In collaboration with local planners and installation companies, building management installed almost 600 kWp on municipal roofs in 2024. A further approx. 1700 kWp will follow in 2025. The aim is to have all suitable roofs equipped with photovoltaics in 3-5 years and to operate them ourselves.
© 2022 by Joerg Hempel, © Publication rights with Jörg Hempel, Lousbergstraße, 52072 Aachen, Germany clarify, all rights reserved by Joerg Hempel, 2022, Any use is subject to a fee. Publication only for a fee, copyright notice and receipt/ permission required for reproduction, mention of copyright, complimentary copy; use of the image outside of journalistic reporting requires special agreement. For any usage other than editorial please contact the archive. ALSO MENTION OPTIONALLY THIRD PARTIES COPYRIGHTS! ALSO MENTION OPTIONALLY THIRD PARTIES COPYRIGHTS!
PV system of the KKG with a view of the cathedral and town hall
Climate-neutral energy supply and integrated climate protection concept
A key component of a future climate-neutral energy supply for municipal buildings is the expansion of photovoltaic areas.
The foundation stone for the City of Aachen's current PV strategy was laid and agreed in the 2020 integrated climate protection concept - the consistent expansion and operation of the systems under its own management.
Predecessor model:
In previous years, municipal roofs were made available to third parties for the construction and operation of a PV system in return for a small lease. Demand for this model fell sharply due to changes in the feed-in tariffs. In addition, the use of the roofs by third parties also led to uncertainties regarding the occurrence of damage etc..
ANDREAS SCHMITTER, © www.schmitter-fotografie.de
PV system Laurensberg 2024
Potential study
An initial potential study carried out by the building management team in 2021 - the potential expansion areas for each building were estimated using maps - showed a potential expansion capacity of approx. 14,000 kWp. This meant a possible electricity production of approx. 12,500 MWh/a. This could cover approx. 50 % of the electricity consumption of the municipal buildings.
Property-specific investigations
The subsequent property-specific, cross-team building management investigations get to the bottom of various issues.
Questions:
- What does the actual shading situation look like?
- Does the statics of the building allow for the additional load of a PV system?
- What is the condition of the roof?
- Is an extensive refurbishment including insulation necessary before installing the PV system?
- What is the condition of the electrical installation?
- What is the feed-in option into the grid?
- What other measures are required when building a PV system?
© 2022 by Joerg Hempel, © Publication rights with Jörg Hempel, Lousbergstraße, 52072 Aachen, Germany clarify, all rights reserved by Joerg Hempel, 2022, Any use is subject to a fee. Publication only for a fee, copyright notice and receipt/ permission required for reproduction, mention of copyright, complimentary copy; use of the image outside of journalistic reporting requires special agreement. For any usage other than editorial please contact the archive. ALSO MENTION OPTIONALLY THIRD PARTIES COPYRIGHTS! ALSO MENTION OPTIONALLY THIRD PARTIES COPYRIGHTS!
PV system Kaiser Karl Gymnasium 2022
Depending on the outcome of the investigations, a photovoltaic system can be implemented in the short term or the necessary preliminary work (roof renovation, renovation of electrical installations, etc.) can be initiated.
In the worst case scenario, it turns out that the construction of a photovoltaic system on a building is not feasible in principle. This is mainly for structural reasons.
Measures 2024 and 2025
The implementation of these investigations has been in full swing since 2023.
As a result, photovoltaic systems with a total of 596 kWp could be installed on 10 buildings in 2024. For 2025, 23 systems with a total of 1681 kWp are planned.
2024: 10 installed systems with a total of 596 kWp
- 64 kWp Kaiser-Karls-Gymnasium Augustinerbach
- 75 kWp Birkstraße elementary school
- 40 kWp Quartier Schule Reimser Straße
- 41 kWp Quartier Kita Reimser Straße
- 130 kWp Heinrich Heine Comprehensive School Hander Weg
- 100 kWp music bunker Goffartstraße
- 110 kWp Einhard-Gymnasium Robert-Schuman-Straße
- 15 kWp Changing room Ahornstraße
- 10 kWp GGS Brander Feld Schagenstraße
- 11 kWp Stettinerstraße daycare center
2025: 23 planned systems with a total of 1681 kWp
- 60 kWp gymnasium Marktstraße
- 140 kWp Alkuinstraße secondary school
- 35 kWp Am Höfling daycare center
- 65 kWp GGS Am Höfling
- 30 kWp changing room building Sonnenscheinstraße
- 50 kWp Sonnenscheinstraße school
- 30 kWp Montessori School Kaiserstrasse
- 30 kWp GGS Gerlachstraße
- 45 kWp Düppelstraße gymnasium
- 30 kWp OGS and Reumontstraße gymnasium
- 45 kWp GGS Haarbachtalstraße
- 30 kWp gymnasium and indoor swimming pool Birkstraße
- 75 kWp Eberburgweg estate
- 340 kWp Hander Weg school center
- 200 kWp Inda-Gymnasium Gangolfsweg
- 50 kWp gymnasium Einhardgymnasium Robert-Schumann-Straße
- 60 kWp Haus am See, canteen at Einhardgymnasium Robert-Schumann-Straße
- 135 kWp GGS Schönforst Schwalbenweg
- 30 kWp Albert-Maas-Straße daycare center
- 45 kWp Rhein-Maas-Gymnasium canteen
- 35 kWp KiTa Richtericher Straße
- 35 kWp Franz Wallraff Strasse daycare center
- 86 kWp comprehensive school Brand Rombachstraße
In addition, preparatory roof renovations are planned for the following buildings in 2025 in order to be able to tackle the installation of photovoltaics in subsequent years.
2025+: 5 planned, preparatory roof renovations
- Gymnasium Einhard Gymnasium
- Canteen Einhard Gymnasium
- Realschule Alkuinstraße
- School at Rödgerbach Sonnenscheinstraße
- Horbach elementary school Oberdorfstraße
ANDREAS SCHMITTER, © www.schmitter-fotografie.de
PV system Laurensberg 2024
Financing
The potential study also demonstrated the economic operation of the systems. The investments in the systems are amortized over the course of the system's service life through the savings achieved through lower electricity consumption.
For example, 4.5 million euros have been made available in the municipal budget for the years 2023 - 2026 for the expansion.
Direct marketing concept
The expansion is particularly economical thanks to the concept of regional direct marketing developed by the City of Aachen's building management.
In the regional direct marketing model, the city of Aachen acts as an electricity supplier for its own buildings. This makes it possible to supply municipal buildings without PV systems with "surplus electricity" from buildings with PV systems. In this way, external electricity purchases and electricity costs can be further minimized.
This model is now attracting interest from many other local authorities across the region.
Balancing model - self-consumption with regional direct marketing (RDV for short) and sale of solar power
Challenges and status quo
The first photovoltaic systems have gone into operation, the next systems are about to start - it's up and running. Surely everyone involved had hoped for a faster implementation of the first systems.
However, the initial phase of the expansion strategy was under difficult circumstances. Russia's attack on Ukraine once again highlighted the need for a more independent energy supply and also exacerbated the market situation. As many people wanted to buy photovoltaic systems, it was difficult to find companies with the capacity to install systems, prices rose immensely, tenders had to be repeated and implementation was delayed. This was also an unsatisfactory situation for building management, but the situation has since eased.