Water Powered Cars

[Dak]

1. Moving the pollution doesn't really solve anything, does it? Since it is atmospheric pollution, it is going to get to you eventually..

 

by that logic, i may as well live in a chimney

 

shifting it isn't ideal, but it's better than crapping on our own doorstep. i'd also wager that effective waste-managment/pollution-limitation would be easyer in a big plant than in x cars (as would scrapping a plant and replacing it with a fusion plant be easyer than getting x people new fusion cars)

 

skepticLance why not just make and store electricity when the wind's blowing, and use it when it's not?

[SkepticLance]

Dak said :

 

skepticLance why not just make and store electricity when the wind's blowing, and use it when it's not?

 

Mainly for reasons of efficiency. It is possible to do what you suggest. For example, a wind farm can pump water uphill when the wind is blowing. When the air is still, the water can flow back down through a turbine to generate power. The problem is that a very large percentage of the energy is lost in the process. That is not the best way to use wind energy.

[SkepticLance]

lucaspa said :

 

1. Moving the pollution doesn't really solve anything, does it? Since it is atmospheric pollution, it is going to get to you eventually. What we need is fusion power. Then we would have enough cheap electricity to hydrolyze water for hydrogen. Until then, the current methods of cooking coal just makes more pollution.

 

2. There are ways now to keep the hydrogen bonded to porous metals -- titanium is one, I think. Thus, you don't really have a pressurized gas in a fuel cell like was in the bags of the zeppelins. No more danger of explosion than you have with gasoline powered cars -- maybe less.

 

On point 1. Dak is correct. Controlling pollution in a factory is easier than in small motor vehicles. Nitrogen and sulphur oxides can be scrubbed out. In the near future, carbon dioxide will be pumped into very long term underground storage. Some researchers are even working on ways of bubbling the carbon dioxide through ponds filled with algae to remove the nasty gases. Fusion power would be lovely. However, no scientists working in the field suggest it would be available before 2050 at the earliest. See the latest (September 2006) Scientific American for a good article on this subject.

 

Point 2. Hydrogen storage by metal bonding is a great idea, but it is not yet available. At this point in time, we can only use tanks. Probably high pressure storage of gas. Cryogenic storage is also possible, but is much more high tech, and not really suitable for motor vehicles.

[lucaspa]

lucaspa

The coal to hydrogen approach is only one way of doing it' date=' and as you said, not a smart way.[/quote']

 

But the only way now to get the quantity needed to fuel all the cars in the world.

 

Electrolysis by wind simply isn't going to generate anything like the quantity needed. Nuclear is theoretically an option, but the cost of nuclear plants is so high and the problem of waste disposal so tough -- economically and politically -- that it isn't viable to build enough plants to make enough hydrogen.

 

What we need is cheap fusion power. Then we can make all the hydrogen for all the fuel cells we could possibly need. Just one small problem ...

[lucaspa]

On point 1. Dak is correct. Controlling pollution in a factory is easier than in small motor vehicles. Nitrogen and sulphur oxides can be scrubbed out.

 

That isn't how the article described it. The pollutants can't be scrubbed out. They are just going to be emitted. It's just that they will be emitted from a plant in Wyoming instead of in LA.

 

Now, since the entire world is our "doorstep", I don't see how this helps. Yes, the smog in LA is less, initially, but then the entire planet becomes LA. This is progress?

 

In the near future, carbon dioxide will be pumped into very long term underground storage. Some researchers are even working on ways of bubbling the carbon dioxide through ponds filled with algae to remove the nasty gases.

 

What "nasty gases"? The plan would remove the CO2 -- the idea is that the algae convert it to sugar and oxygen thru photosynthesis.

 

Fusion power would be lovely. However, no scientists working in the field suggest it would be available before 2050 at the earliest. See the latest (September 2006) Scientific American for a good article on this subject.

 

I know. I said we needed it, not that we were going to get it.

 

Point 2. Hydrogen storage by metal bonding is a great idea, but it is not yet available. At this point in time, we can only use tanks.

 

I stand corrected. I misremembered the role of platinum in fuel cells. It's not to store hydrogen, but provide a catalytic surface for the electrochemical reaction. http://www.howstuffworks.com/fuel-cell.htm

 

Cars will have to have the high pressure storage, which means some leakage. Hydrogen doesn't need a crack -- it is small enough to diffuse thru a metal. But the leakage is going to be small compared to the amount of hydrogen used by the car.

