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Doctorate in Mechanical Engineering, entreprenuer
Interests: diesel and gasoline engines, cars, aircraft, railroads, electric drives
Recent Activity
They do not give an efficiency but based on their numbers and 1 kW/m2 available from sunlight, I calculate that the efficiency is about 2.5 % but who know what their input really was.
More good news for clean base power. Really hope that they can meet the 2026 startup date for the 12 unit Utah Associated Municipal Power Systems facility.
"The Proterra bus will not do 350 miles in winter conditions." Orange County does not much in the way of winter conditions and most transit buses do not need that much range anyway. Note that it took 28 hours for the FC bus to run 350 miles. Also most transit systems do not run much service at night. And Park City, Utah which does have winter conditions seems to be doing just find with their Proterra buses. My comment about half the efficiency was based on the common assumption of using surplus renewable power (which is mostly non-existent) for electrolysis. "They can make H2 at the fueling yard from renewable methane. " Good luck with that. Steam reformation does not scale well. In the Salt Lake City area, we have 5 oil refineries and I believe that they all get the hydrogen they need for the catalytic cracking from a single source. And just where will you get the renewable methane. Most of it is either used at the source or just added to the pipe line. Anyway, you are just using up something that needs to replaced with fossil natural gas.
The Proterra bus will not do 350 miles in winter conditions.
OK, but the engine would not be able to be rebuilt. Maybe, it is cheaper to just replace the engine if it is damaged.
Proterra offers a BEV bus with 350 miles of range. The difference is that the Proterra bus will use half the energy and be considerably cheaper to buy and operate.
"Lots of trucks chug diesel fumes from LA to Ontario, CA. " And 10 fuel cell trucks will not make much of a difference. They would be much better off spending the money on Battery Electric delivery trucks. I think that the battery electric delivery trucks must be close to a financial break even point if they are not there already. Also Cummins offers Battery powered class 8 cabs that are good for about 100 miles with an optional small diesel for hybrid operations if 100 mile range is insufficient. With slightly better batteries, they would be capable of managing the 150 mile range that they claim is need for drayage operations. Of course, much of the drayage operations require less than 100 miles of range.
Both GM and Ford have announced major future electric vehicle projects. GM just announced a 300 million $ addition to their Orion, MI plant and will be building an updated version of the Bolt and another vehicle based on the updated Bolt technology. I assume that these will be 2020 vehicles and GM is supposed to have something like 8 new electric vehicles for the US market by 2022. The future is clearly battery electric.
The other surprising thing about Toyota is how far down they are on technology in general. The only thing they have is hybrid cars but almost no plug-in hybrids and no BEVs. They have a number CVTs but I would consider this out-dated technology. They had an early lead in hybrids but kept the old Nickel Metal Hybrid battery technology far too long.
Gasbag, I was thinking of the 2-unit coal-fired plant in North Valmy, NV but maybe most of the power goes to Nevada and Idaho but of course it is feeding the grid. Apparently Unit 1 is supposed to close this year But Unit 2 is not scheduled to close until 2025. Also, it is apparently used mostly in the summer to meet peak loads. Davemart, Still trying to figure out the true zero emissions comment. I knew that the IPP near Delta, UT was mostly shipping power to CA.
Davemart, Where does this comment come from? Note that if you want true zero emissions, this provides it, whereas you can't get that by plugging in, just offsets. Even if you use zero emission power to create the hydrogen you are just displacing the dirty power that will be used for other purposes and almost all hydrogen is made with steam reforming of methane anyway. One of the problems with hydrogen fuel cells vehicles is that the overall efficiency is about half that of a comparable battery electric vehicle. And while California may have closed all of their coal fired electric generation, they are still buying coal fired electricity from Utah and Nevada and I am one of the down-winders.
SJC, Even, where I live, SLC, UT, delivery trucks rarely drive more than 100 miles. A battery electric delivery truck is much more cost effective and can be charged overnight. You do not need the added expense of fuel cells and hydrogen. Also, 10C batteries are in development, so you can potentially charge the battery in 6 minutes or less.
Fuel Cells-- a solution looking for a problem since 1838.
