Energy and emissions
The construction industry has a significant impact on the environment, so finding an efficient solution to the world’s energy and emissions challenges is of central importance to STRABAG. Around 37% of global greenhouse gas emissions and 34% of global final energy demand are attributable to the construction and operation of buildings (Global Alliance for Buildings and Construction, 2023). This makes it essential that we expand the use of renewable energies and reduce the overall energy consumption if we want to achieve our ambitious goal of becoming climate neutral by 2040.
Against this background, STRABAG has, among other things, acquired a stake in battery manufacturer CMBlu Energy as a way to invest in the development and production of safe and sustainable energy storage solutions. Through the combination of technology and construction expertise, it is our aim to further advance the energy transition both within the Group and beyond.
Due to the ongoing international geopolitical crises, STRABAG again faced a high degree of volatility in energy and raw materials prices in the year under report. Total energy costs in 2023 amounted to € 413.91 million (2022: € 406.83 million). Despite a sharp increase in output of 8%, however, our total energy consumption and our CO2e emissions remained almost constant. Total energy consumption amounted to 3,477,822 MWh, with a reduction in our fuel and gas consumption accompanied by an increase in the proportion of green electricity. CO2e emissions in 2023 totalled 962,944 t CO2e: Scope 1 emissions amounted to 819,934 t CO2e (2022: 813,242 t CO2e), while our Scope 2 emissions fell by almost 4% to 143,010 t CO2e (2022: 148,453 t CO2e) in the market-based calculation.
Rules, responsibilities and due diligence
Forward-looking environmental and energy policy
The environmental and energy policy updated in the year under report was expanded to include the two aspects of expertise in the energy sector and optimisation of the environmental and energy data basis. By increasing our expertise in the development of renewable energy infrastructures, we aim to actively advance the energy transition and reduce emissions from construction materials, building processes and the equipment fleet. With the help of measurable and specific key figures, the goal is to effectively manage improvement measures and ensure consistent climate reporting.
To better manage and optimise our energy consumption, we are working to expand the ISO 50001 certification of our corporate entities. In 2023, ISO 50001 had been rolled out in corporate entities responsible for around 77% (2022: 69%) of the output volume. Additional local measures and audits for energy management cover a further approximately 6% of the output in the countries where we operate. An environmental management system certified to the international ISO 14001 standard has been introduced in almost all Group countries. Certification here covers nearly 93% of the Group measured by output. Energy experts and specialists from STRABAG’s energy management team ensure that a continuous improvement process is documented and reviewed in the course of standardised audits.
The establishment of various internal bodies ensures that all of the Group’s organisational units are involved in the flow of information on environmental and energy issues. These bodies exist at the corporate, management and country level, led by the Steering Committee on Energy and the Environment. The committee meets at intervals of several weeks to exchange information on current or proposed projects and on environmental and energy-related topics for Group reporting. By involving experts from various organisational units, the steering committee brings together specialist knowledge in order to develop specific measures to optimise energy consumption while taking into account the legal and regulatory framework.
Objectives and indicators
Energieverbrauch
The energy and CO2e data for the Group are systematically captured and analysed using CarbonTracker, a software that was developed in-house and has been used and regularly updated since. The main aspects of the data collection process were revised during the 2023 financial year to allow the data basis to be updated throughout the year in line with the Group’s aim of continuously improving data quality.
Fuel as a significant source of energy
Based on the information obtained from CarbonTracker, we are developing concepts to reduce the use of fossil energy sources and lower the resulting greenhouse gas emissions in the long term through more efficient conventional or innovative machines. The Group’s most important energy source is fuel, which accounts for about 57% of the total energy costs and therefore holds the greatest potential for savings for the Group. FuelTracker, which was developed analogously to CarbonTracker, allows us to analyse the fuel use of the STRABAG passenger car and commercial vehicles fleet.
