Water Powered Cars

[Gunnar]

Toyota’s water-fueled engine could dethrone electric cars

Really? Does anyone here not see the inherent problem with this Idea?

It is very likely and even probable that water powered cars may be cheaper to build and buy, and maintain but how will we obtain the energy to produce the hydrogen? The vast majority of hydrogen on earth is bound to oxygen in the form of water. Toyota's concept is to obtain the hydrogen by splitting water into hydrogen and oxygen via electrolysis and then burning the resulting hydrogen to produce power, which converts it back into water again. Unfortunately, no conversion process can be more than 100% efficient, thus even if we could manage to burn the hydrogen with 100% efficiency (which is thermodynamically impossible), the most power we can produce is barely enough to just replace the hydrogen we used, with nothing left over to do anything else!

Thus, it will always take much more energy to produce all the hydrogen we need than we could possibly obtain by burning it! We would obviously have to use some energy source other than hydrogen fuel to electrolyze enough water to fulfill our energy needs. If we had enough of that other source to produce all the hydrogen we needed, why not use it all directly for our energy needs instead of wastefully converting any of it into hydrogen fuel first?

If we burn fossil fuels to power hydrolysis to obtain hydrogen, we potentially put more greenhouse gases into the air than if we burned the fossil fuels directly for energy, were it not for the fact that central power plants generally burn the fuel more efficiently than motor vehicles.

Despite conservative and fossil fuel company self-serving lies to the contrary, renewable energy sources such as wind turbines, solar and hydro-electric power are already competitive with and even cheaper than fossil fuel energy, and certainly better for our environment and health.

https://solartechonline.com/blog/is-ren ... -analysis/

Key Insights
Renewable Energy Achieves Cost Dominance: With 81% of renewable projects now producing electricity cheaper than fossil fuel alternatives, the energy economics landscape has fundamentally shifted. Solar PV at 4.4 cents/kWh and onshore wind at 3.3 cents/kWh significantly undercut fossil fuels at 10 cents/kWh, marking a decisive economic victory for clean energy.

Massive Economic Savings Already Realized: Global energy savings from renewables reached $409 billion in 2023 alone, demonstrating the real-world financial impact of the renewable transition. This represents just the beginning, as cost advantages are projected to expand further with renewables expected to be one-third cheaper than fossil fuels by 2030.

Job Creation Multiplier Effect: Renewable energy investments create three times more jobs per dollar invested compared to fossil fuels, with 16.2 million people currently employed in the sector globally. This employment advantage, combined with $2.9 trillion in annual health cost savings from reduced air pollution, creates substantial broader economic benefits beyond direct energy savings.

Storage Costs No Longer a Barrier: Battery storage costs have plummeted 89% since 2010 and are projected to fall another 50-70% by 2030. Even accounting for grid integration and storage costs (typically adding 0.5-1.5 cents/kWh), renewables plus storage remain competitive with fossil fuels in most markets, eliminating the last major economic objection to renewable deployment.

Yet, even some leading fossil fuel companies are increasingly recognizing the benefits of and need for transitioning to renewable energy!

Top 10 Renewable Energy Initiatives by Oil Companies

Which makes me wonder why more fossil fuel companies are not lobbying Trump and Congress for subsidies for clean energy projects, just as they have heretofore gotten huge subsidies for their fossil fuel business.

[Res Ipsa]

Isn’t hydrogen functionally a form of energy storage, like a battery? Yes, there will be losses in every step of the process, but that’s true of using batteries as storage. Part of the challenge of electricity is having either sufficient production capacity or storage to meet peak demand. It could be batteries, hydrogen, pumped reservoirs, heated materials, or other methods I’m not current on. There may be differences in efficiencies, but putting our eggs in different storage baskets seems sensible to me. Does that make sense? You are much better informed than I on energy transition issues.

I’m guessing the fossil fuel companies’ emphasis on fossil fuel subsidies has to do with the cost of transitioning to clean energy and not wanting to abandon assets.

I read that the Saudis are going to increase production soon, driving the price of oil down. It’s already too low to make our unconventional sources profitable, so I’m not sure what big oil is thinking. Beyond that, we’re ramping up natural gas export capacity at a time when the rest of the world is moving away from fossil fuels. Given the view that the US is an unreliable trading partner, who do we think is doing to buy our natural gas?

Maybe there’s a rational explanation out there. I’d sure love to hear it.

[Chap]

Thus, it will always take much more energy to produce all the hydrogen we need than we could possibly obtain by burning it! We would obviously have to use some energy source other than hydrogen fuel to electrolyze enough water to fulfill our energy needs. If we had enough of that other source to produce all the hydrogen we needed, why not use it all directly for our energy needs instead of wastefully converting any of it into hydrogen fuel first?