[CPL.Luke]

there was a good article in scientific american that talked about how nuclear is going to come back (august 2006 issue) because of newer technologies allowing for less waste to be produced and other economic factors pushing up the price of coal and oil.

 

so maybe in a decade we'll have nuclear plants

[ecoli]

there was a good article in scientific american that talked about how nuclear is going to come back (august 2006 issue) because of newer technologies allowing for less waste to be produced and other economic factors pushing up the price of coal and oil.

 

so maybe in a decade we'll have nuclear plants

If we find a good way to absorb the building costs, I would see this as a possiblity. And, if we can educate people that nuclear power isn't as dangerous and scary as hollywood would have us believe.

[Dak]

That isn't how the article described it. The pollutants can't be scrubbed out. They are just going to be emitted. It's just that they will be emitted from a plant in Wyoming instead of in LA.

 

Now' date=' since the entire world is our "doorstep", I don't see how this helps. Yes, the smog in LA is less, initially, but then the entire planet becomes LA. This is progress?[/quote']

 

The plant in wyoming need not be a petrol plant. it could be a nuclear plant, thus significantly reducing the amount of polution produced powering x cars.

 

In addition, if someone suddenly figures out how to make 100% efficient solar panels (or some other prettymuch completely green power source), it'll be easyer to replace the nuclear plant in wyoming than it would be to replace x cars in LA.

 

easyer, centralised pollution managment.

[Cap'n Refsmmat]

That isn't how the article described it. The pollutants can't be scrubbed out. They are just going to be emitted. It's just that they will be emitted from a plant in Wyoming instead of in LA.

The point is that the plant in Wyoming would be more efficient than the car in LA, meaning that less pollutants would be emitted for the same energy use (theoretically).

[CPL.Luke]

cp'n your forgetting how inneficient our power distribution system is, I believe the statistic is something like 30% of the power generated actually reaches people for use.

[Cap'n Refsmmat]

Hence why the hydrogen plant would have to be right next to the power generation plant. I haven't, however, accounted for the distribution of the hydrogen, which adds to its environmental cost - although gasoline goes through the same process as well.

[Sisyphus]

cp'n your forgetting how inneficient our power distribution system is, I believe the statistic is something like 30% of the power generated actually reaches people for use.

 

Actually, in the U.S., there's only about a 10% loss from transmission. So it's 90% efficient. But then, most power plants are relatively local. There is a reason we have plants all over the country and not, say, one enormous plant in Wyoming. The point still stands that power plants can more easily be made clean and efficient than cars.

[CPL.Luke]

there are also designs that use a nuclear reactor to thermally "crack" the water. So essentially the water goes over the reactor as a coolant, gets broken down by the heat, and then is used to heat something else which in turn would generate electricity. so you would end up with the byproducts of hydrogen oxygen and electricity.

 

there are toher designs which would use the gamma flux and or neutron flux to crack the water.

 

 

EDIT: I stand corrected on the power distribution efficiency

[lucaspa]

The plant in wyoming need not be a petrol plant. it could be a nuclear plant, thus significantly reducing the amount of polution produced powering x cars.

 

The plant is Wyoming is the one converting coal to hydrogen. It is that process that produces the pollution. It's not the generation of the electricity that is the problem; it's the production of hydrogen from coal.

 

Now, if you can get power to do electrolysis on the scale needed for all the cars out there, then that is a different story. But the problem so far is that no power source generates that much electricity. So instead you use less power and get hydrogen from the huge reservoirs of coal -- hence Wyoming. But that gives you lots of pollution -- both air and water.

 

BTW, if you are generating hydrogen by hydrolysis, then the plant is on the shore of an ocean. After all, you don't want to use fresh water -- that too is a scarce resource and getting scarcer.

[lucaspa]

The point is that the plant in Wyoming would be more efficient than the car in LA, meaning that less pollutants would be emitted for the same energy use (theoretically).

 

You are thinking in terms of generating electricity. Instead, think of pollution in getting hydrogen from coal.

 

However, even in terms of hydrolysis, do you seriously think that renewable energy sources such as wind or solar are going give enough electricity to get the hydrogen you need? Remember, we use about 13 of million barrels of oil a day just in the US for fuel for cars and trucks. Think of how much hydrogen that is.

