EV owner here. Why would I want to drive to a fueling station when I can fuel up at home with electricity? And from a maintenance level, ev’s have substantially fewer parts and almost zero maintenance, whereas hydrogen perpetuates the ICE-engine paradigm... frequent oil changes, many moving parts, lots of service costs at the dealership. The economics of H2 may be different at the commercial scale, but we use a Chevy Bolt in a far northern climate and get nearly 200 miles of range in the winter. The future is already here, and H2 missed the consumer vehicle bandwagon.
After many false starts, hydrogen power might now bear fruit
131–140 of 343 posts
Re: After many false starts, hydrogen power might now bear fruit
#132Hydrogen has an efficiency problem. You need to convert other forms of energy to hydrogen at a loss. Then you need to store it and transport it, which is costly and may impose quite some energy cost for cooling or compression. Then you need to convert it back to electricity, also at a loss. If you start at electricity, the electrical grid and batteries would be much more efficient. If you start at oil or gas, you cou…
I like this diagram from Volkswagen visualizing the energy loss at every step for hydrogen versus BEV: https://images.hgmsites.net/lrg/hydrogen-vs-electric--volksw... This image (don't know the source), which includes oil and coal, is also a good visualization: https://i.imgur.com/Wuhnlvu.png Even simpler: https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg
I would like to have seen more elaboration on transmission losses in the power grid. For example, if we imagine solar cells in Sahara generating energy for Europe, is power grid transmission feasible or does hydrogen look better in comparison?
Re: After many false starts, hydrogen power might now bear fruit
#133Earlier quoted context omitted.
Electricity has a transmission problem though - there are some parts of the world with lots of clean energy, which we can't fully take advantage of because we can't transport electricity that far. Hydrogen allows us to use that clean energy to power cars in other parts of the world, since you can produce hydrogen in those places and then ship it to places without much clean energy. Also you can presumably stop and st…
Do you know more about hydrogen transport? I heard it is quite more complicated and expensive than LNG (closest equivalent), because hydrogen leaks more easily.
I don't buy that hydrogen transport could ever be more efficient than shipping high-voltage electrons over copper.
Re: After many false starts, hydrogen power might now bear fruit
#134Earlier quoted context omitted.
Feedstock is the problem here: there's simply not enough net primary productivity on the planet, and humans already appropriate ~20%. There are some marginal gains possible, but on the order of single-digit percentages of present fossil fuel consumption. Maybe low double-digits. The US had a largely biofuel based transport system in 1900. Horses consumed 20% of all US grain production, the population was under 100m,…
According to the U.S. Department of Agriculture, the U.S. has 434,164,946 acres of “cropland”—land that is able to be worked in an industrial fashion (monoculture). This is the prime, level, and generally deep agricultural soil. In addition to cropland, the U.S. has 939,279,056 acres of “farmland.” This land is also good for agriculture, but it’s not as level and the soil not as deep. Additionally, there is a vast am…
US oil consumption for transportation was 14.16 million barrels per day (595 million gallons per day) in 2018:
https://www.eia.gov/energyexplained/oil-and-petroleum-produc...
That's 595,000,000 * 365 = 217,175,000,000 gallons per year of oil.
Using 100% of cropland producing at 369 gallons of ethanol/acre gives
434,164,946 * 369 = 160,206,865,074 gallons per year of ethanol.
That's only 74% as many gallons as oil consumption.
It's actually much worse than that, because the energy content of a gallon of ethanol is only about 65% the energy content of a gallon of oil:
https://en.wikipedia.org/wiki/Energy_density#Tables_of_energ...
This much ethanol would only provide 48% of the energy currently consumed by oil based transportation.
It's actually much worse than that because most crop land is already used to grow crops eaten by animals and people. If we feed all the crops to transportation machinery, others will go hungry.
Re: After many false starts, hydrogen power might now bear fruit
#135Following Musk's thinking... i'd really like to see that energy density volume vs mass chart adjusted for average vehicle weight. i.e see the total system, engine, storage components and fuel converter etc. On that graph, compared to petrol, liquid hydrogen appears to be about 4x larger by volume but interestingly only 2/5ths of the weight. The electric motors are lighter sure, but then what about the mass and volume…
Not once you include the storage tanks.
