Gasoline Fuel Cell Would Boost Electric Car Range

December 5th, 2011 by Nicholas Brown

Fuel Cell Powered Chevrolet Equinox

Introduction to the Problem

You, like most people, may already be familiar with the fact that electric vehicles have a relatively short driving range compared to traditional gasoline powered vehicles.

Most people do not need to drive more than 80 miles per trip, but range anxiety is a problem helping to prevent the widespread adoption of electric vehicles.

People, in general, would like to have a driving range significantly more than the distance they usually drive, just in case they have to drive far, which is perfectly understandable.

This issue can be addressed, albeit with consequences, using a backup electricity generator that can either charge the electric vehicle’s batteries, directly power the vehicle’s electric motor if the battery dies, provide additional power to the motor if necessary, or all of the above.

One of the consequences of including a generator in an electric vehicle is that it will increase the vehicle’s weight, and hence degrade efficiency as well as performance. Another consequence, and the most important one, in my opinion, is that the generator is very expensive, so it increases the price of the vehicle.

However, the point is that the backup generator can extend driving range to several hundred miles. Chevrolet did this with the Volt.

Volt owners enjoy the peace of mind that comes with knowing that they can drive even farther than they could in a traditional gasoline-only vehicle, which provides a range of only a few hundred miles.

Now, back to reality: Backup generators are too expensive, and they are also too inefficient (despite being more efficient than a hybrid gasoline engine).

New Generator Could Address Range Issue Efficiently

Researchers at the University of Maryland have developed a type of generator that they say would boost the driving range of electric vehicles (with the help of some fossil fuels) and keep carbon dioxide emissions low. Some key points:

The generator uses solid-oxide fuel cells, which can be powered by some readily available fossil fuels, such as natural gas, diesel, and gasoline (unlike hydrogen fuel cells).
The key reason this could boost range is because the energy density of gasoline is very high (12,500 Wh/kg).
The researchers developed a new electrolyte materials and changed the cell design a bit in order to make it more compact than traditional solid-oxide fuel cells. Traditional solid-oxide fuel cells are too large for vehicles, but the researchers say this new one produces ten times more power for its size. This means that it could be ten times smaller than a traditional gasoline engine and produce just as much power, making it a much more suitable candidate for electric vehicles.
Another problem with traditional solid-oxide fuel cells is that they have to be heated to very high temperatures of 900 ⁰C in order to function correctly (this is the operating temperature). The researchers say that they lowered the operating temperature by hundreds of degrees to 650 ⁰C, which is not only a cheaper and easier temperature to maintain, but cheaper materials can be used. (Higher temperature materials tend to cost more money.)

This improvement is impressive, but it still needs work. Turning it on and off with each trip would cause too much wear and tear, shortening it’s life, so the car would need to include a battery pack that it would keep charged. Also, these fuel cells still use fossil fuels — so, even though they could help to facilitate the adoption of more efficient electric vehicles, they would still rely on economically and environmentally unsustainable fossil fuels a bit.

h/t Technology Review | Photo Credit: svacher

About the Author

Nicholas Brown writes on CleanTechnica, Gas2, Kleef&Co, and Green Building Elements. He has a keen interest in physics-intensive topics such as electricity generation, refrigeration and air conditioning technology, energy storage, and geography. His website is: Kompulsa.com.

http://esotericwombat.blogspot.com/ EsotericWombat

This is nice and all, but the solution to range anxiety is to electrify the highways.
Anonymous

Interesting article on a very important subject. The rapid advancement of technology is amazing. Now that the large car companies like General Motors and Ford have started to utilize the technology that has been around for awhile, maybe it will snowball towards faster realization of these Eco-friendy technologies.
Anumakonda Jagadeesh

Gasoline Fuel Cell is future energy storage.

Dr.A.Jagadeesh Nellore(AP),India
E-mail: anumakonda.jagadeesh@gmail.com
http://twitter.com/TooomPlahn Thomas Plahn

Are they burning fuel to heat it up or using electric from the battery? I’m just wondering…

Size and I’m assuming weight would be big benefits to this system The Chevy Volts dua power plants (battery/generator) add weight and take up room that could otherwise be allotted to passengers or luggage.

