1. General information
Location and description of the intervention
City or FUA
Frankfurt am Main
Region
Europe
Native title of the NBS intervention
Green wall for CITI Data Centre
Short description of the intervention
The data centre for Citi Bank in Frankfurt is the first in the world to put sustainability at its heart, setting radical new standards in an industry at the forefront of the fight against global carbon emissions (1). The functional and aesthetic aspects, as well as their CO2 balance and later reusability, played a decisive role in the selection of all materials. Disguising the full volume of the data hall, the iconic green wall features indigenous plants and is fully irrigated by harvested rainwater. The wall, measuring some 55 m by 12 m high, complements the extensive green roof and helps maintain a constant building temperature throughout the year while reducing thermal gain in the summer months. (1)
Address

Heinrich-Lanz-Allee 47
60437 Frankfurt am Main
Germany

Location
Point location, which indicates where the NBS takes place
Total area
660.00m²
NBS area
660.00m²
Type of area before implementation of the NBS
Building
Website of the intervention
http://www.arupassociates.com/en/case-studies/citi-data-centre/
Timeline of intervention
Start date of the intervention (planning process)
2006
Start date of intervention (implementation process)
2007
End date of the intervention
2008
Present stage of the intervention
Completed
Please specify "other" stage of the intervention
The center was completed under its original budget in just seven months (1).
Goals of the intervention
1. Increase the aesthetic appearance of the data center (1);
2. Increase the comfort of the data center employees (1);
3. Contribute to maintaining a constant building temperature throughout the year (1);
4. Prevent the thermal gain in the summer months (1);
5. Reduce the visual impact of the building to its surroundings (2).
Quantitative targets
1. Usage of power (1)
2. Amount of recovered energy (1)
3. Reduction of CO2 emissions in tons (1)
4. Liters of water wasted for cooling saved (1)
Monitoring indicators defined
1. MWh a year for heating (2)
2. CO2 emissions in tons (2)
Sustainability challenge(s) addressed
Climate action for adaptation, resilience and mitigation (SDG 13)
Climate change adaptation
Green space, habitats and biodiversity (SDG 15)
Green space creation and/or management
Environmental quality
Air quality improvement
Health and well-being (SDG 3)
Improving mental health
Sustainable consumption and production (SDG 12)
Sustainable consumption
Climate change adaptation: What were the goals of the NBS?
Build resilience
Climate change adaptation: What activities are implemented to realize the conservation goals and targets?
Implement green walls or roofs to lower indoor temperature and provide insulation
Implementation activities
1. Installation of a green wall of 55m long and 12m high (1, 2);
2. Using harvested rainwater for the irrigation of the green wall (1).
Type of NBS project
Creation of new green areas
Please specify other type of green wall
Unknown
NBS domain and interventions
Ecological domain(s) where the NBS intervention(s) is/are implemented
Nature on buildings (external)
Green walls or facades
Type of Green Wall
Other
Vegetation Type
Other
Amenities offered by the NBS
Unknown
Services
Expected ecosystem services delivered
Regulating services
Local climate regulation (temperature reduction)
Carbon storage/sequestration
Habitat and supporting services
Habitats for species
Cultural services
Aesthetic appreciation
Scale
Spatial scale
Sub-microscale: Street scale (including buildings)
Beneficiaries
Primary Beneficiaries
Private sector/Corporate/Company
Citizens or community groups
Governance
Governance arrangements
Led by non-government actors
Non-government actors
Private sector/Corporate/Business
Please specify the roles of the specific government and non-government actor groups involved in the initiative
The Client, Citigroup company that manages the operation of the data center. Architecture & Engineering was commissioned to Arup Associates - a transnational architecture and engineering company (1)

Project Team (4):

