Electric Hybrid

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John.Roo

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Even though I agree with you that there might be better ways to decrease the emissions, it is not that easy to just blame the other polluters and do nothing in the aviation. Every area should take its own responsibility and try to decrease the emissions. There are really no low hanging fruits that could decrease the emissions to the needed level. The concept of implementing the measures based on cost effectiveness is good but why should a power plant or industry take 100% of costs and aviation do nothing? The solution to this is to implement the CO2 tax on everything which will lead to the market implementing those solutions that are most cost-efficient. But I guess a 50$ CO2 tax on a kilo of beef will not be super popular in any country.
I agree that aviation also have to try to decrease emisions. Just... I am not sure about the CO2 tax. Can be only my subjective feeling but uder word "tax" I see increased costs for final user, but no control if money collected on that tax were used for something really helpfull.
Same situation is with many projects... Sometimes governament spent a lot of money for "study" or some "concept" and result is.... nothing practical.
If there would be interest to start to use electric airplanes in aeroclubs and for training, lets support this with something simple. For example - no VAT or some other TAX on electric airplanes for aeroclubs. Simple, clear, helpfull ;)
 

John.Roo

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I think you are on to something here, but the approach still jumps ahead a few questions too far. I'd say the first questions are:
- Is increased atmospheric CO2 a problem worth addressing? If so:
- How do we address it in the most efficient way (best total CO2 reduction per increased cost inflicted?)

I'll skip question number one. To question number 2, I'd bet we can reduce CO2 a lot more efficiently in other ways rather than electrifying flying machines. They are an application where liquid fuels are particularly appropriate. Given that, your idea of making those liquid fuels in a more "carbon conscious" way appears to be attractive. But, we still need to not get ahead of ourselves, as it could be that biofuels etc don't give us the bang for the buck we'd get from, say, reducing CO2 emissions from fixed sites, reducing other greenhouse gasses, etc. The "do everything" approach isn't the best one.
The first thing you need to ask yourself is what the aim of the electric planes is?
I really like this question...

Sport flying? Aeroclub flying? Fun flying?
All this categories are ready for electric propulsion.

Long cruise distance required? Large general aviation airplanes?
Sorry, but at actual stage of battery development is electric propulsion not really a way. Maybe already mentionned biofuel etc.

But in all this categories is large space for improvement.
Aerodynamic efficiency will decrease energy necessary for horizontal flight = less energy used or less fuel burned. I agree that aviation cannot stay away from requirements reducing emissions.
 

Vigilant1

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Malovanyy, I think we are in fundamental agreement, but I think the framing of the issue is crucial to getting to a solution.
If we want to reduce greenhouse gasses (not just CO2, but we want to reduce the impact of all of them in the aggregate), we need accept that it will be expensive and require changes in behavior that will reduce our material wellbeing. That's the truth-- if we could improve our material wealth in ways that produced fewer greenhouse gasses, we'd be living that way already.

Every area should take its own responsibility and try to decrease the emissions.
.... The concept of implementing the measures based on cost effectiveness is good but why should a power plant or industry take 100% of costs and aviation do nothing?
"Areas" can't take responsibility. Power plants and industries pay no costs. Ultimately, costs are paid by consumers, and their resources are finite. Theoretically, if the price of goods accurately reflecter all costs (to include negative externalities now pushed onto others) consumers could make rational decisions based on price alone. Unfortunately, every effort so far to make prices reflect true total costs have bogged down into a hopeless morass of government bureaucracy, rent seeking, influence pedalling, and inter-national inequity. It appears, for now, that such efforts are hopeless.

Meanwhile, as a person, I have finite resources. Even if reducing greenhouse gasses were a high personal priority, I'm pretty sure each dollar spent on a more efficient car or truck, home insulation, etc would have a much bigger influence than a dollar spent on a more efficient airplane. If that's so, some people would argue that it is foolish or even immoral to use the resources for the electric plane. I won't make that case. But, in their present state, battery powered aircraft have such low utility and high costs relative to IC powered aircraft that I would certainly choose to find another place to take the pain.
 
