Hydrogen Fuel Cell

The holy grail is to store energy as hydrogen. Hydrogen can store 142 mega joules of energy per kilo gram. Our favorate energy source is gasoline(some hate it) at 46 mega joules per kilo gram. Better yet, If a hydrogen fuel cell is used to power a car it is 60 percent energy effecient versus an internal combustion energy at 16%. The Honda Clarity will travel 100 miles on a kilo gram of hydrogen while a Toyota Prius will tavel 7 miles on a kilo gram of gasoline.Theoretically the ICE is a Rube Goldberd design compared to the fuel cell. However; The hydrogen solution has been just as ellusive as the holy grail.

Here is good link for comparing energy storage densities. You will see that NG is a good energy storage "device".
http://en.wikipedia.org/wiki/Energy_density

PS: The exhaust is water vapor. No pollution from the fuel cell!

Tags: cell, fuel, hydrogen

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Replies to This Discussion

Permalink Reply by DubleDeuce on August 23, 2008 at 8:26pm: Michael,

You throw the word free around MUCH too freely. Both the wind turbine and the solar panel you speak so fondly of, are capital intensive. ONE 1.2MW (1,200,000,000 watts) wind turbine costs upwards of 1.3 million bucks. They last for maybe 30 years. That is 3,611 dollars a MONTH just for capital cost. That does NOT include the time cost of money (juice to you in the 'hood) , or the cost of infrastructure to hook up your new toy train to the grid. And you are stumbling over the words <<both options have only initial costs of any consequence >> and telling me it is free? Gimme a break.

We ALL KNOW the process by which hydrogen can be culled from water. It has been done for over 150 years. But we also know that the process is NOT cost effective. If you want to be the first kid on your block to say that you are driving a hydrogen powered car, FINE. Pony up the Franklin's and have at it. But don't tell us it is FREE.

And regardless of the cost, the fundamental fact is this, "It TAKES more energy to separate the hydrogen than the amount of energy you will get back.". You can't get around it by instituting some hijacked cable scheme from your neighbors pole to say that the Premium Channels are FREE. 3-5 in the big house for theft of services ain't my idea of free and it is NOT a business model for the average American consumer.

The Deuceman; ▶ Reply to This

Permalink Reply by Mike Johnston on August 24, 2008 at 8:13am: Electrolysis is one of those things which a lot of people who know very little about the subject speak with authority on it.

By your logic then electric cars are useless because it takes more energy to charge the batteries in the car than you get back out of the batteries. This is true as is your statement regarding hydrogen (since producing the H2 is akin to charging a battery) but since fuel cells are just another type of battery I really don't see much difference between the two in broad terms.; ▶ Reply to This

Permalink Reply by Kenneth Koch on August 24, 2008 at 10:22am: You alway lose energy when you change it's form. Does that mean we shouldn't make an effort to aquire food?; ▶ Reply to This

Permalink Reply by RAS on August 21, 2008 at 4:12am: Quote [" 142 mega joules of energy per kilo gram. Our favorate energy source is gasoline(some hate it) at 46 mega joules per kilo gram."

The volumes are not the same. One is a liquid at room temperature and the other is a gas. The comparison based on the weight (actually mass in your example) is only part of the picture.

To illustrate this, think how heavy an empty gas can compaired with a full gas can...same size not the same mass.; ▶ Reply to This

Permalink Reply by Mike Johnston on August 21, 2008 at 5:25am: There is an almost equal amount of hydrogen (roughly a pound) in both a gallon of gasoline and a gallon of water.

If the atmosphere was composed of primarily nitrogen and ozone as opposed to nitrogen and oxygen you could burn water as a fuel just like we do gasoline in our normal atmosphere.

Just an interesting little tidbit of info...; ▶ Reply to This

Permalink Reply by Tom Czubernat on August 21, 2008 at 4:03pm: There is much research being done on this subject by many "garage mechanics."

For burning in cars, the H2 O2 gas, sometimes called "hydroxy" or "Brown's Gas" can be produced on demand in a fairly small package. Some experimentalists are having good luck using pulsed, square wave DC current. http://tech.groups.yahoo.com/group/WorkingWatercar/ There is also a working "water torch." http://www.watertorch.com/

Many people talk about conversion inefficiencies. While important, the main point is that it's a renewable fuel, if produced by PV or wind. If produced on site, it's totally clean, minus equipment production.

