View Single Post
Old 06-18-2009, 08:45 AM   #79
Junior Member
Bimmerman's Avatar
Join Date: Dec 2004
Location: Bouncing off the Rev Limiter
Posts: 437
Originally Posted by Darth_Yuthura View Post
It's irrelevant to the issue..
No, it is absolutely relevant.
Originally Posted by Darth_Yuthura View Post
...I was bringing up. I am going to give a rhetorical statement that I know people must already have figured out, but just so they know where I am...

Hydrogen is not in itself an energy source like coal, nuclear, or solar. It is a method by which energy can be transfered from a source to its destination.
Please listen to me this time.

What you describe is fuel. "A method of transferring energy" is the definition of fuel. Fuel in the sense of stored potential energy to thermal, sonic, light, kinetic, electric energy. Batteries fall under this definition as well.

Gaseous hydrogen is a fuel, analogous to coal, nuclear, or sunlight.

Gaseous hydrogen can be combusted. So can coal.
Gaseous hydrogen can be combined with gaseous oxygen to create water and electricity. Coal can be liquified and burned in liquid form. Uranium can be split via nuclear fusion to produce byproducts and electricity.

Coal is burned as a fuel to heat water inside the coal-fired power plants. Hence the term "coal fired."

Hydrogen itself, a single molecule that is, does not exist in nature. It does not come in solid or liquid form. It is not a thing. It is a fuel upon which a process must be performed in order to transfer energy.

Originally Posted by Darth_Yuthura View Post
It must be backed by another form of energy and no matter what form that is, any method you use will have a net loss of energy.
So mining coal and combusting the coal to heat water to spin turbines and compressors to generate electricity is a net loss of energy? Nuclear power is a net loss of energy? Burning gasoline in your lawn mower is a net loss of energy?

What IS a net loss is the hydrolysis performed on water to obtain H2 and O2. That is a net loss of energy for the chemical reaction. It does not happen spontaneously in nature, and therefore there must be a net energy input for it to happen. It is also true that less enegy is recovered upon combustion of said H2 than was required to break the H-O bonds. Absolute, verified fact. Fuel cells, whether in cars, the space shuttle, or your toaster, operate at a lower loss, as the energy recovered from recombining H-O is closer to that required to break the bonds.

Originally Posted by Darth_Yuthura View Post
When you use a chemical reaction to power your vehicle, you will get less energy back than what you used to produce the fuel in the first place.
False. Absolutely false.

Gasoline combustion is a net positive energy. Otherwise it would not have ever been profitable. The production, transport, refining, and purchase all cost a good deal in terms of energy and money, but the energy released upon combustion is far higher and is greatly positive. Well to wheel efficiency is positive, not negative. Therefore, your statement is false and misinformation.

It's true for hydrolysis to produce hydrogen, but is false again for the catalytic conversion of water to H2 and O2. That happens above a certain temperature, and requires significantly less energy to raise the catalyst above 50°C than is released upon H2 combustion or fuel cell shenanigans. This is still lab research stuff, and not likely to come to market anytime soon, but still invalidates your point. Using hydrogen to fuel the car of the future, regardless of powertrain configuration, is not necesarily a net negative.

Originally Posted by Darth_Yuthura View Post
My source is two years old, so maybe the production methods have improved, but in 2007, the net return was about 54% of what was invested to produce the hydrogen fuel.
Post it. Numbers can be skewed to mean almost anything. The hydrogen fuel industry is in its infancy, and as a result it will cost a lot to develop anything that is not a negative ROI for a while. That doesn't mean it isn't worth pursuing. Furthermore, many powerplants are producing excess energy, so even hydrolysis is a viable option.

Originally Posted by Darth_Yuthura View Post
Bad wording. You only get a fraction of the energy you originally invested into the hydrogen fuel. There is always going to be a net loss from changing one form of energy to another (solar to electrical, electrical to chemical(hydrogen), chemical back to electrical(fuel cell), electrical to kinetic energy) Might as well just go right from solar to electrical and skip the hydrogen fuel altogether. You only lose about 3% of electricity for each 1000 km it has to be transmitted.
Yes and no. You are correct in that there are losses. That is what companies spend thousands of dollars on engineering R&D in order to reduce these losses. Solar is a joke. It only works profitably in a select few environments on earth. Who in their right mind would buy a solar powered car, house, bus, city, computer in the Pacific Northwest? If 54% (from your missing source) is what you consider a fraction, than you must think a 35% thermally efficient power plant is atrocious.

Originally Posted by Darth_Yuthura View Post
And these powerplants that don't operate so efficiently... that has to also be taken into account if you are outputting hydrogen with that electricity from a power plant. And so how does this 100% powerplant capacity thing make any difference? It would just mean having to build more power plants in order to produce the hydrogen you are advocating for. It might be a means to harness this excess energy that otherwise would be wasted, but beyond that, nothing about it makes sense.
I don't think you understand my point. Because plants don't run at 100% capacity, there is the headroom to create hydrolysis "plants," to coin a term, that would not require additional power plants or sacrifices on anyone's part. In the case of nuclear power, upping the load on the plant (read: percent of max capacity) doesn't even consume more resources.

Would commercial hydrolysis plants require the conventional powerplants to consume more fuel? Absolutely. Keep in mind that gasoline refineries don't magically operate without power, that steel works don't melt steel without power and fuel, that your computer doesn't run without power, that our entire society runs on electricity. If the powerplant is operating below capacity, or in many cases, producing a surplus of energy, adding another load to the line will not accidentally the whole earth.

A racing addiction makes a crack addiction look like a vague desire for something salty. -Randy Hickman

Fear disturbs your concentration. - Sabine Schmitz
Bimmerman is offline   you may: quote & reply,