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Aesquire

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That Powerpaste might just solve the second biggest problem with a Hydrogen economy. Storage under pressure is only a little more dangerous than carrying compressed Oxygen. It's an accident hazard, not the most serious threat but real. Cryogenic storage of Liquid Hydrogen is very hazardous, Astronauts level in a moving vehicle, IM not so humble O. Heating Hydrogen soaked metal matrices to release? Yeah, not in my Ultralight. Promising new
Stuff!

The biggest problem is Hydrogen is basically energy storage media, it takes a lot of electrical power or chemical processing and energy to make. You're just taking the coal from the ground and adding several extra steps losing money and energy at each one, to put it in your vehicle. That's true to a less wasteful degree with coal to gasoline conversion. ( WW2 Germany and Carter administration project )

Yes, you can use clean nuclear, or bird killer windmills, or vast solar farms, but despite the happy result of burning Hydrogen not emitting CO2, you generally just move the pollution elsewhere, and waste power to do it.

It's a good idea if power is cheap. My entire life has been waiting the 20 years for Fusion, ( more than 3 times ) which is the ideal cheap power. And politicians object when you want to burn them for energy, for some reason. ;)

I won't get into a religious argument on Climate effects of various stuff. How many dead Eagles are acceptable to have an expensive short lived wind farm. Or my opinion that efforts to clean up actually toxic waste on our planet is a better choice for limited funding. ( like the lake of waste... The dystopian lake filled by the world’s tech lust that provides the materials for the light weight motors we want powering our stuff. )

I do want to rudely puncture any self righteous illusions that there's a Free Lunch with electric cars, scooters, or airplanes. TANSTAAFL I'm not opposed to electric vehicles! I may actually buy an Electric bicycle, or motor for my canoe, or even a car. I'd love an electric powered motor glider, even the Pit Trike, with It's limited performance.
 

Aesquire

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Ignoring the vast sociopoliticalscience implications, o_O

With Hybrid drives or battery or IC you have to ask if it is more efficient? Will it work at all? Limitations? Costs? And what advantage am I seeking?

With motor gliders & electric, you have the system that can most easily use the battery's limitations... designers were forced into that direction, it was a short while ago the only application that actually worked with battery power.

We seem to have advanced to practical short ranged light sports planes. Hybrid systems with onboard fuel burning engines is perfectly logical. And we have the example of the Prius, that leverages the fact that most of the time the car is running at low to medium "throttle". How applicable is that to steady state power needs in aircraft, as far as fuel efficiency goes? Even if it's not as efficient as, say, a Rotax 912 to have a Hybrid drive, it might be an attractive option. Depending on what advantages you take of the benefits that electric gives you.

I'm waiting to see how the ability to have motors remote from power storage affects "normal" airplane design.

Designs for very quiet "trainer" or LSA?
 

Vigilant1

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We seem to have advanced to practical short ranged light sports planes.
Perhaps this varies by location. In the US, I'm not aware of any totally electric or hybrid light aircraft (as distinct from a motorglider) that is practical. Do you know of one? Here, the Pipistrel Alpha is laughable from an economic and utility perspective even for the niche mission of very localized training.
And we have the example of the Prius, that leverages the fact that most of the time the car is running at low to medium "throttle".
The main reason a hybrid setup can make sense in automotive use is the stops, starts of city driving. Vehicles that come in pure IC and hybrid versions (Highlander, etc) frequently see little difference* in their highway mileage because the power demand is steady state. No advantage from regenerative breaking. And, highway driving, the vehicle's weight is largely immaterial as far as fuel consumption is concerned. In an airplane, there's virtually no opportunity to use regenerative braking. In an airplane, the extra weight of a hybrid (they will weigh more) has a much bigger impact on fuel use than it does in a car because it causes extra drag (induced drag due to lift).

* ETA: Depending on year and test conditions. 2010 Highlander IC V6 got 24 mpg highway, 2010 Highlander V6 Hybrid got 25 mpg on the highway. A 4% reduction in fuel burn, and for that I get to carry around a heavy battery and reduce my useful load? And a whole passel of additional flight critical hardware to maintain? No, thanks.
 
