This week, AutoblogGreen reported on the evolution of GM’s fuel cell cars. The new fifth generation fuel cell stack is much smaller than the previous fourth generation stack. Reading the features of the new FC seem to indicate that GM is trying to “turn the corner” on fuel cells – this unit is designed for manufacturing, as well as dramatically reducing the amount of platinum catalyst used by 62.5%, from 80g to 30g (1.06oz) at the same output power level (93kW/120HP). Thats about $1350 in platinum for the fuel cell. The goal is to eventually get the platinum content down to 10g, less than $500, and to manufacture about 10,000 per year by the middle of the 2010-decade.

Technology is still progressing in terms of making fuel cells affordable and small enough to put into a car. But there are still a number of other pieces to get a hydrogen infrastructure in place.

Hydrogen isn’t naturally found: There is no hydrogen mine, or hydrogen reserves. There are a few ways to “make” hydrogen – electrolysis of water (50% efficient) or steam-based reformation of natural gas into hydrogen. Compared to just plugging in a car and charging batteries for an electric vehicle these are less efficient, however there is currently a limit on how many batteries you can put in a vehicle before you start sacrificing passenger room and cargo space. Pure EVs might only have a range of 100-200 miles.

Vehicle Range: Strides are also being made in this arena as well – Toyota recently announced that their FCHV-adv Highlander SUV that got an extrapolated 431 miles per tank (they drove about 300 miles and extrapolated based on the fuel left in the tank). Previously, the range on fuel cell vehicles had been between 200-300 miles per tank.

Hydrogen Fueling Stations: While there are plenty of gas stations, and you have electrical outlets in your home that would allow you to recharge an EV, there aren’t a whole lot of hydrogen refueling stations, let one ones open to the public. California might have 46 retail locations by 2014, but many are private ones that are built for small capacity refueling of fleet test vehicles or OHVs/golf carts.

Fuel Cell Stack Lifetime: The fuel cells at the turn of the century would last for about 35,000 miles. The fourth generation fuel cell as it is now can get 80,000 miles before it needs to be replaced. The new fifth generation will get a little more than 120,000 miles per GM. This is still low compared to a traditional gasoline engine which can last a very long time if the owner takes good care of it.

There is one shining opportunity for fuel cells though. Its to team up with E-REVs and become the alternate generator, replacing the gasoline engine. The two fit together quite well – you don’t need too big of a tank because you only need 300 miles combined (40 on electric, the remainder on FC), turning on and off the FC doesn’t make noise or vibrate, unlike traditional gasoline engines, and they’ll have much lower duty cycles – 120,000 miles for the FC would be enough to outlast the batteries by a large margin. And hydrogen stations wont need much storage capacity because you’ll probably only be filling up every 6-8 weeks (they see a lower visits per FC vehicle), which means their storage infrastructure doesn’t need to bee too large – instead of lots of equipment to extract hydrogen from water or natural gas and the storage to sell thousands of kg of hydrogen per day, they only need the equipment to generate and store a fraction of that.

The year 2015 has been talked about for the production of fuel cell vehicles. Thats about the time I would expect the Voltec power train to start appearing in other vehicles. It would seem to be a great opportunity to allow a few vehicles to be sold – probably geographically limited to start, since the hydrogen infrastructure will still be sparse. As production ramps to 100,000 in 2020 and 1,000,000 in 2025, they can not only displace the electric generator int he Volt and other future E-REV cars, but also the engine in standard plug-in hybrids.

While 2012 is only three years away, Toyota has a firm base on which to develop a PHEV – the Prius. Taking the Prius platform and adopting it to PHEV would require some engineering changes – notably the ability to transfer more of that battery energy to the wheels. The Gen III Prius can output up to 60kW of power through the electric traction drive. Toyota would need to develop a system to expand that number up to about 80kW to allow a Prius to drive at reasonable rates

To get a good idea about what size battery they would need, I consulted a recent Argonne national labs electric vehicle study that showed a car with an 8kWh li-ion battery pack (5kWh usable) would be able to drive for about 15 miles at city driving speeds before using gasoline. This would seem to match up with Toyota’s 12-18 mile target. This 8kWh pack (by 2012) would probably source 1,500W/kg and have a specific energy of 100Wh/kg, and would weigh 100kg with the battery and electronics. Neither of which are unreasonable targets.

The Argonne study indicates that for the average driver, it would reduce fuel consumption by 62% over a conventional vehicle and a 48% reduction over a standard hybrid electric vehicle. This would almost double the MPG of the Prius from the current 50MPG to 97MPG. These figures are dependent on commute distance and driving conditions however – those with longer commutes or more highway driving would likely see reduced fuel economy.

via GCC