Thread: Hydrogen as a facilitator for renewables.

Normally the problem cited for a "hydrogen economy" is that hydrogen is not actually a source of electricity. It's just a storage medium. In the process of using electricity to create hydrogen via electrolysis, and then reconverting that hydrogen back into electricity, you'll lose about 3/4 of the original electricity. However, if we're talking about electricity generated via wind or solar, the electricity is not coming any real cost. Isn't 1/4 of something better than 100% of nothing?


It seems to me that if we just get ourselves comfortable with the idea that we're only going to get 1/4 of the normal expected output, and decide to simply build 4 times as many wind mills and solar panels as we had previously intended, then there would be no reason at all that they couldn't serve as base load power source.

There's really no resource-imposed limit on how many wind mills or solar panels we can build is there? In theory, we could build 10 times as many as we need, or even 100 or 1000 times as many, if we were determined.

Wouldn't it be better just to direct 100% of the renewable energy directly into demand, instead of wasting 75% of it through the conversion into storage media?

Chevrolet Equinox Fuel Cell Passes 1 Million Miles
No Gasoline or Tailpipe Pollution in Reaching Unprecedented Milestone

http://www.gm.com/vehicles/innovatio...ion_091109.jsp

I think this article belongs in this thread. Every thing sounded good, but they didn't quote any estimates as to what a hydrogen fill up would cost, if these cars actually went in to production. Also, they didn't say how much one of these cars would cost.

They sound very doable and if I can afford it, I'd like to own one.

At least it had what I consider a practical range as well, just over 150 miles, and fairly quick refuel time of 5-7 minutes.

I suspect that if a market for hydrogen as an automotive fuel was developed the hydrogen would be produced by the cheapest lowest technology method available, which is, I believe, gasification of coal. A major byproduct is CO2. If it can be sequestered, great. But it won't be sequestered unless it's regulated.

Originally Posted by inow

Wouldn't it be better just to direct 100% of the renewable energy directly into demand, instead of wasting 75% of it through the conversion into storage media?

Please explain how you would power a car, bus, etc. that way. You lost me there.

Originally Posted by Bunbury

I suspect that if a market for hydrogen as an automotive fuel was developed the hydrogen would be produced by the cheapest lowest technology method available, which is, I believe, gasification of coal. A major byproduct is CO2. If it can be sequestered, great. But it won't be sequestered unless it's regulated.

If I recall, the figure is something like 44 kilo-watt-hours of power to produce the equivalent of 1 gallon of gasoline for energy. At 10 cents/kwh, that is $4.40 a gallon without any production, payroll, profit, maintenance costs etc. factored in. Now if that is say 75% efficient, and gas is only maybe 30% efficient, we might be able to pull it off if that equivalent number I heard is fuel energy, and not output from the drive-shaft. I personally think hydrogen has too many problems still for it to be viable any time soon.

Originally Posted by Wild Cobra

Originally Posted by Bunbury

I suspect that if a market for hydrogen as an automotive fuel was developed the hydrogen would be produced by the cheapest lowest technology method available, which is, I believe, gasification of coal. A major byproduct is CO2. If it can be sequestered, great. But it won't be sequestered unless it's regulated.

If I recall, the figure is something like 44 kilo-watt-hours of power to produce the equivalent of 1 gallon of gasoline for energy. At 10 cents/kwh, that is $4.40 a gallon without any production, payroll, profit, maintenance costs etc. factored in. Now if that is say 75% efficient, and gas is only maybe 30% efficient, we might be able to pull it off if that equivalent number I heard is fuel energy, and not output from the drive-shaft. I personally think hydrogen has too many problems still for it to be viable any time soon.

Better than I thought. Gas cost more than $6.00/gallon after we add subsidize, a part of our defense spending and environmental cost. So it's getting in the ball park.

Of course there are other obstacles to get over. Public reluctance to purchase anything until they know they'll have a network to refuel or get their car repaired.

There's also the Hindenburg factor.

Originally Posted by inow

Wouldn't it be better just to direct 100% of the renewable energy directly into demand, instead of wasting 75% of it through the conversion into storage media?

