Electric Airplane Developments
Batteries are rapidly getting smaller and the capacity increasing.
There was a fleet of thirty electrically driven taxis in Amsterdam around 1910 (out of a total of 240 registered cars). Back then the expectation was that electrically powered vehicles were the future. Look how far we've come since then....
The first Porsche: Electric but two tonnes of weight.
https://newsroom.porsche.com/en/prod...ory-18563.html
https://newsroom.porsche.com/en/prod...ory-18563.html
Jan Olieslagers Energy density does not necessarily = danger...
However, as most clearly realise, with conventional electric transportation it's the energy density of the supply that's the limiting factor at present.
What brings things into perspective is a comparison of the best portable electric source (let's say a Lithium-ion battery) against a unit of petroleum. If we use Joules per kilogram we find that 1kg of petrol has ~44MJ/kg, a Li-ion battery has ~0.6MJ/kg, give or take. Thus conventional fuel typically contains around 70 times the energy per kilo than electric.
This is offset to some extent by the relative efficiency of converting this energy into power that will propel your 'plane. It's a complex field, but for the purposes of a simple comparison let's assign an efficiency of 90% to electric, and 30% to a combustion motor.
However, while the electric system has much greater efficiency, from a practical perspective it clearly remains overwhelmed by the vastly superior energy density of petroleum.
So, there have been significant advances in (electric) energy storage over the past 20-30 years but, unless there is a 'eureka' moment, I feel it will be quite a long time before it becomes fully viable and comparable to 'conventional' fuel-powered aircraft.
FP.
However, as most clearly realise, with conventional electric transportation it's the energy density of the supply that's the limiting factor at present.
What brings things into perspective is a comparison of the best portable electric source (let's say a Lithium-ion battery) against a unit of petroleum. If we use Joules per kilogram we find that 1kg of petrol has ~44MJ/kg, a Li-ion battery has ~0.6MJ/kg, give or take. Thus conventional fuel typically contains around 70 times the energy per kilo than electric.
This is offset to some extent by the relative efficiency of converting this energy into power that will propel your 'plane. It's a complex field, but for the purposes of a simple comparison let's assign an efficiency of 90% to electric, and 30% to a combustion motor.
However, while the electric system has much greater efficiency, from a practical perspective it clearly remains overwhelmed by the vastly superior energy density of petroleum.
So, there have been significant advances in (electric) energy storage over the past 20-30 years but, unless there is a 'eureka' moment, I feel it will be quite a long time before it becomes fully viable and comparable to 'conventional' fuel-powered aircraft.
FP.
Yes Jan, but then petroleum products burn and fuel tanks explode. Fatal Carbon Monoxide poisoning is also all too common. First Principal outlines neatly where we are.
The development of electric vehicles is dependant on more than only the battery. As for how rapid things will develop, nothing before has stimulated the need more than the environmental concerns of today.
The development of electric vehicles is dependant on more than only the battery. As for how rapid things will develop, nothing before has stimulated the need more than the environmental concerns of today.
Last edited by Fl1ingfrog; 25th Apr 2022 at 20:51.
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Without major advances in battery technology which is unlikely to happen soon the energy/weight factor makes practical endurance/range aircraft impractical.
Hydrogen is a lot more promising but will need a very expensive refueling infrastructure. There are also questions about carbon neutral production of hydrogen, this would need a lot of green electricity.
There is a lot of work going on to solve the problems, my best guess is that light aircraft will use electric motors powered by hydrogen fuel cells.
All of this is unlikely to happen very quickly for light aircraft which have a service life of 40+ years so there will be no rush to replace these expensive assets with new technology. Avgas will be with us for decades more.
Hydrogen is a lot more promising but will need a very expensive refueling infrastructure. There are also questions about carbon neutral production of hydrogen, this would need a lot of green electricity.
There is a lot of work going on to solve the problems, my best guess is that light aircraft will use electric motors powered by hydrogen fuel cells.
All of this is unlikely to happen very quickly for light aircraft which have a service life of 40+ years so there will be no rush to replace these expensive assets with new technology. Avgas will be with us for decades more.
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Avgas will be with us for decades more.
Having passed my three score years and ten little to nothing of the past feels that far away. I bought my first mobile in 1992. I say bought but you rarely did because they cost then £2000 or $3000 dollars so you rented on a lengthy contract. The phone was the size of a ladies handbag. the battery would hardly last more than a couple of hours of use so I had four. Each battery was the size of a machine gun cartridge. The telephone did one thing: make and receive telephone calls. Today, my mobile slips into my shirt breast pocket and has the facility of a powerful computer. The battery is tiny and will last all day if not two. There is very little it can't do including being a high definition camera and act as a comprehensive GPS; both for aviation and with road moving charts/maps for navigation. For road use the software can be free with apps such as Waze. All this is for a few hundred pounds.
