probably coming too slowly. There is plenty of thorium, and lots of U238 for fast breeder plants.
When (if)* fossil fuels run out and people start freezing to death in winter and going hungry all year round, you are going to see much less opposition to nuclear plants, partly because they will be using greenies for fertilizer.
*Thomas Gold wrote a couple of well-researched books that convincingly argued that 'fossil' fuels are mostly primordial, the bio components are contamination from the deep biosphere, and that there is a hell of a lot more of it than oil/gas/coal companies will admit to. Power from the Earth and The Deep Hot Biosphere.
(Score: 2) by Dr Spin on Saturday December 15 2018, @11:51AM
electric cars don't look a great idea from the energy or pollution point of view.
But think of the politicians! Electric cars allow you to have aspirations!
(And politicians do not need to take reality into consideration).
Warning: Opening your mouth may invalidate your brain!
(Score: 1) by khallow on Sunday December 16 2018, @05:14AM (6 children)
Straw man argument. Are we living at the best standard of living possible? Do we have long life spans in excess of a million years. Do we live everywhere we could possibly want to live in the Solar System? No? Then we have plenty of room for growth despite its unsustainability. And plenty of reason to expect our eventual standard of living will be much higher than present.
It's like demanding that humans stop growing when they're three week old fetuses because growth is unsustainable while ignoring that three week old fetuses are absolutely useless.
(Score: 0) by Anonymous Coward on Sunday December 16 2018, @08:25AM (1 child)
He said indefinite growth, presumably meaning infinite growth based on his comment about a finite planet, not growth. And while 3 week old fetuses do grow, humans don't grow indefinitely. Most stop growing in their teenage years.
(Score: 1) by khallow on Sunday December 16 2018, @08:20PM
I bring your attention to the following comment which was part of my original quote.
The assumption was that we had already reached the limit of growth and any further growth would just make things worse - just like assuming that there's no reason to grow a three week fetus any more, merely because one assumes that growth is bad.
(Score: 2) by Lester on Sunday December 16 2018, @10:55AM (3 children)
We can think about other planets, but now that is SF. I'm talking about solutions in the short - medium term, in 50 years. I don't think we will be in Mars or on a Jupiter's satellite in 50 years. But we are going to hit planet limits in 50 years, energy and other natural resources. In fact, we have already hit them. Copper has sky rocket it's price because some years ago one of the biggest mine of the planet got exhausted. But copper problem is nothing compared with future shortage of oil.
No. We are already in troubles. Well, not "We", but a great part of human kind. And in not too long, "we", middle class in western countries, are going to be in troubles. Next generation, people now is 20 years, has a mean standard of living lower than me, 50 years. There are more high paid jobs, there are much more pathetic jobs and there are much, much less, middle class jobs. And the future is not going to be better. The truth is that all new economy demands less workforce.
I suggest to read this link Mana [marshallbrain.com]
(Score: 1) by khallow on Sunday December 16 2018, @08:22PM (2 children)
Probably not, actually. there's a lot of room for all those resources, particularly energy.
(Score: 2) by Lester on Monday December 17 2018, @10:39AM (1 child)
No, there is not room for fuel oil at all. Peka of oil [wikipedia.org]. In fact, many experts state that we have already reach the peak, but thanks to crisis there is low demand.
(Score: 1) by khallow on Monday December 17 2018, @12:44PM
Fuel oil is not a subset of fossil fuel.
Uh huh.
(Score: 2) by suburbanitemediocrity on Saturday December 15 2018, @06:46PM
35MJ/kg
(Score: 0) by Anonymous Coward on Saturday December 15 2018, @09:33PM
Problem solved.
(Score: 0) by Anonymous Coward on Sunday December 16 2018, @06:42PM
wind resistance goes up more then squared with speed.
that's alot of "waste" to get somewhere fast.
if it were up to me we would be (long distance) traveling much slower (and in style) (i can live off sandwiches for a few days).
doing intercontinental electrically and via a zeppelin should be viable?
with everything going towards free and made by robots (including themselves) a lot of people
will have a lot of time on their hands busying themselves further with their hand-held time waster
and if the same trip takes ten times longer they get to spend more time with their favorite device
without making much fuss. the next time they look up they'll be at the destination anyways ...