Holden, Ford and Toyota called the government's bluff and departed, shutting the biggest local manufacturing operations in the country and a huge talent pool of engineers, designers, manufacturing experts, metallurgists and generally clever people all slowly dissipated elsewhere.

But most never lost their unbridled passion for the car industry. Lenny Cucksey is one such person.

A former Holden manufacturing engineer, Mr Cucksey has now joined forces with two ex-Atlassian software engineers, Paul Slade and Noah Wasmer, to create the electric vehicle start-up Roev, which this weekend is displaying one of its many transport concepts at the Australian Electric Vehicle Association's inaugural EV Expo at Exhibition Park.

The Roev product looks, to all intents and purposes, like a conventional Toyota Hilux dual cab utility.

But in place of a diesel engine, under the bonnet is a big battery pack with an electric motor slung beneath.

It's a neat and highly-professional installation and using clever software, can not only operate as an electric ute but as a four-wheeled battery pack which uses vehicle-to-grid technology to charge up during the day and send its power back into the grid at night when the vehicle is parked up.

Roev's chief executive officer Noah Wasmer said the choice of the Hilux for their display was deliberate.

"It's a product everyone in Australia knows, is tough and reliable, and sells in big numbers," he said.

"By choosing it to show our technology demonstrates to fleet buyers how by switching out the internal combustion engine they can create their own microgrids and develop efficiencies in their fleet usage they never previously thought possible.

"So many of the big fleets have vehicles just sitting idle when by using vehicle-to-grid technology, these vehicles can be making money for them.

"It's not a one-size-fits-all strategy but perhaps can inspire people to think outside the box and generate the discussion."

Public interest in electric vehicles, with the fulsome support of the ACT and federal governments, is accelerating at a rate unheard of just a few years ago.

One Sydney company riding that wave example is Fonz, which produces electric motorcycles and a scooter it calls Arthur (after the original Happy Days Fonz, Arthur Fonzarelli).

A big attraction for commuters with the Fonz is that the briefcase-sized battery sits under the seat and can be quickly unclipped and carried off for recharging at the office or at home. And the off-the-mark performance, as is the case with all electric motorcycles, is as quick as conventional bikes three times the $10,990 price.

Chief executive Michelle Nazzari started Fonz 12 years ago and after a lengthy lean patch, is now riding a wave of interest.

EV Expo tickets are available online via Eventbrite.