Environmental Performance

In the area of mobility, basic distinction is made between business-related travel of employees and the university’s own vehicle fleet. Trips made to and from the university by employees and students for the purpose of work and study, respectively, are excluded from the analysis.

Business-related travel

In 2019, systematic recording of employees’ business-related travel was converted to the MACH-ERP system. This now allows targeted data queries concerning business-related travel, including the selected means of transport and travel distances. The previous management system does not allow targeted queries and, due to the inhomogeneity and quantity of the data, fully comprehensive individual evaluation is not possible. Thus, for the reference year 2019, only air travel within the scope of business-related travel was considered. This results in a sum of 556 individual flights from 278 outward and return flights, the majority of which is attributable to 326 flights (59%) from within Europe; see Table 3. However, at 143.3t CO₂, transatlantic flights account for the largest proportion of total CO₂ emissions due to the longer distance travelled. The CO₂ footprint is calculated using the CO₂ calculator of the German Environment Agency (UBA 2021).

As described above, in the evaluation for 2019, only air travel can be considered. It may be assumed, however, that air travel generates the largest proportion of emissions. In any case, the conversion to the MACH-ERP system is to facilitate recording and evaluation of all business-related travel in future.

This includes trips with rental vehicles and private cars as well as train or bus journeys. The present report should therefore be viewed only as an initial stocktaking exercise. The scope of the balance will continue to refer to the employees of the Bauhaus-Universität Weimar.

Vehicle fleet

The vehicle fleet of the Bauhaus-Universität Weimar comprises eleven vehicles, which are differentiated in their function between the five segments Construction and Transport, Operational Technology (heating/sanitary, electronics), University Directorate, Internal Mail and the independent vehicle of the »Versuchstechnische Einrichtung« (experimental technology facility; VTE). The following data on kilometres driven, days of use and specific consumption are recorded and provided by the Service Centre for Facility Management – Vehicle Fleet. The two BMWs used by the University Directorate are leased vehicles with a term of one year; the annual exchange of these vehicles falls within the period under consideration. The consumption of both lease iterations was considered as a sum for the annual report; there is no separate differentiation between the models. The E-Citroën of the Internal Mail segment is an electric vehicle, whilst the remainder of the fleet runs on diesel. The Ford bus (9 seats), with an above average mileage of 40,753 km (see Figure 2) and the BMW 730 and BMW 5 are used exclusively by the university’s transport service. The Opel Astra, VW Caddy, and VW Crafter may be used freely by all members of the university.

The CO₂ footprint of the vehicles listed in Figure 3 is not calculated on the basis of mileage, rather via the fuel consumption in litres documented in logbooks, or the specific CO₂ emissions of 2.65 kg CO₂2/l Diesel (UBA 2016), at 35.87 MJ/L (AGEB 2018). Excluded from the diesel CO₂ consideration is the E-Citroën of the Internal Mail segment (9,529 km), as this is operated with green electricity and is recorded at 0 g CO₂/kWh; see chapter 3.2 Electricity, p. 14. Operation of the E-Car requires an output of 1,991 kWh.

As expected, the high mileage of the Ford bus (approx. 40,000 km) also results in the highest CO₂ emissions. This is followed by the VW Crafter from Construction and Transport (approx. 20,000 km). In addition to the classification based on distance travelled, consideration of the vehicle fleet according to specific CO₂ emissions also makes sense. Such a consideration sees large vehicles such as the Multicar, the VW Crafter, the Mercedes Vitos and the Ford bus leading the statistics (>250 g CO2/km); see Table 4.

Electricity consumption of the Bauhaus-Universität Weimar is derived from the consumption and billing data of the Service Centre for Facility Management. These data were made available to the authors by the Service Centre for Facility Management in cooperation with the research project »Bauhaus2050: Energy efficient refurbishment of city quarters reducing CO₂ emissions allowing for heritage listed building stock in Weimar« of the professorships Building Physics (Prof. Dr. Conrad Völker) and Modelling and Simulation of Structures (Prof. Dr. Guido Morgenthal).

