• Repple (she/her)
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    81 year ago

    I like that hydrogen ladder graphic, nice way of communicating things it is good and bad for. I will say though, If we had (or do) invested more in nuclear power, thermochemical production of hydrogen in nuclear plants could bring overall efficiency closer to to that enjoyed by BEVs (by improving power plant efficiency rather than by improving car efficiency) but that’s just a pipe dream at this point.

    • @Eheran
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      21 year ago

      They can not be as efficient as a BEV, even when the hydrogen is produced with 100 % efficiency.

      • Repple (she/her)
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        41 year ago

        That is absolutely true. But if the hydrogen production increases the power plants overall efficiency from 30% to 50% (estimates are in that realm) then the overall efficiency of the system is competitive, since as compared to current nuclear generation the efficiency of the hydrogen production is greater than 100% as we’re using energy that is waste in the current system.

        Of course, using electricity in that model is still more efficient so long as the markets for better uses of hydrogen aren’t saturated, but if we went all in, then it might be possible for it to be the case.

        • @Eheran
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          01 year ago

          30 % efficient power plant? That is low, like… below the level of a stationary diesel engine (generator). A cogenerating power plant is at 60 % and can be as high as 80 % when the thermal energy can be used near the power plant.

          In other words: you are correct when you compare to such an outdated power plant, but since you already have to build new, you need to compare to a new, efficient plant without hydrogen generation.

          Even in the context of nuclear power, 30 % is very low and a new reactor would be at nearly 50 % just for electricity. But with nuclear the hydrogen generation would make sense, but absolutely not for use in fuel cells. Hydrogen is needed everywhere where they currently need to use methane.

          • Repple (she/her)
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            11 year ago

            Wikipedia quotes 30% for diesel generation. https://en.m.wikipedia.org/wiki/Diesel_generator (see typical operating costs)

            According to the EIA, natural gas has the highest efficiency at around 43% as of 2015. Coal, oil, and nuclear plants all fall around 33%, with nuclear keeping a slight lead. https://www.energyandcapital.com/articles/how-efficient-is-nuclear-really-/76858

            Additionally I did specifically say that electricity would still be better for cars unless hydrogen production were such that more suitable uses were fully supplied.

            • @Eheran
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              01 year ago

              Why do you quote a blog that mixes efficiency with other parameters as a source for power plant efficiencies? In any case, you need to compare state of the art plants with each other, not a mixture of up to 70 year old plants with a new plant.

      • @[email protected]
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        fedilink
        21 year ago

        If we assume hydrogen is 100% efficient, the one improvement over battery electric vehicles, is no need for a battery. I know there’s a lot of debate about how recyclable batteries are, but we have limited global resources to produce batteries at scale.

        • @Eheran
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          01 year ago

          They still need a battery, but it can be smaller. But then you need the fuel cell, which is not exactly better in any way. Like super rare metals (Platinum) and less durable.