Project Management:
Citi Realty Services assisted by Drees & Sommer GmbH

Technology Services: Citi Technology Infrastructure
Architecture/ Mechanical & Electrical Engineering Services: Arup Associates
Main Contractor: BAM Deutschland AG/Imtech Deutschland GmbH & Co.KG
Key actors - initiating organization
Private sector/corporate actor/company
Transnational network
Land owners
Private sector or company
Key actors - Other stakeholders involved (besides initiating actors)
Private sector/corporate actor/company
Transnational network
Land owners
Private sector or company
Participatory methods/forms of community involvement used
Unknown
Policy drivers
NBS intervention implemented in response to an Regional Directive/Strategy
Unknown
Please specify the "Regional Directive/Strategy"
NBS intervention implemented in response to a national regulations/strategy/plan
Unknown
NBS intervention implemented in response to a local regulation/strategy/plan
Unknown
Mandatory or voluntary intervention
Voluntary (spontaneous)
Enablers
Presence of specific city-level GI/NBS vision/strategy/plan - mentioned in connection to the project
Unknown
Presence of specific city-level GI/NBS section/part in a more general plan - mentioned in connection to the project
Unknown
Please specify other vegetation type
Indigenous small plants (1)
Presence of city network or regional partnerships focused on NBS - mentioned in connection to the project
Unknown
Presence of GI / NBS research project - mentioned in connection to the project
Unknown
Subsidies/investment for GI / NBS in the city - mentioned in connection to the project
No
Co-finance for NBS
Unknown
Co-financing governance arrangements
Unknown
Was this co-governance arrangement already in place, or was it set up specifically for this NBS?
Unknown
Financing
Total cost
€10,000 - €50,000
What is/was the Cost/Budget (EUR) of the NBS or green infrastructure elements?
Unknown
What are the total amount of expected annual maintenance costs?
Unknown
What is the expected annual maintenance costs of the NBS or GI elements?
Unknown
Please specify cost savings
Unknown
Please specify total cost (EUR)
Citigroup has invested 170 million euros in its data centers in Europe, the Middle East, and Africa (6). The Citigroup Frankfurt project is a part of this larger investment, but the cost of the green wall is unknown.
Source(s) of funding
Corporate investment
Please specify other source of funding
Citigroup company financed the project (1).
Type of fund(s) used
Direct funding (grants, subsidies, or self-financed projects by private entities)
Non-financial contribution
No
Business models
Risk reduction model
Which of the involved actors was motivated by this model?
Private for-profit actor (e.g. firm, insurer)
Type of innovation
Technological
Product innovation
Please specify technological innovation
Arup Associates’ project of the regeneration of the Citi Data Centre in Frankfurt is a pioneering work in the sphere of sustainable solutions for managing data centers. This data center was the first in the world to be rated LEED Platinum and a broad sustainability agenda included dramatically reduced energy consumption, ‘free cooling’ from the ambient environment and sourcing electrical energy from zero-carbon sources (5).
Novelty level of the innovation
The innovation is completely new without connections to previous initiative(s)
Please specify novelty level of the innovation
The project is the world’s first LEED Platinum-awarded data center (1).
Replicability/Transferability
Unknown
Please specify Replicability/Transferability
Unknown
Impacts, benefits
Environmental impacts
Climate change
Lowered local temperature
Reduced emissions
Enhanced carbon sequestration
Environmental quality
Improved air quality
Green space and habitat
Increased green space area
Description of environmental benefits
- 660 m2 of green space was created with the plantation of indigenous plants in the green wall (1);
- The installed green wall contributed to energy and water efficiency and sustainable maintenance of the data center, however, the qualitative impact of the green wall itself is not specified in public records. The notable features include:
1. The Citi data center uses 30% of the power required for services that a conventional data center would use;
2. Optimized cooling design resulting in enhanced free cooling rate of 63%;
3. Reverse osmosis water treatment for cooling saves 50M litres per annum;
