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Electric Vehicles Research
Posted on October 26, 2010 by  & 

Future technologies of electric buses and taxis

Buses and taxis are an excellent launch pad for new technologies. In the new IDTechEx report, Electric Buses and Taxis 2011-2021 we assess all the options and the markets resulting. For example, bus and taxi fleets are often owned by government and therefore freer to do things that have no payback.
Governments will often spend heavily to save the planet and reduce pollution in city centers. Taxis alone can be responsible for 20% of pollution in some city centers despite representing only a few percent of the vehicles. This is because of their intensive use. Promised benefits of electric vehicles such as longer life in use will mean dollars to a bus or taxi fleet owner but may not be detectable to the private purchaser.
Trolleybuses and trams
There has been some advance in trolleybuses, such as ones that have traction batteries so they can decouple and move freely for short distances, for example during a terrorist attack or where infrastructure is troublesome to install. In China, there is a study of huge trams that will straddle existing roads with minimal disruption to existing free running traffic. However, at least 90% of the future demand for electric vehicles will continue to be for free running (untethered) versions and here the innovations are coming thick and fast.
Fuel cells
Many trials of fuel cell boosted battery buses and taxis continue all over the world but with no major rollout. Nevertheless, fuel cell powered buses will be commercially available within the decade, notably for those seeking green credentials rather than a payback. In addition, some car manufacturers plan major rollouts of fuel cell powered cars before the end of the decade and, if successful, these will also appear as taxis.
Fleets see the benefits
Both bus and taxi fleets are more suitable than private cars for the adoption of new electric technologies such as battery swapping (with recharged batteries), use of lower cost, longer lived ultracapacitor power without a traction battery, energy harvesting. In the case of energy harvesting there are now serious programs to garner electricity from shock absorbers, active suspension, solar cells, regenerative braking and heat harvesting. Truck fleets also have freedom to innovate, as experts Motiv Power Systems Inc can explain.
There is even the prospect of transparent solar cells over the whole bus: think of how much electricity that could produce. Inductive (contactless) charging is more feasible with vehicle fleets. This is because bus and taxi fleets are professionally managed with little variety of models in one fleet and often predictable routes and major funding for both infrastructure and purchase of innovative vehicles. Much of an electric bus powertrain can be on the roof, with weight evenly distributed, releasing more space for passengers.
That does not mean that all these new innovations will succeed however. We are not optimistic about the ongoing trials in Italy, South Korea and elsewhere of inductive pick up of power from gantries or the road because of inefficiency, cost and the likelihood of obstruction. That sort of thing works better with electric toothbrushes.
Battery swapping
Consider the idea of swapping discharged batteries with charged ones - something of a nightmare with private cars because the position and fixing methods of the batteries in the wide variety of electric cars available is not standardised and there is no significant progress in that direction.
Indeed, a private person would think twice about allowing their shiny new $10,000 traction battery to be swapped for a rusty old one near the end of its life and conceivably dangerous. And where will those $500,000 swapping stations be when she needs one and who covers that cost?
The opposite is true with a bus or taxi fleet. The vehicles can be identical and the depot and route facilities owned by one company and professionally managed. Battery swapping makes great sense here.
Concepts that are impracticable with private cars become a serious proposition. Consider using very frequently charged ultracapacitors with 20 year life instead of batteries. Consider using fuel cells with their massive up front cost but, in due course, a payback when used intensively.
Fuel cells
Trials of a succession of fuel cell boosted battery taxis and buses continue one after the other with no major rollout. Cynics say it is always ten years away and has been since the invention of the fuel cell in the 1840s but this decade will see more action we believe because governments will fund fuel cells particularly in buses without payback, because of agendas such as creating a fuel cell industry.
This is despite the fact that the creation of a safe hydrogen distribution network is extremely expensive as is the hydrogen, and the fuel cell actually acts rather like the conventional engine in a hybrid. It has to be protected from load variations if it is to work efficiently.
Gas turbine range extenders
More immediately attractive is filling that position of a constant-speed constant-torque engine in a hybrid with a gas turbine and these can now be seen in a variety of buses, such as DesignLine ones made in New Zealand and powertrains of Adura Systems in the USA that is developing its own turbines.
Today Capstone is one supplier of these turbines and Bladon Jets Ltd is following with microturbines specifically designed as range extenders where the shaft and blades are in one piece to reduce cost even further. Indeed, all turbine range extenders accept biofuels and other fuels without retuning, have lower cost, greater reliability (look at the jet planes above you compared with the cars stuck at the roadside) and simpler construction.
Unique conference
The forthcoming conference Future of Electric Vehicles in San Jose California 7-8 December looks at all forms of electric vehicle by land, water and air with an emphasis on future breakthroughs and cross fertilisation of ideas. See
Speakers include bus and car manufacturer Fiat, hybrid bus powertrain leader BAE Systems, Afs Trinity Power Corporation on the next hybrid powertrains, KPIT Cummins Info Systems Ltd on commercial vehicle conversion to hybrid, Bladon Jets, Siemens and a host of developers of the third generation batteries, printed electronics and electrics, wireless sensors and actuators and new forms of energy harvesting.
This is leading to a ground up redesign of buses, cars and taxis in place of the current shoehorning of electrics into old platforms and bodies or at least legacy thinking as how vehicles should be designed.
Early Bird Bookers get a free copy of the new $3000 report, "Electric Buses and Taxis 2011-2021" and there are visits to KleenSpeed (200 mph Formula One pure electric racer, family EVs) and SunPods (solar powered charging stations).

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Posted on: October 26, 2010

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