Replies to post #55566 on Plug Power Inc (PLUG)

[Jack_Bolander]

Gary - That's a tough question to answer, because the correct answer is ... It depends ... on many factors. Your question is like asking if all 2.0 litre engines produce the same horsepower.

And why do you mention efficiency ? The decision criteria is economics NOT efficiency. Think Dollars/Cents per mile, and Total cost per mile.

To give you a for instance : The most efficient power plant in Germany never runs, because although it is very efficient, the power it produces costs twice as much as the next best system. And because Germany dispatches power on an economic cost basis, it never runs.

So Amazon, USPS, FedEx weigh which green solution yields the biggest bang for their Buck which in many places is NOT Hydrogen.

[WeTheMarket]

Skitahoe, in mobility applications, hydrogen fuel cells are two times more efficient than gasoline ICE vehicles. Case in point, the Toyota Mirai XLE hydrogen fuel cell car has a 5.6 kg hydrogen fuel tank capacity, and 402 miles range (source https://www.toyota.com/mirai/features/mpg_other_price/3002/3003). One kilogram of hydrogen has the same energy content as 1 gallon of gasoline (0.992 to be precise, source https://h2tools.org/sites/default/files/2017-12/energy_equivalency_calculator.html), so the Toyota Mirai can travel 402 miles on the equivalent of 5.6 gallons of gasoline. No gasoline ICE vehicle comes even close to that performance/efficiency.



2024 Toyota Mirai Fuel Economy and Real-World MPGe (Source https://www.caranddriver.com/toyota/mirai)

There are no published EPA fuel economy estimates for the 2024 Mirai. According to Toyota, the Mirai XLE is good for up to 76 MPGe city and 71 MPGe highway.

[B_B!]

Toyota demonstrates why hydrogen combustion engines are not the answer
FEBRUARY 20, 2024
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Alongside development of hydrogen fuel cell vehicles, Toyota has also been building liquid hydrogen fuelled engines for racing.
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Most of the problems revolve around liquid hydrogen needing to be kept extremely cold, below minus 253 degrees celsius to prevent it vaporising or boiling away.
The fuel pump in Toyota’s prototype vehicle needed to be swapped twice during a twenty four hour race and took three and a half hours each time.
The hydrogen fuel pump wears out quickly and becomes inefficient because oil lubricants cannot be used, otherwise they would contaminate the hydrogen fuel. It is also very difficult to maintain a good seal between the pump components when they are cooled to this extreme temperature.
Even though liquid hydrogen is more energy dense than compressed hydrogen gas, large fuel tanks are required for hydrogen combustion vehicles to have decent range.

The prototype Toyota Corolla was fitted with a 150 L tank and could only drive 65 km between pit stops for refuelling. To illustrate this problem clearly, Jason calculated that a formula 1 race car would need a huge 700 L hydrogen fuel tank to drive roughly the same distance as they do using petrol.
Keeping liquid hydrogen at minus 253 degrees celsius without it vaporising is also problematic for longer periods of time, which is why Toyota developed their prototype specifically for racing where fuel is burned quickly before it can be wasted.

BMW produced a hydrogen combustion vehicle called the BMW Hydrogen 7 between 2005 and 2007. During that time, BMW found it took only 10-12 days for the entire contents of the liquid hydrogen tank to vaporise with the vehicle parked, making it impractical for passenger vehicle use.

Even if these problems with liquid hydrogen could be solved, the overall efficiency of burning hydrogen is wasteful compared with using the same electricity to charge a battery electric vehicle. Overall efficiency for hydrogen combustion engines is similar to petrol and can be as low as 20-40%, whereas electric vehicle efficiency is typically 77%.
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https://thedriven.io/2024/02/20/toyota-demonstrates-why-hydrogen-combustion-engines-are-not-the-answer/


How Do Fuel Cell Electric Vehicles Work Using Hydrogen?
Like all-electric vehicles, fuel cell electric vehicles (FCEVs) use electricity to power an electric motor. In contrast to other electric vehicles, FCEVs produce electricity using a fuel cell powered by hydrogen, rather than drawing electricity from only a battery. During the vehicle design process, the vehicle manufacturer defines the power of the vehicle by the size of the electric motor(s) that receives electric power from the appropriately sized fuel cell and battery combination. Although automakers could design an FCEV with plug-in capabilities to charge the battery, most FCEVs today use the battery for recapturing braking energy, providing extra power during short acceleration events, and to smooth out the power delivered from the fuel cell with the option to idle or turn off the fuel cell during low power needs. The amount of energy stored onboard is determined by the size of the hydrogen fuel tank. This is different from an all-electric vehicle, where the amount of power and energy available are both closely related to the battery's size
https://afdc.energy.gov/vehicles/how-do-fuel-cell-electric-cars-work