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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Permalink Reply by Cobraphx (Matt) on August 19, 2008 at 10:44pm: Nice try to make Hydrogen look like a good idea...

1) According to hondaclarity.org The Honda Clarity FCX gets 68 miles/kg, not 100. You seem to have exaggerated it's efficiency by 32%.

2) According to the Department of Energy, 95% of Hydrogen sold in America is made by steam reforming NG, this process releases 5.5kg of CO2 per kg of hydrogen produced. Not exactly renewable or clean.

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.

4) If you use renewable energy to produce Hydrogen through electrolysis the efficiency of the H2 system gets even worse. To make 1 kg of H2 through electrolysis consumes ~ 192MJ of electricity. Now add the 10MJ to compress it to the FCX's 5000psi, we've used 202MJ of energy to get one kg of H2 in the right form for the FCX. But we haven't moved it anywhere yet, let's add 10% loss there (fancifully low) so we get 222MJ (This is 62kWh of electricity) to propel the FCX 68 miles. .

If we take that same 62Kwh of cleanly generated electricity and put it on the grid to power an electric car instead, it's quite a different story. Let's say the grid and charging losses are 33%, that leaves us with 41kWh in the vehicles battery. The Tesla Roadster (0-60 in 3.9seconds) gets 3.3mi/kWh or goes 135mi on the energy to produce 1kg of H2 at 5000psi (double the efficiency of the FCX). The GM volt gets about 5mi/kWh or 205mi on 41kWh. (triple the efficiency of the FCX) The Aptera Type-1e gets 12mi/kWh according to numbers posted on their site, this means it would go 492mi on that same power (more than seven times the efficiency of the FCX).

Hydrogen pales in comparison to electric cars that are are on the road now, and is miserable against cars that will be on sale before the first Hydrogen Fuel Cell vehicle is for sale on a showroom floor.; ▶ Reply to This

Permalink Reply by Kenneth Koch on August 20, 2008 at 7:46am: You make some good points. I used to think that the hydrogen holy grail was a long way off but new technical achievements are forcing me to reconsider.

I read that a new and improved Honda Clarity would hold 5Kg of H2 and get 100m/Kg.
Lets use the 2008 numbers of 70m/Kg and a H2 capacity of 4Kg.

We both agree that NG is currently the prefered source for H2. I don't think we should compare grid energy with electrolysis. We could compare miles per Kg of NG in a ICE, a battery powered car and a hydrogen powered car. OK?

NG contains about 53 Mega joules per Kg
Gasoline has about 47 Mega joules per Kg
It takes about 4Kg of NG to make 1 Kg of hydrogen
It takes about 3.5 Kg of gas to make a gallon of gas.
Using the above numbers:

A prius gets 48 m/g so it would go 14 miles on a Kg of gas or 15 miles using a Kg of NG (oops I was off by 2 in my first post)
A 2008 Clarity will go 68 miles on a Kg of H2 or 17 miles on a Kg of NG
A Volt goes about 1.5 miles on a Mega joule. We will loose at least 75% of the 53 Mega joules getting the NG energy to the battery. The volt then travels 20 miles on a Kg of NG.

I don't see why your using words like "nice try!" and "miserable"

http://en.wikipedia.org/wiki/Energy_density; ▶ Reply to This

Permalink Reply by Cobraphx (Matt) on August 20, 2008 at 10:25pm: Sorry about the "nice try" part, but miserable efficiency when FCV are compared well to wheel to with electric vehicles is what it is. Only 10-30% as efficient seems like a huge waste of clean green electricity, and lack of efficiency is exactly why we have an energy problem now.

If you are using H2 produced from NG to power the Honda FCX Clarity, you might as well just burn the NG in a CNG Prius. You get the same efficiency in a $26,500 converted Prius as in the $500,000 Honda FCX Clarity. Here's a reference http://www.arb.ca.gov/msprog/zevprog/symposium/presentations/brooks... take a look at page 23, update the Honda to the 2009 efficiency of 68mi/kg and you are in a dead heat with the CNG Prius. Not too exciting for $475,000 more IMO.; ▶ Reply to This

Permalink Reply by Chris Cozby on November 13, 2008 at 1:02pm: 2008 Ford F-150 5.4 Triton V-8
16 MPG pre H2O2 injection
23 MPG post H2O2 injection
Several tests were completed under, and only under the very same conditions (down to the same fuel pump athe the same station) and the results where consistant. Could not smell any emissions in the exhaust, etc.
This is not a fuel cell, it is on board generation using the energy that is already present under the hood. If anyone would like to know more, please feel free to email me and we will discuss further.

