Press releases

• Mayor Sibylle Keupen believes the city is well on the way to climate neutrality.
• The total energy consumption of the city of Aachen has fallen by 25 percent since 1990.
• The greatest savings were achieved in the electricity sector, with wind energy accounting for the largest share.

A look at Aachen's CO2 balance shows: The efforts are paying off. Emissions have been falling continuously since the reference year 1990, even if there is still a lot of potential for savings in some areas that urgently needs to be tapped - also in order to get as close as possible to the goal of climate neutrality by 2030.

Aachen's Lord Mayor Sibylle Keupen believes the city is on the right track: "A look at our carbon footprint shows that we have already taken a big step towards climate neutrality. It shows what is possible when we stick together as a city society. For example, with 150 signatories to the Climate City Agreement and the EU's Mission Label, we have already reached milestones that distinguish Aachen as a pioneer for climate-friendly change. But we are still a long way from reaching our goal. Together - citizens, businesses, initiatives and the city administration - we can create a future-proof, liveable and clean Aachen. Every measure brings us closer to our goal. Climate neutrality is our opportunity to shape a sustainable future for current and future generations."

Heiko Thomas, Councillor for Climate and Environment, City Operations and Buildings, adds: "Aachen was selected by the EU as a participant in the 'Climate Neutrality 2030' mission and is fully committed to using all its municipal resources to achieve the EU target. This is because the mission goal, which a total of 100 European cities have set themselves, is based on scientific findings that require action as quickly as possible. According to current estimates, Aachen will not be able to achieve the 2030 target in some sectors, such as heating. In the electricity sector, however, it will! This strengthens the city of Aachen to continue to make every possible effort to live up to its role model function in Germany and Europe in the future."

Dr. Carin Jansen, Head of the "Climate-neutral Aachen 2030" office at altbau plus e. V., emphasizes the importance of the urban community: "Climate neutrality is a mammoth task. It cannot be achieved by the city administration alone. That's why the Climate City Agreement is a great opportunity for us, as it means that partners from industry and business are also making a commitment. We are very proud that we were able to reach the 150 signatories mark a few days ago. To achieve the goal of climate neutrality, we need the entire urban community. We are therefore working on being able to include individual citizens in the agreement soon."

BISCOor STAWAG electricity mix
A carbon footprint has been drawn up regularly for the city of Aachen since 1993, and annually since 2010. The international reference year 1990 was selected as the base year. Different methods are used throughout Germany to calculate CO2 emissions. The BISKO method has established itself as the standard method, which, in addition to emissions from energy sources that can be easily measured or estimated locally, such as gas, oil and district heating, assumes for the electricity sector that wherever grid electricity is used or consumed, its emissions correspond to the "federal mix" of energy sources.

When balancing CO2 emissions for the EU "100 Climate Neutral and Smart Cities" mission, the electricity sector is differentiated into three areas, in contrast to the BISKO standard:

• locally generated electricity based on wind, photovoltaics, etc.,
• The very low-CO2 electricity marketed by STAWAG in Aachen, which recognizes STAWAG's many years of investment in the expansion of renewable energies,
• Electricity from third-party suppliers that supply customers in Aachen; the federal mix is assumed for this electricity due to a lack of differentiated information.

This accounting method therefore makes the city's commitment visible and measurable and also recognizes STAWAG's early commitment to investing in renewable energy projects nationwide.

"The city's energy consumption has fallen by 25 percent since 1990," says Klaus Meiners, Head of the Climate and Environment Department, positively, but he also has to admit: "Particularly in the heating and mobility sectors, the potential for efficiency and savings is only being exploited slowly and not to a sufficient extent." Aachen's CO2 emissions are therefore continuing to fall, but remain below the agreed targets.

