The hydrogen economy

I saw a talk on fuel cell technology and despite the fact the speaker and content was dismal I did learn a lot. For those unfamiliar with fuel cell technology a fuel cell like a battery is a chemical source of electricity, but unlike a battery it is not self contained so as long as H2 and O2 are added it keeps producing power. It is the king of the hydrogen economy!
However, they are as of last Wednesday wholly impractical for large scale electrical generation. First off a 200KW fuel cell costs a million dollars. Worse yet the fuel cell stack isn’t even good for a year (<5,000 hours) at half power, and being generous the replacement stack is a third of the cost of the unit, and the availability is ~70%. Discounting the cost of fuel which is compressed hydrogen which I generously estimate as $200 an hour (which at the availability I state is $1.2 million a year), you are still spending $1.3 million for a 100KW generator. Compare this to a marine diesel 200KW generator (for a mere $26,000 and offers 99.9% availability), run at half power on $3 a gallon vegetable oil ($210,000 a year in fuel), with a $4,000 a year maintenance cost, you savings is $2,260,000 the first year and $1,319,333 every year after. Plus, the exhaust can be used to boil 1,000s of gallons of water a day to recover even more energy (ok so can a fuel cell). Vegetable oil is carbon neutral, contains more energy that is put into its production and helps farmers because the USA is the world leader in oilseed production, and the meal is animal feed. The killer for hydrogen as fuel source is that it requires more energy to make than be extracted.
Why? Hydrogen is an energy storage form, not a fuel. Unless we start mining the sun hydrogen is not available on earth unless it is bound with something else generally carbon and/or oxygen. Hydrogen is therefore generally produced from catalytic cracking of hydrocarbons into CO (or CO2) and hydrogen (this process requires platinum catalysts which aren’t cheap. The catalyst is slowly degraded by the sulfur and salts in the fuel, or in an instant with the wrong grade of fuel, so required frequent replacement. Even better as the catalyst fails the byproducts can ruin the fuel cell stack) or by the hydrolysis of water into hydrogen and oxygen (guess where the electricity for this process comes from? Coal and nuclear power!) Other strikes against hydrogen are it is hard to transport and store, the 900 C flame of burning hydrogen is invisible,“spilled” hydrogen destroy the ozone layer faster than CFCs and it requires huge amounts of clean water to produce huge amounts of hydrogen. Where exactly will we be getting that water when water shortages are common?

Ok so fuel cells aren’t going to met the base load or even power cars, why develop them? Well, because small ones can replace batteries when the cost per watt is premium and the convenience of pouring a mix of methanol and water into it is better than charging. So laptops, cell phones, remote relay stations and satellites can use them, sure the battery they replace cost $100 and they cost $400, but you never have dead battery since you can use Everclear as fuel.
Why not cars? The conversion between watts and horse power is 750W to 1HP, so a small engine producing 100HP is replaced by a 75KW fuel cell. To be fair you can use batteries and capacitors to boast the amount of power to get off the line but you still need a 7.5KW fuel cell to get sustained performance at highway speeds. As a reference point high end lawn mowers use a 7.5KW engine and cost $400 dollars. From a practical standpoint mount a lawn mower engine in the fuel cell car and have it run a high current DC generator and pocket the huge savings. Since you will get 60MPG you won’t be getting gas much, you can use the money to buy lots of snacks and drinks to keep you going between trips to the gas station. The government can save money too, since they will be the ones paying to put hydrogen at the pumps. If they really want to spend the money on something they can pay to develop renewable energy.
How can the hydrogen economy be saved? Pending a major advance that can rapidly convert water and sunlight into hydrogen and oxygen, and a major advance in the storage of hydrogen, it can’t. Now the technology can be put to good use. For example wind power is mostly available in the morning when demand is low so it is wasted since electricity can’t be stored. There is the magic word: stored. If the electricity is going to be wasted anyways use it to hydrolyze water, and store the energy as hydrogen. Now you could use the hydrogen and fuel cells or better gas turbines for peaking generation at high demand, but looking at a map of where wind generation is common puts it close to cities with lots of oil refineries. Guess what! Oil refining requires huge amounts of hydrogen to crack heavy tars and waxes into lighter produces like jet fuel, diesel and gasoline. They will pay a premium for renewal hydrogen, and even better they can produce more fuel grade oils from the same amount of crude oil.
Now I can be accused of not thinking long-term since I still say internal combustion engines are better, but I counter with hydrogen isn’t long term either. We need base load generation and clean cars, not fancy batteries. Long term (as in 30 years) is efficient biomass, solar, wind and tide energy, to produce base load and make low cost synthetic fuels. Better battery, transmission and capacitor technologies will be required to move and store the “not on demand” renewal power sources. Nuclear power is going to be required too, since if coal is out and fusion isn’t practical, fission is the only solution. However, the point of this essay is not to propose radical change but to better work with what we have. Sure if a fusion reactor comes online in the next few years, or someone develops a integrated fuel cell system that can use “$3 a gallon vegetable oil” for fuel, cost about the same as a diesel engine of similar output and run for years at 99% availability I will admit I was wrong. In the mean time perhaps someone (like the DOE) will give me a grant start a lab, plant several thousands of acres of mesquite trees and demonstrate the power of biomass. (Of course I have a better plan that I let on, since this site is freely available I would get ripped off if I gave out the whole plan.)

I didn't put references since the information I used is free available on the internet, but if you want some let me know.