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On the right is GM's fourth generation fuel cell stack, used in the 2007 Equinox FCV. On the left is the dramatically shrunk, lighter fuel cell, which still outputs the same power.  (Source: GM via Treehugger)

The old Equinox engine with its fuel cell system is seen on the left, with the petite new system on the right.  (Source: GM via Treehugger)
Company plans to sell vehicles with the system by 2015

Is the automotive market ready for fuel cell vehicles?  Is it even ready for electric vehicles?  

In both cases GM thinks the answer is "yes" and it is leading the charge to deploy these technologies.  The 2011 Chevy Volt, set to launch later this year, will be the first mass market electric vehicle to be sold in the U.S. (past EVs saw limited distribution).  And GM announced today that it was beginning testing of production-intent fuel cells in preparation for a 2015 fuel cell (FC) vehicle launch.

In 2008, we tested GM's Equinox FC vehicles on the roads of Las Vegas.  Since then the fleet has logged the most miles of any fuel cell fleet GM is aware of -- 1.3 million everyday miles in total.

GM has applied those lessons to make a dramatically improved next generation fuel cell systemdesign.  The design is 220 pounds lighter, is about half the size, and uses only about a third of the precious platinum that the 2008 cells used (80 grams used in the old stack, 30 g in the new stack).

Charles Freese, executive director of GM's Global Fuel Cell Activities states, "Our learning from Project Driveway has been tremendous and these vehicles have been very important to our program.  The 30 months we committed to the demonstration are winding down, but we will keep upgrades of these vehicles running and will continue learning from them while we focus efforts on the production-intent program for 2015."

The launch of official testing of the new design will coincide with the wind down of GM's 2007 project, dubbed "Project Driveway".  Elaborates Freese, "Some of the 119 fuel cell electric vehicles in Project Driveway will receive hardware and software upgrades and will become part of a technology demonstration program with the U.S. Department of Energy. Others will be driven by businesses and a few will be used to continue showing that, with proper fueling infrastructure, hydrogen fuel cells are a viable alternative to gasoline-powered vehicles.  We will continue to use the Project Driveway fleet strategically to advance fuel cell technology, hydrogen infrastructure, and GM's vehicle electrification goals."

Stephanie White, a fuel cell advocate who was among the first Project Driveway participants and is an avid blogger on hydrogen in the automotive sector, was the first individual to receive a long-term loan of the next generation fuel cell vehicle.  

She describes her past experiences, stating, "Driving the Chevy fuel cell around LA has been an amazing experience.  People are always stopping me to ask questions about the vehicle and I tell them how powerful and eco-friendly it is."

Durability remains a concern for the cells.  They currently are good for about 80,000 miles.  GM hopes to bump that to 120,000 miles by 2015.  GM also hopes to get the amount of platinum used in the stack under 10 g, while maintaining equivalent power.  By 2015 the company plans on producing about 10,000 fuel cell vehicles a year.

GM still faces significant challenges even if it can produce a moderately affordable fuel cell design.  Foremost is the lack of hydrogen infrastructure.  With no infrastructure in place throughout much of the country, FC vehicles may only be able to operate in limited areas like New York and California.

 



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RE: Hydrogen creation efficiency?
By randomly on 3/20/2010 1:08:22 AM , Rating: 3
Theoretical efficiencies and efficiencies taken out of context can lead one to an overly optimistic (or pessimistic) conclusion. Efficiency percentages can be deceptive because it's unclear what the reference values are, Lower heating value or higher heating value, STP or pressurized, wet or dry. I find it best to look for the total energy input to yield 1 kg of dry hydrogen at 300 bar and stay away from efficiency numbers. It's always good to reference results obtained from real world systems as a reality check.

Existing Hydrogen automotive refueling stations based on electrolysis consume about 75 Kwh/ kg of hydrogen produced. This includes all the necessary processing steps needed to make the hydrogen vehicle ready including the water removal and pressurization for loading it into the vehicle.

Automotive fuel cells will output about 16 Kwh from that kg of hydrogen, this is roughly equal to a gallon of gasoline in an ICE. This is almost an 80% loss from the starting energy source.

Electrolysis production of hydrogen and fuel cell recovery of the electrical energy is essentially a different form of a battery. To compare it to Lithium battery technology
It's advantages are:

Higher energy density - 800 wh/ kg including the container (high pressure composite wound tank, but NOT including the fuel cell systems needed to recover the energy. Lithium batteries are 100-350 wh/kg. The larger the amount of energy you want to store, the bigger the advantage for Hydrogen.