The purpose of the storage media is to conserve the energy generated during off peak hours, when nobody is consuming it. (Unconsumed energy just gets lost.) If the sun is shining and nobody decides to turn on their lights, then we convert the energy into hydrogen. Then, later on, when the sun has gone down and people start turning on their lights, we burn the hydrogen.

If the sun happens to be shining at the same time as they want to turn on their lights, then we can skip the hydrogen part.

Originally Posted by Wild Cobra

Originally Posted by inow

Wouldn't it be better just to direct 100% of the renewable energy directly into demand, instead of wasting 75% of it through the conversion into storage media?

Please explain how you would power a car, bus, etc. that way. You lost me there.

You're lost because nobody ever suggested anything about powering cars, buses, etc. You've unconsciously added a variable into the OP which was not present when I offered my response to the OPs question.

It's a good question, don't get me wrong, and it may even have been implied/implicit in the OP, but it's not a question I was seeking to address.

Originally Posted by inow

Originally Posted by Wild Cobra

Originally Posted by inow

Wouldn't it be better just to direct 100% of the renewable energy directly into demand, instead of wasting 75% of it through the conversion into storage media?

Please explain how you would power a car, bus, etc. that way. You lost me there.

You're lost because nobody ever suggested anything about powering cars, buses, etc. You've unconsciously added a variable into the OP which was not present when I offered my response to the OPs question.

It's a good question, don't get me wrong, and it may even have been implied/implicit in the OP, but it's not a question I was seeking to address.

Why use hydrogen then when we have electricity? Do you have another method of producing hydrogen that doesn't create it's own problems on the environment?

When did I suggest we use hydrogen?

I think the whole point is you can store energy as hydrogen a lot better than you can store it as electricity.

DoE Invests In First Flywheel Power-Storage Plant

http://www.popsci.com/technology/art...y-power-demand

This sounds more like what you are looking for. Anyway I think it should be added to this thread.

Originally Posted by Wild Cobra

Why use hydrogen then when we have electricity? Do you have another method of producing hydrogen that doesn't create it's own problems on the environment?

You can create hydrogen just by running an electric current through water. It separates the "O" from the "H2" in "H2O". But as I mentioned earlier, you only get about 25% of the energy back if you use that method.


Now I'm curious what the return rate is on fly wheels. I bet it's a lot better than it is for Hydrogen.

Originally Posted by kojax

Originally Posted by Wild Cobra

Why use hydrogen then when we have electricity? Do you have another method of producing hydrogen that doesn't create it's own problems on the environment?

You can create hydrogen just by running an electric current through water. It separates the "O" from the "H2" in "H2O". But as I mentioned earlier, you only get about 25% of the energy back if you use that method.


Now I'm curious what the return rate is on fly wheels. I bet it's a lot better than it is for Hydrogen.

Probably so. Imagine a magnetic (frictionless) bearing, supporting a flywheel several tons, spinning in a vacuum. It would hold what ever energy was put into it for a pretty long time. Even with low friction ceramic bearings, this may be the ticket to storing wind and solar power until needed.

I used to work on rotary UPS... A motor driven flywheel that has an alternator on the other side to generate electricity. Should commercial power fail, it started a six cylinder turbocharged diesel. When we did the 50,000 hr maintenance, it took several hours for the flywheel to spin down. One time we had a commercial power failure, and the engine didn't start right away. Our frequency went down by about 5 hz. before we got the engine going, but we still had full 40 kw available to our communications equipment, and was probably drawing at least 25 kw at the time.

Flywheels are probably a better tech overall, but I think hydrogen still has some advantages. It requires less complicated machinery, so hydrogen production and consumption has the potential to be a sort of a cottage industry. With the right legislation, people could put hydrogen generators in their homes, and contribute by making hydrogen when the power grid had an oversupply of power, and then sell the energy back at peak consumption times or something.

The other advantage is that hydrogen is transportable. If you wanted to say... build a huge hydroelectric dam in a place that was very far from where anyone lives (like some regions of Northern Canada or Alaska), then converting the energy into hydrogen would mean you could send it anywhere on Earth.

