Hybridization of tractors and construction equipment

Last changed: 07 June 2011

The environmental impact of using non road mobile machinery (such as tractors, wheel loaders and excavators) is mostly associated with the emissions of fossil carbon in the form of carbon dioxide. As they are responsible for about four percent of the total CO2 emissions from Sweden it is imperative to make them more efficient and less polluting.

A number of methods exists to reduce the emissions. One possibility is to use alternative fuels such as biogas and biodiesel. Another solution is to use electricity as energy energy carrier. What makes electricity really interesting is that it allows for changing the entire system of the vehicle, allowing for components that can recover energy. It is therefore possible to use the machines more efficiently with less emissions, even without using a single kilowatt hour from the grid.

The research form part of STandUP for energy, a collaboration between SLU, Uppsala University, the Royal Institute of Technology (KTH) och Luleå University of Technology. One of the projects is founded by the Swedish Transport Administration.


Large non road mobile machinery (> 37 kW) used in Sweden consume 880 000 tons of fuel yearly and emit 2 800 000 ton CO2 (2007), corresponding to about 4 % of all CO2 emissions. It is therefore of interest from an economical as well as an environmental point of view to reduce the fuel consumptiuon and emissions by increasing the efficiency of the machines.

As these machines on average have a high average power usage they need to be able to store much energy. Within the foreseeable future it is therefore unlikely that any energy carrier will be able to compete with liquid fuels (such as Diesel), as the alternatives (such as batteries) are more expensive and less capable of storing energy. It will however be possible to make the machines more efficient by replacing existing components with electric ones that have high efficiency and therefore can utilize the supplied energy better.

Over a longer time frame it is lilkely that batteries will become cheeper and have a better performace, allowing for plug-in solutions to become more competitive. By replacing Diesel with electricity substantial emission reductions can be achieved. With total electrification it is in principle possible to get no local emissions at all.


The early 21th century have seen a substantial increase in the interest of using electricity for road vehicles. The same factors that make electricity interesting for road vehicles apply to other types of vehicles, though the relative utility might vary   


The purpose of the research is to investigate issues related to hybridization/electrification of non road mobile machinery when they differ from those of road vehicles (either in their kind or magnitudes) and can be expected to substantially affect the hybridization/electrification process. For issues that dont differ from those of hybrid road vehicles, for example recycling of batteries. no projects are planned.