Joule was an electric five seat passenger car by Optimal Energy, a

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

n company based in

Cape Town Cape Town is the legislature, legislative capital city, capital of South Africa. It is the country's oldest city and the seat of the Parliament of South Africa. Cape Town is the country's List of municipalities in South Africa, second-largest ...

. According to the company, it was to have a nominal driving range of 150 km and a top speed of 135 km/h. Designed to achieve a Euro NCAP 4 star safety rating, it complied with the stringent EU standards. It was a

concept car A concept car (also known as a concept vehicle or show vehicle) is a car made to showcase new styling or new technology. Concept cars are often exhibited at motor shows to gauge customer reaction to new and radical designs which may or may not ...

that was never released commercially; development ceased in April 2012, and in June 2012 Optimal Energy announced its intention to close down.

Unveiling

The Joule was first unveiled to the general public at the

2008 Paris Motor Show The 2008 Paris Motor Show took place from 4 October to 19 October 2008, in Paris expo Porte de Versailles. This edition of the Paris Motor Show featured a high number of hybrid and electric vehicles (EVs), that led a blogger with ''The New York T ...

on October 2, 2008. It underwent some interior and exterior changes, most notably the change from a six-seater to a 5-seater vehicle, before being revealed to the public at the 2010 Geneva Motor show on 2 March 2010 in a form that was close to the final version.

Optimal Energy

The Joule was the first electric car to be produced by Optimal Energy, the

based company has been working on the concept since 2004. The design of the car was done by Jaguar car designer

Keith Helfet Edsel Keith Helfet (born June 1946) is a South African automotive designer. After demonstrating little academic promise in South Africa, Helfet turned to art. He had a natural affinity for automotive design and was accepted as a student into th ...

, who is best known for the XJ220, and the

F-type F-type may refer to: *F-type asteroid, a type of carbonaceous asteroid *F-ATPase, a membrane protein *F-type main-sequence star, a hydrogen-fusing star * F-type Prisons, high-security prisons in Turkey *MG F-type Magna, six-cylinder-engined car pr ...

concept car. The Joule showed the same 'flowing lines' as his previous designs. Kobus Meiring, Optimal Energy CEO, suggested that

sustainability Sustainability is a social goal for people to co-exist on Earth over a long period of time. Definitions of this term are disputed and have varied with literature, context, and time. Sustainability usually has three dimensions (or pillars): env ...

of the

Internal Combustion Engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal comb ...

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

has fuelled the increasing need for sustainable vehicle propulsion systems. This, as well as increasing

fuel prices The usage and pricing of gasoline (or ''petrol'') results from factors such as crude oil prices, processing and distribution costs, local demand, the strength of local currencies, local taxation or subsidy, and the availability of local sourc ...

and rising country taxes, caused Optimal Energy to embark on the production of a vehicle that could meet these needs.

Investment to date

Funding was primarily through government investments, in particular, the South African Department of Science & Technology (DST) through the Innovation Fund, as well as other private investments. The Innovation Fund invested about US$5 million in the project. The Industrial Development Corporation (IDC) of South Africa is a major shareholder, with 22% of equity in Optimal Energy.

Class

The Joule was classed as a five-seat passenger car.

Specifications

*Length - *Turning Circle - *Mass - *Seats - Five *Boot space - *Top Speed - Governed at *Acceleration - 0–60 km/h in less than 5 sec *Range - *Charge time - The battery has a nominal recharge time of 10–12 hours

Closure

A small pilot fleet of Joules was manufactured in conjunction with

Hi-Tech Automotive Hi-Tech Automotive is a low volume, specialist car builder and design house located in Port Elizabeth, South Africa. Most of the vehicles produced are exported, notably to the US and UK. The main distributor of the cars built by Hi-Tech is Su ...

in Port Elizabeth during 2010. The car was expected to be sold in South Africa as well as Europe from 2014, but production ceased in April 2012 after Optimal Energy failed to find a commercial partner. Optimal Energy announced its intention to close down in June 2012. It was widely reported in the media that the company was bleeding cash, the production date had been pushed back four times, and the proposed sales figures were unrealistic. Optimal Energy required more than R2bn to bring the model to production, by which time it would have been obsolete. With the private sector unwilling to invest, the government declined to commit more taxpayers' money to an enterprise which was not commercially viable. The pilot Joules were donated to the

Nelson Mandela Metropolitan University Nelson Mandela University, formerly Nelson Mandela Metropolitan University, is a public university in South Africa. Established in 1882 as Port Elizabeth, Art School it comprises the former University of Port Elizabeth, the Port Elizabeth Te ...

. It was reported that three were torched in a student protest, and the remaining Joule is in poor condition, with access denied to journalists. In January 2025, it was revealed that the remaining Joules were intact and not destroyed. Two of the units were sold to a private company, who intend to put one on display and restore another one to operational condition to create awareness of EV's in South Africa. Two Joules are on display at the

James Hall Museum of Transport James Hall Museum of Transport is a transport museum that aims to preserve and promote the history of over 400 years of transport in South Africa in particular, and Africa in general. It is the largest transport museum in Africa. It is located ...

in Johannesburg.

References

{{reflist Electric concept cars Cars of South Africa de:Optimal Energy#Optimal Energy Joule