Originally Posted by kojax

Flywheels are probably a better tech overall, but I think hydrogen still has some advantages. It requires less complicated machinery, so hydrogen production and consumption has the potential to be a sort of a cottage industry. With the right legislation, people could put hydrogen generators in their homes, and contribute by making hydrogen when the power grid had an oversupply of power, and then sell the energy back at peak consumption times or something.

As far as flywheels go I'm willing to wait and see how well the New York facility works out.

The other advantage is that hydrogen is transportable. If you wanted to say... build a huge hydroelectric dam in a place that was very far from where anyone lives (like some regions of Northern Canada or Alaska), then converting the energy into hydrogen would mean you could send it anywhere on Earth.

This is a concept I like very much. However building dams in remote parts of Canada or Alaska sounds very expensive. I'm not sure that bottom line is looking good to anyone at this moment in time.

Originally Posted by kojax

The other advantage is that hydrogen is transportable. If you wanted to say... build a huge hydroelectric dam in a place that was very far from where anyone lives (like some regions of Northern Canada or Alaska), then converting the energy into hydrogen would mean you could send it anywhere on Earth.

There are vast reserves of natural gas on the North Slope. So far it's taken 30 years of talking about a pipeline to get it south, or even west to an ocean terminal. Maybe in another ten years we may have a natural gas pipeline.

Pipelining hydrogen is more challenging than natural gas. It tends to leak out a lot (small molecule), and causes cracks in steel and has a much smaller energy density in volumetric terms so needs to be highly compressed. Road and rail transport from remote Arctic areas are not likely to be economically viable. Saying hydrogen is transportable is to minimize the significance of a very large number of technical issues.

Are there any other more practical ways to transport hydrogen? Like part of some liquid solution or absorbed into a solid?

==
As for the dams in remote locations, while it might be more expensive, many of the largest US dams were also built in remote locations and many still are pretty remote. Many of the same companies went on after the FDR projects and built massive dams in places like Afghanistan a half a century ago.

Originally Posted by Lynx_Fox

Are there any other more practical ways to transport hydrogen? Like part of some liquid solution or absorbed into a solid?

==
As for the dams in remote locations, while it might be more expensive, many of the largest US dams were also built in remote locations and many still are pretty remote. Many of the same companies went on after the FDR projects and built massive dams in places like Afghanistan a half a century ago.

There is no doubt that hydrogen would make a very attractive energy source and remote hydroelectric dams to produce it might become a viable option at some time. But I don't think it will ever get to that. I think that technology will be developed to produce it on demand as needed, through some sort of catalytic reaction that will allow a reasonable production cost ratio. I can't remember where I saw or heard this but I remember something about GM having a working process similar to what I described, that they will be using for hydrogen filling stations if their hydrogen power cell cars ever catch on.

Originally Posted by Bunbury

Pipelining hydrogen is more challenging than natural gas. It tends to leak out a lot (small molecule), and causes cracks in steel and has a much smaller energy density in volumetric terms so needs to be highly compressed. Road and rail transport from remote Arctic areas are not likely to be economically viable. Saying hydrogen is transportable is to minimize the significance of a very large number of technical issues.

I would think hydrogen blimps could be used, but I guess the quantities would still always be too small to make it worth the trouble. So I guess that wouldn't be cost effective, unless the blimps were transporting something else other than hydrogen as well.

Originally Posted by Lynx_Fox

As for the dams in remote locations, while it might be more expensive, many of the largest US dams were also built in remote locations and many still are pretty remote. Many of the same companies went on after the FDR projects and built massive dams in places like Afghanistan a half a century ago.

Good point. I suppose it doesn't really matter how far a power source is away from civilization. If the power is cheap enough, probably some industries will move into the area and simply pay their workers more to live in a wasteland so they can manufacture energy-intensive products more cheaply.

At least it had what I consider a practical range as well, just over 150 miles, and fairly quick refuel time of 5-7 minutes.




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