The Economics of Hybrid Buses

The City of Toronto’s Executive Committee agenda for October X contains a report on the City’s Green Fleet Plan for various agencies.  By far the biggest of these is the TTC, and in an accompanying report, we learn just what the economics of the hybrid bus fleet are.

On page 15, the TTC presents a chart showing the fuel efficiency of its fleets, and it is worth noting that fuel consumption per vehicle km is rising at the same time as the average capacity of the vehicles is falling.  This is partly due to the additional systems, notably air conditioning, that are present on newer vehicles.

Of the total fleet, just over a quarter (450 out of 1653) are hybrids, and these consume about 10 percent less fuel than their pure-diesel cousins (based on experience to date).  This implies that the increased fuel consumption on the diesel fleet is even higher, proportionately, than the consolidated figures imply because of the offsetting benefit of the hybrids.

In the longer term, the relative fuel savings of hybrids may rise as they operate on routes with dense, stop-start traffic where the benefit of electric propulsion and battery energy storage will shine.  Nonetheless, there will be a considerable net cost of owning hybrid buses relative to diesels over their lifespan.

The TTC expects to spend $110-million on diesel fuel in 2009.  This includes a saving of $3.6-million for the existing hybrid fleet, and that saving will rise to somewhere around $6-million annually by the time that the fleet is about 50% hybrid (854 out of 1864) in 2011.  That’s a per vehicle saving of  about $7,000 per year.  We do not know yet what savings, if any, on maintenance will accrue to the hybrid fleet.

The capital cost premium for a hybrid bus is about $200,000, and the hybrid saving is only about 3.5% per year on this additional investment.  In time, if the capital cost premium comes down, the cost of fuel goes up, or the average percentage saving across the fleet rises, the numbers will converge and the rate of return will improve.

Meanwhile, it’s a shame we don’t have comparative figures for the cost of trolleybus infrastructure for our major routes.  Two decades ago, the TTC sacrificed its trolleybus system on the twin altars of environmental responsibility and natural gas buses.

Postscript:  The supposed economic advantage of natural gas as a fuel was almost entirely due to the fact that it was not taxed.  A large chunk of the TTC’s annual fuel bill is in tax paid to the Province of Ontario.  Without this tax, the economics of buses in general would be rather different.  Oddly, because the dollar saving from reduced fuel consumption would actually be lower without the tax, the economics of hybrid buses would look even worse if this tax were rescinded.

24 thoughts on “The Economics of Hybrid Buses

  1. One also has to ask whether the best possible use is being made of these buses. Despite “idle free routes” being touted at the moment, only one of the last three (non-hybrid) buses I boarded at Coxwell Station since the announcement was shut down as prescribed by the policy. Now, it may be considered offside to turn off a 70 because you lose the display which indicates which branch it is, but in that case don’t advertise the bus as idle free!

    Steve: The “Idle Free” concept is one of those brainwaves that loses sight of issues of day-to-day operation. There should be a way to keep route signs operational from battery power, and of course there is always the issue of heating and cooling. Letting a bus cool off or warm up means that you must expend additional energy just to get it back to the desired temperature.

    With respect to hybrid buses, the fuel consumption on idle should be quite low, and we need to know whether this policy actually makes sense for that part of the fleet.


  2. Thanks for the quick analysis. Indeed, it will be interesting when the hybrid busses move away from the relatively high-speed suburban routes to dense urban routes.

    As an aside, why in the heck are they using Hybrid busses on the 191 Highway 27 express!? I shake my head every time I see one of these busses schlepping it’s batteries up and down the 427 at 100+km/h….


  3. To what do you attribute the lack of trolleybus infrastructure data? Is there a bias against this technology? Vancouver has kept its trolleybuses up to date. Could it be a source of the missing data?

    Steve: In Toronto, it’s simply a case that they let their old system disintegrate, and there was never any incentive to revisit the issue. In Vancouver, there is certainly data on vehicle capital and maintenance costs. We would also need to determine the cost of building infrastructure from scratch, although some of this might be available as an offshoot of the Transit City plan where we are building new electrically operated lines far from existing routes.