Isn’t hydrogen functionally a form of energy storage, like a battery? Yes, there will be losses in every step of the process, but that’s true of using batteries as storage. Part of the challenge of electricity is having either sufficient production capacity or storage to meet peak demand. It could be batteries, hydrogen, pumped reservoirs, heated materials, or other methods I’m not current on. There may be differences in efficiencies, but putting our eggs in different storage baskets seems sensible to me.

Res Ipsa is correct. While all transformations of energy from one form to another involve some energy leaking away into simply warming the surroundings of the process etc., there are times when it might be useful to store energy by producing hydrogen from water and later extracting thermal energy by letting it burn - when, unlike fossil fuels, the only combustion product will be ... water. Unlike gasoline combustion, there will be no nasty stuff for people to breathe and damage their lungs, and no carbon dioxide to accelerate global warming.

[Physics Guy]

Right. Hydrogen is not an alternative to fossil fuel as a net energy source, but might be an alternative to batteries and petroleum as a way of distributing energy.

The distribution part is important even for fossil fuel, to the point where even if it required the full energy input of a gallon of diesel oil to extract and refine and deliver that gallon of diesel, we might still operate diesel vehicles. We could use wind or water or solar or nuclear power to produce the diesel fuel, and then it would be convenient to pack all that power into just a few gallons of oil, and send vehicles on their way for a few hundred miles before they had to refuel.

A gallon of liquified hydrogen could yield nearly 20 kWh of energy by combustion. Tesla currently gets up to about 100 kWh in its batteries. So if it were as simple as putting 10 gallons of liquid hydrogen into a typical 10-gallon car fuel tank, hydrogen vehicles could comfortably outrange electric ones. Electric cars currently all look weirdly thick, like guys with their pants hiked up to their armpits, because they cram so much battery under the floor, but 10 or 20 gallons of LH would fit in a normal fuel tank.

I don't know that I want to drive around with ten gallons of liquid hydrogen in my car. Sounds kind of scary. But maybe it's no worse than driving anything else.

Water vapor is also a greenhouse gas. So I'm not sure we can just switch from pumping the atmosphere full of CO2 to pumping it full of H2O. Unlike CO2, though, water vapor can condense out as rain, and it tends to do that before it reaches cold upper altitudes.

[¥akaSteelhead]

Hydrogen binds readily, pure hydrogen is rarely found in nature. Industrial hydrogen is cracked out of hydrocarbons. Electrolysis of water for hydrogen production is best done at scale, like attached to a nuclear power plant. Electrolysis at the car level would not be as efficient as at scale, and storing hydrogen in a tank at the car - which in turn poses storage problems as it is very reactive and difficult to store, which may be why they propose cracking it out of the water..... There are "difficulties" with hydrogen as a fuel source.

[Res Ipsa]

Right. Hydrogen is not an alternative to fossil fuel as a net energy source, but might be an alternative to batteries and petroleum as a way of distributing energy.

The distribution part is important even for fossil fuel, to the point where even if it required the full energy input of a gallon of diesel oil to extract and refine and deliver that gallon of diesel, we might still operate diesel vehicles. We could use wind or water or solar or nuclear power to produce the diesel fuel, and then it would be convenient to pack all that power into just a few gallons of oil, and send vehicles on their way for a few hundred miles before they had to refuel.

A gallon of liquified hydrogen could yield nearly 20 kWh of energy by combustion. Tesla currently gets up to about 100 kWh in its batteries. So if it were as simple as putting 10 gallons of liquid hydrogen into a typical 10-gallon car fuel tank, hydrogen vehicles could comfortably outrange electric ones. Electric cars currently all look weirdly thick, like guys with their pants hiked up to their armpits, because they cram so much battery under the floor, but 10 or 20 gallons of LH would fit in a normal fuel tank.

I don't know that I want to drive around with ten gallons of liquid hydrogen in my car. Sounds kind of scary. But maybe it's no worse than driving anything else.

Water vapor is also a greenhouse gas. So I'm not sure we can just switch from pumping the atmosphere full of CO2 to pumping it full of H2O. Unlike CO2, though, water vapor can condense out as rain, and it tends to do that before it reaches cold upper altitudes.

If I recall correctly, the percentage of water vapor in the atmosphere is a function of temperature. Excess water vapor injected into the atmosphere condenses back out. Water’s vapor is treated as a feedback and not a forcing.

[Chap]

Water vapor is also a greenhouse gas. So I'm not sure we can just switch from pumping the atmosphere full of CO2 to pumping it full of H2O. Unlike CO2, though, water vapor can condense out as rain, and it tends to do that before it reaches cold upper altitudes.

If I recall correctly, the percentage of water vapor in the atmosphere is a function of temperature. Excess water vapor injected into the atmosphere condenses back out. Water’s vapor is treated as a feedback and not a forcing.

Yup. You can pump all the CO2 you like into the atmosphere, and it will remain gaseous, and act as, well, a greenhouse gas. But at any given temperature there is a maximum percentage load of water vapour that the atmosphere can hold, and once you reach that, it will simply condense out as droplets. And the lower the temperature the less water vapour the air can hold before it saturates.

