The Myth of Fuel Cell Buses (2)

Recently, I wrote about the proposal by one neighbourhood group at the waterfront to use hydrogen fuel-cell buses in place of LRT.  Many thanks to all who contributed feedback to that piece.

This item contains a lot of technical bumpf and calculations.  If anyone finds an error in this, please let me know and I will be happy to correct it, even if that worsens my own argument.  I would like some real information to be “out there” on the issue rather than a lot of hype.

At Toronto Hydro, we learn:

In windspeeds of 6m/s, the turbine produces 110 kW and the turbine reaches its rated capacity of 750kW in windspeeds above 14m/s.  On average, the 750kW wind turbine will generate 1,400 megawatt hours (MWh) of electricity per year, equivalent to the electricity needs of about 250 homes, and can displace about 494 tonnes of carbon dioxide.

Meanwhile, there is a lot of information available on the site that tracked the European Union’s fuel cell experiment.  The ticker on the left side takes you to a collection of reports at this link including the July 2006 final report.

From that report we learn a number of things:

  • The number of buses in the trial was 27. 
  • The total fuel consumed was 192,000 kg of hydrogen.
  • The total distance travelled was 841,123 km.
  • Ergo, the fuel consumption was 22.8 kg per 100 km, and the average bus travelled 31,153 km.
  • The average speed of operation was 12.8 km/hr which, by Toronto standards overall, is low, but not far off the mark for congested downtown operation with frequent stops.  Also, the value varies considerably from city to city probably as a function of the type of service, just as speed and diesel fuel consumption in Toronto vary a lot from route to route.

As for fuel production:

  • One litre of water produces 1 normal cubic metre or .09 kg of gas.  (A normal cubic metre is mesaured at 0 degrees C and 1.013 bar pressure.)
  • This process consumes 4.8 kWh for the electrolyser, and 5.1 kWh for the transformer, rectifier and gas cleaning.  Thus a total of 9.9 kWh is required to produce .09 kg of gas. 
  • This translates to 110 kWh to produce 1 kg of gas.
  • Note that less than half of the power consumed actually goes into splitting water into hydrogen and oxygen.
  • Some future saving may be possible for turbine based production by directly linking the turbine output to the electrolyser.  In this project, electrical power was usually drawn from the grid and had to be converted to the appropriate form for use in hydrogen production.

The economics of the trial in various countries were highly sensitive to transportation costs.  In other words, if you don’t have the gas right where you need it, you will pay a lot to get it there and this is counter to the purpose of saving energy.

From the TTC’s own stats, we know that an average bus travels about 69,000 km per year, or about 230 km per day (counting Saturdays and Sundays as half days).

One bus day therefore consumes (230/100) * 22.8 kg of gas =  52.4 kg of gas.

The power required to produce this gas is 52.4 * 110 = 5,764 kWh = 5.76 mWh.

For one year, the power required is 5.76 * 300 = 1,728 mWh.

The turbine at the CNE produces 1,400 mWh per year (average) and so is capable of powering less than one bus.

I have not even mentioned the question of fuel storage, maintenance and safety of very large gas volumes.  Although the brochures show nice little clusters of gas tanks, these are for very small numbers of buses in each trial city.  A reasonable fleet would be at least 100 vehicles, probably 150 or more, and the fuel storage would be correspondingly larger.

Siemens looked at the energy consumption of a Combino LRV in Basel and Potsdam about 10 years ago in this paper, and found that it consumed under 200 kWh per 100 km.  I have rounded up the actual numbers cited in the article which were 153 (Basel) and 184 (Potsdam).  The lower consumption in Basel was due to a higher rate of energy recovery due to the duty cycle of the vehicle (better regenerative brake recovery).

A hydrogen bus needs 22.8 kg of hydrogen to travel the same distance, and that costs 22.8 * 110 = 2508 kWh to produce.  Even a huge reduction in the conversion losses would not reduce hydrogen’s energy cost per vehicle km to anything near that of an LRV.  Oh yes, there’s also the little matter of vehicle capacity — the Siemens tests were conducted with an equivalent passenger load of 65, and that’s not a full vehicle.  That’s well above the service design capacity of a bus.

10 thoughts on “The Myth of Fuel Cell Buses (2)

  1. Very interesting.

    The wind turbine strikes me as a red herring.  Any turbine that could be built to fuel these buses can and should be built anyway to supply the electrical grid with clean power.  It’d be cheating to claim zero emissions by using wind turbine energy, when you’d be forcing someone else to get their power from conventional sources.  The only way I can see to truly keep emissions low would be to produce the hydrogen at night, when there’s less use of coal and gas plants in Ontario’s electricity mix.

