Hydrogen Vehicle Generates Its Own Fuel

An anonymous reader writes "Our friends at The Arizona Republic have the scoop: 'The truck is hydrogen-powered and creates its own fuel from solar energy and water, a technical feat that rivals the advanced technology being researched by major auto companies and universities. The four-cylinder engine is tuned to run on hydrogen, which is produced by a hand-built electrolysis system mounted in the bed.' You can also help this project."

Comments

Text of project description page

[greg_barton]

From http://centralphysics.com/discuss.htm before it was slashdotted...

History

Since the Mid 1990's Central High School in Phoenix has been involved in Alternative Fuel Vehicles. Originally the club was called "The Electric Vehicle Club" and we built and raced an electric car. Over the last 10 years our interests have broadened to many areas of environmental technologies and thus we are now the E-tech Club.

During the 2000-2001 school year, Senior Laci Blackford, president of our club (then the electric vehicle club) proposed that we design and build a hydrogen vehicle. Laci began research and some electrolysis design that year. Over the next 3 years several students were involved, but it was club president Soroush Farzin who, with Sponsor Mr. Waxman, coordinated the progress and turned Laci's idea into reality!

This project, to make a cleaner transportation vehicle, was motivated by the threats to our health and environment due to automobile-related pollutants. The hypothesis was that a vehicle can be powered by water and sunlight. The ultimate goal of this four-year project was to design and build a vehicle powered by hydrogen, which is generated on the vehicle from water and sunlight. The basic components of this include electrolysis cells, solar panels, a hydrogen purifying system and a storage system, all of which are mounted on a vehicle with an internal combustion engine that has been modified to run on hydrogen.

In fall 2001, we began by building a 5-watt solar-hydrogen unit and researching many safety issues associated with this technology. During the 2002-2003 school year, a 4-cell solar-hydrogen producing unit with over 320 watts of power and a purifying system were built.

In school year 2003-2004 an entirely new electrolysis unit was assembled, various components such as float valves were designed, built and tested. A storage system was also designed and tested. Ultimately, a 1998 Chevy S-10 pickup truck was purchase and modified to run on hydrogen. The solar-hydrogen system was mounted on the truck and the first vehicle in the world to run on sunlight and water was working.

Conclusion

Solar-Hydrogen Transportation Vehicle was motivated by threats to our health and environment. It was planned to build a self-sufficient vehicle that was powered by a renewable source of energy, hydrogen. This three-year project proved that a vehicle can be engineered so that it is capable of creating its own fuel by using water and sunlight, which are literally free.

This project proves that it is possible for a vehicle to produce its own fuel from sunlight and water. A Solar-Hydrogen Producing Unit has been made, which is capable of producing, purifying, pressurizing and storing hydrogen. Also, a vehicle has been converted to run on hydrogen, which is capable of doing whatever a regular vehicle can do. This project gathered known technologies and put them together to make a new field of technology.

The members of this project understand that this vehicle is not the ultimate solution to conventional gasoline-powered cars, but if it is shown that a car can run on water and sunlight, improvements may eventually lead to a practical alternative to fossil fuel powered vehicles.

The first air plane flew a few feet before it landed. Today, airplanes fly between continents. This is the example the club has kept in mind throughout the whole project.

Note: Soroush has moved onto studying mechanical engineering at Arizona State University and is interested in high performance engines. Laci is in her final year of her undergraduate program in mechanical engineering at Cooper Union College in New York City. She has continued her research in hydrogen production as well as storage in metal hydrides.

No performance comparison to batteries

[Engineer-Poet]

And it makes you wonder. When you've got a very limited amount of power input, you want to get it to your load (the axle) as efficiently as possible. Is electrolysis and an internal-combustion engine even remotely competitive with batteries for that purpose?

From what I've seen, the answer is no (electrolyzer @ ~70%, engine @ 25%, overall efficiency ~18%; batteries ~70%). It appears that you could get 4x as much range out of a solar-battery system, even more than you can get out of an electrolysis/fuel cell cycle.

Re:It's near performance already

[AKAImBatman]

No matter how many ways I try to parse your post, you're not making any sense. Allow me to explain:

The energy used by the car for propulsion is the energy already stored in the water.

No, it's stored in the hydrogen. The water is "pre-burned" hydrogen and oxygen. At a perfect conversion rate, it takes exactly as much energy to convert water to hydrogen and oxygen as you get from making hydrogen and oxygen into water.

In other words, you add energy to the system and it gets stored in a fuel form. The energy doesn't already exist in the system.

The energy from the solar panels is not the limiting factor.

Eh? Let's say we get 200 watts/m^2 of sunlight. The solar panels are only going to be ~20% efficient. That brings us down to 40 watts of energy. The electrolyzer is probably about 50% efficient, bringing our final storage rate to ~20 joules per second. That works out to about 72 kilojoules per hour. Which at a "mere" 2kw of constant use would provide exactly 36 seconds of driving time. (Actually less due to further inefficiencies.)

They'd actually get more power by storing the solar power in batteries, then using an electric drive. The only trick is that batteries tend not to be as energy dense as hydrogen.

Now, it might be true that even at perfect efficiency, you'll never get enough hydrogen from the water using solar power, but that's a different calculation that what you're doing.

What calculation am I doing? Energy is energy, and power is power. You've only got so much of it in a system, so you have to make the most of it.

Re:Ok, It's Satire, But..

[hankwang]

On an average weekend I ride over 100 miles on a bicycle, averaging about 20 mph. The amount of food and water required for these rides is actually very minimal and close to what I normally consume.

At that kind of speed (pretty impressive, unless you're doing that in a flock), your muscles deliver 200 W to the bicycle, which is about 800 W in terms of burned food. For those 100 miles, that is 14 MJ, equivalent to 0.9 kg carbohydrates, or 0.4 kg of fat/oil. A normal daily consumption for an inactive adult male is around 10 MJ. I strongly doubt that your inefficient metabolism is converting 14 MJ per non-weekend day into heat. It is more likely that you use your body fat (a couple of kg) and the glycogen storage in the muscles and liver (up to 700 g carbohydrates for a trained athlete). The rest of the week you replenish your fuel stock.

My experience is that I feel too tired to be hungry after a single day of cycling, which seems to agree with your observation. However, during a cycling holiday (3 weeks, 5-7 h per day) I surely eat massive amounts.

Anyway, fat and gasoline have about the same energy content, so a fast cyclist does 400 km per liter (1000 miles per gallon). Which is quite efficient compared to a car.