The fact that this system is being considered is tribute to GM’s foresight in bringing the Volt to market. GM is in an ideal position to take advantage of advanced power generation technologies such as fuel cells. No other company has a production model that could take advantage of these.
http://www.sequence-omega.net Anthony

The eventual goal as stated in the source article of 350C seems a bit hot, but maybe its reasonable. As stated, it seems like a great way to provide for range extension, as well as for providing a fast-refill capability on longer journeys.

By the time this becomes commercially viable (5-10 years) batteries will be able to get us around town (100+ miles) no problem. But a four or five hour drive isn’t possible due to a number of issues (battery size, fast recharge, etc). Having a small fuel tank and this as a range extender (if its twice as efficient as ICE) would allow people to drive for 300-400 miles, along with being able to stop, refill the gas tank in five minutes, and be off for another 300 miles.
- Anonymous
  
  Fast recharging isn’t really a problem. The Toshiba SCiB lithium-ion battery that Honda is using in their EVs will take a 95% recharge in less than 20 minutes.
  
  What we need is around 175 miles of highway range. That would allow a 500 mile driving day with two short stops. About what people would do with ICEVs.
  
  The question is whether range will increase or fuel cell price decrease fastest.
  - http://www.sequence-omega.net Anthony
    
    The problem with fast charging isn’t the batteries.
    
    Lets walk through this – 175 miles of highway range is about 350Wh for a Volt-style vehicle, or 61kWh. So at what rate do you have to recharge that battery to get 61kWh into the battery in 5 minutes? 1.28MW. How big of copper conductors do you need to push 1.28MW of 600V/2100A DC power back into the battery? The tables I have don’t go up that high – you’d need at least seven 4/0 AWG copper conductors in parallel to carry that much current.
    
    How is the grid going to handle going from 0 to 1.28MW for 5 minutes then turning off? You’d need some sort of grid-side load balance to take some of the load.
    - Anonymous
      
      You need the sort of electrical service that we install at highway interstates. The sort that will power multiple deep fat fryers and lots of AC. That’s where we’re putting Level 3 chargers now.
      
      And you’d need some honking big connectors.
      
      Do the math with close to 20 minutes. Don’t distort the issue by using five.
      
      0.35kWh/mile. 175 miles. Add in another 10% for charging inefficiency. 18 minutes. Say 67kWh.
      
      (I tried with an online DC calculator and the size looked too small.)
      
      Yes, there could easily be a need for buffering at the site. Some ultracapactors or batteries could do that part of the job as well as lowering peak needs.
    - Anonymous
      
      Here’s what I put in…
      
      600 vdc
      335 amps (67kWh/600×3 – one third of an hour charge time)
      5′ for cable length. Obviously could be much shorter with clever design. 2% acceptable loss.
      Calculated size 9 AWG
      
      1% acceptable loss = 6 AWG
      5% acceptable loss = 13 AWG
      
      As infrequently as most people would use a Level 3 charger (or should we call this a Level 4?) I would think a 5% loss would be acceptable. Charging up with $0.12/kWh power would make the total cost only ~ $0.40 higher.
      
      You see a mistake I made? I’m not used to working with these sort of numbers. I’m sort of a 120vac guy.
onthefence

The other important consideration is efficiency of energy conversion. And maintenance costs. Not to be a naysayer, but 650C is still pretty hot to be carrying around in your car. That said, this is another concept that could be the saving grace for a complete conversion to plugin vehicles.

Range is not so much something to worry about, but it is a reality, an important nuance to bring up. In other words, why haven’t we heard of the thousands of EV drivers over the last decade and a half complain about getting stuck with no charge because they didn’t plan properly. It’s because if you have half a brain, you won’t put yourself in that situation. You’ll use your secondary gas car or rent/borrow a gas car or take public transit to make that long trip. It becomes part of your routine mental process, just like you constantly monitoring your cell phone charge state.

But range COUPLED WITH CHARGE TIMES means that EVs are only practical for certain types of transit. This is an important distinction from range anxiety. You can’t drive cross country very efficiently for example, but you COULD do it as shown by a number of cross country or around the world EV races.

Hopefully people will begin to understand EVs better than they currently do.
- Anonymous
  
  love this:
  
  In other words, why haven’t we heard of the thousands of EV drivers over the last decade and a half complain about getting stuck with no charge because they didn’t plan properly. It’s because if you have half a brain, you won’t put yourself in that situation. You’ll use your secondary gas car or rent/borrow a gas car or take public transit to make that long trip. It becomes part of your routine mental process, just like you constantly monitoring your cell phone charge state.