Davemart I do not dismiss hydrogen. There are a number of important industrial uses for hydrogen. Direct Reduction of Iron may become an important one. On of the major current uses is light fuels from heavy oils. Unfortunately, almost all of of the hydrogen is currently made by steam reformation of natural gas. If excess wind energy ever exists and it was economical to use electrolysis to make hydrogen, this would be a better use of the hydrogen as opposed to try to use it to run fuel cells for transportation.
Brom The RPM is fixed by the engine and in my case the gear ratio. You want to have full power available at takeoff. I will be using a 3 blade propeller. If you want to cut the tip speed, it is possible to add blades and reduce the diameter. In general, adding blades reduces the efficiency slightly so, as always, everything is a trade off. The propeller pitch is also adjustable. In my case, it is only ground adjustable but the Beaver will almost certainly have in flight adjustable pitch. Also, with an electric motor, you have more control over both the torque and the RPM so in flight they will be able to increase the pitch and reduce the RPM. With a seaplane, the important thing is to have enough power to get up on the step or in a planning mode to minimize the water drag. Once they are in cruise mode, they will probably cut the power back to about 55% of takeoff power.
EP Typically, propellers start to make considerable noise at about 0.7 mach so it is common to keep tip speeds of propellers or wind turbine blades below this limit. Some military helicopters run over this limit but are still well below mach 1. In the early 50's Republic built a prototype version of the F-84 with a gas turbine and a supersonic propeller. It made so much noise that it was quickly labeled the Thunder Screech and apparently make people sick 1/2 mile away. The Russian Tu-95 (Bear Bomber) has counter-rotating propellers that can exceed Mach 1 tip speeds and is considered the noisiest plane in existence. For reference I am building a STOL aircraft with a Rotax 914 engine with a max propeller speed of 2385 RPM. With a 75 inch dia propeller, the tip speed is about 0.69 mach but I also have scimitar shaped blades which will delay the onset of noise. Also, at a more common cruise power setting the tip speeds will be about 0.62 mach. I am hoping the plane will be relatively quiet as I am not a fan of noise
SJC Read The efficiency is about 65-70% but there is a note that the process does not scale well. Then you lose about 10% in compression so you are at 58-63% and then 60% for the fuel cell and you have 35-38% at best. Also, you still need to account for transportation losses somewhere. The newer combined cycle gas turbines are about 60% efficient (GE was claiming 62% last year). Even if you lose 10% in transmission, you still have 54% and all the battery stuff cancels out as you need the batteries anyway in a fuel cell vehicle. Hydrogen does not win
Hydrogen has lots of problems. You have to make it, compress it, transport it, and store it and you really cannot store it without some leakage. About the best number I could find for electrolysis efficiency was 79% and a more typical efficiency is 70% or less. By the time you add in compression loss, you are down to 73% at best or more typically ~65% or less. Then with the Fuel cell efficiency of 60% you are down to 39% to 43% and this is without transport. Also with a fuel cell vehicle, you still have to account for the same losses that you would have with a BEV, inverter, motor, and battery inefficiencies.
Not really. You still need to provide the energy to convert the water to H2 and O2 and not matter how good the catalyst is you will still end up using about twice the energy generating H2 and then using it in a fuel cell as just putting it in a battery and using it directly.
Projections that far into the future do not make much sense. In the 1890's people were trying to project how deep the horse manure would be in the streets of America.
It may be a mega trailer in Europe but it is over 8 ft shorter than the common US standard trailer (44.6 ft vs 53 ft) and about 5.5 inches narrower than was is common in the US.
What is the proposed purpose of this engine? Hyper-sonic cruise missiles? Hyper-sonic Transport? Does not seem well suited to space launch as you need some atmosphere for it to work.
What percentage comes from all of the hydrogen that is supposed to be made from excess renewable power? I am guessing that it is zero but this might be a better use for the hydrogen if excess renewable power really does exist. I think that this supposed excess renewable power also could be used to make hydrogen for direct reduction of iron ore to iron without the use of coke.
My question would be if this has any reasonable chance of being cheaper than converting CO2 plus solar to corn or grass and then using fermentation to make ethanol. I would guess not
I suspect that this device is just a platform to test sensors, etc. and that any practical device will have a more practical form factor.