  4. It would seem to me that an intangible benefit of the hybrids is the dramatic reduction in noise pollution. Diesel Orion VIIs are exceedingly loud, and come full service on all routes (whenever it does), certain neighbourhoods would probably be kicking and screaming about a diesel making its rounds every half hour down residential streets.

    Steve: That was one of those intangibles about trolleybuses too. When we start talking about buses roaming through quiet neighbourhoods, the noise of the bus, whatever the technology, is a major issue.


  5. One should not expect to see large jumps in fuel economy just because it is a hybrid. Compare a gasoline only Camry to a Camry hybrid, the fuel gains are not exactly “game changing.” The Daimler Chrysler site indicates that a diesel Orion VII gets about 3.5MPG while a hybrid one gets about 5MPG.

    One must remember that it takes a lot of work to extract more fuel economy. Toronto summers are hot and the air conditioners must work all the time. When the air conditioner is on, the engine cannot shut down. In this screnario, the hybrid system is really a supercharger, supplementing the diesel engine in acceleration.

    The way the driver operates the bus also affects the fuel economy. With a hybrid system, one should slowly engage the brakes for the brake regeneration to capture more energy. Of course, this will slow down the average speed. Everything is a trade off in life. Still, getting 50 people on a 3.5 MPG bus is better than 50 people driving 13MPG Chevrolet Tahoes individually.

    Now if Bombardier can get their MITRAC technology into their GLT vehicles…. A rubber tire tram that can run on electricity. When there is no electric overhead wire, it can run on a diesel engine and assisted by an electric motor. This is useful in places like Queen St where the rubber tire tram can steer around a left turning vehicle.


  6. One of the huge issues for Hybrids is battery wear, most if not all of the cost difference of a hybrid is the cost of the batteries, and batteries wear out, so in a few years when hybrids start needing new batteries at $200,000 per bus, how many of those are going to end up being converted to conventional diesel, as it will be cheaper.

    Of course the other way of looking at things is, how easy/hard would it be to convert it into a trolley bus. Which should be the real intent on heavy traffic downtown lines that can’t be converted to streetcar lines.


  7. So, Steve, you know my reactionary bias for trolleybusses. Given that, is it still cheaper to operate hybrids, given that there is no need for infrastructure?

    Steve: One big issue with trolleybuses has always been that the vehicle (at least the propulsion system) outlasts that of a diesel bus, and that, in theory anyhow, the lower vibration levels of electric propulsion also contribute to reduced body fatigue. That said, there are many other variables at work including technological obsolescence.

    Both the old PCC fleet and the original Toronto trolleybus fleet had electrical gear that could be refurbished for newer body shells. The same is not necessarily true for modern vehicles. The CLRVs are a good example, and in the originally proposed rebuilding program, they would have received completely new electronics. The original equipment has been difficult to maintain over the years, and savings are available simply by replacing this with modern electronics. Electric motors, of course, will outlast any car or busbody.

    We don’t have definitive costs yet for hybrid bus costs over the life of the vehicle or any sense of how much could be recycled into a new bus. We also don’t know whether the diesel engine will last out the 18-year planned lifespan of the bus body, or as on pure-diesel vehicles, will have to be changed out partway through the hybrid bus life. There’s also the question of how later generation hybrid vehicles will fare compared to the early models when the industry was still figuring out how to build them.

    As for infrastructure, I suspect that will always be an obstacle except in cities that already have electric operations (and hence an understanding of the technology and existing staff expertise). It’s not just a question of stringing overhead, but of creating a whole set of maintenance skills that would have to be expensed against a relatively small operation. The same issue faces a city that has only buses and is building its first LRT line. There needs to be an overriding need for supporting additional technology such as the capacity and speed an LRT route would have, or a network strategy that views the investment in technology as part of a long-term plan.

    Even Vancouver may have reached the point where their trolleybus system won’t grow, and may even contract slightly if service on Broadway is supplanted with LRT or some form of Skytrain.

    Sorry to sound so vague, but the issues are complex and some information we just don’t have yet.


  8. About hybrids being quieter than regular diesel buses. There are jurisdictions looking for ways for to make hybrids cars louder ( because they are too quiet. People have become so accustomed to noise made by buses, trucks, and automobiles, that if there is no traffic noise we think something is wrong.