 

"Hydrogen is also about five times as expensive, per unit

of usable energy, as gasoline. Simple dollars are only one speed

bump on the road to the hydrogen economy. Another is that supplying the energy required to make pure hydrogen may itself

cause pollution. Even if that energy is from a renewable source,

like the sun or the wind, it may have more environmentally

sound uses than the production of hydrogen. ...

 

"Hydrogen could be derived from coal-fired electricity,

which is the cheapest source of energy in most parts of the country.

Critics argue, though, that if coal is the first ingredient for

the hydrogen economy, global warming could be exacerbated

through greater release of carbon dioxide.

Or hydrogen could come from the methane in natural gas,

methanol or other hydrocarbon fuel [see illustration on page

72]. Natural gas can be reacted with steam to make hydrogen

and carbon dioxide. Filling fuel cells, however, would preclude

the use of natural gas for its best industrial purpose today: burning

in high-efficiency combined-cycle turbines to generate electricity.

That, in turn, might again lead to more coal use. Combined-

cycle plants can turn 60 percent of the heat of burning

natural gas into electricity; a coal plant converts only about 33

percent. Also, when burned, natural gas produces just over half

as much carbon dioxide per unit of heat as coal does, 117

pounds per million Btu versus 212. As a result, a kilowatt-hour

of electricity made from a new natural gas plant has slightly

over one fourth as much carbon dioxide as a kilowatt-hour

from coal. "

 

But this isn't the end:

 

"When natural gas is cracked for hydrogen, about 40 percent

of the original energy potential is lost in the transfer, according

to the DOE Office of Energy Efficiency and Renewable

Energy. Using electricity from the grid to make hydrogen by electrolysis

of water causes a loss of 78 percent."

 

So, since most electricity is generated by coal-fired plants, that's a lot more release of greenhouse gases to make the hydrogen because the process of electrolysis is so inefficient.

 

All quotes from "Questions about the Hydrogen Economy" in Scientific American, May 2001.

 

BTW, when I mentioned binding metals to hydrogen for storage, my fuzzy memory was also thinking of metal hydrides as a way to store hydrogen. That's also in the article.

[Dak]

whats wrong with using nuclear plants?

[lucaspa]

Hence why the hydrogen plant would have to be right next to the power generation plant. I haven't, however, accounted for the distribution of the hydrogen, which adds to its environmental cost - although gasoline goes through the same process as well.

 

But the problems are much bigger with hydrogen.

 

"That is, if such a pipeline were even practical to build. Given

hydrogen’s low density, it is far harder to deliver than, for instance,

natural gas. To move large volumes of any gas requires

compressing it, or else the pipeline has to have a diameter similar

to that of an airplane fuselage. Compression takes work, and

that drains still more energy from the total production process.

Even in this instance, managing hydrogen is trickier than dealing

with other fuel gases. Hydrogen compressed to about 790

atmospheres has less than a third of the energy of the methane

in natural gas at the same pressure, points out a recent study by

three European researchers, Ulf Bossel, Baldur Eliasson and

Gordon Taylor.

A related problem is that a truck that could deliver 2,400

kilos of natural gas to a user would yield only 288 kilos of hydrogen

pressurized to the same level, Bossel and his colleagues

find. Put another way, it would take about 15 trucks to deliver

the hydrogen needed to power the same number of cars that

could be served by a single gasoline tanker. Switch to liquid hydrogen,

and it would take only about three trucks to equal the

one gasoline tanker, but hydrogen requires substantially more

effort to liquefy."

 

"Among hydrogen’s disadvantages is that it burns readily. All gaseous fuels

have a minimum and maximum concentration at which they will burn. Hydrogen’s range is unusually broad, from 2 to 75 percent. Natural gas, in contrast, burns between 5 and 15 percent. Thus, as dangerous as a leak of natural gas is, a hydrogen leak is worse, because hydrogen will ignite at a wider range of concentrations. The minimum energy necessary to ignite hydrogen is also far smaller than that for natural gas. And when hydrogen burns, it does so invisibly. NASA published a safety manual that recommends checking for hydrogen fires by holding a broom at arm’s length and seeing if the straw ignites."

 

Quotes from same article as before

[lucaspa]

whats wrong with using nuclear plants?

 

Besides the operating safety issues and the possibility of releasing large quantities of radioactive and toxic materials a la Chenobyl? The tendency for rogue governments to use the plants to make bomb-grade uranium or plutonium (as Iran is suspected of doing)? How do we dispose of the spent fuel rods -- highly radioactive and toxic? And what do we do with the radioactive plant itself after it's worn out?