So, for me, 20 - 30 years ahead is no time at all, its if it was tomorrow. Avgas is already struggling to survive as petrol is required less and and in some parts of the world impossible to buy. It may not be the case that Avgas is only expensive then, in the foreseeable future, but it could prove difficult to obtain irrespective of price. Mineral oils already are only available because of the total loss demand of the food processing industry. Oil producers don't see their future in petroleum products. They would stop making avgas and mineral oils tomorrow if they could.
So, for me, 20 - 30 years ahead is no time at all, its if it was tomorrow. Avgas is already struggling to survive as petrol is required less and and in some parts of the world impossible to buy. It may not be the case that Avgas is only expensive then, in the foreseeable future, but it could prove difficult to obtain irrespective of price. Mineral oils already are only available because of the total loss demand of the food processing industry. Oil producers don't see their future in petroleum products. They would stop making avgas and mineral oils tomorrow if they could.
Last edited by Fl1ingfrog; 26th Apr 2022 at 16:47.
Avgas will be with us for decades more.
Energy density does not necessarily = danger
"Avgas will be with us for decades more."
Who are "us"? There is talk of big oil/gas development by Eastern nation organisations in the Kurile Islands region. Not everyone is going "carbon neutral".
Who are "us"? There is talk of big oil/gas development by Eastern nation organisations in the Kurile Islands region. Not everyone is going "carbon neutral".
Published in Avweb today;"Diamond Aircraft says the electrified version of its DA40 single will have up to a 90-minute endurance and charge time of 20 minutes. The company announced on Wednesday it has chosen Safran’s ENGINeUS electric motor to power the eDA40. “With Safran we are having an expert partner for electric propulsion systems aboard,” said Liqun (Frank) Zhang, CEO, Diamond Aircraft Industries Austria. “The smart motor’s state-of-the-art technology including smart features paired with a well-advanced certification process is the logical choice for our eDA40. We are looking forward to the first flights scheduled for end 2022.”
Diamond announced the program last October. The aircraft is aimed at the training market and Diamond is predicting a 40 percent decrease in operating costs for flight schools. The 90-minute endurance likely won’t be achieved immediately but will be possible as battery technology evolves. Diamond is predicting certification for the motor by mid-2023 and basic EASA certification of the aircraft in late 2023 or early 2024."
So perhaps we won't be waiting as long some doubters believe
Diamond announced the program last October. The aircraft is aimed at the training market and Diamond is predicting a 40 percent decrease in operating costs for flight schools. The 90-minute endurance likely won’t be achieved immediately but will be possible as battery technology evolves. Diamond is predicting certification for the motor by mid-2023 and basic EASA certification of the aircraft in late 2023 or early 2024."
So perhaps we won't be waiting as long some doubters believe
There are totally new aspects to think about, battery health one of the most prominent. Like charging software, charging power used and peak power use, battery temperature, environmental temperatures in cruise flight, battery aging. It will take a while until this is good enough for Joe public.
There are totally new aspects to think about, battery health one of the most prominent. Like charging software, charging power used and peak power use, battery temperature, environmental temperatures in cruise flight, battery aging. It will take a while until this is good enough for Joe public.
So perhaps we won't be waiting as long some doubters believe
Last edited by Jan Olieslagers; 4th May 2022 at 17:26.
To me it seems rather that we will wait longer than some hopers believe. Especially in the very conservative environment of aviation in general, and private aviation in particular.
Massachusetts-based commuter airline Cape Air has signed a letter of intent (LOI) with Eviation for the purchase of 75 all-electric Alice aircraft. The terms of the agreement have not been made public. As previously reported by AVweb, Eviation announced in June 2019 that Cape Air would be its first commercial customer for the aircraft, which is still in development.
“Truly sustainable aviation not only reduces the impact of air travel on the environment but also makes business sense,” said Jessica Pruss, Eviation vice president of sales. “We are proud to support Cape Air, a recognized leader in regional air travel, to chart a new path in delivering innovative solutions that benefit airline operators, passengers, communities and society.”
Cape Air currently flies more than 400 flights a day to locations in the Northeast, Midwest, Montana and the Caribbean. According to Eviation, the Alice will have a top cruise speed of 250 knots, maximum payload of 2,500 pounds and single-charge range of 440 NM. The aircraft will seat nine passengers and two crew members and is powered by the magniX magni650 electric propulsion unit. Eviation noted last February amidst a leadership change that it was expecting to fly the Alice for the first time “in the upcoming weeks.”
This company thinks differently:
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Today's Telegraph has a piece on the Sherwood E Kub having flown for a thirty-minute flight over Norfolk.. .. smart looking aircraft, except for the upside-down depiction of the Union Jack.:</
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Sherwood E Kub having flown for a thirty-minute flight over Norfolk
Fossil fuels are not dead. The post globalisation world will see to that. By the time legacy fossil fuels are getting difficult to extract there will be a range of synthetic liquid fuels on the market. Crude oil can be made from algae, or from thin air. Liquid hydrocarbon fuels and internal combustion engines will be around for a very long time.