    I guess bicycles would also are too quiet for some.

    I don’t think hybrids buses are quiet, when compared with trolleybuses.


  9. In the TTC meeting minutes of May 21, 2008, there is the following:

    “Chair Giambrone submitted a communication requesting that staff investigate and report on the cost effectiveness, environmental benefits and operational impacts of re-establishing trolley buses on some of Toronto’s busiest (non Transit City) routes.

    Chair Giambrone moved that his communication be referred to staff for report. The motion by Chair Giambrone carried”

    I have heard nothing since.

    Steve: Yes, many of us are looking forward to that report, but I am not optimistic that it will make a strong case for TBs.


  10. To Benny Cheung:

    Bombardier’s GLT technology is quite limited, and while it was cheaper to build, Nancy, and Caen ran into many, many problems with their system.

    Also, I read that the trams are causing extensive damage to the road with ruts.

    Also, Bombardier will not sell any more systems until the problems are fixed. So I do not see the TTC buying a proprietary system.

    Steve: See Wikipedia for more info. This is not a viable technology especially given Toronto’s weather. It seems to combine the worst features of several technologies in one product.


  11. Until recently, I lived on Oakwood which has a combined headway at rush hour of about 2 minutes. I’ve literally heard the bus pass by tens of thousands of times. The buses on Oakwood are now about 75% hybrid.

    The brand new hybrids are easy to pick out, they are definetly quieter and make a higher piched, less noticeable sound. The ones that have been around a few weeks are a little clunky and chug along like a new diesel bus. The ones that are a few months old seem to make 80% as much sound as a diesel. At this rate, by next year they will all be just as loud. From my experience, it is obviously false that hybrids are quieter.


  12. Steve, Just a little sidebar on this discussion. It is sad to see that the trolley buses are no longer around considering how well they are still going strong in Edmonton and Vancouver (and those are very large systems).

    Steve: Edmonton recently decided to abandon the remainder of their system.

    I know hindsight is 20/20 but you wonder sometimes how and why decisions are made. I saw on a site not long ago where Lyon, France had recently started up a new trolley route (but it was called something different). They were using longer new technology accordian-style trolley buses. Apparently, the sound is minimal. And any of you who ever took the Annette, Lansdowne, or Ossington buses will remember that they were pretty quiet.

    Steve, I know the cost of a trolley bus is a bit more than a regular bus, but I also know that the street life of the trolleys is double that of the other buses. I know your favourite thing is to push for LRT(which I agree with) for good reason. But why hasn’t anybody thought of revisting trolley coaches especially for the central core?

    Steve: There are few routes in the core left that are not already run with streetcars and require their capacity. Several years ago, Bay was a trolleybus route, but a variety of factors led to declining ridership and service. Wellesley was on the list to be studied for TB conversion in the late 1980s, but that never happened. Spadina has become a streetcar line.


  13. There was a lot of literature out saying that CNG buses would be much quieter than diesels. In fact, they were noisier than their diesel counterparts of the time. The hybrids are definitely quieter than the roaring diesel Orion VIIs but are more in line with the noise level of older diesels. I too am not overly optimistic that there will be a ringing endorsement of re-establishing a trolley coach system at this time, however with TC infrastructure being constructed the case may be more favourable once some part of TC is actually built. Once there is a network of modern substations in place, then the costs of a trolley coach system are mainly the vehicles and overhead, which have long lives to spread the costs over.


  14. My “Red Rockets” were the slightly pudgy off-white Brill two-trolley pole buses (second bus with H Hydro logo) that were definitely quiet, and while neither red nor rockets, were they durable: lasting 28 YEARS… the last vehicle run on August 4th, 1976, when I started my first job, at GF in Toronto

    Translink’s predecessor was BC Hydro… which had morphed from BC Electric the successor to the original BC Electric Railway that provided electric power for streetcars and street lighting beginning in 1898. By 1920 there were over 200 miles of interurban streetcar lines.

    After the war streetcars were abandoned in favour of electric trolley buses, a more economical alternative to fixing the huge backlog of deferred streetcar maintenance due to scarce labour and material resources during WWII. Is this where David Gunn’s beloved “State of Good Repair” originated?