    As for the stats, another way to slice the numbers would be by cost.  This shouldn’t be a deciding factor — it’d be reasonable to pay a premium for a cleaner technology — but I was interested in how hydrogen buses compare, cost-wise:

    Hydrogen bus: $122.89 per 100 km.  (Based on your numbers and an average electricity price for Ontario in 2006 of 4.9 cents/kWh.)
    Hybrid bus: $45-$65 per 100 km. (Based on web articles that say hybrid buses get 3.19 to 4.5 mpg; and a diesel price of 86 cents/litre.)
    LRV: $9.80 per 100 km. (Based on your 200 kWh and the same electricity price as above.)

    The low LRV “fuel” costs relative to buses is a bit of a shocker — are the CLRVs anywhere near as efficient?

    Steve:  I will investigate this.


  2. The love affair for fuel cells has never ceased to amaze me.  The have their place but it is not in large fleets of buses until someone comes up with a more efficient method to obtain hydrogen.  If the electrolysis of water and the fuel cell were both one hundred per cent efficient then it would be a break even swap with LRT and trolley buses but they are nowhere near that and would probably be lucky to get to 50%.  (Maybe they could use cold fusion?).

    While I don’t recall seeing any figures I bet that an LNG bus cannot run into service at 5:00 am and stay there until 2:00 am the next morning.  I know that lots of transit properties run vehicles in and out of service with the operators but I bet that this would be a significant cost increase in Toronto.  I am afraid that the Fuel Cell discussion will have the same affect as GO-ALRT and Mag-Lev: that is to delay the building of what could be done while we study what cannot be done. 

    Keep up the fight and try to get some of these politicians to go to Melbourne to see what can be done.


  3. Excellent analysis, Steve.  Although, I firmly believe that whenever there is the goal to educate “the masses” about the benefits of rail-based energy needs v.s bus-based, all the detailed statistics and background information about the various technologies can sometimes confuse those who are not familiar with the concepts.

    Steve:  It’s worthwhile pulling together all of the references in one place so that those who are interested can read further on their own.  Think of this post as a gigantic footnote.

    Any streetcar or any rail-based transit system is fed by electricity infrastructre, which is a one-time cost at time of construction.  When more green or sustainable methods of generating energy are developed, the new type of power can simply be fed directly into the electricity system to distribute power to run the fleet.  With gas, diesel, hybrid, or any kind of buses, they all have to be replaced/retrofitted whenever newer greener power generation methods are implemented, and costs go up with each technology switch.  

    And as you mentioned, all sorts of other cost issues arise: power storage, new repair training, different parts, inventory management, maintaining several vehicle types within the same fleet.

    It seems pretty clear to me that keeping it simple is better…especially with the way TTC runs its show.  It’s the same logic why we don’t replace all the appliances in our homes whenever the province decided to switch between different power generation methods.


  4. I was fascinated to hear about this community group’s interest in hydrogen / fuel cell technology for the new routes that will be built & operated in future waterfront developments.

    I’ve had to do some research and calculations on hydrogen as an automobile fuel for a chemical engineering course that I recently completed, and having done so I fully understand that hydrogen autos (or buses) are still waiting for some major technical breakthroughs in order to become even marginally marketable.  In fact, my hypothesis is that all of this hype about hydrogen as a viable fuel has largely been created by the motor vehicle industry in order to help them appear to be searching for environmental alternatives (people know that the technology is still in its infancy, so the auto makers “cannot be blamed” for taking a long time to release marketable hydrogen vehicles; meanwhile, perfectly viable existing technologies such as hybrid, clean-diesel, and even fully electric vehicles are very slow to come to market).

    The fact is, many people are under the mistaken impression that hydrogen is the next big thing for cars (and buses, it seems), and by current standards they are wrong.  But it is a sexy technology, so to speak, and, unfortunately, in Toronto the same cannot be said for LRT.

    I’m not going to totally write off hydrogen fuel technology, because as an engineer I understand that the state-of-the-art can change, but I have serious doubts as to whether hydrogen will actually surpass line electricity as the transit “fuel” of choice within the service life of any of these vehicles.

    At any rate, what I see here is more a case of a community opposed to streetcar technology (as they know it) than a communtiy that actually believes in this pie-in-the-sky solution.  I am confident that no city/TTC engineer would take such a proposal seriously at this time, and so I see this as yet another opportunity to educate the public about what trams could/should/can be, rather than what they are here in Toronto.

    I know I always say this, but I really think that a good first step would be to simply render new, low-floor trams into the drawings presented to the public, instead of pasting in images of A/CLRVs, because, right or wrong, when people see these behemoths they come to expect more of the same you-know -what.


  5. The only argument I can see for fuel cell is that it’s a way to store electricity generated in low-demand times.  Can we compare it with pumping the water back up Niagara Falls?


