HYDROGEN HERE!

[kyleb]

Why would I burn hydrogen for energy? Fuel cells are the way you do this with nearly 70% conversion efficiency to electricity and motive force, more than twice what is available under our current system of fuel use.

How do you get that H2? That's the problem.

Pick a fossil fuel. Burn it. Turn the resulting heat into electricity.

The best efficiencies are shy of 50%. Call it 47%. Then, you push that across the grid and lose 2% in transmission losses, so your house, shopping center, or manufacturing plant nets receiving 45% of the energy that was contained in the coal, natural gas, or whatever. So the process to deliver that power is 45% efficient.

Then, let's assume you repurpose that generated electricity and make Hydrogen. You start with the same 45% energy efficiency reviewed above. Then, you electrolyze water at an efficiency of somewhere between 50 and 90%. I'll choose 75%. So you multiply that 75% efficiency by the 45% calculated earlier (to account for the energy to run the electrolysis equipment), and you've got Hydrogen generated at something like 33% efficiency.

Next, you run that H2 through an efficient fuel cell at 80% efficiency and you're at an ultimate efficiency of 27% for delivered power.

So fossil fuels (or nukes) can deliver energy to your doorstep at 45% efficiency, or you can add a bunch of steps to the process and generate H2 at 27% efficiency. Which is better?

And if you waive a magic wand and say "I can make more efficient hydrolysis process or better fuel fuel cells", whatever those efficiencies are, they will still result in more lost power and additional capital investment than skipping the steps entirely.

In today's world, using perfectly good energy to generate Hydrogen makes no sense. All you're doing is throwing away a bunch of energy.

 

[JeffDG]

In today's world, using perfectly good energy to generate Hydrogen makes no sense. All you're doing is throwing away a bunch of energy.

An excellent summary.

The only way Hydrogen becomes a worthwhile energy source is when we step the use of Hydrogen from the chemical realm to the nuclear one, http://en.wikipedia.org/wiki/ITER

 

[Henning]

It's no where near that efficient Henning, and you are only talking about energy yield from the H2 in the tank, not the efficiency of producing the H2.

Nope, I'm not, you may want to take another look at what's come about in the last few years, University of Maryland has done some interesting work in both cost and efficiency of SOFCs.

 

[Henning]

How do you get that H2? That's the problem.

Pick a fossil fuel. Burn it. Turn the resulting heat into electricity.

The best efficiencies are shy of 50%. Call it 47%. Then, you push that across the grid and lose 2% in transmission losses, so your house, shopping center, or manufacturing plant nets receiving 45% of the energy that was contained in the coal, natural gas, or whatever. So the process to deliver that power is 45% efficient.

Then, let's assume you repurpose that generated electricity and make Hydrogen. You start with the same 45% energy efficiency reviewed above. Then, you electrolyze water at an efficiency of somewhere between 50 and 90%. I'll choose 75%. So you multiply that 75% efficiency by the 45% calculated earlier (to account for the energy to run the electrolysis equipment), and you've got Hydrogen generated at something like 33% efficiency.

Next, you run that H2 through an efficient fuel cell at 80% efficiency and you're at an ultimate efficiency of 27% for delivered power.

So fossil fuels (or nukes) can deliver energy to your doorstep at 45% efficiency, or you can add a bunch of steps to the process and generate H2 at 27% efficiency. Which is better?

And if you waive a magic wand and say "I can make more efficient hydrolysis process or better fuel fuel cells", whatever those efficiencies are, they will still result in more lost power and additional capital investment than skipping the steps entirely.

In today's world, using perfectly good energy to generate Hydrogen makes no sense. All you're doing is throwing away a bunch of energy.

I pick Thorium as the fossil fuel. Here's the deal, we can't just look at money any more, we no longer live in the natural order where we can apply that principle and survive as a species.

 

[kyleb]

I pick Thorium as the fossil fuel. Here's the deal, we can't just look at money any more, we no longer live in the natural order where we can apply that principle and survive as a species.

Henning, it isn't a money issue, it is a resource issue. Whether the resource is Thorium, Dilithium Crystals, or Coal. Ultimately, you're proposing wasting those resources compared to a conventional model.

 

[Everskyward]

Here's something that exists already.

http://themindunleashed.org/2014/09/move-tesla-new-car-powered-salt-water-900-horsepower.html

The car is powered by the electrolyte flow cell power system, which is a part of the NanoFlowcell technology. The system works in a similar way to a hydrogen fuel cell, except for the fact that salt water is used for storing power. In particular, two liquids with metallic salts, which act as the electrolyte, are combined in such a way that the electrochemical reaction takes place. After that, electric motors use this reaction to generate electricity, which is then stored and distributed by super capacitors. The efficiency of this system reaches 80%, since the car has almost no moving parts in it, and the produced waste heat is insignificant in comparison with cars powered by lithium-ion batteries.

 

[SixPapaCharlie]

Saw this on the way to work this morning. Thought of this thread.

 

[FormerHangie]

Here's something that exists already.

http://themindunleashed.org/2014/09/move-tesla-new-car-powered-salt-water-900-horsepower.html

That's a different type of battery, one where two liquids are combined to create a reaction that generates electricity. There aren't many details given, but I would assume that once combined, the liquids would be stored in a waste tank, and when the car would be need a refill of those liquids, the waste would be emptied and I assume reprocessed.

I've heard that so far, these types of batteries have been too large to put in a car. Maybe this one is better, but from the way they promote it, I'd be very suspicious of anything they say.

 

[Everskyward]

That's a different type of battery, one where two liquids are combined to create a reaction that generates electricity. There aren't many details given, but I would assume that once combined, the liquids would be stored in a waste tank, and when the car would be need a refill of those liquids, the waste would be emptied and I assume reprocessed.

I've heard that so far, these types of batteries have been too large to put in a car. Maybe this one is better, but from the way they promote it, I'd be very suspicious of anything they say.

Did you watch the video? The car really exists.

 

[Capt. Geoffrey Thorpe]

"Well to wheels" is a good subject to search on if you want to find papers that compare various energy alternatives. But, many are written by people with an agenda which tends to color the results. And, even those that attempt to be as unbiased as possible have to make a lot of assumptions that provide significant room for error.

Then there is the question - what is the objective: Reduced greenhouse gasses? Reduced dependance on oil? "Sustainability"? You get different solutions based on which of those problems you are attempting to solve.

 

[Cap'n Jack]

Nope, I'm not, you may want to take another look at what's come about in the last few years, University of Maryland has done some interesting work in both cost and efficiency of SOFCs.

Still have a long way to go. Here's the ref: http://www.umerc.umd.edu/projects/solid05

I pick Thorium as the fossil fuel. Here's the deal, we can't just look at money any more, we no longer live in the natural order where we can apply that principle and survive as a species.

Thorium is a fossil fuel?

 

[FastEddieB]

Thorium is a fossil fuel?

Nice catch.

Now he's just making stuff up!