The green car - déjà vu all over again?

The green aXcess vehicle was actually the second version of the marque to be produced. The first version, a red car which got a lot of exposure in the late 90s, was not a hybrid and was intended purely as a coat hanger for components. It was structurally weak and could not legally be driven on European roads, although the then Minister for Trade, Tim Fischer, drove it across the Sydney Harbour Bridge.

AXcess Mark II was a hybrid and a much more serious attempt to develop “Australia’s own car”, fully roadworthy, with performance, space, style and comfort on a par with a small-to-medium-sized saloon.

It was also built with manufacturing costs in mind - the target was for the vehicle to cost only $3-4,000 more than its conventional counterpart, meaning that with fuel consumption in the low 3s it would pay for itself in the first year of operation.

It was based on a cosmetically altered version of the Holden Astra body, then still years away from release in Australia, donated to the project by Holden.

Onto this shell was grafted a plethora of Australian-made components contributed by some 80 Australian firms - everything from leather seats by Howes (one of the companies to pick up big overseas sales) to instruments, lights, brakes, tyres, magnesium wheels, novel control systems and a swag of other innovations that have since appeared in regular production cars.

Under the bonnet, it had advanced Australian technologies including electric motors, batteries and energy management from CSIRO and high-power “supercapacitors” based on CSIRO research to deliver and absorb large amounts of power quickly.

The “switched reluctance” electric motor was expected to be cheap to mass produce - possibly as low as $100 per unit - because it did not require expensive winding on the rotor or permanent magnets.

Water-cooled and driving the front wheels, the motor was also robust, needed no gearbox, and became a generator by reversing the switching, thus putting power back into the batteries when slowing down or braking.

While cars like the Toyota Prius use expensive nickel metal hydride batteries, the aXcess team specified a beefed-up version of the familiar, and relatively cheap, lead acid battery.

Improvements developed by CSIRO gave these new batteries the edge with lighter weight, and a quicker charge time. These improvements were achieved by redesigning and compressing the plates, and working with Pasminco to rewrite the international standard for lead purity.

The “supercapacitors”, originally developed by an Australian company, Cap-XX, for radios and small electronic power systems, were capable of delivering and absorbing power quickly as required during acceleration and braking. The car had 100 of them, each about the size of a chocolate block, packed into a suitcase-sized container.

In the years since aXcess was made, CSIRO continued to work on its energy storage technologies and achieved a further breakthrough when they found a way to combine the battery and supercapacitor into one package. This has eliminated the need for the elaborate electronic controller used in aXcess.