Trolleybus fact and fiction
Introduction
From
time to time there has been concern that the electric trolleybus system operated
in Vancouver would be abandoned. These concerns recently reached a new high when
over-enthusiasm for the Ballard fuel cell bus led to a pervasive perception that
the trolley system would soon be on its way out. The situation has since calmed
down considerably, with TransLink deciding to purchase new trolleys over the
next few years. Nevertheless, the long-term future of the trolley system remains
a concern as there remains opposition to the trolleybus from some quarters. In
order to help inform the public, we provide the following information to help
maintain constructive dialogue.
Myths
First, we present the following myths:
- There has been no significant investment in the system recently
- Other technologies can provide all the benefits of trolleybuses without
the wires
- Compressed natural gas buses are cleaner than trolleybuses
- No one makes trolleybuses any more
- Trolleybus systems are generally being abandoned
- Trolleybuses are really expensive to operate
- Trolleybuses can't be accessible to wheelchairs
This article presents facts countering these myths. Other relevant articles
include those on:
Interested readers may also want to check out Richard DeArmond's electric
trolleybus web site and the Vancouver
Trolleybus web site.
No investment?
Trolley opponents would like us to believe that no investment has been made
recently in the trolleybus system, and thus when the current fleet is
life-expired in 2003, it would not be a waste to shut the entire system down.
The facts, however, tell a different story. The trolley overhead in Vancouver
is in generally good shape and is being actively maintained. The system was
extended in September 1988 by 3.1km to UBC at a cost of $1.5 million. The system
has also recently been extended to Metrotown at a cost of $1.4 million. The wood
poles on Powell street have been replaced at a cost of $700 000. New trolley
overhead maintenance trucks have been purchased at a cost of $800 000.
It has been estimated that the total system is worth $100 million. In
addition, the 12 original rectifier stations (electrical substations that
convert higher voltage AC to the 600V DC used by the trolleybuses) were all
replaced by 1994 at a cost of $15 million.
Technology will provide a better solution?
Much attention has recently gone to the Ballard fuel cell bus. This bus uses
a hydrogen fuel cell to produce electricity which is then used to power electric
motors. Such a bus potentially has the advantages of electric traction (small,
efficient motors, quiet, quick acceleration, ability to recover energy when
slowing) but the disadvantage of carrying a fuel source and "fuel source
converter". In fact, the Ballard fuel cell bus necessarily contains all the
components of a trolleybus except for trolley poles. Thus, claims that the
Ballard bus will be cheaper than a trolleybus do not make sense. Other hybrid
technologies using electric traction have the same problem - they are all
essentially trolleybuses carrying their own power source.
In terms of useful work versus energy provided to the vehicle, the current
fuel cell bus is 46% efficient. Trolleybuses are on the order of 80% efficient.
In addition, the overall energy efficiency of the fuel cell bus will be lower,
as compared to a mostly hydroelectric powered trolleybus, due to the
inefficiencies inherent in producing hydrogen (e.g. the electrolysis of water to
produce hydrogen is only 60% efficient).
The economics of hydrogen as a fuel, at present, make the fuel cell bus
impractical. According to Bus World, a "fill-up" for the Ballard bus
costs US$250 vs. US$72 for a diesel bus.
So then, is the Ballard bus worth pursuing? Certainly! Assuming the price of
hydrogen relative to diesel changes, the Ballard bus can provide quiet, zero
emission (well, zero nasty-compound emission) service using a renewable energy
source on routes which do not justify the cost of providing trolley overhead. In
other words, it is a possible replacement for internal combustion engine powered
buses, not trolleybuses.
Natural gas powered buses are "clean air buses", aren't they?
Compressed natural gas (CNG) buses have been touted as "clean air
buses", implying "zero emission". This is just plain false. CNG
buses produce all the pollutants diesel buses produce, just at substantially
lower levels. Recent "clean diesel" engines, however, have closed the
gap significantly. Pollutants specific to CNG engines are only just being
researched. In any event, CNG buses produce carbon dioxide, which is known to
cause global warming.
So, then, what about the comparison between trolleybuses powered by a natural
gas fired power plant (e.g. Burrard Thermal) and CNG buses? Well,
- the power plant can be made twice as efficient as an internal combustion
engine (currently they are approximately the same efficiency)
- the power plant produces emissions away from urban areas, and can decrease
its emissions during times of high pollution levels
- the trolleybuses aren't powered just by Burrard Thermal anyway! Burrard
Thermal provides 7.5% of the province's power - almost all the rest is
hydroelectric (zero emission!).