  6. I’m surprised nobody has suggested the obvious solution.  Raze Ontario Place and replace it with a large nuclear power station.  Uranium Place would be able to produce more than enough electricity to supply hydrogen for the new fleet of buses.  It also would allow provincial politicians to close those nasty coal-fired generating stations.  Everybody wins!

    Now if you’ll excuse me, it’s time for my medication…


  7. Yes, Uranium Place might actually be enough power to pump water and push transit, #1 and #2 power draws in TO.

    Steve:  Actually, the #1 draw is pumping water and running lighting systems combined. 

    Yes, there is no free lunch, the energy to make hydrogen has to come from somewhere.  Hydrogen is a technofix, and less practical in many ways compared with the hybrids of fuel and batteries.  One has to also look at the full embodied energy and lifecycles of materials too.

    Yet the Red Rumbles and the Red Rackets are a problem and not just in the Harbourfront area, but through the city, and it’s a shame we don’t have the lighter PCC cars anymore – and for the sake of the buildings and residents we have to be careful about the weight of the vehicles.

    But let’s put all of the energy consumption levels in perspective – clearly the mobile furnaces are the major problem, and we shouldn’t be too fussed about a bit of gaspillage with the transit compared with the ongoing heating of the planet with the various excessways clogged with cars.

    The most energy-efficient vehicle: the bike, though it’s true it’s not always for everyone, and TO’s a rather big city, and it’s cold today.


  8. Hi Steve,

    I hope you don’t take this the wrong way, but you obviously know transit better than anyone else.

    Did you ever consider working for the TTC in some kind of senior planning capacity? Or, anywhere in the organization at a management level where you could influence a decision?

    Steve:  My experience with the TTC has been that it swallows people up and they are never seen again.  Indeed, a friend of mine worked there for a time and told me he knew more about what was going on in the TTC when he was on the outside than when he worked there.

    Remember too that the relatively cordial relationships between advocates and TTC management are a recent phenomenon.  In the dark days of Al Leach, it was a firing offence to talk to me.

    All people do around here is complain, but the situation out there on the street never gets better. It’s just a waste of energy.

    If the folks here want to make a change, it’s not going to happen by posting messages on a board, or calling the TTC’s complaint department.  I think the best person to approach for an online Q & A would be Adam Giambrone.

    Steve:  Actually I know that Adam (or at least his staff) and others at City Hall regularly read this blog.  I post the “horror stories” from time to time to establish the sort of thing that happens and that desperately needs changing.  Many of us have commented on the lack of proper signage and information.  Even more (on other sites) have commented on the mess that is the TTC’s website.

    Sending this sort of thing in to the TTC in a letter is a huge waste of time.  For one thing, they don’t have enough staff to deal with it all.  For another, there’s a need to sort the wheat from the chaff — find the complaints that indicate a pervasive problem that needs fixing rather than a single instance where a rider had a bad experience.  If we are going to make transit attractive to people like you who only ride the subway, then we have to fix a lot of things on the surface network. 

    I hate to sound like a gloomy gus, but I think people here are “holding on to dream that’s gone”.  They have a nostalgic fondness of riding the TTC’s subways and streetcars from their childhood (when it was actually good), and can’t realize that those days are long gone.

    Steve:  In which case, we may as well just pave over the city and abandon it to the car.  I don’t think so.  The TTC can be good if only it will stop always finding excuses, always blaming some external factor for problems of its own making.  This has been going on for decades, including back in “the good old days”.


  9. Hi, Steve.  Thanks for humouring me by approving my flippant comment about Ontario Place.

    I found your blog very recently, by accident, and I’ve been enjoying it immensely.  Since the group of regular posters seems small, allow me to offer an introduction. 

    I’m from Toronto, specifically the Don Mills area.  In transit terms, I mostly used the 54 or 54A Lawrence East bus to get to Eglinton station, or the 91C bus to get to Woodbine.  I left Toronto in 1993 and now live in Cleveland, Ohio.

    I’m saddened to read of how TTC service has deteriorated since then.  I’m not sure how much I will be able to contribute, but I will be following your blog with interest.



  10. Here is a crack at CLRV power consumption.

    The CLRV has 2 motors rated at 185 hp.  One hp is .55kw.  So a vehicle under full acceleration requires about (2 x 185 x .55) 203kw.

    Now the time considerations.  Assume 100 km travel takes 5 hours (Avg 20 km/hr), the vehicle is under power 25% of the time, and electricity is $.049/kw-hr. 203 x 5 x .25 x .049 = $12.43 per 100 km.  Lots of room for argument about the assumptions, but $9.80 looks reasonable for a lighter vehicle.


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