Eigenrieden Quarry: Climate neutrality in the extraction of raw materials

Photo of the quarry Eigenrieden

STRABAG pilot project of Mineral Baustoff GmbH for decarbonization in Thuringia

The Eigenrieden limestone quarry aims to gradually reduce CO2 emissions associated with the extraction of raw materials and the production of building material aggregates and crushed stone, with the goal of becoming the first climate-neutral quarry in Germany in 2027. This decarbonisation pilot project makes the facility, operated by our subsidiary Mineral Baustoff GmbH in Thuringia, a pioneer in sustainability, environmental protection and innovation throughout the industry. The project is also intended to set an example and serve as a model for the climate-friendly transformation of other raw material sites within the STRABAG Group.

Bird's eye view of Eigenrieden limestone quarry © Mineral Baustoff GmbH
Bird’s eye view: Carbon emissions are gradually being reduced at the Eigenrieden limestone quarry with the aim of extracting raw materials in a climate-neutral way.

The Eigenrieden limestone quarry currently has a deposit of about 6 million tonnes of rock in the Lower Muschelkalk strata. Mineral Baustoff GmbH produces roughly 220,000 tonnes of building material aggregates and crushed stone here every year. To date, the equipment and machinery at the quarry have been powered conventionally using diesel fuel. As a result, the facility emits about 490 tonnes of CO2 a year. The aim is to gradually reduce these carbon emissions to almost zero by the end of the current decade through a series of steps involving several subprojects. To achieve its decarbonisation goals, Mineral Baustoff GmbH is switching from diesel-powered equipment to electricity or electric powertrains and climate-neutral fuels – step by step and across all three stages of the production process: extraction, processing and loading.

Timeline climate-neutral raw material extraction

New processing plant: PV panels for sustainable solar power

At the end of 2023, a high-efficiency, electric-powered stationary processing plant has replaced the previously used diesel-powered mobile equipment. The new crushing and screening plant that is already under construction will – like all STRABAG locations and construction sites in Germany – be powered by green electricity from hydropower sources. A high-performance dust mitigation system and noise-absorbing insulation of the crushers, screening machines and belts help to minimise dust and noise emissions.

By 2027 at the latest, the energy needs of the raw material processing plant are to be largely covered by solar power from an in-house photovoltaic system. To ensure the autonomous operation of the plant, Mineral Baustoff GmbH plans to have two PV arrays (2 to 4 ha) with electricity storage built on land adjacent to the quarry.

Processing plant with green electricity © Mineral Baustoff GmbH 
The diesel-powered mobile crushers and screening machines will be replaced by a new stationary processing plant at the end of 2023, with energy requirements initially covered by green electricity from hydropower and, in the medium term, by solar power generated in-house from the planned photovoltaic system.

Electric autonomous haul trucks for transport in the quarry

To systematically reduce carbon emissions during raw material extraction at Eigenrieden, we are primarily focusing on the gradual introduction of electric-powered, autonomously operated haul trucks.

Promotional seal Federal Ministry for Economic Affairs and Climate Protection © Presse- und Informationsamt der Bundesregierung

Mineral Baustoff GmbH is one of seven partners in the ongoing ELMAR research project (8/2022–7/2025), which aims to integrate electric heavy-duty machines into the decarbonisation of the raw materials industry. The project, led by RWTH Aachen University, has received €6 million in funding from the German Federal Ministry for Economic Affairs and Climate Protection (BMKW). Vehicle manufacturing partner in the project is Volvo.

Trial operation of the first electric self-driving Volvo heavy-duty haul truck in Eigenrieden is scheduled to start in the summer of 2024. In the future, three of these emission-free trucks will be in use at the quarry to transport the extracted limestone to the processing plant. These trucks will not only reduce the carbon footprint of the quarry; they will also make a lasting contribution to improving occupational safety and health during the raw material extraction work.

  • Mineral Group is at the very beginning of the construction value chain – and we see it as our duty to contribute to the creation of a more resource-efficient and climate-friendly life cycle for buildings and other structures.

    Wolfgang Wagner
    Head of Mining Planning at Mineral Baustoff GmbH and Sustainability Officer at STRABAG Construction Materials / Recycling

HVO biodiesel and hybrid powertrains

Starting in 2024, the excavator used in the extraction process and the large loaders for loading the trucks will be fuelled with synthetic biodiesel (HVO diesel from hydrogenated vegetable oil) instead of conventional diesel fuel. The use of biofuel will not only reduce carbon emissions by more than 80%; it will also significantly lower particulate matter pollution and nitrogen oxide emissions. As soon as appropriately sized extraction machines are available on the market, the conventional excavator will also be replaced by a modern, fuel-saving hybrid model with energy recovery to further improve the carbon footprint of the quarry operations.

Wheel loaders and excavators with HVO diesel © Mineral Baustoff GmbH 
In the future, the loaders and excavators at the Eigenrieden quarry are to be fuelled with HVO diesel from hydrogenated vegetable oil.

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