Doubling fuel capacity is relatively cheap, you just double the volume of the gas cylinder. With Lithium batteries however doubling the capacity doubles the cost, this tends to freak out the car companies.

Rapid recharge (refueling) rate - 4-10 minutes, Lithium batteries 5-30 minutes.

Disadvantages:
FC have poor overall cycle efficieny 20-25% vs 90+% for lithium cells so require 4-5 times the energy for equal results. Incremental improvements will be made here but there are no apparent major improvements possible.

There is no hydrogen delivery infrastructure, the cost to build it would be enormous and take many years. Without that infrastructure in place it is difficult to incrementally deploy FC vehicles.

There are also lots of other issues outstanding, safety issues with high pressure tanks, flammability and explosive nature of hydrogen, high pumping costs, embrittlement issues, High FC cost and complexity, FC lifespan, catalyst poisoning etc. but those issues probably can be managed or workable solutions found however they will add years to when a practical fuel cell system can be deployed on a significant scale.

If one eliminates reforming natural gas there are currently no economical sources of hydrogen production. Until you've eliminated all fossil fuel power production there are always going to be better places to use your electrical power than producing hydrogen with electrolysis.

The only potentially cost effective approach for hydrogen production is high temperature nuclear reactors running a sulfer-iodine synthesis cycle. Unfortunately none of the GEN IV high temperature reactor concepts is expected to be deployable till 2030+. Because of the difficulty of high temperature reactor materials development, even the reactor types with high temperature potential will be unlikely to run hot enough to drive a sulfur-iodine cycle with the early versions.
An MIT study concluded that even with expected technology improvements that by 2020 FC vehicles would still be less efficient well to wheels than a simple Diesel hybrid.

Car companies like FC more than batteries because system cost is fairly independent of fuel capacity and there is more potential to cost reduce FC than to cost reduce batteries. Cheaper costs for car companies is good, but the much higher fuel cost and a huge fuel infrastructure cost will have to be paid for by the consumer.
On the other hand batteries can be deployed incrementally in PHEV where limited battery range like the 40 mile Volt will still address the needs of 80% of the commutes, uses the available gasoline infrastructure for long distance travel, and allows a slow ramp up of electrical infrastructure to handle charging loads. When a smart grid is implemented charging PHEV's can be used for grid energy storage for load balancing of the grid which will make wind power and other intermittent sources somewhat more valuable than currently.

By the time FC's are ready for deployment in a decade their window of opportunity may have closed with the market driven advancement of batteries, PHEV's, Smart grids etc.


RE: Hydrogen creation efficiency?
By porkpie on 3/20/2010 1:33:08 AM , Rating: 2
"Rapid recharge (refueling) rate - 4-10 minutes, Lithium batteries 5-30 minutes."

Was this a typo? What sort of postulates are you using to get an automotive Li-Ion array recharged in 5 minutes?


RE: Hydrogen creation efficiency?
By randomly on 3/20/2010 10:18:26 AM , Rating: 2
It's a attainable rate based on current lithium charge rates. The charge rate is limited by cooling and the facilities to deliver the power at high rate. The batteries themselves can take these kind of charge rates.

I should have said this is for PHEV(8kwh)class battery capacity, not a full range electric vehicle. That was an error.

For a fairer comparison in similar range and usage models with FC charge times of 60-90 minutes is more realistic.


RE: Hydrogen creation efficiency?
By JediJeb on 3/22/2010 10:39:36 AM , Rating: 2
quote:
Existing Hydrogen automotive refueling stations based on electrolysis consume about 75 Kwh/ kg of hydrogen produced. This includes all the necessary processing steps needed to make the hydrogen vehicle ready including the water removal and pressurization for loading it into the vehicle.


What is the energy required to produce 1 gallon of gasoline? As in how many Kwh does it take to produce one gallon of gasoline from crude oil?

If we are to compare Hydrogen to Gasoline in efficiency of production we need to know that power cost as well. I know right now gasoline is better than hydrogen, but everyone leaves out how much energy it takes to distill gasoline from crude oil when they start making comparisons to hydrogen or other fuels like ethanol. You don't just drain gasoline off from the crude you have to put energy into it to distill it just like you would ethanol, or to electrolyze hydrogen. Even if you are burning some of the oil to get the heat to make the gasoline you have to account for that. If it takes 20Kwh to make a gallon of gasoline then that makes it much more efficient than hydrogen, if it take 80Kwh then you are getting closer to them being equal. I can search and find lots of numbers touting % efficiency but no hard numbers on what it takes to actually produce the gasoline.


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