4. Overall CO2 emissions reduction of 11,750 t/a; (4).
Economic impacts
Unknown
Description of economic benefits
Unknown
Social and cultural impacts
Health and wellbeing
Improved mental health
Description of social and cultural benefits
There is only expected impacts regarding the social benefits of the installed green wall, namely that it contributes to the mental well-being of employees of the Citi data centre.
Type of reported impacts
Expected impacts
Achieved impacts
Indicators
Green wall area (660 m2); free cooling rate; savings in water treatment for cooling (50M litres per annum); CO2 emissions reduction (11,750 t/a) (4).
Environmental, social and economic impacts
Climate action for adaptation, resilience and mitigation (SDG 13)
Green space, habitats and biodiversity (SDG 15)
Environmental quality
Health and well-being (SDG 3)
Economic development and employment (SDG 8)
Analysis of specific impact categories
Job creation: The NBS created ...
No information available
Please specify other method used to evaluate the impacts of NBS
Unknown
Negative impacts: Did the project cause any problems or concerns?
No information was found regarding negative impacts of the project
COVID-19 pandemic
Unknown as of September 2020
Methods of impact monitoring
Process of recording NBS impacts
No evidence in public records
Methods used to evaluate the impacts of NBS
Unknown
Evidence for use of assessment
Presence of an assessment, evaluation and/or monitoring process
Yes
Presence of indicators used in reporting
Yes
Presence of monitoring/evaluation reports
Yes
Link to monitoring/evaluation reports
http://www.citigroup.com/citi/news/2009/090423b.html
Availability of a web-based monitoring tool
No
Impact assessment mechanism
Name of any specific impact assessment tools
Unknown
Use of GIS in mapping impacts
No evidence in public records
Citizen involvement
Citizens involvement in assessment/evaluation
Unknown
Citizens involvement in the analysis of the assessment/evaluation
Unknown
Follow-up to the evaluation / assessment
Unknown
References
Web links relevant to the intervention
Arup Project Description
Building Co News Article
Masterplan 100 % Klimaschutz Frankfurt am Main
Data Center LEED Platinum Accreditation
Arup feedback
Citigroup eröffnet "grünes" Rechenzentrum
List of references
1. Citi Data Centre : ARUP ASSOCIATES. (2008). Accessed Accessed on September 26 2020, https://www.arup.com/projects/citigroup-citi-data-centre
2. Arup’s Low Energy Citi Data Centre Building. (2009). Accessed on September 26 2020, http://www.building.co.uk/arups-low-energy-citi-data-centre/3130455.article
3. Stadt Frankfurt Am Main. (2017). Masterplan 100% Klimaschutz: Stadt Frankfurt Am Main | Dezernat Umwelt Und Gesundheit | Umweltamt. Accessed on September 26 2020, https://frankfurt-greencity.de/frankfurt-green-city-status-und-trends/klima-freiflaechen/masterplan-100-klimaschutz/
4. Citi. (2009). Citi Achieves First Ever LEED Platinum Accreditation for a Data Center. Accessed on September 26 2020, http://www.citigroup.com/citi/news/2009/090423b.html
5. Arup. (2013). Thoughts | Bring Data Centres in from the Cold. Website not available September 2020
6. Heise Online (2008). Citigroup eröffnet "grünes" Rechenzentrum, Accessed on September 26 2020, https://www.heise.de/newsticker/meldung/Citigroup-eroeffnet-gruenes-Rechenzentrum-208982.html
Additional comments
The Citigroup Data Center in Frankfurt is the first project in Germany to be LEED® (Leadership in Energy and Environmental Design) certified and is the first LEED Platinum data center worldwide. This certification process was facilitated by Arup (1).
Comments and notes
Comments
1. Unfortunately, I could not specify the objectives as required in the comments. Available data do not provide concrete numbers and measured goals.
2. The overall strategy of the city cannot be referred here as well. Masterplan "100% Climate Protection Frankfurt am Main" indicated at first is more about the renewable energy strategy that is not applicable to the case of the Data Centre.
Pictures of the NBS
/sites/default/files/nbs/images/citigroup_data_center_frankfurt_c_christian_richters_large.jpg
Public Images
Green wall
Green wall
Source: https://www.google.hu/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0ahUKEwi6sseokJPVAhWJDZoKHa78B7EQjxwIAw&url=https%3A%2F%2Fwww.arup.com%2Fprojects%2Fcitigroup-citi-data-centre&psig=AFQjCNHkVXq5qSIyZ810U9u3HzdIPiwBYg&ust=1500477470541868