ELMAR: Research on Electric-Autonomous Transportation and the Implications for Mine Design and Energy Management

The ELMAR research project, funded by the German Federal Ministry of Economics and Climate Action (BMWK), aims to integrate and demonstrate electric and autonomous transport vehicles in raw material extraction operations. This will be done with special consideration of maintaining process reliability and ensuring electrical supply security, as well as their coupling to renewable energy sources within the framework of suitable representative application scenarios (use cases). This article describes the basic principles and objectives of the ELMAR research project as well as the research objectives of the Institute for Advanced Mining Technologies (AMT) of RWTH Aachen University (RWTH), Aachen/Germany, within the ELMAR project. These are the development of a mining energy model and optimized mining planning, as well as a transformation concept for raw material extraction operations.

1  Motivation

A secure supply of mineral raw materials is an essential basis for Germany’s competitiveness and prosperity and is based on the three supply pillars of domestic raw material extraction, imports and recycling. Without a secure supply of the raw materials needed for the energy and mobility transformation, the German government’s climate policy goals in the area of energy and transport cannot be achieved. In 2018, about 550 Mt of sands, gravels and natural stones were extracted in about 2,700 mostly medium-sized and small enterprises. For their part, raw material extraction operations are among the most energy-intensive industries and the highest process-related emissions in Germany are in the ceramics, stone and earth sectors. Consequently, domestic raw material extraction must be part of the decarbonization strategy not only as a supplier of raw materials, but also to become CO₂ neutral as an industrial sector in the future and to remain competitive. Today, a significant proportion of energy use is accounted for by internal transport, which is mostly realized by means of mobile diesel-powered vehicles. Different trends can be identified for the future of mining. These consist of electrification, digitalization, and the increasing use of autonomous technologies (1,7).

Electrification is closely linked to an associated increase in operational energy requirements (2). Increased political, social and environmental demands are reinforcing this trend by also seeking to reduce CO₂ emissions in the context of raw material extraction (3). Decarbonization and ESG compliance are also being considered to regulate access to finance and are key to obtaining the “social license to operate”. Based on current research, many decarbonization solutions are expected to be commercially viable within the decade (4). The use of diesel-powered machinery, which is mostly used today, for the loading and transport process in the context of resource extraction can account for up to 50 % of total energy consumption, depending on the operation (5).

Replacing diesel-powered transport machines with lower CO₂ alternatives is therefore one of those measures taken to reduce emissions. According to current research, battery electric vehicles (BEVs) are currently one of the alternatives, both for surface and underground operations (6). The integration of these battery electric transport machines in raw material extraction is associated with changes in charging infrastructure, energy demand management, and process stability. Likewise, it is necessary to rethink the processes and to consider and take into account the energy supply side as part of the process design.

If it is possible to convert existing operations and new operations to be built in the future to (battery) electric operation, which not only means replacing the machine technology used, but rather adapting the operational processes and infrastructure to the changed process- and energy-related framework conditions, an important contribution can be made to achieving Germany’s energy and climate policy goals. Similarly, the findings, approaches and technologies can be transferred to other mining transport processes with equally challenging conditions, which are characterized by a dynamic variability of the individual process steps, which in turn exhibit a high degree of dependency and complex interdependencies (1, 7).

This is precisely where the “ELMAR” project enters the topic, laying the foundations for the use of electric, autonomous mobile heavy-duty transport machines in raw materials extraction.

2  Research project: Integration and demonstration of the use of electric heavy-duty transport machines in raw material extraction (ELMAR)

ELMAR is a research project funded by the BMWK with a duration of three years (end: July 2025) with a funding volume of approximately 6 M € and a total volume of around 11 M €. The aim of the project is the electrification of internal transport in raw material extraction based on battery-electric and autonomous transport vehicles. With a special focus of maintaining process reliability in production and ensuring electrical supply security, as well as coupling these to renewable energy sources, the research project is developing solution approaches which will be demonstrated and validated in three representative application scenarios. The holistic approach from the production and energy demand side to the energy supply side enables the targeted optimization of both sides.

2.1  General information

The project consortium is composed of a total of eleven partners with expertise in complementary fields, as listed in figure 1.

The Institute for Advanced Mining Technologies (AMT) of RWTH Aachen University, Aachen/Germany, is coordinating the overall project and is researching the impact of electrification on resource extraction operations as part of the project to enable the development of two key technologies from this. One is the development of a mining energy model and optimized mining planning for consumption forecasting and operational optimization. Furthermore, the AMT is developing a transformation concept for the electrification of raw material extraction operations within the framework of ELMAR. In addition, the AMT is responsible for the implementation of the transport solution within the Nivelstein Living Lab as one of the use cases.