As shown at the beginning in the overall overview (Table 1), electricity consumption in 2019 is 4% higher than the 5-year average from 2014 to 2018. The calculation basis is shown in Table 5.

he Bauhaus-Universität Weimar obtains its electricity via a green electricity tariff from electricity supplier Thüringer Energie AG, which is based on a CO₂ footprint of 0.0 g CO₂/kWh. This results in a CO₂ footprint of 0.0 kg CO₂ for total electricity consumption in 2019; see Table 6.

The data basis for heating energy consumption is the consumption and billing database of the Service Centre for Facility Management. All heating energy is in the form of heating oil, district heating and natural gas. The total heating energy requirement of the Bauhaus-Universität Weimar amounts to 10,879,859 kWh, as illustrated in Figure 5. In the reference year 2019, the energy requirement is composed of 9,702,929 kWh natural gas (89%), 1,176,930 kWh district heating (11%) and 0 kWh heating oil (0%).

The numerical representation of the data series from Figure 5 can be seen for the years 2014– 2019 in Table 7. As shown at the beginning in the overall overview (Table 1), the total energy requirement in 2019 is thus 3% higher than the 5-year average from 2014 to 2018. Whereas heating oil and natural gas represent classic, fossil primary energy sources, district heating requires a more detailed top-down examination. This involves a gas-powered boiler in the building complex at Steubenstraße 6, 6a and 8. The gas boiler is located within the properties of the Bauhaus-Universität Weimar and is operated and maintained by the Weimar public utility company. However, it is not clear from the billing whether the kWh provided are billed in heat output or in kWh of natural gas. A distinction (inclusion of boiler efficiency) is necessary in the calculation of the CO₂ balance. In the further calculation, the second case – billed primary energy output of natural gas – was used.

Table 8 illustrates the conversion of specific CO₂ emissions per kWh into the total CO₂ footprint (UBA 2016). The heating value for heating oil was presumed to be 9.8 kWh/l for better comparability. For the heating energy consumption of the Bauhaus-Universität Weimar in 2019, this results in a CO₂ footprint of 2,177,206 kg CO₂.

As with electricity and heating energy, the collection of data pertaining to produced waste is also carried out by the Service Centre for Facility Management. The disposal of different types of waste is also carried out by different waste management companies: household waste, biowaste and paper are disposed of fortnightly – and glass upon request – by the Weimar public utility company (municipal service), whilst the disposal of lightweight packaging (LWP) and extraordinary collections of bulk goods in skips are carried out by Remondis®. The fortnightly collection of waste ensues in waste containers with capacities of 60l, 80l, 120l, 240l or in mobile garbage bins (MGBs) with a capacity of 1,100l. In total, the Bauhaus-Universität Weimar has at its disposal 114 waste containers with capacities for 16.9 m³ household waste, 5.4 m³ biowaste, 7.7 m³ LWP, 20.0 m³ paper and 4.7 m³ glass; see Table 9.

During the regular collection of waste containers by the municipal service, no individual weighing is carried out on the vehicle. Due to this gap in data collection, the actual weight can only be estimated indirectly via literature and comparative values. Table 10 illustrates the average waste densities used in this report of the different types of waste. Furthermore, a specific filling level of 80% is assumed as an annual average for the waste containers. Due to the assumptions and uncertainties in the data collection, there are also uncertainties in the evaluation, the assessment of which is correspondingly imprecise.

The returnable containers are skips and rubble skips or document destruction bins. In these cases, the weight is transmitted directly by the waste disposal company via invoicing, meaning no conversion via literature and estimated values is necessary. The calculated waste volumes of the waste containers and returnable containers are shown in Table 11. According to the data, the largest individual waste type (excluding building materials) is domestic-waste-like commercial waste (household waste), accounting for 88.0t (27.9%). The separately collected waste materials LWP, paper and glass account for a total of 122.0t (38.7%).

A calculation tool from the University of Leoben was used to calculate the CO₂ footprint (MUL 2012). In the accompanying study, the authors explicitly point out that the climate balance tool applies to Styria only to a limited extent. However, the region is suitable for the purpose of a comparison scenario. The processing, treatment or recycling and landfilling of waste material flows are considered. Transport routes, which would also have to be newly created for an individual case analysis in Weimar, are not considered. No data is available concerning building materials. In this context, a separate climate balancing for the waste management processes of the Bauhaus-Universität Weimar would be desirable.

