City-Data Forum Lots of new Hydrogen powered cars coming to market, all with the same drawback (pollution, wind turbine)
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10-31-2014, 09:27 AM
 Location: Pikesville, MD 5,229 posts, read 11,929,893 times Reputation: 4846

People don't know the physics that yields hydrogen inferior to electric cars. When you extrapolate hydrogen from water through electrolysis you lose a lot of energy in the process. And you need about 10,000 liters of hydrogen at atmospheric pressure to generate the same energy as one gallon of gas (Gas Gallon Equivalent). People who are excited about those HHO cells used to "improve" gas mileage that can yield a few liters per minute should start being real about this. When comparing electricity input to wheel energy output efficiency, an electric car is around twice as effective as a hydrogen powered car. Besides, a hydrogen powered car still needs a battery to drive peak loads of the motor. The primary reason a Tesla Model S P85 can accelerate from 0-60mph in 4.2 seconds is that the battery can output above the 416hp or 310,000 Watts of electricity for these few seconds. No fuel cell for any reasonable amount of money can make such peak energy output. For example, the maximum output of any vehicle fuel cells from Balard is 21,000 Watts or only 7% of what a Model S P85 needs! Thus, you might be able to power your car from a fuel cell while not accelerating, but the more sports acceleration performance you want from it, the more battery capacity (= horsepower in the end) you need. In fact, you can easily calculate that the 416hp of a Tesla Model S turns into an output of each tiny Panasonic 18650 Lithium cells (7000 or so of them) to be above 40 Watts. That's a lot of peak power from such small battery cell by the way.

Thus, if you want a hydrogen powered car to be as fast as a Tesla Model S P85...GUESS WHAT? You either need a large battery with a high peak power output or a huge fuel cell that in both cases will ruin the economics.

Besides, every mile of driving ends up costing twice as much in your hydrogen powered car, so what is the real point?
And worst of it is that when people get spoiled about not wasting time at the pump anymore and can just leave home with the car fully charged and range is a non-issue, who the heck will want hydrogen? Freaking waste of time to drive to hydrogen stations...that aren't even there now or in any near future anyway.

And now battery technology is in development that will be more durable than the car, so the problem of battery wear during the life of a car is likely also going away.

10-31-2014, 12:20 PM
 Location: SC 2,967 posts, read 4,172,290 times Reputation: 6825
These cars will never take off until the cost of the replacement batteries/cells/components goes low enough. They are a waste of money when costs of replacement parts swallows up any potential savings that were expected to be gained.

10-31-2014, 12:51 PM
 Location: Volcano 12,971 posts, read 23,565,150 times Reputation: 10574
Quote:
 Originally Posted by Merc63 People don't know the physics that yields hydrogen inferior to electric cars. .
I agree with most of what you say, and Elon Musk famously said "Hydrogen's energy density is crap!"

I am keeping an open mind on the subject, however, because I think it will be a horse race for a while, and there are major government forces at play, especially in Japan. Besides, the market is unpredictable. People like or dislike things, buy or don't buy, based on factors that are often unknowable in advance. Remember when the number of cupholders in a car was a key parameter?

Yes, the HFCEVs are generally not going to be the screamers that EVs can be (The new Tesla SD does 0 - 60 mph in 3.6 seconds... in a five seat, four door family sedan!) but the Hyundai range of 369 miles is 30% better than the Tesla, and that will be of prime importance to some buyers.

We shall see...

10-31-2014, 12:53 PM
 Location: Volcano 12,971 posts, read 23,565,150 times Reputation: 10574
Quote:
 Originally Posted by Bmachina These cars will never take off until the cost of the replacement batteries/cells/components goes low enough. They are a waste of money when costs of replacement parts swallows up any potential savings that were expected to be gained.
I'm always amused to see what people focus on when knocking something new, and I've learned that use of the word "never" often invalidates the prediction, especially when used in connection with high tech development...

10-31-2014, 01:09 PM
 Location: SC 2,967 posts, read 4,172,290 times Reputation: 6825
Quote:
 Originally Posted by OpenD I'm always amused to see what people focus on when knocking something new, and I've learned that use of the word "never" often invalidates the prediction, especially when used in connection with high tech development...
The technology has been around for a long time. I never really had an opinion on it; I'm just quoting what I have been told, coming from a family of automotive engineers who are actually making the cars we drive. This is their informed opinion. Not one of the auto engineers in my family will drive a hybrid, or any other unconventional car at this point in time.