Sincerely,
Chris

cozbyc@gmail.com; ▶ Reply to This

Permalink Reply by DubleDeuce on August 23, 2008 at 11:57pm: <<It takes about 3.5 Kg of gas to make a gallon of gas.>>

SEE, even converting from gas to gas you loose some in the process. :--)

The Deuceman; ▶ Reply to This

Permalink Reply by Chris Cozby on November 13, 2008 at 1:02pm: 2008 Ford F-150 5.4 Triton V-8
16 MPG pre H2O2 injection
23 MPG post H2O2 injection
Several tests were completed under, and only under the very same conditions (down to the same fuel pump athe the same station) and the results where consistant. Could not smell any emissions in the exhaust, etc.
This is not a fuel cell, it is on board generation using the energy that is already present under the hood. If anyone would like to know more, please feel free to email me and we will discuss further.

Sincerely,
Chris

cozbyc@gmail.com; ▶ Reply to This

Permalink Reply by goneaway on August 24, 2008 at 5:30pm: while I agree that "electric only" has its place and that is for retired people to drive to the supermarket..

even in a perfect world you are talking about limited distances and extended recharge times.

When I was in college I would drive from swarthmore to princeton 3 times a week if i owned an AVERAGE not a million dollar electric plugin i could have never done that.

Today i am lucky enough to work from home thanks to the Interweb but if i couldnt I would have to drive 160 miles round trip minimum which i could never do in an electric plugin.

I dont live in the middle of nowhere.
Everyone I know commutes well over an hour and being only 80 miles from the 5th largest city in the country and one of the largest in the world I have absolutely ZERO access to a train or bus to take to the city if i had to. Well not completely true i could walk a little over 10 miles to a bus...

Its a lofty ideal

but it wont sell to someone that is making a decent income and has stepped into the dark side and bought a SUV or Mustang Cobra

I mean CRAP I owned a real 60's muscle car mustang that could smoke the tires until they blew off the car.... but once it was apparant that a few of my friends died in 2 different wars fought over oil it wouldnt matter how much money i had if it was going to people that hate us.....

The most disgusting site i often see are idiots driving alone in a SUV or Large Truck with a Yellow or American Flag Ribbon on the tail gate...

They dont have a clue that they are funding at least $1500 a year on average .... people that hate us.....

$1500 in countries where the average income for a year is $300 is enough to do some real wrong.... To put it in american money it would be like someone gave an average american $250,000. what do you think you could get the average american to do if given $250K???
Now Multiply 250k by every SUV on the road in america..

so when i look out on the highway from my porch and see a few thousand SUVs going up the street every day IT TICKS ME OFF....

o wait what was the question

oh yea

pure plugins wont work for most people... at least not untill you can get a few hundred miles on a charge.; ▶ Reply to This

Permalink Reply by Chris Cozby on November 13, 2008 at 1:01pm: 2008 Ford F-150 5.4 Triton V-8
16 MPG pre H2O2 injection
23 MPG post H2O2 injection
Several tests were completed under, and only under the very same conditions (down to the same fuel pump athe the same station) and the results where consistant. Could not smell any emissions in the exhaust, etc.
This is not a fuel cell, it is on board generation using the energy that is already present under the hood. If anyone would like to know more, please feel free to email me and we will discuss further.

Sincerely,
Chris

cozbyc@gmail.com; ▶ Reply to This

Permalink Reply by RWC1972 on August 20, 2008 at 9:11am: You're also making the assumption that 1 kg of hydrogen and 1 kg of gasoline occupy the same space when in fact they do not.

A typical car carries 10 to 16 gallons of gasoline onboard, taking space of 30 to 45 liters. Assuming that hydrogen fuel cell vehicles have twice the efficiency of gasoline vehicles, they will have to store between 5 and 8 kg of hydrogen, which would take anywhere between 200 and 400 liters of space, almost 10 times larger than current gasoline tanks.

So what does energy density matter when the application is not practical?; ▶ Reply to This

Permalink Reply by Kenneth Koch on August 20, 2008 at 9:36am: The new Honda Clarity will use a new light wieght carbon fiber fuel tank that can handle H2 at 10,000 PSI. Honda has mentioned effiencies of 60% vs 16% for an ICE. These are some of the technical improvements that cause me to think that a practical solution may be on the horizon.

In the near time US NG is a much better fuel than foriegn oil IMHO. I would like to hope that their is a longer term solution also. For now; drill drill drill..................; ▶ Reply to This

Permalink Reply by Mike Johnston on August 24, 2008 at 8:20am: Compressed H2 doesn't take up much space.; ▶ Reply to This

Permalink Reply by Mike Johnston on August 24, 2008 at 6:02pm: There is around a pound of hydrogen in each gallon of gasoline. You can't compare the density of a liquid with a gas. You have to compare by weight, so a gallon of gas equals a pound of hydrogen in terms of the amount of hydrogen.; ▶ Reply to This