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Aviatorzaki77

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DIAMOND AIRCRAFT
View attachment 107185
View attachment 107186
Info from web:
"Two electric engines have been added on a forward canard, which combined can generate 150kW of take-off power. The diesel generator is located in the nose of the aircraft and can provide up to 110kW of power. Two batteries with 12kWh each are mounted in the rear passenger compartment, and act as an energy storage buffer.
Pure electric, the aircraft has an endurance of approximately 30minutes. The hybrid system extends this to 5 hours.
"
It looks like a cri cri scaled version with electric propulsion system.
 

Aviatorzaki77

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I did some numbers on that. Removing the fuel and 2/3 of the passengers from a 737-300 or -400 would free up 49,000 pounds, plus maybe another 3000 for seats and so on. At the typical 1/60 energy density of batteries per pound compared to jet fuel, I get an allowable battery of 9803 KW, or about 13,000 horsepower for one hour. The 737's engines are around 22.000 pounds thrust, which translates, at 650 MPH to 38.000 per engine, or 76,000 HP total, or close to 57,000 KW. That battery would fly the airplane for less than 15 minutes. And you still need energy for taxiing, flight reserve to an alternate, heating/air conditioning and pressurization.

My numbers might be off some, but even if I'm off by a factor of ten, it explains why we don't see any electric airliners yet.
Engine weight to electric motor is at least 50% saving.for 2 engine = 5,000 Lbs,CFM56-5A series produces 22,000 Pounds x 2 44000 pounds trust,8000 KW Needed to produce same thrust but at 80% Speed,500 Mph, I have calculated for duct fan with 48in blades 24in pitch at 7200 RPM,SO there will be four duct fans instead of 2.
 

mquinn

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That is OK - it was discussion only about possible price, not calculation of wing main spare ;)

My friend is now building small electric aerobatic one seater - he expect to have enough energy for 10 minutes of training.
Normally he is flying with Jak 52 :cool:
Now he is testing cells, looking for affordable propulsion system etc. Really good job.

By the way... another info about electric motors.
For example Pipistrel has 60 kW for TakeOff, but he cannot use 60 kW for more than few minutes due to motor overheating. So most of time is electric Velis flying at 17-20 kW of cruise power.
I have +-similar experience - on Phoenix I have 60 kW for TakeOff but 30 kW max. cont. power.
So in fact you really cannot discharge battery in 20 minutes.... ;)
I would love to do an aerobatic electric plane - what is he using for inverted electrical? Is he concerned the electrons will spill out when going inverted? (sorry, not enough coffee this morning and have been working in the shop all night)
 

Dan Thomas

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Engine weight to electric motor is at least 50% saving.for 2 engine = 5,000 Lbs,CFM56-5A series produces 22,000 Pounds x 2 44000 pounds trust,8000 KW Needed to produce same thrust but at 80% Speed,500 Mph, I have calculated for duct fan with 48in blades 24in pitch at 7200 RPM,SO there will be four duct fans instead of 2.
And you need stator blades in there as well. More weight. And maybe a real-life measurement of the fans in those engines is in order. 48" is tiny. You need a lot of stuff in there to absorb 38,000 horsepower, and a couple of 48" rotors at 7200 RPM just ain't gonna do it.
 
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Vigilant1

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Given the low specific energy and energy density of batteries (compared to liquid fuels), I'd think any practical electric passenger or cargo planes, will be using open props and cruising at much less than 500 knots. Maybe 200 knots. And at those speeds, surface transportation looks more attractive for the shorter legs that these planes could feasibly cover. So, the planes might be suitable for sightseeing or short trips to destinations not accessible by road. That's a small market.
 

Dan Thomas

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Given the low specific energy and energy density of batteries (compared to liquid fuels), I'd think any practical electric passenger or cargo planes, will be using open props and cruising at much less than 500 knots. Maybe 200 knots. And at those speeds, surface transportation looks more attractive for the shorter legs that these planes could feasibly cover. So, the planes might be suitable for sightseeing or short trips to destinations not accessible by road. That's a small market.
And then there are the airplanes that are used to reach remote destinations and long way away. Think Alaska, Northern Canada, many parts of South America and Africa, and places like Russia and its Siberia. Huge distances in all of them, and a lot of undereducated folks have no idea of the vastnesses out there. We have been travelling to those places using aircraft since the 1920s and '30s, and if we convert to electric across the board, those places will go back to being inaccessible.

