Friday, September 12, 2008

Hydrogen Combustion, Electric Vehicle Comparison

Continuing the story of the "Alternative Energy and Sustainable Living Show": Abe, the owner of a hydrogen combustion car, was parked next to the EV area so we spent some time chatting. The comparison of hydrogen combustion and EVs made for a good discussion.

Before discussing the finer points, there are several things that Abe and I agreed on that should be pointed out. 
Both of these solutions:

  1. Can be powered by domestic electricity. This can greatly improve national security.
  2. Can be powered by renewable energy. This reduces pollution and greenhouse gases.
  3. Are cheaper than gasoline.
Here is the five or six point comparison from my EV driver perspective.
1) Efficiency (kWh per mile)
His hydrogen tank took about 50kWh of electricity to make the H2 to fill up. This gave him about 50 miles of range. Comparably that same 50kWh would give an EV like Gary's Insight over 160 miles of range.
2) Refill Time
For refilling, Abe had to take the hydrogen as it was produced and compress it into his car's tank. He did not have a method to have it highly compressed and waiting for a quick fill-up. He said that it would cost him about 60 thousand dollars to install a hydrogen quick fill station. Without such a station it takes him about 5 hours to fill up. EVs are currently comparable to this charge time. With existing outlets charging can take 4-6 hours. With industrial levels of power and fast charge stations (that are not generally available) charging up to 80% levels can be done in 5 minutes. Both HC and EVs are currently slow to refill and could be faster with the right infrastructure.
3) Range
Abe’s 50 hydrogen range is comparable to the range of most EVs. After Abe's 50 miles worth of hydrogen are exhausted, he can flip a switch and run on gasoline. A few EVs have "range extenders" which are not much more than a fuel powered generator that can be hauled as a trailer or is included in the vehicle. With hydrogen combustion this range extending would likely be common, whereas it is rare (today) with EVs.
4) Infrastructure
For electric cars, there are power outlets in every home and business in America. You can go to any home store and pick-up a long extension cord. Granted some apartment dwellers and other people that park on the street or ill-equipped garages may not have convenient access to outlets, but the technology of installing an outlet well understood and can be done by any electrician.  Comparably, hydrogen is not generally available, so unless you live near one of the few hydrogen stations, or can generate it yourself it is not currently viable.
5) Cost
This one has two sub sections: upfront costs and operating costs.
5a) Upfront costs: The initial cost to convert a vehicle from gasoline to hydrogen is small compared to converting a car to electric. I have heard of EV conversions being done for less than $2000 using motors from a scrapped forklift and batteries discarded from a FedEx fleet. However, I have also heard of EV conversions that use AC motors and lithium batteries that cost $25000. Converting a car to hydrogen combustion still utilizes the internal combustion engine and does not require expensive batteries. It does, however, require that you have a fueling method. If you have to build this yourself, in your home, this is not free.
5b) Operating costs: As discussed in item 1, Efficiency, above the EV is about 1/3rd the cost to fuel per mile and additionally would require far less maintenance. The current cost of gasoline is about $4 per gallon. At $0.10 per kWh that $4 will get you about 40 miles in Abe’s hydrogen combustion car and about 130 miles in Gary’s EV.

What is the final tally when we compare Abe’s HC and Gary’s EV?
1) Efficiency – The EV is about 3 times more efficient.

2) Refill Time – This one is a draw. Both are currently slow.
3) Range – The “Clean” range of both are equal, but the HC has a range extender.
4) Infrastructure – EVs clearly win this one.
5a) Upfront costs – This is a tossup. It all depends on your source of H2.
5b) Operating costs – EVs are cheaper to fuel and maintain.

Score: EVs 3, HC 1, Draw 2

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