# Why battery-powered aircraft will never have significant range

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#### blane.c

##### Well-Known Member
I understand that, but what is the best range in calm conditions ?

View attachment 120634

Closely related to Demoiselle:

Range would be around 30 miles powered? It is slow it cruises more like 40/46 than 55/61 and about 40 minutes of battery.

#### Sraight'nlevel

##### Well-Known Member
Range would be around 30 miles powered? It is slow it cruises more like 40/46 than 55/61 and about 40 minutes of battery.

Ok....then we are already at 1/5 of the performance of the IC engined derivatives.

And only 11 miles less than the world record endurance record in 1908: Wilbur Wright flying at Le Mans, September 21, 1908

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#### Saville

##### Well-Known Member
Yes but if you have your own wind turbine or solar cell system, you fly almost free.

Unless the wind is not blowing and/or it's night time.

Gas pumps work in a dead calm at night.

And you have to factor the costs of your own wind or solar system into the cost of ownership of the airplane.

And if ti's a wind turbine you have to factor in the hundreds of thousands in cost of decommissioning the turbine:

"Decommissioning the Palmer's Creek Wind facility in Chippewa County, Minnesota, is estimated to cost $7,385,822 for decommissioning the 18 wind turbines operating at that site, for a cost of$410,000 per turbine."

I haven't done the calculation but I suspect that the cost of a personal wind turbine system or solar cell system that can recharge an electric airplane in a reasonable amount of time (15 minutes) would be highly prohibitive. Not to mention how the neighbors would find it.

Or do you imagine that the airport woudl allow you to install a wind turbine next to the hangar in which your plane is stored?

If you have a battery bank, charged from your own wind or solar system, from which you charge the airplane, then you are supporting the costs of 2 battery banks.

I say "personal" system because you used the phrase "your own" in your statement.

#### Sraight'nlevel

##### Well-Known Member
Unless the wind is not blowing and/or it's night time.

Gas pumps work in a dead calm at night.

And you have to factor the costs of your own wind or solar system into the cost of ownership of the airplane.

And if ti's a wind turbine you have to factor in the hundreds of thousands in cost of decommissioning the turbine:

"Decommissioning the Palmer's Creek Wind facility in Chippewa County, Minnesota, is estimated to cost $7,385,822 for decommissioning the 18 wind turbines operating at that site, for a cost of$410,000 per turbine."

I haven't done the calculation but I suspect that the cost of a personal wind turbine system or solar cell system that can recharge an electric airplane in a reasonable amount of time (15 minutes) would be highly prohibitive. Not to mention how the neighbors would find it.

Or do you imagine that the airport woudl allow you to install a wind turbine next to the hangar in which your plane is stored?

If you have a battery bank, charged from your own wind or solar system, from which you charge the airplane, then you are supporting the costs of 2 battery banks.

I say "personal" system because you used the phrase "your own" in your statement.

Yes very few have personal/own wind turbines. It would be possible though.

#### Saville

##### Well-Known Member
Yes very few have personal/own wind turbines. It would be possible though.

Lots of things are "possible". It's possible that I might build a hangar at my local airport. But extremely unlikely. So certainly not worth planning my future on.

Giant wind turbines in every pilot's back yard is "possible" but so unlikely that it's not worth speculating on electric airplane futures based on that.

#### blane.c

##### Well-Known Member
We need technology that adds electrons to hydrogen to form helium (inert) and in the process gives off energy for propulsion while simultaneously producing a resonance that counters the force of gravity ... in a controllable way. Its going to be like ... magic!

#### Sraight'nlevel

##### Well-Known Member
Lots of things are "possible". It's possible that I might build a hangar at my local airport. But extremely unlikely. So certainly not worth planning my future on.

Giant wind turbines in every pilot's back yard is "possible" but so unlikely that it's not worth speculating on electric airplane futures based on that.

I am not talking about a giant wind turbine...just a 20-50 kw size system....costing around 20-50 K$. #### Rhino ##### Well-Known Member Yes but if you have your own wind turbine or solar cell system, you fly almost free. Red herring. Cost doesn't alleviate turnaround limitations. #### Saville ##### Well-Known Member I am not talking about a giant wind turbine...just a 20-50 kw size system....costing around 20-50 K$.

Ok and can that recharge an electric airplane with substantial range (say 4 hours flight time) in 15 minutes?

#### Tiger Tim

##### Well-Known Member
Ok and can that recharge an electric airplane with substantial range (say 4 hours flight time) in 15 minutes?
Does it need to? I’m too casual to do a fifteen minute turn. An hour would be fine by me.

#### Saville

##### Well-Known Member
Does it need to? I’m too casual to do a fifteen minute turn. An hour would be fine by me.

It does if you wish to compare operation convenience with ICE engines. Takes me about 15 to refuel my plane but I'm pretty leisurely about it unless there's a line waiting.

If people have to wait 2 hours to recharge then the e-planes lost a huge part of the possible customer base.

And as I understand it, the recharging time is both a function of the electrical recharging system outside the plane and the batteries themselves.

#### Tiger Tim

##### Well-Known Member
It does if you wish to compare operation convenience with ICE engines. Takes me about 15 to refuel my plane but I'm pretty leisurely about it unless there's a line waiting.
A friend of mine who’s big into EVs would probably argue that it takes fifteen seconds to plug in and walk away. In that way it may be more convenient than an ICE. I don’t know what’s required as far as infrastructure installation and upkeep cost goes to charge an airplane but perhaps an electrified future would have a row of 5-10 places to charge versus the current 1-2 gas pumps.

