Putting Green Power in Perspective (Updated)

[See the end for the update which discusses the bus fleet.]

Green Power comes up from time to time in the transit wars, especially when anti-LRT and anti-trolley bus factions trot out observations about “dirty” peak power.  Strangely, we never hear this sort of remark about subways, but some of those projects have enough hot air in them that Calgary’s “Ride The Wind” slogan has a whole new meaning.

Calgary is proud that its LRT network is entirely powered by wind energy, and I thought it would be worthwhile to compare the TTC’s power requirements with the capacity of the wind farm that Calgary uses.

TransAlta Wind supplies the power, and their current installed farm of 252 turbines generates 731,000 MWh (MegaWatt hours) per year.  They are planning to expand with higher-output turbines.

For comparison, the generator at the CNE, a comparatively small installation, produces 1,815 MWh per year.  Its generator is one quarter the capacity of the newest TransAlta installations.

The TTC’s annual power requirement is cited as 436,000 MWh in a December 2007 report on their environmental plan (at page 9).

Supplying the TTC would require a wind farm on the order of 50 of the new generators planned by TransAlta, presuming that we could obtain comparable all-year wind in Ontario matching Alberta’s climate.

This would not, strictly speaking, power the TTC but would feed into the grid to offset demand elsewhere.  The TTC’s demand has strong peaks, and wind just doesn’t work that way.  Some peak power will inevitably come from peak generation capacity, whatever technology that may be.

As the TTC moves to increase its use of electricity for propulsion, there will be a lot of debates about the power source.  In all of this it’s worthwhile to know the scale of what we are discussing.

Update:  In another thread, the enternal question of trolley buses and possible alternatives is churning again.  Supposing that the automotive industry actually manages to create an electric bus (remember that this is the same industry that is in danger of going bankrupt for lack of meaningful R&D).  What would an electric bus fleet’s power requirement be in Toronto?

As a starting point, I will use the trolley bus because it is a well-known, well-documented form of electric bus using modern propulsion equipment.  It is highly unlikely that any new vehicle will improve substantially on its power consumption.  The power consumption for trolley buses reported by APTA (American Public Transit Association) is .18 mile/kWh.  This is equivalent to 5.56 kWh/mile or 3.45 kWh/km.

In 2007, the TTC bus fleet operated 107,609,000 km, and if this had entirely been at the average consumption of the trolley bus fleets included in APTA’s numbers, this would require 371,251 MWh of power.  Note that this is not far below the existing electrical power requirements of the TTC.  If we add the numbers together, we get more than all of the wind power now generated by TransAlta Wind.

Alas, if we insist on using battery or fuel cell buses, we will suffer very considerable conversion losses within those systems, and the total power requirements will be even higher.

15 thoughts on “Putting Green Power in Perspective (Updated)

  1. A corollary to this is that the TTC should run streetcars on the Blue Night routes (apart from 301 where it does already) because electricity is cheap at night. However, it may be that TTC does not receive time-priced power but has contracted for fixed prices, since that would make peak operations quite expensive.

    Steve: TTC’s power purchases are rather complex, and are adjusted to the prevailing market conditions. They are part of a co-operative of municipal agencies for bulk purchase of power, but they do pay a premium for peak demand. They are, by the way, Toronto Hydro’s largest customer.


  2. There is probably little advantage in operating more blue night streetcars.

    The 301 and 306 are already operated with streetcars, and much of the rest of the streetcar network has no blue night service at all.

    The short sections of other streetcar routes that do have blue night service are probably better served as an add-on to a longer bus route.

    Even Bathurst is probably better served by bus, as it’s a relatively short route and making people transfer at bloor in the middle of the night just to continue a north/south journey seems a questionable proposition.

    That being said, 312 used to operate with streetcars, and I would hope that it would return to streetcar operation once the ROW is completed, if only because it would look better not to have buses running along a route with a ROW at any time of the day.

    Steve: The St. Clair night bus runs west to Jane and south to Jane Station. Converting the route to streetcars would require a split at Gunn’s Loop. There is a proposal to extend the 512 west to meet the proposed Jane LRT, but I am not holding my breath to see that actually built.


  3. We don’t have the wind conditions here in Ontario that are found out west. If you explore the countryside around Calgary, you’ll see many farmhouses with specially construction baffles as protection from the wind and the dust it carries.

    Electricty is cheap at night – but streetcars have high maintenance requirements and costs. I’d guess that if the TTC were to run them at night, there would be fewer available during the day.

    Steve: The cost of running a streetcar is dominated by the operator’s wages, not the energy cost. We wouldn’t run really good night service just to use off-off-peak power.


  4. Regarding the source of the electricity, I read a news article in the Star recently that claimed Ontario would be able to go coal-free as early as within 2 years from now, well ahead of its self-imposed deadline.

    Steve: But don’t forget those dirty nukes. The green supporters hate them too. I am always amazed at people who claim to support transit but don’t want diesels and don’t want dirty electricity, forgetting that transit itself yields a huge reduction in pollution and congestion by getting people out of cars.

    Sadly, this pseudo-green card has been played by opponents of trolley buses and LRT on various occasions, usually in the interest of diverting attention to their own preferred technology.


  5. Sidenote- the 310 suffers from horrible schedule adherence issues, so maybe a split at St. Clair or Bloor could be benificial.


