Low Energy Vehicle

A Low-energy vehicle is any type of vehicle that uses less energy than a regular vehicle. The higher efficiency can be achieved by changing the vehicle's design, and/or by modifying its powertrain. The biggest influence on the fuel consumption is not the engineering quality but the vehicle specification such as top speed, safety reserves and load capacity. This is explained by the physical relations later in this article.

Energy consumption as low as 5-12.5 kWh/100km (180-450 kJ/km) is achieved directly by battery electric microcars. The energy efficiency of the power generation has to be considered however - geothermal, solar or hydraulic power have the best ratio- caloric the worst.Overall energy generation and distribution efficiency for Europe is about 40%,so the overall energy consumption of electric cars lies in the range 0.45 to 1.1 MJ/km. Looking to the year 2050, consumption levels of 1.6 l/100 km (0.64 MJ/km) in diesel-fuelled cars and 2 l/100 km (0.7 MJ/km) in petrol-fuelled cars are deemed feasible.The energy consumption figures for petrol and diesel cars should be increased by 18% to represent the oil used in processing and distributing oil-based fuel, to 0.75 MJ/km for diesel, and 0.82 MJ/km for petrol.

Technological support for low energy operation may also come from driver assistance systems since driving style can be adapted to achieve lower energy consumption. Energy management becomes possible with hybrid vehicles with the possibility to recuperate braking energy and to operate the (ICE) at higher efficiency on average. Hybrid power trains may also reduce the internal combustion engine ICE-engine size thus increasing the average load factor and minimising the part load losses.

Purely electric vehicles use up to 10 x less energy (0,3 to 0,5MJ/km)than those with combustion engines (3 to 5MJ/km and up to 10MJ/km for SUVs) because of the much higher motor and battery efficiencies. Maximum ranges are improving with new LiIon electrochemical storage batteries. Criticism about grid generation efficiency does not reflect that combined heat and power production has efficiencies of about 80% and it is easier to burn biofuels in thermal power plants than to produce biofuels out of them by GTL or FT-methods. It is not likely that purely IC powered vehicles will match the energy efficiency of EVs especially in transient operation. Hybrid electric vehicles will have to reduce the IC-size to beat them.