Personally, I am all for alternative vehicles. The faster we can loosen our dependency on oil, the better, but our country is being run by business men who are vested in making sure we are strapped to oil indefinitely.

Also, I did not state "never" across the board. The word never was followed by the word "until."
Quote:
 cars will never take off until the cost of the replacement batteries/cells/components goes low enough.

10-31-2014, 01:31 PM
 12,973 posts, read 12,754,191 times Reputation: 5419
There are all sorts of technical variations possible as this develops. The efficiency and cost of PV systems alone can change the outcome over a large range. A factor of two in cost and two in efficiency and suddenly local generation of hydrogen as a home and car fuel storage media may become feasible.

Numbers that good or better may be in the cards for the next ten or fifteen years. And hydrogen does not have to go head to head with battery. It simply needs to get low enough in cost that it is not an issue.

It would appear clear that one could do the calculation as to what various PV and hydrogen costs would do to the cost of the overall system.

The need for battery banks in hydrogen fueled vehicles has always been clear. The fuel cell is simply not a peaking source. It needs to run smoothly at close to an optimum operating point. That, and regeneration makes a battery bank a certainty. The size of that bank may well be a variable, likely marketed heavily, for its impact on performance.

I have been quite interested in the overall efficiency of a hydrogen power system from input electricity to delivered electricity. Anyone ever see such numbers.

10-31-2014, 02:15 PM
 Location: Pikesville, MD 5,229 posts, read 11,929,893 times Reputation: 4846
Quote:
 Originally Posted by OpenD Yes, the HFCEVs are generally not going to be the screamers that EVs can be (The new Tesla SD does 0 - 60 mph in 3.6 seconds... in a five seat, four door family sedan!) but the Hyundai range of 369 miles is 30% better than the Tesla, and that will be of prime importance to some buyers. We shall see...
That Hyundai range won't matter if there's no hydrogen refueling station when you reach the end of the range. You'll be as screwed as if you are going off in a non-Supercharger networrk direction in a Tesla...

What really needs to happen is that people realistically view their day to day travel habits and realize that starting every day out with a full tank from being plugged in at home will take care of 99% of their day to day use even in a 60-100 mile range vehicle.

10-31-2014, 02:54 PM
 2,004 posts, read 1,201,719 times Reputation: 2909
What needs to happen is that alternatives to gasoline need to become as convenient to use as gasoline. The best way to get people to accept and use something is to make it so that they don't have to change what they do. Unless I'm willing to make caring about the environment my first priority or the alternatives to gasoline offer me some huge benefit then I'm going to keep using gas. Parity isn't really enough if the cars cost more.

10-31-2014, 03:34 PM
 Location: Volcano 12,971 posts, read 23,565,150 times Reputation: 10574
Quote:
 Originally Posted by Year2525 What needs to happen is that alternatives to gasoline need to become as convenient to use as gasoline. The best way to get people to accept and use something is to make it so that they don't have to change what they do. Unless I'm willing to make caring about the environment my first priority or the alternatives to gasoline offer me some huge benefit then I'm going to keep using gas. Parity isn't really enough if the cars cost more.
Let me correct that for you...

Quote:
 "What needs to happen for some people is that alternatives to gasoline need to become as convenient to use as gasoline."
Simply stated, people are already buying cars that don't fit the old gas buggy paradigm. In the US 100,000 EVs were sold last year, and another 100,000 will be sold this year, and planned production will go up next year. And many of those have under 100 mile ranges.

This is where I find most of the criticism of new car technologies falls short, when it fails to take into account that there are dozens of different niches that different cars fill, many that don't fit the critic's personal preferences, so there is no single parameter that can be used to predict the success or failure of a vehicle type. None. It's far more complicated than that.

10-31-2014, 03:45 PM
 2,004 posts, read 1,201,719 times Reputation: 2909
Please don't correct my opinion, that is rude. If I make a mistake in facts then by all means and I'll appreciate it. Otherwise, I'll kindly ask you not to correct my opinions, they are mine to state.
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