Project Overview

BER02 is the first data center on maincubes' planned mainHub Berlin campus in Nauen, on about 14 hectares of former farmland at the eastern entrance to the town. maincubes says the campus can deliver up to 200 MW initially and grow to more than 400 MW, with BER02 offering 144-186 MW of IT capacity depending on design. 

The building is designed for AI and high-performance computing as well as cloud workloads, with air, liquid, and hybrid cooling options, a design PUE of 1.2 or lower, and no process water use. 

The first construction visible on site is energy infrastructure. A 110 kV substation and a 6 km company-owned cable route to the Wustermark substation are being built by JSM Group, which topped out the substation building on 13 October 2026. 

BER02 Project Location

BER02 is located on the mainHub Campus in Nauen, Havelland district, Brandenburg, just west of Berlin, Germany. The data-center campus sits on an approximately 14-hectare (137,000 sq m) site along Berliner Straße, 14641 Nauen. 

Its location offers proximity to Berlin’s growing digital and AI market, grid access, and nearby wind and solar energy resources 

Technical Specifications

Project Background

maincubes was founded in 2012 and has been majority owned by DTCP since September 2024. Its first Berlin facility, BER01 in the GoWest district in Schmargendorf, offers 5,100 m² of whitespace and is listed as government-leased.  

maincubes completed the land purchase in Nauen in October 2024 after about 12 months of talks with developers and regulators. The site is a campus developed with AM:PM Grund Group and sits on about 14 hectares. 

The land use and development plan took legal effect on 2 July 2025, and on 4 August 2025, maincubes announced a 200 MW grid connection agreement with E.DIS, with supply from 2027 and a 110 kV on-site substation planned. 

A groundbreaking for the substation and cable route followed in March 2026, and JSM Group began construction of the critical power infrastructure. 

maincubes BER02 Current Status

The maincubes BER02 Data Center Facility is currently under construction. Groundbreaking in March 2026 started a 110 kV substation and 6 km cable route. JSM Group topped out the 200 MVA substation building on 13 October 2026, and maincubes says it is on schedule. 

Building services start at the end of October, followed by four transformers. maincubes lists BER02 as under construction, with construction starting in Q1 2026 and ready for service Q3 2028. No tenant has been named. 

Stakeholder Details

BER02 Project Cost

The total capital cost of the maincubes BER02 Data Center campus has not been publicly disclosed as a project-specific figure. However, maincubes secured EUR 2.475 billion in platform debt financing in January 2026.

It comprises EUR 1.775 billion in committed facilities and EUR 700 million in an uncommitted accordion, to refinance its existing portfolio and fund new developments, including the 200 MW mainHub Berlin campus at Nauen. 

This financing is therefore expected to support BER02’s construction, grid infrastructure, and future expansion options, although it is not exclusively allocated to BER02. 

Project Scope

The following is the Project Scope of the maincubes BER02 Data Center project:

• High-density AI and HPC Infrastructure: The facility is designed to support high-density racks for artificial intelligence, machine learning, and HPC workloads. It enables customers to deploy power-intensive computing systems at scale. 
  

• Flexible Cooling Systems: The design includes air cooling, liquid cooling, and hybrid cooling options. This flexibility allows maincubes to accommodate both conventional enterprise workloads and modern AI hardware with higher heat loads.
  

• Provide Reliable Power Supply: A dedicated 110 kV substation will be built on the site, with redundant 110/20 kV transformers arranged in a dual-busbar configuration. It will provide reliable, scalable power supply to the campus.
  

• Renewable-energy integration: The campus is planned to integrate electricity generated by regional solar and wind installations directly at the new substation. This reduces dependence on conventional power sources. 
  

• Waste-heat reuse: Excess heat from data-center operations will be supplied to Nauen’s district-heating network and other users. This converts waste heat into a useful local energy resource. 

Project Timeline

maincubes BER02 Latest News

Below is the latest news of the maincubes BER02 Berlin Data Center:

Substation topping-out

JSM Group topped out the substation building on 13 October 2026, six months after construction began. maincubes said the work is on schedule. About 250 tonnes of structural steel and 3,500 m² of precast walls and ceilings are installed, and over 27 km of conduit is laid on the cable route. 

Benefits

The following are the benefits of the project:

• Boosts IT Capacity: BER02 will add 144-186 MW of IT capacity near Berlin, helping meet rising demand for cloud services, artificial intelligence, and high-performance computing. 
  

• Supports AI & HPC Growth: The campus is designed for high-density, compute-intensive workloads, enabling AI developers, cloud providers, and research institutions to deploy advanced computing infrastructure locally. 
  

• Provides Reliable Supply: A secured 200 MW grid connection with E.DIS, supported by a dedicated 110 kV substation, ensures stable electricity supply for the campus.
  

• Improves energy resilience: A planned battery energy storage system (BESS) can store renewable electricity and support grid stability, helping maintain reliable operations during fluctuations in generation or demand.
  

• Reduces environmental impact: Energy-efficient design, renewable power, and a target power usage effectiveness of below 1.2 will help lower the campus’s overall energy footprint.
  

• Improves connectivity and market access: Located west of Berlin, the campus offers access to strong network infrastructure, multiple carriers, and proximity to Central and Eastern European markets. 

Conclusion

The maincubes BER02 Data Center campus is a key digital-infrastructure project, developed in Nauen. It is designed to provide 144-186 MW of IT capacity for cloud, artificial intelligence, and high-performance computing workloads. With a secured 200 MW grid connection and a dedicated 110 kV substation, the facility is positioned to meet Germany’s rapidly growing demand for scalable digital infrastructure.

The campus plans to integrate renewable solar and wind power, use battery energy storage, and recover waste heat for Nauen’s district-heating network. These measures help reduce the environmental footprint of large-scale computing while creating direct benefits for the local community and regional energy system. 

Upon operation, BER02 will strengthen Berlin-Brandenburg’s position as a leading digital and AI hub in Europe. It will support hyperscale customers, attract technology investment, create construction and skilled operational employment, and provide the reliable, energy-efficient infrastructure needed for the next generation of cloud and AI services.

Track the Latest Data Center Projects In Germany

Subscribe to our upcoming and ongoing Data Center Projects in Germany with ease to access reliable, high-quality insights on forthcoming and completed Projects across the country.

Our user-friendly platform provides essential details, timely updates, key stakeholder contact information, and business opportunities tailored for engineering companies, industry professionals, investors, and government agencies.

Start a free demo to take your business to the next level.