 

Remember, plutonium is several times more toxic chemically than cyanide.

 

Other than all these problems, there's nothing "wrong" with nuclear plants.

[Dak]

the operational safety issues can be ameliorated significantly by following adequate safety protocols (chernobyl only happened once), the question of 'rougue states' is somewhat irrelevent, because 1/ i doubt that they're any more happy about us having nukes than we are of them having nukes, and 2/ i doubt that third world countries will be amongst the first to develop hydrogen power (itll be the well developed countries, which allready have nukes, that adopt it first), and the disposal issues, whilst problematic, are a lot less environmentally damaging overall than coal-burning plants.

 

so... i still think that switching petrol-burning cars for more nuclear plants that split hydrogen from water to fuel either hydrogen-cell or hydrogen-internal-combustion-engine fueld cars would be more environmentally friendly.

 

plus, if a new, greener, power source is developed, it'll be easyer and quicker to replace the nuke plants rather than all the cars... H2 power, by putting the actual power generation all in one place, makes it easy to manage.

[lucaspa]

by that logic, i may as well live in a chimney

 

And, if pollution continues, you will be!

 

However, some of the pollutants are greenhouse gasses. Since burning coal is still the cheapest form of generating electricity, even if you use hydrolysis, that means burning a lot of coal to make the electricity to make the hydrogen. And global warming is indeed global.

 

skepticLance why not just make and store electricity when the wind's blowing, and use it when it's not?

 

How do you store electricity? Batteries are the only method I know of now. Of course, making hydrogen and then using hydrogen fuel cells would be another method of "storing" electricity. But now you have the problem of transporting the hydrogen. And that's not trivial.

[lucaspa]

the operational safety issues can be ameliorated significantly by following adequate safety protocols (chernobyl only happened once), the question of 'rougue states' is somewhat irrelevent, because 1/ i doubt that they're any more happy about us having nukes than we are of them having nukes, and 2/ i doubt that third world countries will be amongst the first to develop hydrogen power (itll be the well developed countries, which allready have nukes, that adopt it first), and the disposal issues, whilst problematic, are a lot less environmentally damaging overall than coal-burning plants.

 

First, I tend to agree with you about building more nuclear plants. But we can't minimize the problems. The difficulty with a breach like Chernobyl is that if one occurs at, say, the plant just up the river from NYC, you put tens of millions of people at risk. In that case, any failure rate, no matter how small, becomes intolerable. And you put the plants near the cities so that loss from transmission is reduced.

 

Second, the problem of rogue states is very relevant. Remember, the use of petrol is greatest among the developing world, and that's where you have the rogue states. Since hydrogen is so tough to transport, Iran is going to want to have its own hydrolysis for its hydrogen vehicles. And that means nuclear plants in Iran. And we know how well that is working out right now and how well it has worked out in N. Korea. The chance of nuclear weapons being used increases with the number of states that have them. The odds that you will get ONE irresponsible state approaches 1. And, with several states (including the probable opponents) having nuclear weapons, then you get the probability of a nuclear exchange and nuclear winter. That's as catastrophic as global warming, right?

 

Of course, there is also the problem of security. The more nuclear plants, the more difficult to guard them all. And this the temptation for terrorists to attack a plant -- either to cause nuclear accident or to get their hands on the material. Just a few ounces of plutonium put in the reservoir of NYCs water supply, and the deaths are in the millions. Yes, plutonium is that bad a poison.

 

Third, the problem of waste disposal is such a long term problem. Isotopes with half-lives of millions of years. And don't forget the plants themselves. After 50 years of operation, even the pipes and walls of the plants are slightly radioactive as neutrons convert some of the atoms to radioactive isotopes.

 

plus, if a new, greener, power source is developed, it'll be easyer and quicker to replace the nuke plants rather than all the cars... H2 power, by putting the actual power generation all in one place, makes it easy to manage.

 

Didn't you read the problems of transporting H2? You can't put the power generation in "one place". You have to have electrolysis plants everywhere, and that means the power generating plants everywhere.

 

What you are saying is that environmental downside to nuclear plants is less than the environmental downside of coal or other petrochemical generating plants + the release of greenhouse gasses by cars. I agree with that, but it's not a slam dunk. It depends on how serious you think global warming is going to be.