Trolleybuses powered by hydroelectric power produce no air pollution - CNG buses
do. CNG buses are as noisy as diesel buses and do not accelerate up hills as
well as trolleybuses. CNG buses are not a replacement for trolleybuses.
No one makes trolley buses any more, do they?
The following manufacturers are currently building trolleybuses to fulfill
outstanding orders: AGT, Breda, New Flyer Industries, Graf & Stift, Hess,
Ikarus, Jelcz, Kapena, Kyiv, LAZ, Mafersa, MAN, MASA, Menarini, Mercedes-Benz,
Mitsubishi, Moyada, Hess, Neoplan, Novabus/Kaman, Osaka Sharyo, Rocar (DAC),
Samara Transport, Socimi, Solaris, Severny Troleybus, Skoda, Van Hool, Volvo,
YuMZ, ZIU.
Isn't everyone getting rid of their trolleybus systems?
No.
While it is true that some North American systems have recently been
abandoned (e.g. Hamilton, Toronto), there are still hundreds of trolleybus
systems in operation world-wide, and new ones being built. For example, an 11.2
km long trolleybus line has recently been constructed in Quito, Ecuador as a
rapid transit system with 22 stations and high level platforms. The line uses 54
articulated trolleybuses.
This list of orders for trolleybuses and
dual mode trolleybuses (trolleybuses with off-wire capability) since 1990
should dispel the myth that trolleybus systems are being abandoned everywhere.
The list shows that over 100 systems have ordered a total of over 2,600
trolleybuses over the last decade.
What about cost?
Surveys done in Vancouver and Seattle show the cost of operating trolleybuses
to be slightly higher than that of diesel buses. The cost of trolleybus
operation includes the cost of maintaining the trolleybus network and the higher
initial cost of the trolleybuses, which is offset by the much lower energy cost
(trolley buses use less than half
the energy that diesel buses do to go the same distance). A couple of notes
are in order, however:
- The Vancouver study unfairly compares trolleybuses in stop and go traffic
to diesel buses which include many highway express routes.
- Trolleybuses could actually be cheaper - the Vancouver study shows the
cost per vehicle kilometre of electricity and overhead line maintenance to
be less than the cost of diesel fuel - except for the high maintenance
costs which seem at least partly related to the particular model in use in
Vancouver
- The cost of diesel fuel is low at present, but cannot remain so
indefinitely - it is, after all, a non-renewable resource. As well, the cost
can be made higher very quickly - viz. the 1973 Arab oil embargo.
In 1993 a BC Transit report estimated the cost of a brand new trolleybus to
be 1.5 times that of a diesel bus, but the trolleybus was expected to last 30
years and the diesel bus 20, so helping to balance the additional cost. The
previous fleet of Brill trolleybuses did last over 30 years. The current
Vancouver fleet is now to replaced when the vehicles are about 20 years of age,
although a desire to provide accessible transit service could be seen as a
secondary motivation for replacement.
So why do trolleybuses cost more? The answer likely lies in the economies of
mass production. Clearly there is a much larger market for diesel engines, since
they are used in trucks and buses throughout the world. The huge population of
diesel engines has resulted in very competitive manufacturing and maintenance
industries. The market for transit buses as a portion of this entire market is
relatively small, and the market for trolleybuses is even smaller. An obsession
with incorporating the latest high-tech electronic components on new
trolleybuses also serves to drive up costs and ensure "teething
troubles" when new models are introduced.
TransLink's board of directors decided on June 21, 2000 that new, low-floor
trolleybuses would be purchased as follows:
Replacement
of existing 244 12m (40-foot) trolleys |
205
12m rigid trolleys, and either
60 12m rigid trolleys or 40 18m articulated trolleys |
Fleet
expansion option to meet requirements to 2006 |
Either
60 12m rigid trolleys or 40 18m articulated trolleys (option to be
decided in 2004) |
A new TransLink Board of Directors was appointed in January 2002. The new
Chair, Doug McCallum, Mayor of Surrey, made the following comments at a January
17 conference:
"The first thing we are going to look at is how we can
get fuel cell buses in this region because the technology, the world technology,
is in our region and we should be using it. Electric power, is another clean
energy source and we need to find out how we can put more electric buses in our
system."
Be sure to visit the Vancouver
Trolleybus web site for more details on the benefits of trolleys and why
they must be retained.
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