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Electric Cessna Caravan


Al Czervik
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Every enthusiast loves to talk about using electricity (with batteries) vs petroleum. It’s green! But when asked about total carbon footprint, answers are illusive.

How is the electricity generated which is used to charge the batteries? Wind? Solar? Hydro? Nuclear? Coal?

If one wheels a petroleum burning internal combustion powered generator out onto the tarmac to recharge those batteries doesn’t that defeat the purpose?

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1 hour ago, railfancwb said:

Every enthusiast loves to talk about using electricity (with batteries) vs petroleum. It’s green! But when asked about total carbon footprint, answers are illusive.

How is the electricity generated which is used to charge the batteries? Wind? Solar? Hydro? Nuclear? Coal?

If one wheels a petroleum burning internal combustion powered generator out onto the tarmac to recharge those batteries doesn’t that defeat the purpose?

Not to mention all the energy used during the mining and processing in order to manufacture the batteries in the first place.  

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1 hour ago, willie-pete said:

Well, at least you can't pump AvGas in it instead of Jet-A or vice versa.

 

:whistling:

No hot starts, hot sections, etc.  It will be interesting to see what the operating costs will be compared to versus the PT6 power over the course of the power plant life and what the range will eventually be.

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For the life of me, I cannot figure out why we're not doing proper hybrids, like diesel/electric locomotive engines and ship engines. Where a smallish ICE powers a generator that keeps the batteries charged. 

That is actually efficient, and therefore "green". That stupid plane is nothing but a marketing exercise.

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5 minutes ago, M&P15T said:

For the life of me, I cannot figure out why we're not doing proper hybrids, like diesel/electric locomotive engines and ship engines. Where a smallish ICE powers a generator that keeps the batteries charged. 

That is actually efficient, and therefore "green". That stupid plane is nothing but a marketing exercise.

I run train for a living

that diesel is 16 cylinders, an oil drum of lubricant, 4000 to 5500 gallons of fuel.

green, they are not

 

now the dynamic brake system that charges the batteries As you slow down. That has promise for cars if it can be regulated through the brake pedal and feel like normal

 

.

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1 hour ago, Al Czervik said:

No hot starts, hot sections, etc.  It will be interesting to see what the operating costs will be compared to versus the PT6 power over the course of the power plant life and what the range will eventually be.

My first thought was

how long before the batteries need to be changed?

 Let alone the oil and lube needed for the moving parts like prop, shaft, wheels, etc

I don’t think it’s quite as green as portrayed

 

.

 

.

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3 minutes ago, Dric902 said:

I run train for a living

that diesel is 16 cylinders, an oil drum of lubricant, 4000 to 5500 gallons of fuel.

green, they are not

 

now the dynamic brake system that charges the batteries As you slow down. That has promise for cars if it can be regulated through the brake pedal and feel like normal

 

.

Just talking about the concept, not the specifics of a train. By "green" I meant efficient. "Green" is a stupid, PC description, "efficient" should replace it.

Regenerative braking for electric/hybrid vehicles has been a thing for quite some time now. Evidently they have it working decently well in regards to pedal feel.

Edited by M&P15T
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1 minute ago, M&P15T said:

Just talking about the concept, not the specifics of a train. By "green" I meant efficient.

Regenerative braking for electric/hybrid vehicles has been a thing for quite some time now. Evidently they have it working decently well in regards to pedal feel.

The system used in vehicles is gridless. And are partially efficient, but not economically so.

an excellent area for development 

 

.

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4 minutes ago, Dric902 said:

The system used in vehicles is gridless. And are partially efficient, but not economically so.

an excellent area for development 

 

.

Can you explain "gridless" for me? Sounds interesting.

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6 minutes ago, M&P15T said:

Just talking about the concept, not the specifics of a train. By "green" I meant efficient. "Green" is a stupid, PC description, "efficient" should replace it.

Regenerative braking for electric/hybrid vehicles has been a thing for quite some time now. Evidently they have it working decently well in regards to pedal feel.

The word 'efficient" does not fit well with "green".

Look at emissions controls on modern vehicles. If you really look at how most of them work you will see that they introduce inefficiency into what would otherwise be an efficient means of powering a vehicle.

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12 minutes ago, Dric902 said:

The system used in vehicles is gridless. And are partially efficient, but not economically so.

an excellent area for development 

 

Gridless when you talk about in flight regeneration, but as soon as you park and plug in to charge the batteries, you are on the grid.

There is also a huge load on the grid during production. How many real girdless miles does it take to offset that?

I do agree that there is potential for some significant developments, but those will come about slowly.

Edited by jmohme
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23 minutes ago, Dric902 said:

I run train for a living

that diesel is 16 cylinders, an oil drum of lubricant, 4000 to 5500 gallons of fuel.

green, they are not

Perhaps its my memory.  But would you mind explaining to us...how you managed into such an interesting line of work?

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1 minute ago, jmohme said:

The word 'efficient" does not fit well with "green".

Look at emissions controls on modern vehicles. If you really look at how most of them work you will see that they introduce inefficiency into what would otherwise be an efficient means of powering a vehicle.

Yes, that's exactly what I'm saying, but in reverse. Green doesn't mean efficient, and efficiency is the real need. Green is just a PC term.

I'll argue on modern emissions controls. I believe (feel free to correct me if I'm wrong) that other than catalytic converters, there's not much in the way of emissions controls (like in the 1970s, 80s and 90s) on vehicles anymore. Rather, modern vehicles have such amazingly well orchestrated combustion, due to precisely controlled variable valve and ignition timing (amongst other things, I'm sure), that the particulates left after combustion are incredibly clean. SAAB really started all of that, with their Trionic Engine Management systems back in the day. If their cars were driven in smoggy cities like L.A., what came out of the tail pipe was cleaner than what went into the intake system.