Point of use energy production is the future. That would make us independent of not only foreign oil but, of multi-national conglomerates and government. Imagine one production unit making fuel for your home and your car!; ▶ Reply to This

Permalink Reply by Cobraphx (Matt) on August 21, 2008 at 6:34pm: And the electricity from those clean sources is... wait for it... Clean. That cleanly generated electricity doesn't need to be converted into to hydrogen and then back into electricity to drive a car. I really have no idea why people want to take that clean, renewable electricity to make hydrogen from water (throwing away 40% of the power generated), then compress that hydrogen (throwing away another 10-100% or more), then transport that hydrogen somewhere to be used in a FCV (thus throwing away more energy). Then you use that hydrogen in a fuel cell to make electricity to drive the car (throwing away another 50% of the energy). When you could have put that clen power on the grid and charged an electric vehicle only loosing 15-25% of the energy in the process.

For point of use, you need a solar array 3 to 4 times as large (which costs 3 to 4 times as much oddly enough) to power your house and car if you make hydrogen (60% efficient) and then use a Fuel Cell (50% efficient) to make electricity for the house and drive your FCV than if you just use the electricity to power your home and Battery Electric Vehicle and skip the H2 step. Why would you willingly throw away 60% of the electricity your solar cells can produce just to say you are using HYGROGEN... is it really that cool sounding?; ▶ Reply to This

Permalink Reply by Kenneth Koch on August 21, 2008 at 7:12pm: Matt,
You are making a great point. Some of the problems with batteries are:

1. Charging time
2. Size/range

If I can re-fuel in 5 minutes versus 12 hours I will be content paying (two or three times) more.; ▶ Reply to This

Permalink Reply by Harvey on August 22, 2008 at 12:11am: Sorry to burst your bubble.
15 minute charging time and 600 to 800 mile range...pure electric......
http://thefutureofthings.com/news/1122/nanowire-batteries-to-hold-1...; ▶ Reply to This

Permalink Reply by neil cox on August 22, 2008 at 6:25am: Quote: 3) Sure Hydrogen stores 142 megajoules of energy per kg, but the density is horrible. For reference, gasoline has an energy density of about 30 MJ/liter. Liquid H2 has an energy density of around 9 MJ/liter while compressed H2 has an energy density of 3 MJ/liter at 5000 psi and 5 MJ/liter at 10000 psi. Increasing the density of hydrogen to a usable level (5000-15000psi) requires energy, between 10MJ/kg(5000psi) and 21MJ/kg(10,000psi) and 70MJ to liquefy H2. Unquote
Yes, that is depressing, but we should be able to recover part of the 10 to 21 MJ/kg by using air car technology then put the low pressure hydrogen in a fuel cell. If we use liquid hydrogen, much of the 70 MJ/kg (is that average or best theoretical?) can cool the passengers and the wheel motors in hot weather.
15 minute charging time is possible, but rarely practical with super capacitors, A123 lithium ion batteries, and some other types that may be available in 2009. If your 100 kilowatt hour battery needs 100 kilowatt hours for a full charge, the average charging power is 400 KW = 1000 amps at 400 volts. Typically the power company wants about $100,000 to bring you that much power and they will charge you extra, if you only charge a few cars per day = use of demand. Some industrial customers already have 400+ kWh service, so they could charge electric cars quick when they were using only part of their service for about 10 cents per kWh, which may be less than you pay at home to take ten hours to charge 100 kWh = 42 amps at 240 volts.
100 kWh likely is not enough to take even a tiny car like the Tesla 600 miles. The present Tesla has a 56 kWh battery pack that is approximately half the weight of the car. Neil; ▶ Reply to This

Permalink Reply by Kenneth Koch on August 22, 2008 at 6:38am: I've read about the silicon nanotubes before this. If your placing positive ions in the anode don't you also have to place negative ions in the cathode in order to store useable charge? I see no proposed solution for the cathode.

15 minute charge to go 600 miles? That is a lot of coulombs!!!

Would that not take about 5400 amps of current? at 110V AC.
If you used 11,000 volts it would still be 54 amps. Then there would half to be one heck of an AC to DC converter.; ▶ Reply to This

Permalink Reply by neil cox on August 22, 2008 at 7:58am: Hi Ken, your 5400 amps (at 110 volts) is about right for 600 mile range of a mid size car. Much bigger ac to dc converters are used for million volt DC power lines, but they are very costly.
A large photovoltaic array of solar panels can easily supply either 5400 amps or 11,000 volts or anything in between, so we can quick charge electric cars if we have enough solar panels AND bright sun light. 11,000 or even 550 volts can be deadly, if you make a mistake. Is CNG safer? Neil; ▶ Reply to This