As an OEM, the Volvo Group is involved in the ELMAR project with a total of three Group divisions. These are Volvo Autonomous Solutions (VAS), Volvo Construction Equipment and Volvo Trucks. In the project, these business units are responsible for the provision and further development of the transport system, as well as for site design.

As a software company and digital service provider, PSI AG is part of the consortium with two business units (Renewable Energy and FLS). The expertise from the optimization of energy and material flows will lead to the development of a cloud-based platform for integral real-time control and optimization for climate-neutral raw material extraction planned in this project.

Furthermore, three companies are involved from the operator side. Mineral Baustoff GmbH, part of the STRABAG SE Group, has set itself the goal of sustainable and environmentally friendly raw material extraction and efficient raw material management. Within the scope of this project, this partner acts as operator of the use case “Eigenrieden”.

The Nivelsteiner Sandwerke und Sandsteinbrüche GmbH is involved as an associated partner. The company is a medium-sized, traditional and future-oriented enterprise in the sand and gravel industry in the Aachen region, which has been active as a family business since 1904. In close cooperation with the AMT, the company supports the research project by providing the required operating areas for the implementation of the electrified transport process within the living lab in the second use case “Nivelstein”.

Knauf Gips KG, which operates in Germany, specializes in systems for drywall and flooring, plaster and facades. Natural gypsum and anhydrite are important raw materials here, which are extracted both underground and above ground in several operations. Knauf as a partner participates in this research project as operator of the third use case “Altertheimer Mulde”.

Another partner from the field of academic research is the Institute for Power Electronics and Electrical Drives (ISEA) of RWTH. For the research area of electrical storage technology and energy supply, ISEA is developing various models for the charging management of electrical mining machines as well as the optimized charging control.

As part of its research and development activities, TITUS Research GmbH works on the integration and design optimization of mission-specific sensors and actuators. TITUS is involved as a partner with tasks in airborne process automation and digitalization.

2.2  Aims of the research project

To achieve the goals of the overall project, the following focal points will be addressed in the project:

1. Conceptual design, planning and preparation of the use cases.
2. Validation of prototype vehicles and step-by-step demonstration of an electrified and integrated transportation process.
3. Build-up of a cloud-based service platform to link the energy consumption and supply side with digital twins and process data in the AI-based decision model for active control.
4. Development of a mining energy model and optimized mine planning for consumption forecasting and operational optimization.
5. Development of an energy supply model for the optimization and decoupling of the local energy supply.
6. Optimization and design of the energetic coupling of extraction operation and (local) energy generation including storage systems.
7. Development of an airborne acquisition and digitization of operational data.
8. Development of a transformation concept for raw material extraction sites to define requirements, target states, implementation scenarios and cross-industry transfer of results.
9. Implementation of the project findings for the “Altertheimer Mulde” greenfield project.

The technological basis of the research project is formed by the battery-electric and autonomous transport machines developed by VAS, with the TA15 (Figure 2).

In addition to full autonomy, a novel feature of this system is the approach to fast charging based on a conductive charging concept. The TA15s have a payload capacity of 15 t. Volvo’s approach within the TARA system is to enable economical transport through the combination of autonomous driving, fast charging system, as well as higher vehicle numbers. The choice of the fast-charging system allows the use of a smaller battery capacity, as the transport troughs are electrically charged at regular time intervals by conduction. This eliminates the need to transport an unnecessary amount of battery mass (8). The integration of this innovative transport system is to be demonstrated in real application scenarios as part of the use cases planned in ELMAR.

2.3  Use Cases

Within the scope of ELMAR, two pilot plants were selected as use cases in which the TA15s are to be integrated and demonstrated. These are the “Eigenrieden” limestone quarry of Mineral GmbH and the “Nivelstein” quartz sand plant of Nivelsteiner Sandwerke und Sandsteinbrüche GmbH. Furthermore, the underground gypsum mine “Altertheimer Mulde” of Knauf, which is currently being planned, functions as a greenfield use case for the further utilization and implementation of the results from the preceding two use cases.

In Eigenrieden, a total of up to three TA15s will gradually go into research operation, as the introduction of electrically operated and autonomously driving vehicles for raw material extraction in the quarry is a core element on the way to CO₂ reduction. The sustainability plan for the quarry also includes the perspective switch to climate-neutral fuels for construction machinery and the use of PV. The Eigenrieden limestone quarry has been part of STRABAG since 2009. The quarry currently has a deposit of around 6 Mt of rock in the strata of the lower limestone. The annual production volume of building material mixtures and chippings is around 220,000 t (9).