Energy use within the Group1
Form of energy | Unit | 2019 | 2020 | 2021 | 2022 | 2023 |
Fuel | MWh | 1,986,883 | 1,732,783 | 1,754,901 | 1,961,591 | 1,959,920 |
Gas | MWh | 430,143 | 332,625 | 428,683 | 416,171 | 396,746 |
Heating oil | MWh | 165,764 | 142,857 | 151,406 | 153,519 | 159,970 |
Pulverised lignite | MWh | 481,235 | 500,732 | 503,083 | 475,975 | 497,900 |
District heating | MWh | 48,826 | 42,665 | 41,645 | 42,806 | 41,011 |
Conventional electricity | MWh | 432,755 | 384,741 | 294,022 | 320,974 | 307,765 |
Total energy consumption from non-renewable sources | MWh | 3,545,607 | 3,136,403 | 3,173,740 | 3,371,036 | 3,363,312 |
Green electricity2 | MWh | n. a. | 26,700 | 100,837 | 96,366 | 114,510 |
Total energy consumption | MWh | 3,545,607 | 3,163,103 | 3,274,577 | 3,467,402 | 3,477,822 |
1With the exception of pulverised lignite, energy consumption is determined by cost. Energy costs are converted into quantities using average prices for specific energy sources and countries, based on invoice amounts. The energy units are converted to MWh (analogue to calorific value) using conversion factors from the following sources: For fuels and heating oil, the German Federal Ministry for Economic Affairs and Climate Action (BMWK). For pulverised lignite, the calculation is based on the quantities and calorific values provided by the supplier.
2This concerns the purchase of green electricity in Austria and Germany within the framework agreements (approx. 80% of the total electricity consumption in the respective countries).
CO2-Bilanzierung
The CO2e footprint in the Group
Carbon footprint: calculation method
The CO2e footprint for the 2023 financial year refers to the Group’s full scope of consolidation and includes the CO2e emissions caused in 60 countries. The emissions are reported in Scope 1 and Scope 2 in accordance with the definition of the Greenhouse Gas Protocol, with the greenhouse gases CO2, CH4 and N2O included in STRABAG’s calculations since 2020. Scope 1 emissions are calculated based on the standard unit of calorific value (kWh) using the conversion factors from the IPCC 2006 Guidelines for National Greenhouse Gas Inventories. For pulverised lignite, factors from the local suppliers were additionally used.
Scope 2 emissions for electricity and district heating have been reported separately since 2020 using market-based and location-based methods (see Data Appendix). Where district heating data was not available for a certain country, the Group average value derived from the available data was used. For the market-based calculation, CO2e emission factors from our local electricity tariffs are used. If market-based factors are not available, location-based factors are used. These factors are based on the International Energy Agency emissions database from 2020. A changeover to the latest version of the database is planned for the 2024 financial year.
Calculating the STRABAG Group’s emissions is the fundamental basis for developing measures to reduce emissions along the value chain. Specially established task groups address specific issues in this context, such as possible energy-saving measures at our construction sites or the development of an uniform CO2e calculation standard to enable the calculation of emissions from construction projects in the early bidding phase.
In the year under report, we continued to work on the calculation of Scope 3 emissions by comprehensively testing the ERP system for Scope 3 calculation requirements. Based on the findings, it was decided to extensively adapt the ERP system to be able to calculate valid Scope 3 emissions along the entire value chain. The reporting of Scope 3 emissions is therefore being established step by step.
Carbon footprint: assessment results
Within the Group, a total of 819,934 t CO2e were emitted directly by the company in the year under report (Scope 1), with an additional 143,010 t CO2e attributable to electricity and district heating use (Scope 2). The calculation was made using the market-based method. Scope 2 emissions using the location-based approach amount to 183,908 t CO2e.
Emissions of the STRABAG Group
Slightly more than half of the CO2e emissions in the Group result from the use of fuels, mainly diesel. Around 18% is attributable to pulverised lignite and around 14% to electricity (market-based). Germany, Poland, Austria and the Czech Republic together are responsible for the greatest share of these emissions (approximately 67%). With 74%, these countries also accounted for the greatest share of the Group’s output volume in 2023.
CO2e emissions
by energy source in 2023
CO2e emissions (market-based)
by country in 2023
Asphalt mixing plants are another significant source of energy consumption at STRABAG. In 2023, the energy consumption and emissions at our asphalt mixing plants in Germany amounted to 93.6 kWh per tonne of asphalt mixture produced (2022: 92.6 kWh/t) and 29.6 kg CO2e per tonne of asphalt mixture produced (2022: 29.8 kg CO2e/t). The increase in specific energy consumption is due to comparatively low production volumes at a number of production sites.