Compared to the base year 1990, the savings according to the BISKO balance sheet are now 39 percent. If locally generated electricity from renewable energies and the "STAWAG electricity mix" are taken into account, the saving increases to 46 percent. The average annual saving has noticeably increased to around three percent over the past four years. Of course, influences such as the coronavirus crisis and the war in Ukraine also play a role here. However, the significantly improved emissions factor in the electricity sector due to the expansion of renewable energies has played a significant role in the reduction. The share of renewable energies in local electricity generation amounted to 16% in 2023 - a good figure for a large city, but one that can still be increased. At 111 gigawatt hours, wind energy already makes the largest contribution today.

According to the BISKO analysis, the absolute CO2 savings in 2023 compared to 2022 are 102,000 tons. The average CO2 savings target of 77,000 tons per year anchored in the 2020 climate protection concept (IKSK) was slightly missed on average for the period 2019 to 2023: around 73,000 tons of CO2 were saved per year for the last four years.

51 percent of CO2 emissions were saved in the electricity sector
The highest relative reduction in emissions since 1990 was achieved in the electricity sector: 51 percent according to the BISKO method and even 71 percent when calculated according to the Aachen electricity mix. These are 473,000 tons and 656,000 tons of CO2 saved respectively. In the heat sector, in second place in terms of savings, 548,000 tons were saved. Unfortunately, these good results are clouded by the transport sector, where emissions were actually 17,000 tons higher than in 1990. However, no municipal data is available here and the reliable national figures for 2023 will not be available until autumn 2025.

Meiners sums up: "The goal for the electricity sector is to achieve climate neutrality by 2030. This would be a major step forward, especially as the demand for electricity is growing. The figures and our efforts show that we are taking the goal of climate neutrality absolutely seriously as a city administration."

Building renovations and the expansion of renewable energies
In recent years, the city of Aachen has invested heavily in the expansion of solar energy and the renovation of buildings through funding programs. Between autumn 2020 and the end of 2023, 2,842 funding applications were submitted for photovoltaic systems, storage systems, plug-in solar devices, solar thermal systems or the retrofitting of so-called post-EEG systems (systems that no longer receive a lucrative feed-in tariff after 20 years). A small proportion of the funding also went to neighborhood festivals, where interested parties were able to learn about photovoltaics first-hand and from experts in order to convince them of the technology. In total, around 3.9 million euros in funding was provided and the number of applications rose sharply from 439 in 2021 to 1,390 in 2023. The total investment of the funded projects amounted to around 45 million euros - a sum from which Aachen's skilled trades also benefited. In 2022 and 2023 alone, 1,147 plug-in solar systems were funded. This funding has now expired. The funding focus is now being placed on commercial properties and apartment buildings, as the growth in these two areas is still relatively low.

There was also strong funding for energy-efficient building refurbishment: From May 2021 to October 2024, a total of 1,186 applications for funding were received by the Climate and Environment Department and a funding sum of over six million euros was raised. The total investment of the funded projects amounted to around 62 million euros.

And the end is not yet in sight for wind energy either: the city is expecting new turbines in the coming years, as these can now also be applied for and approved outside areas not specifically defined for this purpose. Repowering is also a way of improving the performance of old turbines and thus producing more energy with the same number of wind turbines. Meiners is enthusiastic about the increase in renewable energies: "It is important to emphasize that renewable energies also strengthen our independence. This is particularly important in the current global political situation, as decentralized energy and storage systems are crisis-proof. Sustainable energy systems are also a location factor for industry."

The city is also making further progress with municipal heating planning: a first draft of the municipal heating plan has been under discussion in the political committees since this month (December 2024) and is due to be approved by Aachen City Council in summer 2025. There will also be a public consultation beforehand. This municipal heat planning for Aachen sets out the framework for a climate-neutral, secure and economical heat supply of the future and shows which options for a climate-neutral heat supply can be exploited or developed in which urban area - district heating, geothermal energy or heat pumps, for example.

"Reducing CO2 emissions is not only good for the climate, but also for our city!" emphasizes Thomas. "This improves the quality of life in Aachen and we once again stand out as a science and research location."