As an associated partner of the research project, the Nivelsteiner Sandwerke und Sandsteinbrüche provides different areas of the Nivelstein plant. The implementation will finally be conducted by the AMT within the framework of the “Living Lab” and represents the second use case for the ELMAR research project, in which TA15 operation is planned for internal transport. Both use cases will include a 5G network for the operation of the transport machines as well as a local battery storage for an optimal energy management.

The underground gypsum mine “Altertheimer Mulde” of Knauf planned near Würzburg is the third use case. The findings from the ELMAR project are to support the planning regarding the complete electrification of the underground operation. The status as a greenfield project should be emphasized. All planning already includes the possibilities of an electrified vehicle fleet and operation management adapted to the electric load from the very beginning. Figure 3 gives an overview of the three use cases.

2.4  Research objectives AMT

As part of ELMAR, the AMT is researching two goals for the electrification of resource extraction operations. These are:

1. Development of a mining energy model and an energetically optimized operational mine plan for consumption forecasting and operational optimization.
2. Development of a transformation concept for raw material extraction sites to define requirements, target states, implementation scenarios and cross-company transfer of results.

3  Development of a mining energy model and optimized mining planning

This sub-goal pursues an approach based on the consideration and modeling of relevant energetic parameters for mining planning and production control. These include on-site energy generation, e. g., through PV systems, energy storage through local battery storage systems, optimization of vehicle energy consumption and production targets and constraints. These energetic influencing factors are taken into account with the help of this sub-goal in daily production control and short-term planning, but also in medium- and long-term planning. This approach of an energetically optimized operational mine plan can then be transferred to the tactical or strategic mine plan. With the geometric expansion of a mining operation, e. g., the energy requirement in transport also increases accordingly due to the extension of the travel routes, which can represent a considerable challenge, particularly for the process reliability of battery-electric transport vehicles. With the help of the energy-optimized and model-based mine planning to be developed, it will be possible to reduce emissions and achieve sustainable and efficient energy management in raw material extraction.

The basis for this sub-objective of the AMT is data acquisition and modeling of the transport system. Here, the transport process is modeled, and a suitable energy-optimized mine plan is developed. As part of the coupling of modeling and simulation, the optimization results can be integrated back into the models. These models are then validated in the use case operations and iteratively adapted to the real process. In this way, it becomes possible to test different scenarios and alternative production methods in a real application environment.

The considered components of the energy model to be developed are:

1. Vehicle energy characteristics: Knowing the power requirements and energy consumption patterns of vehicles is critical to accurately assessing and modeling their energy performance.
2. Geometric and energy characteristics of the routes: The geometric aspects of routes, including their length, gradients, rolling resistance and curvature, play a significant role in energy consumption during transportation. Incorporating such information, along with energetic characteristics such as route parameters and traffic patterns, allows for more accurate modeling of the energy requirements of each transportation route.
3. Mass flow of transported material: Quantifying and integrating this information into the energy model enables a comprehensive analysis of the energy demand associated with the transport process.

The transformation concept described below and the energy-optimized decommissioning plan are mutually influenced by each other’s outcomes. Certain models, such as the vehicle’s energy model, are shared and the results from the short-term plan can be utilized to optimize mid-term decisions, e. g., infrastructure location.

The results of forecasting of the specific energy demand of the transport vehicles can furthermore be processed for the planning of the network capacity as well as the integration potentials of renewable energy sources. Building on this, energy resources can thus also be optimized by identifying opportunities for load shifting and demand reduction, as well as taking into account off-peak energy generation or excess availability of renewable energy.

Overall, such an energy consumption model enables efficient raw material extraction, renewable energy integration and infrastructure planning support. It also optimizes the use of energy resources and ultimately facilitates the making of informed and data-driven decisions about the deployment of battery-powered transportation vehicles.

4  Development of a transformation concept for raw material extraction companies

The development of a transformation concept aims to implement a systematic and modular methodology for the conversion of conventional operating models to electrified transport in raw material extraction based on the use cases of the ELMAR project.

Electrification goes far beyond the mere replacement of combustion engines by electric drive systems. It should be emphasized that, in addition to changes in the machine constellation, other operational areas such as mine site and route design, operational energy conditions and local infrastructure must be equally considered. The necessity of this transformation concept is derived from the complex problem of operational and process transformation as well as the effects of electrification, which are difficult to estimate.