That's my entire point.
Re: After many false starts, hydrogen power might now bear fruit
#136I've been diving into this literature a bit recently, and it's been mostly encouraging. Affordable clean energy is realistic. Clean energy sources are typically the cheapest sources of energy [0]. The intermittent production issue is solvable: At ~150 $/kWh storage, a combination of storage and renewables is the cheapest energy source 95% of the time [1]. The cost of different energy storage methods is coming down ex…
I've read about a couple of solar projects that projected x/kWh and turned out to be much worse in production. Pakistan's big deployment is one example, it was planned to be 100MW but only produced 18MW. Mostly because they didn't factor in the dust that would cover the panels, keeping them clean was very expensive (I'm curious how this applies to other proposed desert deployments). Nor factoring in the typical malai…
Solyndra's failure had nothing to do with technology at all. They failed because Chinese manufacturers undercut them in price, quite severely. Allegations of dumping (or fraud, on the other side) notwithstanding, what this says is that solar is actually much cheaper and more readily available than Solyndra's investors expected. And that's sort of the opposite of your point, no?
Similarly the Tesla plant is doing exactly what it said it was going to do, when it was supposed to be finished, within the budget it had, and AFAIK is making money. You're asserting that it can't scale because it... worked?!
As far as the Pakistani misdesign, yeah, I'm sure that's going to happen too. Nothing works perfectly.
Nonetheless this seems like a pretty oddly constructed list of reasons why solar is "much worse in production". It seems to my eyes like it's doing much better than expected.
Re: After many false starts, hydrogen power might now bear fruit
#137Earlier quoted context omitted.
Transporting hydrogen is expensive. It also has a tendency to leak.
> It also has a tendency to leak. But I mean, that has to be a limitation of current technology, right? There has to be engineering solutions that we can devise to make it as safe statistically as for example gasoline transport?
Safe probably yes. Economically competitive is much harder.
Re: After many false starts, hydrogen power might now bear fruit
#138Hydrogen has an efficiency problem. You need to convert other forms of energy to hydrogen at a loss. Then you need to store it and transport it, which is costly and may impose quite some energy cost for cooling or compression. Then you need to convert it back to electricity, also at a loss. If you start at electricity, the electrical grid and batteries would be much more efficient. If you start at oil or gas, you cou…
I like this diagram from Volkswagen visualizing the energy loss at every step for hydrogen versus BEV: https://images.hgmsites.net/lrg/hydrogen-vs-electric--volksw... This image (don't know the source), which includes oil and coal, is also a good visualization: https://i.imgur.com/Wuhnlvu.png Even simpler: https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg
With regard to https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg
if the capture and separate elements can be decentralized,
then distribution and one storage phase are eliminated.
In other words, if a refueling station can do solar or wind capture and electrolysis on-site, the economics are better. This would be unlikely for stations in urban or high-density areas, but for rural and suburban locations it might be a win.
Re: After many false starts, hydrogen power might now bear fruit
#139Earlier quoted context omitted.
isn't methane much worse for the environment than generating power from hydrogren?
It depend where the (carbon in the) methane comes from. If it comes from the ground, the exhaust contributes to global climate disruption. Venting methane is worse, but that would be wasteful, too.
It also depends where the hydrogen comes from. If you produce it from water, your byproducts are oxygen. If you produce it from methane, your byproducts are carbon dioxide. Issue is that water has 2 hydrogens and methane has 4, so typically it is produced by using methane.
Re: After many false starts, hydrogen power might now bear fruit
#140I've been diving into this literature a bit recently, and it's been mostly encouraging. Affordable clean energy is realistic. Clean energy sources are typically the cheapest sources of energy [0]. The intermittent production issue is solvable: At ~150 $/kWh storage, a combination of storage and renewables is the cheapest energy source 95% of the time [1]. The cost of different energy storage methods is coming down ex…
I've read about a couple of solar projects that projected x/kWh and turned out to be much worse in production. Pakistan's big deployment is one example, it was planned to be 100MW but only produced 18MW. Mostly because they didn't factor in the dust that would cover the panels, keeping them clean was very expensive (I'm curious how this applies to other proposed desert deployments). Nor factoring in the typical malai…
Tesla's Australian battery was not for storage, it's for power quality.