  6. Steve: If the problem is that the 310 can’t stay on time, maybe it needs a different schedule. Breaking the line is a good way to guarantee that the two halves of the route won’t make a proper connection and passengers will wait in the cold.

    And, yes, this is rather off topic in this thread.


  7. “I am always amazed at people who claim to support transit but don’t want diesels and don’t want dirty electricity, forgetting that transit itself yields a huge reduction in pollution and congestion by getting people out of cars.”

    What’s wrong with that? And who says they forget about the private vehicle reduction. It may not be as simple as some might think but isn’t getting away from “dirty” energy a worthy goal? It would be retrograde to inititate new transit using that old technology.

    Steve: There is a difference between a goal and unthinking opposition. My concern is that the idea of “dirty” electricity has been used selectively to stir up opposition to transit proposals, and this has even been heard in the context of Transit City. If we want to unburden Ontario’s generating system of coal and nuclear, that is a much larger task than simply saying we won’t build any more electric transit lines.


  8. Steve — not to pick nits, but the abbreviation for megawatt-hours should be “MWh” with a capital “M”. Using a lower-case “m” implies that you’re talking about milliwatt-hours!

    Steve: These are spectacularly efficient vehicles, and very small turbines!

    I will correct the post, but should note that the same mistake appears in various source documents I referenced where only the “W” was capitalized in deference to Mr. Watt.


  9. In the future when everyone’s charging their electric cars, transit’s power usage will pale in comparison.

    Steve: This may be, but the whole point of my post was to show the extent of infrastructure needed just to power the TTC. Note also that cars get charged overnight. TTC needs a lot of peak power. No electric bus that I’ve heard talk of will run all day on an overnight charge. Even a single trip would be a challenge, and there’s a limit to how many batteries you can drag around on a bus.


  10. The TTC’s electrical requirements are going to greatly increase soon as all these LRT routes are built, subways expanded and streetcars increased. I know we need the juice but I hope they close Nanticoke and the other coal fired electrical plants soon.

    Steve: There is a very large steel works sitting right beside Nanticoke that depends on it for power. Nanticoke needs to be replaced, not just closed as a publicity stunt.

    We need electricity but the environment can’t take much more carbon emmissions. I have always wanted Ontario to built a hydro corridor from Quebec. I know that the Boston area, all of New England is builiding a hydro corridor from Quebec so the North East can get some of this relatively green power. Ontario would need to change the frequency of Quebec’s power because they transport it in a way that isn’t compatible to the way Ontario transports power on our own grid.

    I recently moved to T.O. from Vancouver and I lived in the West End. That area of Vancouver is well served by trolley buses. They produce zero local area pollution and they are much quiter then diesel buses. I am sure there are a few neighborhoods here in Toronto that could use the return of trolley buses. This too would increase the TTC’s electrical needs.

    Nuclear is expensive but I think it is better then coal. Clean coal is still just a myth.


  11. I am going to piss off the enviromentalists off, but frankly I could care less about carborn emissions and the like. If the TTC needs power then let’s fire up those coal plants and get the system the power it needs. I only support trolley coaches because it’s cheaper on an operating cost perspective.


  12. Fuel cell buses? “They’re still coming! Just a few more tests, and a few improvements, and a re-vamp of the technology, just wait another year. Oh, their performance is terrible? Just another year or so, we’re still improving them! The technology is almost there” ….. the Leafs will win a Stanley Cup before the fuel cell bus and hydrogen bus ever become economical.


  13. Exactly Robert: the point with trolleys is that you only need motive equipment, not power generation equipment. With diesel, diesel-hybrid, CNG and fuel cell you have to make the power before you can use it to drive the wheels.

    As for Wilson being convenient for power, that’s true – although I still wouldn’t have chosen Lawrence West for a trial “network”.

    But if the issues around voltage can be surmounted, the old Coxwell/Danforth yard is pretty close to the subway so maybe it could be the base for the trolleys – not least because 22/22A Coxwell would be a candidate for trolleyfication, interlining with streetcars as it does, being a heavily patronised route and given the TTC’s reluctance to extend the streetcar network to Danforth as an ROW would not be available. The Cherry-Portlands yard could be similarly fitted out in a dual role. One yard could be for stabling while the other would be a maintenance yard.


  14. I know you alluded to this in your piece. But Pincher Creek (where Calgary’s Windfarms are located) is quite windy, even to Alberta standards. I remember passing through there and having to battle on a trip back to Calgary.

    Would there be a place in Ontario which could generate that type of wind? Perhaps offshore windfarms on Lake Ontario?

    Steve: Toronto Hydro has a project to put an anemometer station out in the lake to collect data on actual wind conditions for a potential wind farm. One comment I can make is that the turbine on the waterfront at the CNE grounds is becalmed a lot of the time.


  15. There is a good website, http://www.republiclocomotive.com/ac_traction_vs_dc_tracion.html

    The high voltage, 25 kV single phase used by mainline railways must be stepped down with a transformer, about 2 tonnes for an electrified GO bi-level car, rectified and filtered to give DC then fed though a variable frequency 3 phase inverter to feed the traction motors. I do not think anyone wants 25 kV trolley bus over head and the weight penalty for all the power conversions is too high.


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