    In 1952 BC Premier W.A.C. (Wacky) Bennett (Premier Bill’s Father) was elected and over 20 years as Premier launched a massive expansion of hydro-electric capacity in the province (infrastructure without a dime of Federal subsidy!)

    Where better to demonstrate the advantages of BC taxpayers going into hock to finance this hydro expansion than on the streets of its two largest cities: Vancouver & Victoria, running of course BC Hydro trolley buses. Now that’s what I call stealth lobbying! 😛

    I remember riding on the Brills over streetcar tracks set in cobblestone roads throughout Vancouver’s downtown eastside (it was always an adventure as a child when a pole or two came loose on turns, the lights and heat went off and the driver got out and stretched, pulled the pole cords to position and reseat the poles on the dual overheads.)

    Bobby B (born & raised in Vancouver & Burnaby BC)

    P.S. Steve… if Toronto did bring back trolley buses… would/could they be made compatible with the streetcar overheads power lines so trolley’s could run back-up on streetcar routes (amazing how far the BC Hydro trolley buses could travel out of their lanes, unlike streetcars, to avoid a blocked lane).

    Steve: This would require the addition of a negative wire for the ground return for the buses, something that would complicate intersections considerably. This would really run into problems if we ever convert to pantographs because of discontinuities in the overhead. Another problem is that any new TB network would likely be rather remote from the streetcar routes. Finally, there’s those pesky tunnels and tight loops. It’s an idea, but a difficult one to implement.

    By the way, there was a limited amount of joint TB/SC overhead in places where the TBs shared the SC wire as the positive line. In other locations, the SC and TB overhead were separated so that (a) they could pass each other and (b) so that TBs could reach the curb easily.


  15. I would like to comment on this issue, but up front I admit my bias. If you have read my earlier posts you will remember that I am “in love with and enthralled” by the GM Diesels. They truly were the best buses ever and it is a mystery to me, why 40 years later bus technology should have deteriorated to the Orion standard. When Orions accelerate (Diesels and hybrids) it is at a rapid rate which is stressfull for standees. When they brake, the brakes grab and the deceleration is jerky. I never stand on one of these awful buses without holding on tight – often on two poles with two hands just to make sure. The jerky braking also minimises the energy recovery from the hybid technology.

    The incremental benefit to the environment of spending an additional $200,000 per bus for unproven technology that may require high maintenance is not evident. If the batteries require replacement, that too will have an environmental impact. If, as posted above, a diesel bus with 50 passengers has 3.5 mpg and an average car has 25 mpg (higher than suggested above) then 50 cars with one passenger are only getting ½ (.5) mile per gallon. It is not difficult to see that the bus is 7 times as efficient and with 7 passengers breaks even. It is not necessary to spend enormous amounts of money to theoretically – but not practically – improve bus fuel consumption. It is already the “Better Way” and the $200,000 per vehicle could be better deployed getting more people out of their cars.

    In off peak hours, with spare capacity, the incremental cost – environmentally and fiscally – of an additional passenger is NIL. if the service is already running.

    Hybrid buses are a politicians dream. For an efficient transit system that uses every dollar wisely and to maximum effect they are a nightmare.

    Steve: Yes, but politicians love spending money on “green” whether it makes sense or not. They want to be seen as “doing something”. The original batch of hybrids was more or less forced on us by the Feds who, in return for their capital contribution, insisted that they be “greener” than what they replaced. Net new buses, that would get people out of their cars, didn’t count as “green” unless they were hybrids.

    The TTC has just managed to kick the biofuel habit, but I suspect it will take several more years of dubious performance by hybrid buses before there is a move back to pure diesel.

    Look how long it took the TTC to admit that CNG buses were a bad idea, that their performance and life-cycle cost did not meet initial claims.


  16. You know what? I’d love to see ETBs come back to Toronto but I can guarantee you 100 per cent that it will NEVER EVER happen. Any chance of an ETB revival simply does not exist. Period. I’ve been proven right about LRT not being derailed on Eglinton as well as there not being any extension eastward of the Sheppard stubway.

    Steve: Lest your fantasies of infallibility attract the attention of those critics who feel this blog is the centre of transit evil, I should point out that predicting anything to do with transit is like flipping a coin and anticipating the outcome from past performance. Indeed, the coin is still very much in the air on Eglinton, and the fate of the Sheppard corridor is still unsettled.