Because of the data calculated concerning waste containers, the fact that recording of MGBs is only done manually and that, in the case of glass, disposal is not documented, unambiguous and reliable evaluation is not possible. The following CO₂ balance is based on data for Styria from 2010/2012 and should therefore only serve as qualitative evidence for the identification of CO₂ hotspots and not as a reliable indicator thereof. The waste volumes and CO₂ emissions were therefore marked accordingly in the overviews in Table 1 and Table 2.

In addition to the domestic-like types of waste, such as household waste, biowaste, green waste, LWP, paper, glass, building materials and bulky waste, the Bauhaus-Universität Weimar also generates hazardous waste. This waste is disposed of on demand by the facilities and is recorded centrally by the Service Centre for Facility Management using the waste code from the Abfallverzeichnis-Verordnung (German waste catalogue ordinance); see Table 12. In addition, the volumes of the Faculty of Civil Engineering are documented by the Hazardous Substances Officer. The waste is classified and disposed of by Remondis®.

Conversion of the disposed of hazardous waste into a CO₂ quivalent footprint was dispensed with due to the undifferentiated classification.

As in the above categories, the consumption and billing data of the Service Centre for Facility Management serves as the data basis for drinking water consumption and wastewater generation.

Development of the drinking water requirement and corresponding wastewater generation for the years 2014 to 2019 is illustrated in Figure 6. As shown at the beginning in the overall overview (Table 1), drinking water consumption in 2019 is 18% lower than the 5-year average from 2014 to 2018. Wastewater generation is as much as 28% lower than the 5-year average. The difference ensues from the year 2014, for which a large discrepancy between drinking water consumption and wastewater generation is listed. However, the determination of wastewater generation is not an actual measurement, but rather an indirect calculation on the basis of drinking water consumption. This is carried out by the municipal service. How this discrepancy emerged in 2014 is not clear from the data submitted. The data were nevertheless included in the 5-year trend. The underlying numerical calculation basis for the graphical representation in Figure 6 is listed in Table 13.

For calculation of the CO₂ footprint, the necessary electricity and primary energy requirement for drinking water treatment and wastewater disposal and purification for Weimar must first be determined. No separate data on CO₂ equivalent expenditures are available from the public utility company; accordingly, assumptions had to be made in some cases, or – in the absence of key figures – reference had to be made to literature data. In the drinking water treatment of the Weimar public utility company, an energy consumption of 1.43 kWh per m³ of drinking water with 185 g CO₂/kWh applies (Wasserversorgung Weimar 2020). This results in the Bauhaus-Universität Weimar emitting 4,212 kg CO₂ in connection with the provision of treated drinking water. In the area of wastewater disposal, no city-specific key data are available for Weimar’s wastewater utilities. The calculation is based on data from literature, for example a specific wastewater volume of 120 l/(PE∙d) and a specific purification energy of 35.1 kWh/(PE∙a) (Kolisch 2014). This results in a specific energy consumption of 0.80 kWh/m³ wastewater, which corresponds to 174 g CO₂/kWh in the municipal electricity mix of the Weimar public utility company (SW-Weimar 2020). The CO₂ footprint for the treatment of wastewater at the Bauhaus-Universität Weimar is thus 2,451 kg CO₂; see Table 14.

The materials and procurement category covers numerous large and small procurements necessary for the operation of the university, research, project work and teaching. It has not yet been possible to develop a system for the documentation and balancing of all procurements. Utilisation of printer paper is used as an example for this discussion, partly because data concerning the use of printer paper are centrally recorded by the Service Centre for Facility Management within the scope of the »climate-neutral state administration 2030« project. Production of classic printer paper requires not only the raw materials wood and water, but also a great deal of energy. A large amount of energy is still required even when recycled paper is used as a substitute for wood fibres. Calculation of the CO₂ equivalent footprint for the use of printer paper is based on the consumption of ordinary DIN A4 paper. The Bauhaus-Universität Weimar thus consumes 2,374,775 sheets which, at 80 g/m², corresponds to 11.85 t of paper; see Table 15. The CO₂ balance of paper consumption is calculated using the online tool of the Initiative Pro Recyclingpapier, based on a study by the IFEU Institute (IPR 2006; IFEU 2006). A distinction is made in this connection between fresh fibre paper and recycled paper. Since it is not clear from the data collected whether fresh fibre (1,060 g CO₂/kg paper) or recycled paper (886 g CO₂/kg paper) is used, the average value (50:50) was used to calculate the footprint of 11.53 t CO₂; see Table 15.

