The vehicle is a compact six-seater that looks like an uncluttered mix of a Renault Scenic and a Citroen Picasso. It is due to make its global debut at next month's Paris Motor Show.
Minister of Science and Technology Mosibudi Mangena drove the silent vehicle at Killarney on Thursday and said afterwards: "At face value, this may seem a foolhardy venture, given the fiercely competitive nature of the car industry, particularly at a time when market conditions for such products are difficult."
Then he added: "This car is simply gorgeous, and many of us would love to drive it."
Cape Town company Optimal Energy has spent over two years developing the Joule, with the help of R50-million from the National Research Foundation's Innovation Fund.
The car was designed by SA-born Keith Helfet, who has also designed a number of high performance Jaguars, such as the iconic XJ-220, XK-180 and F-Type.