On behalf of the Liebherr Group, the consulting firm Frontier Economics conducted a life cycle analysis of greenhouse gas emissions of typical construction machines equipped with various drive technologies. The experts determined how much CO2 arises from production to operation through to the recycling of the machines.
The aim of the analysis was to comprehensively calculate the emissions of the machines and their drives in order to be able to recognise and assess how greenhouses gas emissions can be most effectively reduced. In doing so it is important to look at the overall life cycle of the machines. This ranges from the mining and transport of the raw materials to production and the actual operation of the machine to the disposal and recycling: “Emissions analyses are generally limited to the operating phase. This is not enough for our products because greenhouse gas emissions also occur in the upstream and downstream phases of construction machines’ lifecycles,” states Stephen Albrecht, Member of the Board of Directors of Liebherr-International AG. “To get a complete picture, we examined all stages of the life cycle, including the production of energy and provision of the infrastructure.” These results are combined in a so-called product carbon footprint, which describes the emissions of a product throughout the entire life cycle.
Dedicated solutions: E-drive for small wheel loaders or concrete mixers, hydrogen and HVO for mobile cranes
The study examined three types of construction machines: mobile cranes, truck mixers and wheel loaders. As evidenced by the collected data, the three types require different drive technologies in order to reduce as much emissions as possible due to their different performance requirements: For truck mixers, electric drives make the biggest contribution to emissions reductions provided they use one hundred percent renewable electricity for charging. For mobile cranes, operation with hydrotreated vegetable oil (HVO) shows the biggest savings potential. Important is that the HVO is certified to be produced from plant and food waste, for example, and does not contain palm oil. Hydrogen made from CO2 neutral sources follows in second place. In the long term, operation with hydrogen seems optimal as the availability of HVO in the vast quantities required cannot yet be predicted. However, until the required hydrogen infrastructure and drive technologies are mature, HVO delivers the best results as an interim technology, particularly in existing fleets with combustion engines. Wheel loaders should be operated either with a battery electric drive charged with renewable electricity, or with e-fuels. “The results of the life cycle analysis show that there is no uniform solution for climate-neutral drives of construction machines,” adds Albrecht. Liebherr therefore relies on a technology neutral approach and can thus reduce emissions as much as possible depending on the machine and the application.
A look at the Liebherr product portfolio, which includes 13 product segments and is particularly broad especially in the area of construction machines, illustrates what leads Liebherr to compare various drive technologies. The smallest machines have a power output of 30 kW, the largest have a power output of more than 3,000 kW. All these machines must perform reliably in completely different conditions in diverse applications. “A wheel loader on an urban construction site, for example, is exposed to different conditions than a mobile crane used in the construction of wind turbines,” explained Albrecht. “The former can often be powered by electricity. In contrast, infrastructure projects in rural areas often lack the necessary power supply for an electrical connection. In addition, more energy is often required than can be provided with a battery-operated electric drive."