As much as I hate to say it, the draconian emissions regulations really did push engineers to create cleaner running ICEs. Since really clean running engines are also really efficient running engines, we're seeing amazing power to displacement engines that are efficient, powerful, and clean running. Turbo engines are really showing how they can combine power and torque, with clean running and high efficiency, exceptionally well. Better than naturally aspirated engines by and large.

 

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1 hour ago, M&P15T said:

Yes, that's exactly what I'm saying, but in reverse. Green doesn't mean efficient, and efficiency is the real need. Green is just a PC term.

I'll argue on modern emissions controls. I believe (feel free to correct me if I'm wrong) that other than catalytic converters, there's not much in the way of emissions controls (like in the 1970s, 80s and 90s) on vehicles anymore. Rather, modern vehicles have such amazingly well orchestrated combustion, due to precisely controlled variable valve and ignition timing (amongst other things, I'm sure), that the particulates left after combustion are incredibly clean. SAAB really started all of that, with their Trionic Engine Management systems back in the day. If their cars were driven in smoggy cities like L.A., what came out of the tail pipe was cleaner than what went into the intake system.

As much as I hate to say it, the draconian emissions regulations really did push engineers to create cleaner running ICEs. Since really clean running engines are also really efficient running engines, we're seeing amazing power to displacement engines that are efficient, powerful, and clean running. Turbo engines are really showing how they can combine power and torque, with clean running and high efficiency, exceptionally well. Better than naturally aspirated engines by and large.

 

I should have been more specific in my statements. 

My experience is almost entirely in the Diesel truck and equipment arenas, and even there, my info is pretty dated as I got out of that business about 8 years ago.

As far as the push for emissions control driving the advancements in engine technology, I do not agree. It may have accelerated it, but I firmly believe that we would have reached this point or beyond with or without the EPA.

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1 hour ago, Dric902 said:

My first thought was

how long before the batteries need to be changed?

 Let alone the oil and lube needed for the moving parts like prop, shaft, wheels, etc

I don’t think it’s quite as green as portrayed

 

.

 

.

My real interest is just in power plant operating costs.  For example, the Caravan's power plant is around a million dollars.  The midlife hot section (around 1800 hours) is around $40k.  Overhaul (3600 hours) is around half a million.  Then, there are cycle-limited parts, and parts and labor for some knucklehead not paying attention and allowing a hot start, etc.

The numbers for the electric power plant will have to solidly beat the ol'PT-6's numbers for it to be a viable competitor, because it's range , at present, stinks.  Then, there are required reserve times.

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7 minutes ago, jmohme said:

As far as the push for emissions control driving the advancements in engine technology, I do not agree. It may have accelerated it, but I firmly believe that we would have reached this point or beyond with or without the EPA.

Yeah, I'd agree it accelerated it. Certainly. If we would be where we're at today with the EPA's mandates?.......tough to say. It is a Golden Automotive Age right now. The 60s got nothing on right now.

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4 minutes ago, Al Czervik said:

My real interest is just in power plant operating costs.  For example, the Caravan's power plant is around a million dollars.  The midlife hot section (around 1800 hours) is around $40k.  Overhaul (3600 hours) is around half a million.  Then, there are cycle-limited parts, and parts and labor for some knucklehead not paying attention and allowing a hot start, etc.

The numbers for the electric power plant will have to solidly beat the ol'PT-6's numbers for it to be a viable competitor, because it's range , at present, stinks.  Then, there are required reserve times.

These are the facts that have to be forced out of the "green" crowd.

It has been one of my biggest gripes since the first Hybrids hit the street. The intentional omission of underlying facts. Everything from hidden costs, to the methods of depleted battery disposal and recycling, to safety concerns. You have to push hard to get answers and even then, you had better research those answer for accuracy.

Don't take this the wrong way, I actually support the ongoing development of electric and other alternative fuels. But there needs to be full disclosure of more than just the misrepresented feel good advantages of electric.

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11 minutes ago, jmohme said:

.......to safety concerns......

I don't think folks realize the safety issues of electric vehicles in an accident. In this area, a Tesla in an accident is a huge, traffic stopping, massive FD call-out situation that snarls traffic for hours.

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On 5/29/2020 at 12:11 PM, M&P15T said:

Yeah, I'd agree it accelerated it. Certainly. If we would be where we're at today with the EPA's mandates?.......tough to say. It is a Golden Automotive Age right now. The 60s got nothing on right now.

When the diesel industry first entered the electronic engine control era, the EPA was barely paying attention. The electronically controlled fuel injection was a game changer in many ways. Increased fuel efficiency, longer service intervals, and much longer engine life. This without government mandates

When I retired, the EPA had stepped into the diesel arena in a big way. At that time, most engines had lost so much efficiency that 10% increase in fuel consumption over previous engines of similar spec was fairly normal. Lubricating oils were being heavily laden with soot requiring much more frequent oil changes, so there was also much more waste oil to dispose of, and in some industrial applications, engines had to be upgraded because the torque curves were effected negatively where a 300 hp engine had to be bumped to 335 or 350 just to do the same job.

Back to waste oil. I had asked the company that bought our waste oil what they did with it. At that time, it was hauled to the coast in tankers where it was refined into low grade (dirty) diesel fuel to be burned in marine applications off shore where nobody noticed the black exhaust smoke. Kind of give real meaning to the term "smoke and mirrors"

I would hope that in the 8 years since then, that there have been improvements, but I'm out of that game now so do not know.

Edited by jmohme
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