From these effects, in turn, various fields of consideration can be derived, which must be taken into account in every phase of the transformation. These include the site geometry based on the properties of the deposit and the resulting operating and route design. In addition, the charging times of battery electric vehicles represent a new element in the consideration of the transportation process. Furthermore, the available machines, especially the electrified ones, are the technological basis of the concept. These technologies are accompanied by a new type of infrastructure, which must be integrated and connected into the operations in order to meet the specific requirements of the respective technology. This includes not only the infrastructure for electric charging, but also the communication and monitoring infrastructure. For a successful transformation, these areas of consideration must be harmonized.

For the transformation from a diesel-powered to an electrified transport, four different phases are considered as part of the transformation concept. These are:

1. analysis phase;
2. planning phase;
3. implementation phase; and
4. evaluation phase.

In the framework of the project, the requirements of the raw material extraction sites for electric transport machines are therefore analyzed in the analysis phase. The objectives and focal points of the electrification project are defined and specific measures for electrification are derived. Subsequently, the planning of the electrified transport for the respective operation takes place within the planning phase. The implementation of these measures is followed by an investigation of the effects of electrification on the transformation of raw material extraction sites using the example of the use cases Nivelstein and Eigenrieden within the implementation phase. In the evaluation phase, the results will be assessed and general recommendations for action derived from the findings of the two use cases of the project for the electrification of raw material extraction sites. The aim is that the findings and methodology can also be transferred to other raw material extraction sites.

Based on the developed systematic methodology of this transformation concept, the electrification of raw material extraction sites should be comprehensible, facilitated and more strongly promoted in the future. In this way, it will be possible for raw material extraction to participate in meeting the climate targets of the EU and the German government.

5  Summary

In the ELMAR research project, in addition to the demonstration and integration of electric and autonomous transport, the impact of electrification on operational and medium-term planning in raw material extraction is being researched. Furthermore, a methodology is being developed to accompany the transformation of raw material extraction operations from fossil to electrified transport technologies.

The project consortium consists of the following eleven partners from industry and research:

• AMT;
• Volvo Autonomous Solutions;
• Volvo Construction Equipment;
• Volvo Trucks;
• PSI AG Business Unit Renewable Energy;
• PSI AG Business Unit FLS;
• Mineral Baustoff GmbH;
• Knauf Gips KG;
• ISEA;
• TITUS Research GmbH; and
• Nivelsteiner Sandwerke und Sandsteinbrüche GmbH (associated).

The goal of the ELMAR project is the integration and demonstration of battery-electric and autonomous transport in raw material extraction. This is done with a special focus on maintaining process reliability in production and ensuring the security of electrical supply, as well as linking it to local energy generation using renewable energy sources. An integral part of this is the consideration of planning aspects. This includes mine planning and control as well as medium-term operational planning for a transformation of the transport machines. In this context, the AMT will develop an energetically optimized mine planning as well as a transformation concept for raw material extraction operations to investigate the challenges and opportunities of electrification and approaches to solutions for the integration of electrified transport machines in raw material extraction operations.

In the context of energy-optimized mine planning, modeling the energy consumption of transport machines enables the inclusion of energy optimization already in the planning phase. This in turn leads to the facilitation of the integration of battery-powered transport machines into the mining process. By estimating the energy demand based on different parameters such as transport distances, loading capacities and terrain conditions, the developed model can show different possibilities to minimize the energy consumption and to optimize the transport routes. These findings should thus enable more efficient planning and allocation of operational resources.

The development of a transformation concept aims at the elaboration of a methodology which includes the entire methodical procedure from analysis to planning and implementation to evaluation. In the project, elementary factors and criteria of the transformation are elaborated, which are gained through the findings from the practical implementation of electrification projects. These findings will be used within the methodology of the transformation concept final for the formulation of recommendations for action that go beyond the individual case to make the opportunities and challenges of the electrification of transport machinery visible.

These research objectives will enable an important contribution to understanding the effects of electrification of raw material extraction based on innovative technologies. At the same time, successful electrification forms the basis for ensuring the climate-neutral future viability of this industry.

Funding

The ELMAR project will run until the end of July 2025 and is being funded by the German Federal Ministry for Economic Affairs and Climate Protection (BMWK) under the “Research and Development in the Field of Electromobility” funding guidelines with around 6 M€ out of a total project volume of approximately 11 M €. The project is funded under the project funding number FKZ 01MV22001*.