Three scopes
Projects and initiatives
Reducing emissions is a key component of STRABAG’s sustainability strategy, reflected in various projects and initiatives that extend across the entire life cycle of STRABAG’s business activities. The expansion of our expertise and knowledge is another key factor in this context. A number of training courses were offered in the 2023 financial year, including courses on the energy-saving operation of construction machinery or the promotion of alternative energy systems at STRABAG’s various divisions.
With our roadmap to becoming climate neutral by 2040, we are working together with STRABAG’s operating units and central divisions to develop a concrete path to reducing our emissions, taking into account the development, evaluation and planning of emission-reducing measures.
The decarbonisation measures were developed in joint workshops for each division and included an extensive preparation and follow-up phase. The CO2e reduction potential of the planned measures is currently being assessed. These will then be consolidated and summarised in a Group-wide quantified roadmap to be adopted in the second quarter of 2024 and updated and expanded annually.
A special working group was set up under the leadership of Management Board member Siegfried Wanker to address the transformation of the energy sector. The aim is to pool all relevant expertise on the topic of energy, to present energy consumption in a transparent manner, to create and continuously update an energy target profile, and to initiate and manage projects on the topics of increasing efficiency, substituting fossil fuels and expanding and storing renewable energies.
The aim of our photovoltaic initiative is to assess the photovoltaic potential of all buildings and land owned by the company from an economic, environmental and regulatory perspective. The results of this assessment will be used to derive a strategic framework for the Group-wide expansion of low-emission photovoltaic power generation. All properties owned by the Group in four countries have now been analysed for the feasibility of installing rooftop or ground-mounted systems. Around 50 installations with a total photovoltaic surface of approximately 28,000 m² and a nominal output of nearly 5,100 kWp have already been realised to date. Over 100 further systems are in planning or under construction.
Fossil fuels, especially fuels such as diesel and petrol for our construction machinery, currently make up the largest part of our energy mix. To help us achieve our goal of becoming climate neutral by 2040, we are working to reduce our use of fossil fuels and are testing low-emission alternatives in various settings:
Substitution with HVO
Hydrotreated vegetable oil (HVO) is a sustainable biofuel alternative made from waste oils or residual products such as tall oil. We see HVO as an important component of our Group’s future diverse energy mix. In our German entities, suitable road construction machinery is currently being converted for HVO use for initial test purposes. The aim of the pilot project is to investigate the suitability and behaviour of HVO as a fuel, including its long-term availability.
Feasibility studies on green hydrogen
Several feasibility studies are being carried out to analyse the use of green hydrogen at our asphalt mixing plants and quarries. The studies are also looking into the possibility of fuelling commercial vehicles with green hydrogen and of producing green hydrogen in-house at our production sites.
Hydrogen-powered wheel loaders
The search for alternatives to diesel is a major challenge, especially where heavy construction machinery is concerned. Several pilot projects are testing the operation of wheel loaders using green hydrogen to assess their handling, usability and reliability under various operating parameters.
The Container of the Future project, which involves analysing the energy consumption of mobile site containers, has a potential impact on the Climate-Neutral Construction Project subgoal. The results of the project will serve as a basis to define minimum standards for the energy-efficient design and operation of site containers.
The central division STRABAG Innovation & Digitalisation (SID) in 2023 started a sustainable business travel project. Over a period of 18 months, the project team, with the continuous involvement of the division’s employees, is investigating which incentive systems and framework conditions are required to gradually make business travel more sustainable and convenient.
Outlook
In the coming year, we aim to implement measurement methods and analysis tools to more precisely quantify the energy and emissions reduction potential for our projects. At the same time, we are focusing on improving data quality to allow us to set well-grounded targets and make decisions in the area of sustainable business practice.
Sources – Chapter: Energy and Emissions
Global Alliance for Building and Construction, 2023: 2022 Global Status Report for Buildings and Construction, accessed on 1 February 2024