 

Also, like it or not, nuclear plants are expensive. The safety improvements that you so blithely pass over add exponentially to the cost. That is, getting a 1% improvement in safety from 98% to 99% doesn't add 1% of cost, but multiplies the cost by several fold. For the foreseeable future, coal is SOOO much cheaper than nuclear power there is no way to economically do what you propose.

[CPL.Luke]

Lucaspa I'll refer you to last months issue of scientific american, it had a very good article on the future of nuclear energy. Essentially it stated that nuclear is likely to become competitive with coal over the next decade because of

 

1. Newer nuclear reactor designs are safer (china is buiilding aseris of pebblebed reactors that can literally have their cooling system shut off and they won't melt down)

 

2. modern nuclear reactors burn more of theirfuel, with liquid metal designs consuming 95% (contrasted to curent reactors which consume 5%) of their fuel and leaving waste products that become safe in less than 100 years

 

3. If laws are enacted to require coal plants to burry their waste, then that aditional rise in the cost of coal plants will make nuclear competitive again.

[Dak]

Didn't you read the problems of transporting H2? You can't put the power generation in "one place". You have to have electrolysis plants everywhere, and that means the power generating plants everywhere.

 

You could always have nukes, generating electricity, which goes through wires to local hydrolysis plants, where the electricity (created remotely by the nukes) is used to liberate hydrogen from water. these could be at, say, petrol stations. as a bonus, that would also make the switch to solar easyer if and when more effective solar panels are created (local small companies with huge electric bills will be more inclined, and more able to afford, buying solar panels to lessen their reliance on the expensive nukes).

 

not only would this be 'greener', but i'd wager (in the uk at least) it'd be cheaper than petrol

 

What you are saying is that environmental downside to nuclear plants is less than the environmental downside of coal or other petrochemical generating plants + the release of greenhouse gasses by cars. I agree with that, but it's not a slam dunk. It depends on how serious you think global warming is going to be.

 

Also, like it or not, nuclear plants are expensive. The safety improvements that you so blithely pass over add exponentially to the cost. That is, getting a 1% improvement in safety from 98% to 99% doesn't add 1% of cost, but multiplies the cost by several fold. For the foreseeable future, coal is SOOO much cheaper than nuclear power there is no way to economically do what you propose.

 

I think i heard something about the UK planning to massively nuclearise, and build loads of plants with the new safety improvements. i'll try and find something on it later (remind me if i forget)

[lucaspa]

Lucaspa I'll refer you to last months issue of scientific american' date=' it had a very good article on the future of nuclear energy. Essentially it stated that nuclear is likely to become competitive with coal over the next decade because of

 

1. Newer nuclear reactor designs are safer (china is buiilding aseris of pebblebed reactors that can literally have their cooling system shut off and they won't melt down)

 

2. modern nuclear reactors burn more of theirfuel, with liquid metal designs consuming 95% (contrasted to curent reactors which consume 5%) of their fuel and leaving waste products that become safe in less than 100 years

 

3. If laws are enacted to require coal plants to burry their waste, then that aditional rise in the cost of coal plants will make nuclear competitive again.[/quote']

 

I'll look at that. My reading is backlogged so that I haven't even looked at last month's SciAm and next month's digital edition is in my e-mail already.

 

You addressed 2 of the problems and a big "IF". By "waste" I assume burying the CO2. None of the rest of the waste is a problem.

 

Some of what you say doesn't make sense. For instance, it would seem that the pebble-bed reactors are inconsistent with liquid metal cooling. Also, uranium itself breaks down to isotopes with long half-lives. Time to read the article in depth to address these questions I have.

[lucaspa]

You could always have nukes, generating electricity, which goes through wires to local hydrolysis plants, where the electricity (created remotely by the nukes) is used to liberate hydrogen from water.

 

Yes, but the nukes are going to have to be near the cities involved. That is, you can't have a remote nuclear plant in Wyoming that is shipping electricity to LA. You need the plants in LA. So we have the safety issues.

 

if and when more effective solar panels are created

 

I wouldn't hold my breath over this one. Even plants, with 3.8 billion years of evolution trying to find efficient designs, are not that efficient.

 

I think i heard something about the UK planning to massively nuclearise, and build loads of plants with the new safety improvements. i'll try and find something on it later (remind me if i forget)

 

It's possible. The looming catastrophe of global warming could be such that the risk of a nuclear accident is now viewed as less than the risk of global warming. Risk vs risk.