[Gunnar]

Thus, it will always take much more energy to produce all the hydrogen we need than we could possibly obtain by burning it! We would obviously have to use some energy source other than hydrogen fuel to electrolyze enough water to fulfill our energy needs. If we had enough of that other source to produce all the hydrogen we needed, why not use it all directly for our energy needs instead of wastefully converting any of it into hydrogen fuel first?

Isn’t hydrogen functionally a form of energy storage, like a battery? Yes, there will be losses in every step of the process, but that’s true of using batteries as storage. Part of the challenge of electricity is having either sufficient production capacity or storage to meet peak demand. It could be batteries, hydrogen, pumped reservoirs, heated materials, or other methods I’m not current on. There may be differences in efficiencies, but putting our eggs in difference storage baskets seems sensible to me.

Res Ipsa is correct. While all transformations of energy from one form to another involve some energy leaking away into simply warming the surroundings of the process etc., there are times when it might be useful to store energy by producing hydrogen from water and later extracting thermal energy by letting it burn - when, unlike fossil fuels, the only combustion product will be ... water. Unlike gasoline combustion, there will be no nasty stuff for people to breathe and damage their lungs, and no carbon dioxide to accelerate global warming.

Yes, I actually agree with all the above. Hydrogen can be and should be used (along with other storage methods) to store and concentrate energy produced by other means, like solar and wind power which are intermittent. And it burns much cleaner that any kind of fossil fuels. I love the idea of directly using hydrogen in fuel cells to power vehicles which is certainly much more energy efficient than burning it any type of internal combustion engine. And fuel cells are not nearly as heavy as current batteries that store electricity, and there is an energy cost to propelling electric vehicles burdened by the weight of the batteries they require. But there is also an energy cost to highly compress the hydrogen into very strong but heavy pressurized containers or liquify it to fit it into heavy, highly insulated tanks and keep it liquified so the hydrogen can be conveniently stored in the vehicle until it is needed. So, which is more energy efficient? Using electricity produced by renewable fuels to charge batteries and power our devices directly, or using it to produce hydrogen to power them? It is obvious, of course, that we will have to do both, but I think it would be wise to maximize the former to the extent practical.

[Gunnar]

Isn’t hydrogen functionally a form of energy storage, like a battery? Yes, there will be losses in every step of the process, but that’s true of using batteries as storage. Part of the challenge of electricity is having either sufficient production capacity or storage to meet peak demand. It could be batteries, hydrogen, pumped reservoirs, heated materials, or other methods I’m not current on. There may be differences in efficiencies, but putting our eggs in different storage baskets seems sensible to me. Does that make sense? You are much better informed than I on energy transition issues.

I’m guessing the fossil fuel companies’ emphasis on fossil fuel subsidies has to do with the cost of transitioning to clean energy and not wanting to abandon assets.

I read that the Saudis are going to increase production soon, driving the price of oil down. It’s already too low to make our unconventional sources profitable, so I’m not sure what big oil is thinking. Beyond that, we’re ramping up natural gas export capacity at a time when the rest of the world is moving away from fossil fuels. Given the view that the US is an unreliable trading partner, who do we think is doing to buy our natural gas?

All the above is true and well reasoned, as far as I know!

Maybe there’s a rational explanation out there. I’d sure love to hear it.

So would I!

[Gunnar]

Right. Hydrogen is not an alternative to fossil fuel as a net energy source, but might be an alternative to batteries and petroleum as a way of distributing energy.

The distribution part is important even for fossil fuel, to the point where even if it required the full energy input of a gallon of diesel oil to extract and refine and deliver that gallon of diesel, we might still operate diesel vehicles. We could use wind or water or solar or nuclear power to produce the diesel fuel, and then it would be convenient to pack all that power into just a few gallons of oil, and send vehicles on their way for a few hundred miles before they had to refuel.

A gallon of liquified hydrogen could yield nearly 20 kWh of energy by combustion. Tesla currently gets up to about 100 kWh in its batteries. So if it were as simple as putting 10 gallons of liquid hydrogen into a typical 10-gallon car fuel tank, hydrogen vehicles could comfortably outrange electric ones. Electric cars currently all look weirdly thick, like guys with their pants hiked up to their armpits, because they cram so much battery under the floor, but 10 or 20 gallons of LH would fit in a normal fuel tank.

I don't know that I want to drive around with ten gallons of liquid hydrogen in my car. Sounds kind of scary. But maybe it's no worse than driving anything else.

Water vapor is also a greenhouse gas. So I'm not sure we can just switch from pumping the atmosphere full of CO2 to pumping it full of H2O. Unlike CO2, though, water vapor can condense out as rain, and it tends to do that before it reaches cold upper altitudes.

Understood! Thanks! I always appreciate your knowledge and facility to explain things!