In future, it would be desirable to extend this to other areas of material procurement in the context of an environmental report. Although paper consumption is a classic parameter for measuring environmental balance, it is not sufficient to adequately represent the category of materials and procurement. To improve the data situation, priority should be given to developing a system for recording and balancing and to deriving guidelines for sustainable procurement.

The emissions presented above are compared and classified below. Total CO₂ emissions of the Bauhaus-Universität Weimar of 2,634.7 t CO₂ are presented in the form of a pie chart in Figure 2. This chart illustrates that heating energy (natural gas, heating oil, district heating), shown here as natural gas, accounts for the largest source of emissions by far (82.6%) at the Bauhaus-Universität Weimar. At 1,176,930 kWh from the district heating supply and 9,702,929 kWh from direct consumption of natural gas, a total of 2,177.2 kg CO₂ is emitted. Due to the green electricity contract (0 g CO₂/kWh) of the Bauhaus-Universität Weimar, the electricity consumption of 5,281,744 kWh does not appear in the CO₂ balance. The second largest source of emissions (13.4%) results from the employees’ air travel, the sum of which is threefold the remainder of the combined emissions from the vehicle fleet, waste disposal, drinking and wastewater and the consumption of printer paper.

The overview in Figure 7 shows that natural gas and air travel account for more than 95% of the CO₂ emissions. The greatest energy saving potential at the Bauhaus-Universität Weimar is therefore in the economisation of heating energy. It is important in this connection to investigate how the required heating energy can be reduced not only through structural and technical measures but also through improvements in regulation and control.

However, the focus of emission reduction should not be entirely on aspects of building physics. For example, the elimination of flights within Europe would reduce emissions from air travel by 19.0%, or 67.2 t CO₂. In this context, sustainability strategies must also be developed for the other areas of action, such as vehicle fleet, waste disposal, drinking water consumption and procurement. However, the presentation of total emissions in Figure 7 only includes emissions that have already been recorded; undocumented emissions do not appear in the presentation. As described in the individual categories, it may be assumed that the presentation of emissions according to the subdivided environmental performance does not cover all emission sources of the university. The extent of the emission sources not covered can be estimated by looking at so-called scopes. Scopes distinguish CO₂ emissions by origin and were developed specifically for the evaluation of companies’ climate balances. The model was introduced in »The Greenhouse Gas Protocol« by the World Business Council – an association comprising more than 200 companies – and the World Resource Institute (WRI). The scopes introduced therein differ as follows:

Scope 1 Direct emissions from university-owned sources such as heating, vehicles, etc.

Scope 2 Indirect emissions from the purchase of electricity

Scope 3 »Reporting category« for indirect emissions from goods and services purchased services that occur outside the university

Table 17 shows a graphical representation of environmental performance according to scopes 1 – 3. The labels are subdivided into: fully recorded X, partially recorded (X), not recorded O and not available –.

Primary energy consumption such as diesel, electricity, heating oil and natural gas are already very well documented and can also be well balanced. It may be assumed that all scope 1 emissions are already recorded at the university and are included in the climate balance. Indirect emissions from the purchase of electricity (scope 2) are also recorded by the Service Centre for Facility Management. Due to the green electricity tariff of 0 g CO₂/kWh, however, electricity consumption does not appear in the CO₂ balance.

More difficult is the assessment of scope 3 emissions, such as emissions incurred via provision of energy sources (connection work, grid operation, tanker trucks, maintenance) or, in the case of the vehicle fleet, the production, maintenance and servicing of vehicles. There is also incomplete data regarding air travel (departure and destination airports, stopovers) and other business-related travel (private or leased vehicles, train travel, coach) of all members of the Bauhaus-Universität Weimar. Equally incomplete are the data concerning waste generation and waste management processes specific to Weimar, including transport routes. In this connection, determining city-specific parameters for the purpose of updating the environmental report would be desirable. Finally, consumption of copy paper naturally represents only a small proportion of all consumer goods procured by the university. A great deal of effort would be required with regard to data acquisition and CO₂ balancing in order to fully cover the area of procurement.