Sustainability at Fraunhofer ISI

Combining the demand for electricity and gas, the energy demand of the institute’s building in the Breslauer Strasse in Karlsruhe in 2023 amounted to almost 700 megawatt hours (MWh) per year. Until 2022, roughly the same amount of gas and electricity was required.

In addition to the mains supply, the institute’s building also drew power from two combined heat and power units (CHP), which together covered an average of twelve percent of the energy consumption in the period 2014 to 2022. In 2023, this share fell to three percent as the CHPs operated intermittently due to outages and were run at a reduced capacity due to the shortage of gas in the fall of 2022.

The number of employees does not seem to have a major impact on the energy consumed at the institute. In 2014/2015, some employees were relocated to a different building due to asbestos removal in the west wing, but energy consumption remained more or less constant. During the COVID-19 years between 2020 and 2022, when employees were required or encouraged to work from home, there was an eleven percent drop in electricity consumption. Gas consumption, however, rose by 18 percent.

From March 2020, additional offices were rented in Karlsruhe Technology Park (Emmy-Noether Strasse). 13 people worked there to start with. Over time, more office space was rented. A few offices were added at the additional locations in Heilbronn (from January 1, 2023) and Berlin (from October 2024). The energy consumption for these locations has not yet been (fully) determined. The focus here is therefore on the energy consumption of the institute’s building in Breslauer Strasse.

The gas demand in 2023 for the institute’s building and including the gas required for the CHPs was 230 MWh. Deducting the gas needed to generate electricity results in 215 MWh gas required for heating. This means the energy required for heating is significantly below the figures for 2022 (283 MWh) and 2021 (362 MWh). This is because Fraunhofer ISI took short-term gas-saving measures in the collective effort to avoid a gas shortage in the winter of 2022/2023. For example, the heating in one whole corridor was turned down to 16°C. The employees affected including the institute’s directors, moved to a different corridor over this winter. In addition, employees were made more aware of this issue and among other things were advised to only heat their offices to a maximum of 19°C. Heating settings were adjusted, such as extending the overnight temperature reduction to include weekends. Retaining some of the less drastic measures also resulted in a decrease of gas consumption in the winter of 2023/2024 compared to the winter of 2021/2022. Hydraulic balancing was carried out in the fall of 2023 before the onset of the heating period. In the fall of 2024, the heating systems, which were more than 30 years old, were replaced by a combination of two air-water heat pumps (128 kW) and a gas condensing boiler (220 kW). The goal is to only use the gas boiler at low temperatures and to meet most of the building’s heating demand using the heat pumps. Before deciding to invest in the new system, different variants were compared in terms of their economic efficiency and CO₂ emissions. The above mentioned variant was selected because of the short length of time remaining that Fraunhofer ISI will use the institute’s building – due to the planned new building.

Once a year, employees are given information about how to save energy on top of emails explaining how to heat correctly, posters about energy saving and short presentations at institute or work council meetings.

To lower the institute’s CO₂ emissions, Fraunhofer ISI takes part in the Fraunhofer-wide energy efficiency and climate protection networks (EEKN). As part of the EEKN, external consultants lead an exchange of ideas and experiences among the participating Fraunhofer institutes. The goal of these networks is to achieve a lasting increase in energy efficiency and a tangible decrease in energy costs and CO₂ emissions at the institutes. The idea of the network is based on earlier research projects conducted by the institute. As a result, the EEKN was initiated and managed by an ISI employee within the Fraunhofer-Gesellschaft.

The introduction of an energy management system based on ISO 50001 was started in the fall of 2024 with the aim of acquiring certification in July 2025. The main goal of ISO 50001 is to increase energy efficiency and reduce energy use and CO₂ emissions. 

The institute has installed the first meters for an energy monitoring system on its building, which will enable software to monitor energy use in the future.

The photovoltaic system belonging to the “ISI Power” association, which is an initiative of ISI employees, is going to be replaced. Due to the changes in the regulatory framework, it will be acquired by Fraunhofer ISI and used for its own electricity generation in the future. Quotations for a 10 and 20 kWp system have already been received. A larger system is not economically viable due to the terms of the contract.

If the emission factor of Germany's electricity mix is applied, CO₂ emissions in 2023 increased compared to previous years. This is due to the increase in electricity consumption. The energy monitoring system mentioned above should help to identify the causes of the increase in electricity consumption from 2022 onwards. For several years, Fraunhofer ISI has been purchasing green electricity for the institute building on the basis of the Fraunhofer-wide framework contract. Currently, the green electricity is still mainly provided through guarantees of origin. In the medium term, additional individual solutions and direct electricity supply contracts that specifically contribute to increasing the capacities of renewable energies will expand this approach. If an emissions factor of 0 kg CO₂/year is assumed for the purchased green electricity, total emissions in 2023 could fall from 245 thousand kg CO₂/year to 46 thousand kg CO₂/year.