One needs to look at a good map to understand distance. And then compare the distances you have travelled on the ground to the distances between places on the globe. It's awesome. many of the folks pushing green energy have grown up in the cities and have seldom or never been beyond urban areas. They're the ones that have trouble understanding why it's so hard to find an airplane that has disappeared in the Rockies, for instance. Or the Amazon.

One of my favorite maps is the population-density map of North America. It shows, for instance, that 80% of Canadians live within about 150 miles of the Canada-US border. The other 20% are scattered mostly a little farther north, with road access, but there are still significant numbers that are way out there and they're helpless without the airplane that has lots of range. Some of them work in remote mines and so on, doing work that keeps there rest of us going. With electric airplanes you can kiss that goodbye.

Population density.png

Here's a shot of someplace that's not even considered remote. It's the North Thompson valley near Blue River, BC. I was flying my Jodel home, and my friend was in his Tri-Pacer a couple of miles ahead of me. He's in that little red circle. Now, suppose that airplane disappeared in those mountains and forest and the ELT didn't work, as is common about half the time. Just try finding it.

1613500277781.png
 
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BJC

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Here's a shot of someplace that's not even considered remote. It's the North Thompson valley near Blue River, BC. I was flying my Jodel home, and my friend was in his Tri-Pacer a couple of miles ahead of me. He's in that little red circle. Now, suppose that airplane disappeared in those mountains and forest and the ELT didn't work, as is common about half the time. Just try finding it.
Yup, I’m chicken. I’ve crossed the Rockies three times, and had the same rule each time: I stayed within gliding distance of an airport or a road. Not saying that every road was suitable for landing on, but would have been suitable for being found on. That rule dictated my altitude (typically 8,500 to 13,500MSL) more than the ground elevation.


BJC
 

Dan Thomas

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Yup, I’m chicken. I’ve crossed the Rockies three times, and had the same rule each time: I stayed within gliding distance of an airport or a road. Not saying that every road was suitable for landing on, but would have been suitable for being found on. That rule dictated my altitude (typically 8,500 to 13,500MSL) more than the ground elevation.


BJC
The highways are often too busy to try to land on. I wouldn't want to cause a big accident that got someone else hurt or dead, so my plan was usually to pick some stand of smaller trees near the road and land in that.
 

John.Roo

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And then there are the airplanes that are used to reach remote destinations and long way away. Think Alaska, Northern Canada, many parts of South America and Africa, and places like Russia and its Siberia. Huge distances in all of them, and a lot of undereducated folks have no idea of the vastnesses out there. We have been travelling to those places using aircraft since the 1920s and '30s, and if we convert to electric across the board, those places will go back to being inaccessible.

One needs to look at a good map to understand distance. And then compare the distances you have travelled on the ground to the distances between places on the globe. It's awesome. many of the folks pushing green energy have grown up in the cities and have seldom or never been beyond urban areas. They're the ones that have trouble understanding why it's so hard to find an airplane that has disappeared in the Rockies, for instance. Or the Amazon.

One of my favorite maps is the population-density map of North America. It shows, for instance, that 80% of Canadians live within about 150 miles of the Canada-US border. The other 20% are scattered mostly a little farther north, with road access, but there are still significant numbers that are way out there and they're helpless without the airplane that has lots of range. Some of them work in remote mines and so on, doing work that keeps there rest of us going. With electric airplanes you can kiss that goodbye.

View attachment 107549

Here's a shot of someplace that's not even considered remote. It's the North Thompson valley near Blue River, BC. I was flying my Jodel home, and my friend was in his Tri-Pacer a couple of miles ahead of me. He's in that little red circle. Now, suppose that airplane disappeared in those mountains and forest and the ELT didn't work, as is common about half the time. Just try finding it.

View attachment 107551
I started with shorter distances with our electric Phoenix :)
However not populated, rocky and snowy areas are my favorite :)
 
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