hina and Third World countries that lead acid vehicle battery all too often ends up in the local river or landfill. Birth defects and deaths are the consequence but at least we now know that, for a host of reasons including tighter legislation and more demanding consumers, the lead acid traction battery driving forward bikes, golf carts, forklifts and the like will rapidly decline before the end of the decade. None too soon, because the World Health Organisation reports that 120 million people are currently over-exposed to lead and 99% of those are in the developing world where manufacturing cheap goods comes at a price. Indeed the problem is compounded by the lead acid batteries in 125 million e-bikes in China typically lasting a mere 300 cycles and one year of life.
The unique IDTechEx event Electric Vehicles Land Sea Air USA 2012 that has just taken place in Silicon Valley revealed many of these trends because it alone looked at the full picture, examining all forms of electric vehicle, from electric aircraft which cannot take off with lead acid batteries to tractors that need the new lithium-ion batteries to avoid having the front bog down in the mud. However, because IDTechEx are analysts not evangelists, they exposed a number of other concerns beyond lead.
For example, traction battery maker Electrovaya of Canada pointed out that the n methyl pyrollidone used in the manufacture of most lithium-ion batteries is more toxic than was originally realised because it can cause birth defects for example, so it is now classified as comparable to mercury in toxicity. It does not appear in the final batteries but getting rid of it in manufacture is a big step forward, something that Electrovaya has achieved.
The large Israeli defense company Elbit Systems startled the audience by announcing supercapacitors based on little more than water and carbon that reach the energy density of lead acid batteries but with far longer life and far faster charge-discharge. Fact, the University of Texas, Austin's Cockrell School of Engineering, has recently reported a similar achievement. Such devices work very well at low temperature, something rarely achieved by batteries.
Indeed, it was noted that it is not just a bus operator in the USA that is already powering its buses solely with very green supercapacitors and no batteries, Oshkosh now has a hybrid truck where supercapacitors replace the traction batteries, driven as much by life and performance as by superior green credentials.
Alongside this is the drive to replace rare or potentially expensive materials. As with supercapacitors, this often comes with improved performance - another win-win situation. For example Phoenix, a subsidiary of agricultural and mining vehicle giant John Deere, announced switched reluctance motors newly incorporated into its 944 loader where an extra benefit lies in the constant power/speed ratio.
These are to be supplied by Nidec of Japan which announced its first such traction motors this year claiming that they have achieved the lowest cost point of any traction motor, the point being that these motors, made by its acquisition of SR Drives in the UK, have not only dispensed with expensive magnets containing neodymium and dysprosium, they do not even have a copper winding in the rotor.
Copper prices have been on the move, not just rare earth prices. ACAL Energy announced fuel cells with no platinum catalyst. The rapid progress with energy harvesting such as thermoelectrics, photovoltaics and electricity generating active suspension reported at the event also leads to less need for batteries and toxic or expensive materials.
Nevertheless, one of the biggest sea changes is the continuing replacement of highly polluting conventional vehicles with ones with greener hybrid and pure electric power trains. There was some questioning about whether the robust tapping of vast natural gas reserves in North America and around the world will bring electric vehicle programs to a halt but this proves to be wrong for several reasons. Firstly natural gas is being employed in such things as WrightSpeed power trains for medium sized trucks of which the USA alone has over two million, currently polluting more than cars. This hybrid power train employs a Capstone turbine. Such jet engines have been used in trucks and buses for 14 years and they can burn a wide variety of fuels, so one vehicle shown to delegates in a visit to their premises was burning diesel and the other natural gas, in accordance with the different wishes of the customer.
Wrightspeed in progressing this technology rapidly, right down to designing and making its own PMAC traction motors and gear trains. Retrofitting these powertrains is easy and the payback can be as little as one year, with extra benefits such as better tolerance of frequent stop and start.
The glamor and excitement of the big picture was much in evidence, with awards going to the world's first pure electric helicopter to fly and the world's most economical fixed wing aircraft - Pipistrel - both promising massive reduction in pollution over what is on offer today and, in the case of the helicopter, far greater safety because gearbox and engine failure is now highly unlikely to be fatal, whether hybrid or pure electric is chosen.
The international nature of the event was much in evidence, not least in the fact that the SYNPER helicopter was achieved by a handful of people in Slovenia and the helicopter came from a very determined Frenchman now working in Australia. Both involved staggeringly short timescales.
Other prizes went to the Ryno single wheel motorbike, the Oxis Energy lithium sulfur battery which both out performs current batteries and replaces their rare and/or toxic materials with low cost ones. The LA Department of Water and Power received an award for its comprehensive electric vehicle and smart grid trials. All these advances cross fertilise into other sectors. For example, Pipistrel people believe that their discoveries in aerodynamic moulding and battery failure prediction and warning can be useful in cars. It foresaw silent city hopper planes also resulting from the work. Toyota described its fuel cell commercial vehicle that is well advanced and can lead to fuel cells in vehicles of many configurations. Indeed Mercedes demonstrated a working fuel cell car at the event and Hydrogenics and others presented on fuel cells. Clean just got cleaner.