In 2022, Fraunhofer ISI employees covered a total of approximately 623,165 kilometers on business trips, thereby producing around 80.4 tons of CO₂ or the equivalent in greenhouse gases. This is one of the lowest figures since records began in 2010 and corresponds to a decrease of roughly 86 percent compared to the peak of 588 tons in 2013. The reason for this dramatic reduction is the “aftermath” of the COVID-19 pandemic and the associated change in travel behavior. Since then, digital and hybrid formats for sharing information about research projects have become significantly more prevalent. At the height of the pandemic in 2021, greenhouse gas emissions actually dropped to 4.7 metric tons. This reduction is clearly visible in the figures. Due to a change in 2022 in the way in which rail travel emissions are reported, they have not been included yet.

In terms of air travel, business trips undertaken on behalf of Fraunhofer ISI generated a total of 78.6 tons of greenhouse gases in 2022, which accounted for 95.4 percent of all CO₂ emissions from business trips. However, these emissions were fully offset by purchasing the corresponding CO₂ certificates. Journeys made by rail were next with just under two tons (2.5 percent), followed by car journeys with 1.7 tons (2.1 percent). It is worth mentioning that the number of kilometers traveled by car has recently risen again to a third of the level in 2019.

As in previous years, the most frequently used rail connection within Germany in 2022 was the Karlsruhe-Berlin route, with a total of 424 trips.

In 2023, employees of Fraunhofer ISI covered a total of 1.6 million kilometers on their way to work. This corresponds to around 4,000 kilometers per person. By far the most popular means of transport to get to the institute is still the bicycle: 49 percent of all Fraunhofer ISI employees cycle to work. Two percent walk and nine percent use public transport. Twelve percent use long-distance or regional rail services. 23 percent of employees commute to ISI by car. (Of these, 19 percent have a car with an internal combustion engine and four percent have an electric car).

On their way to work (by car or train), Fraunhofer ISI employees caused emissions of 121 tons of CO₂ or other greenhouse gases. This corresponds to around 302 kilograms of CO₂ per person. Around 63 percent of these emissions were caused by the use of private cars with internal combustion engines and around 36 percent were caused by train travel.

Fraunhofer ISI is participating in the joint research project LamA — Charging at Work. Since May 2022, two charging stations with two charging points each have been set up where Fraunhofer employees can charge their vehicles for a fee. Company vehicles are also charged at these charging points.

To raise awareness of emissions caused by commuting, Fraunhofer ISI took part in the Stadtradeln (city cycling) campaign for the first time in 2022. During the three weeks of the campaign, participating employees cycled between 5,300 and 8,000 kilometers. 

Water is used in several different areas at Fraunhofer ISI. Drinking water is used primarily in the washrooms with toilets, at the water dispenser in the cafeteria, in kettles for tea and in coffee machines, as well as in the cafeteria itself, for cleaning the building and in the shower and changing room in the basement, which is used, for example, by cyclists. During the hot summer months, drinking water is also used in extremely dry conditions to water bushes, hedges and green facades.

The actual water consumption in Breslauer Strasse is directly related to the number of employees working on site. The following figure clearly shows that in 2014/2015, part of the workforce was relocated to another building due to the removal of asbestos in the west wing. During the years of the COVID-19 pandemic from 2020 to 2022, when employees were required or encouraged to work from home, water consumption also decreased.

Data on consumption in the second location at TPK (from March 2020 to the present with 13 people initially), in Heilbronn (from January 1, 2023) and Berlin (from October 1, 2024) are not available.

The amount of new A4 paper ordered fell over the years from around 1.6 million sheets in 2011 to an all-time low of 150,000 sheets (~ 0.7 t) in 2023. The last sharp decline was associated with the COVID-19 pandemic, which halved the amount of new A4 paper ordered. The amount of A3 paper used also decreased. However, since this paper is purchased in bulk to last for several years, the decrease is not as clearly visible.

All printers and photocopiers at Fraunhofer ISI have been using recycled paper ever since 2013. Double-sided printing is the standard setting.

The volume of residual waste at the location in Breslauer Strasse fell from around 35 kilograms per person per year in 2011 to about five kilograms in 2023. In addition to the COVID-19 pandemic and the subsequent work-from-home and flex-space regulations, the relocation of some departments to the second location in the Karlsruhe Technology Park, which started in March 2020, also played a role in the reduction in recent years.

While the amount of wastepaper continued to decrease to around 25 kilograms per employee in 2023, the amount of waste from document shredding depended on each department’s individual clearing-out activities. In 2014/2015, when part of the institute was temporarily relocated for asbestos removal, there was a significant increase in this type of waste before and after the move. In 2023, the figure was three kilograms per employee.

The aim is to negotiate a framework agreement with the Ettlingen-based non-profit limited liability recycling company “AfB”, which regulates the disposal of electronic waste, (e.g., laptops, monitors, smartphones, etc.), ideally for the entire Fraunhofer-Gesellschaft. This would make ISI's old equipment available for re-use (after refurbishment and reprocessing). Negotiations are currently underway and should be finalized in 2025.