If people have to wait 2 hours to recharge then the e-planes lost a huge part of the possible customer base.
I agree, two hours is too much. One hour is probably acceptable for an awful lot of single-engine light GA, even if the current users don’t recognize it.

In any case, I won’t be an early adopter and I’m definitely not one to force others to do things. I just think new stuff can be interesting.

#### Dusan

##### Well-Known Member

You're right. 50% efficiency at max power is a theoretical number, never achieved in practice, but good motors are very close to it. Anyway it's a moot point since no motors can operate at that loading.

A friend of mine who’s big into EVs would probably argue that it takes fifteen seconds to plug in and walk away. In that way it may be more convenient than an ICE.

I can vouch for that. The convenience of charging at home means for me not freezing at -25C plus windchill for 10 minutes at the pump.

#### BJC

##### Well-Known Member
You're right. 50% efficiency at max power is a theoretical number, never achieved in practice, but good motors are very close to it. Anyway it's a moot point since no motors can operate at that loading.
Again, no, those comments are not true for all motors.

BJC

#### Pale Bear

##### Well-Known Member
Wouldn't it be great to be able to convert/harvest to fuel (hydrogen?) at wind farm locations. It must not be practical, or cost effective .. and where does one go, for straight answers? How far away from sound, (and practical) are these green tech systems, from being able to produce hydrogen, let's say? More federal \$'s?

#### Aesquire

##### Well-Known Member
How far away from sound, (and practical) are these green tech systems,

that depends on your religious beliefs, which is a discouraged topic for discussion here.

So I'll be Simple, and blunt. Production of Hydrogen is energy expensive. Easiest done from fossil fuels, most wasteful from electrolysis, and a range in between. Hydrogen is a BATTERY. You put in power, and get a hard to carry gas at STP. You then burn/react it in an engine or fuel cells to run an electric motor.

There are multiple posts on the subject with quite a bit of disagreement on the practicality.

The theoretical advantages seem dwarfed by the practical difficulties. Imho. So I'd put most of the green tech ideas in the category of steam engines burning money where you want high performance for lots less mass and cost.

In airplane terms, the mid 1800s. Ymmv.

#### Sraight'nlevel

##### Well-Known Member
Ok and can that recharge an electric airplane with substantial range (say 4 hours flight time) in 15 minutes?
This recharging has to be designed thoroughly. I bet a system where the stardard batteries are switched in 10 minutes is very doable. Possibly date on the batteries would matter in the charging of the charge...newer batteries would be less costly when charging and vice versa ( you could possibly get charge for free if you have to switch to older ). All batteries would be dumbed after certain amount of charges.

#### John.Roo

##### Well-Known Member
Dear friends,
I flown many hours with electric airplanes. It also means I spent many hours waiting for re-charge For me safety = as low as possible "C" rate for discharge and also re-charge. During takeoff you need max. power, however I try to decrease this period to minimum and use "reasonable " power for safe climb rate.
At any time you have to watch temperature of cells - ideally on as many as possible places. "TMG like" airplane has advantage of practically no power requirements on downwind, baseleg and final = I typically land with "cold" battery and "cold" motor. You can see it here....

However in case you land witn "normal" airplane you have to wait to start re-charge till battery temperature is reasonable. If batery is too hot, than charger should decrease charging power automatically. Temperature management (used in modern electric cars) could help a lot, however it means also extra weight and technical complications. Simple solution is also heavy = use as larger battery as you can.

Another problem is power availability.
In EU (except France) we have available 3 phase 400 V and 16 Amps. So you can reach 1 hour recharge time for 1 hour flying.

Change bateries?
For one seater with 2x 15 kg battery (5-6 kWh capacity) is manipulation simple.
30 kWh battery in two seat TMG = weight of 150 kg. And this means increased risc of damage (if battery falls for example) = increased risc of fire due to damage if some cell inside.

I am fan of electric propulsion systems and I beleive that is near future for simple one seat "TMG like" airplanes or self launch gliders.
Two seat TMG is also possible, but is on the MTOM border for LSA.
If you face reality and accept actual battery / charging limitations than you can enjoy electrically powered airplanes already. Without "pioneers"dreaming, making and testing new solutions we would never develop flying machines

#### Rhino

##### Well-Known Member
Yes, you'd need multiple smaller batteries if swapping is going to work. Developing some sort of standard for size and compatibility, like standards for USB connections, would also be required. Don't want to arrive at an airport and find they only have Beta when your aircraft uses VHS. The weight and hazard issues will likely reduce as time passes. And let's face it, this isn't something that would happen overnight. Just developing a standard would take years of government bureaucratic nightmares. By that time, swapping may not even be necessary.

#### John.Roo

##### Well-Known Member
Yes, you'd need multiple smaller batteries if swapping is going to work. Developing some sort of standard for size and compatibility, like standards for USB connections, would also be required. Don't want to arrive at an airport and find they only have Beta when your aircraft uses VHS. The weight and hazard issues will likely reduce as time passes. And let's face it, this isn't something that would happen overnight. Just developing a standard would take years of government bureaucratic nightmares. By that time, swapping may not even be necessary.
Honestly... I don´t expect that we can expect "standard charging stations" of airfieds in near future.
Only practical solution is on-board charger. Than you need only acces to standard electric plug on airfield. Realistic 10-12 kW on board charger. Weight? I would say that weight of that charger can be below 15 kg (in near future 10-12 kg.... maybe bit less).