A variety of technologies have the potential to enhance the environmental performance of (or even completely replace) the internal combustion engine. Some of the more promising technologies involve using electric motors.
Electric vehicles are those partly or wholly powered by electric batteries. They include:
- Battery electric vehicles (BEVs), wholly powered by batteries charged from external electricity supplies. The Nissan Leaf and Tesla S are examples of BEVs.
- Plug-in hybrid electric vehicles (PHEVs), which can run on either batteries or an internal combustion engine, or both. They can travel on battery-power alone for a limited distance. The batteries in a PHEV can be charged from external electricity supplies and also by their on-board internal combustion engine (which is itself fuelled by petrol or diesel). Mitsubishi Outlander PHEV and BMW i8 are examples of PHEVs.
Older forms of hybrid vehicles charge their batteries by capturing energy when braking (called ‘regenerative braking'). When these batteries are not charged, the engine is a regular internal combustion engine (fuelled by petrol or diesel). Toyota Prius and Honda Civic Hybrid are examples of these kinds of hybrids.
Electric and hybrid vehicles show increasing promise for reducing carbon emissions from the transport sector, but currently make up only a very small part of the New Zealand vehicle fleet (less than 1 percent).
Hydrogen may offer a promising but challenging energy source for transport in the future. Hydrogen-fuelled cars are already being trialled and are available for sale in California and are being promoted in Japan and Korea. Toyota has made its patented technologies freely available.
In New Zealand the Ministry of Business, Innovation and Employment (MBIE) (external link) has taken an interest in this technology, commissioning research on costs and impacts of a transition to hydrogen fuel.
Callaghan Innovation (external link) also takes an active interest in hydrogen technologies (external link) . Callaghan Innovation is currently completing a government-funded research project (external link) .