  17. OK, I realize that I’m not infallible but I thought for sure when the recent big announcement from Metrolinx pretty much settled the issues regarding Eglinton and Sheppard. I guess that’s what I get for thinking, right? On a more down to Earth note, I really do see LRT winning the day in both corridors perhaps not necessarily 100 per cent as originally proposed but it will almost certainly have some kind of presence both places. As for ETBs, I quite honestly bellieve that there isn’t a snowball’s chance in Hell for them to ever return to Toronto and I sincerely believe that a good 95 to 99 per cent of anyone reading this would bet the farm against their return.

    Steve: I think that LRT will “win the day” as you put it, but I wish that the whole debate had not been framed in a “winners and losers” sort of way. Metrolinx dug themselves into a hole by prejudging a technology selection, and it turned out that this was based on faulty ridership estimates. Then it turned into a “Toronto” vs “Metrolinx” fight that was totally unnecessary.

    I agree that ETBs are an unlikely candidate among all the technologies competing for Toronto’s attention, but hope that the hybrid bus costs will converge with those for pure diesels as the technology matures. At least then we won’t be paying a substantial premium for being “green”.


  18. Hi Steve:-

    Since this is becoming an ETB stream, I thought I’d throw in my 2 cents. I believe that in the present day and age of wanting to go green, ETBs are definitely the way to go. Being able to power two or more coaches for the same BTU output as any diesel (hybrids included), especially with the electronic controls now available is a tremendous savings in carbon output. No matter how power for these beasties is generated, even coal, there is no comparison as to which is the greener on the road technology.

    Yes, the cost of installing an infrastructure is high, but that can be amortized over decades versus years. The vehicles can be left outside in all weather when at the barns, be ready to start at the touch of the power pedal, be pre warmed and themselves be amortized over decades.

    Many routes are likely candidates for these vehicles, which will not only improve speeds, thus increasing capacity, they will do the mind blowing, headline grabbing thing of lowering noise pollution. Noise pollution being green too, eh?

    As for the overhead hardware necessary to have TCs and pantograph equipped streetcars sharing the same sky hooks, I believe that it already exists. It shouldn’t be a big problem to investigate the appropriate catalogues for the bits and pieces required and invest in them for the sake of being green.

    Our old TC system was junked because of a number of factors, not the least of which being that since it was so darned reliable, even when neglected. But it was neglected and then for way too long, well beyond the point of no return! Particularly when a provincial government got in that was sold a bill of goods, themselves not having clue one as to the merits of various forms of technology and fuel choice.

    Oh and I’ve heard the argument that the overhead wires are a source of visual pollution. GM promoted BS is what that is for is there not art in symmetry? Look at any massive structure in our fair burg and see the symmetry. Take its picture with overhead in front of one of those buildings and watch that dissapear in the 2D art of photography!



  19. Questions still to be answered — publicly — concerning the existing TTC fleet of already-delivered Hybrid buses:

    What is their reliability?
    How many are out of service awaiting repairs?
    How many fail each day and must be towed back to division?
    Have any been returned to Daimler for repairs/warranty work?


  20. Maybe a silly question. There are a couple of comments in this thread about trolley buses that state or imply that they are a “higher-capacity” mode compared to standard buses. How is that possible, given that both are the same size of vehicle?

    Steve: Electric vehicles can accelerate under heavy load (many passengers, hills) and in stop and go traffic better than diesels. However, with the move to hybrids, this advantage may be reduced. In either case, the capacities are equal in terms of vehicle design, but you need fewer TBs than DBs to provide the same service on a busy, hilly route. Anyone who rides up the hills on routes like Bathurst, Dufferin or York Mills will know the problems DBs can have.


  21. The issue of electric vehicles (ETB & LRT, etc.) “driveability” vs. diesel & gas engines is a complex power vs. torque issue that has always fascinated me, a Chemical Engineer, who never took a MechEng course.

    It’s right out of the Toronto Star’s Wheels’ articles by Gerry Malloy, a Professional Engineer and head reviewer Jim Kenzie who have periodically written lay explanations, that helped me understand the power/torque trade-offs better. See also Wikipedia~torque, if interested.

