taycan_sportturismo
Well-Known Member
A common misconception about H2 is how safe it is (or isn't). Since it's such a light gas, it dissipates extremely quickly. It's only when there is a concentration of hydrogen in an enclosed area that the issue of ignition becomes significant. Otherwise, hydrogen doesn't behave as sensitively as most people would believe.H2 is a fossil fuel play - with similar emissions - just shifted to the refining process from the consumption process…
the most abundant and efficient source for H2 is NOT water (it’s too expensive and chemically stable) - rather you use hydro-carbons (barrels of oil or methane/Natural Gas) - and you strip the Hydrogen from the hydro-carbon chains to “mine” H2…
the over all efficiency for this is low and the amount of electricity consumed is vast…electricity better used directly…
commercial scale H2 has like a 19% overall efficiency - start with 100 kWh of pure electricity - and you end up getting to use about 19% of the original 100 kwh to actually move a vehicle - vs. 65% or better for a BEV
I’d rather just keep the existing fossil fuel plays in place since they are a proven and evolved technology and the overall emissions are about hte same - also over time if some portion of the transportation industry transitions to BEV’s - then the remaining fossil fuel commercial vehicles remain but we make progress on the overall goal...
also H2 is extremely tricky/nasty to deal with and quite volatile - safe/effective/consumer-grade H2 fueling systems are elusive - and given that H2 reacts directly (and poorly) with normal air - the chances for embarassing interactions (i.e. consumers going ’boom’ during fueling) is actually quite high…
I remain dubious as to H2’s practical and scaled usage in future world transportation systems - but I welcome being proven wrong - but my bet is on better battery tech making this all quite irrelevant - a modest increase (foreseeable given current research results) in battery power densities and we’re looking at 600-750 lbs 150 kWh batteries - once you break the 800 lbs barrier for about 150 kWh of stored power that’s a game changer - because that means your BEV is now lighter than it’s equivalent ICE vehicle - with all the advantages of the EV - picture if the Taycan had all the power it has today - but was 500 lbs lighter than the Panamera - cause if you can do 150 kWh for 800 lbs worth of battery pack - we can do 75 kWh for 400 lbs battery pack
now things get really really interesting - and we’re not that far off…once you can go lighter you can either scale the pack up _OR_ down - and given lighter you need less kWh to go same distance…so it gets very very interesting.
It is true that although hydrogen is the most abundant, it is very rare that it occurs by itself. And right now, Steam Methane Reforming is currently the most efficient way to generate Hydrogen gas. But it is not only 19% efficient. Most sources say 25-35% (but that's not anything to brag at, especially considering 65+% for BEVs). Again, I believe there's a way to achieve efficiency parity with BEVs, but we have to simplify the Hydrogen production process to get even close.
As for battery weights and total energy density, that's awesome that we're on track to reach such levels. But how quickly can we reach those levels? Batteries still have to go through the same development and testing process to make sure they're safe and reliable.
And one thing I want to throw out there is the issue of dealing with batteries after we have used them. One option is stationary power, but we have not found a sure-fire way of recycling them efficiently. The goal here for alternate fuels is to reduce our total carbon footprint, so we have to think of the entire picture. Other than their membranes, fuel cells are easily recyclable and won't contribute to end-of-life issues like batteries might.
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