    Electric vehicles accelerate well from start and under heavy loads, as Steve notes, as their electric motors have higher torque, or turning force (than diesel or gas engines) with peak torque at 0RPM~when starting from a stop as buses & streetcars often do.

    Typically gas or diesel engines have to rev up to speed to produce their peak torque in the 1,000-6,000RPM range vs. 0RPM for electric engines. Diesel engines operate at much higher compression ratios and produce much higher torque than a similarly sized gas engine.

    As fuel economy is a function of the effective engine displacement and the RPM needed to move the vehicle’s mass effectively, smaller displacement diesel engines operating at lower RPM consume less fuel and thus produce higher fuel economy than a gas engine for an equivalent torque peak.

    For example, Mercedes Benz’ R series has a 3.0L Bluetec diesel producing only 210HP* @ 3.400RPM but 400 lb-ft of torque at 1,600-2,400RPM; while the gas version MB R has a 3.5L engine producing 268HP @ 6,000RPM and only 258 lb-ft of torque @ 2,400-5,000 RPM**. The diesel R is a bit slower (0.7sec) accelerating to 100KPH but its fuel economy is 2-3L/100k (highway/city) or ~20% better than the gas engine. Source:

    In cars horsepower is heavily marketed (with ever increasing (obscene) HP numbers~over 400, 500, 600 HP) with torque virtually ignored. HP determines the top speed of the car; torque the driveability or ability to accelerate: eg. from a stop or merging to 400-series highway speeds or for passing. Note to OPP/Queen’s Park… think about graduated licences that restrict HP for newbie drivers.

    Obviously buses need more torgue than high end speed so diesel engines are chosen not only for their higher torque but lower RPM, which combine to consume less fossil or bio fuels. ETB are even better than diesel. Full Hybrid cars and buses also benefit from the good start-from-stop acceleration of their electric motors.

    *Torque, or turning force around an axis (force x distance) is measured on a Dynamometer; HP = Torque X RPM, is calculated.

    **N.B. the gasoline R series torque peak begins at 2,400RPM, the top of the diesel engines torque peak. This means the diesel engine doesn’t have to race (e,g, Formula 1 or small high-revving HONDA 4-cylinder engines) to move the bus. I’d love to know what the torque peak of Vancouver’s ETB’s are.


  22. The fuel economy with the Orion hybrids are not impressive. This has nothing to do with the inherent problems of hybrid technology, but with the design decisions made.

    Every new generation of buses have more glass than their predecessors. Glass is heavier than metal. This is why Boeing has to make an all composite Dreamliner to offset the increased weight of larger windows. Whether it is a diesel bus, a GLT tram or a tram, the weight penalty exist.

    Increased glass usage also leads to another probelm. This will require more air conditioning. The Bombardier T1 car has a 12 ton air conditioner per car. The Orion VII has a similar sized air conditioner for a much smaller amount of space as compared to a T1. The reason is due to the greenhouse effect created by the large glass windows. Keep in mind that the average home is cooled by a 4 ton air conditioner!

    The electirc motor on a hybrid does not usually drive accessories like the air conditioner or power steering, since. The electric motor is usually sandwiched between the engine and the transmission. Hence, it cannot drive the belts. If the air conditioner is on, the diesel engine must be on. Perhaps, if the next generation of Orion buses can run an AC unit from batteries, the fuel gains should increase much more.

    To the poster who discussed the cost of replacing batteries, batteries are expensive today. However, as time goes on, battery price should drop. The Orion VII uses lithium ion batteries which should at least 6 years. This is compared to about 3 years when using NiMH batteries. Since lithium ion batteries do not require conditioning, the extra maintenance cost to the TTC is nil during the first six years of ownership.


  23. The TTC should have bought articulated buses for the same price of the hybrids. Articulated buses can be fuel efficient when full of passengers and reduces the need for additional 40 foot buses.

    The main reason why the TTC wont get these buses because they have a cozy relationship with Orion Bus Industries and wont buy these buses until Orion comes up with a model. The TTC wont buy articulaed models from new flyer and Novabus which shows the amount of “politics” in the TTC.


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