A pioneering contract for a carbon-free heating network in Kuebebierg

This low-temperature network will ultimately provide heating and domestic hot water for the future neighbourhood, using advanced decentralised geothermal technology combined with aerothermal energy (heat pumps) and hybrid solar energy production (thermal and photovoltaic).

This exemplary system is fully in line with Luxembourg's and Europe's ambitions to achieve carbon neutrality by 2050. The signing of this contract marks a decisive milestone in the sustainable and forward-looking development of the plateau, embodying the innovative vision of the Kirchberg Fund for the urban planning of tomorrow.

Kuebebierg, a sustainable and innovative neighbourhood

The future Kuebebierg neighbourhood covers 33 hectares. As the last large land reserve belonging solely to the Kirchberg Fund, it will eventually accommodate more than 3,000 homes, as well as public facilities and spaces dedicated to economic activities. In 2022, the consortium led by Güller Güller architecture urbanism won the paid consultation to develop an urbanisation plan for this neighbourhood.

Designed to promote biodiversity conservation, this project harmoniously integrates nature into the urban environment, reflecting the neighbourhood's ‘so urban, so natural’ character. The site is already home to Kuebefarm, an urban farm surrounded by vast meadows ideal for relaxation and outdoor leisure activities, particularly on the playground.

Sustainable mobility is a central pillar of the neighbourhood's development: the extension of the tram line will ensure its role as the main form of public transport, while cycling will be encouraged for individual journeys.

In the medium term, more than 7,000 residents will be able to move in, in an environment that combines social diversity and controlled urban density, promoting a variety of lifestyles.

In terms of energy, Kuebebierg stands out for its ambition to achieve carbon neutrality. To reach this goal, the project is relying on a combination of renewable technologies, accurate modelling of energy needs and a low-temperature heating network. More than 460,000 m² of built-up area will be connected to this network, with the first phase of pipe laying imminent. Work on rolling out the network will continue until 2035.

Three years of preparation for an ambitious project

Before launching the tender process for the Kuebebierg heating network, the Kirchberg Fund spent three years exploring possible options, verifying the technical and economic feasibility of the chosen concept, and confirming its relevance.

Once this framework had been defined, a European public procurement procedure, involving negotiation, was initiated. The private consortium ‘KCH’ won this comprehensive contract, covering the design, construction, operation and maintenance of the network for 20 years. This contract, known as ‘DBMO’ (Design-Build-Maintain-Operate), is an innovative and exemplary approach in the field of energy infrastructure in Luxembourg.

The legal aspect of this particularly complex project was handled in close collaboration between the legal teams of the Kirchberg Fund and the law firm Loyens & Loeff (Belgium), with a view to defining and organising the best form of selection and cooperation between the Fund and the service provider.

In addition, the Kirchberg Fund benefited from the support of international experts, including Rebel for economic analysis, and the engineering consultancies Beissel & Ruppert and Amstein+Walthert for technical expertise.

An innovative device, tailor-made for Kuebebierg

‘This network has been designed specifically for Kuebebierg,’ emphasises Marc Widong, Director of the Kirchberg Fund. "It is a pioneering project in Luxembourg, incorporating a comprehensive approach to the entire infrastructure, from its design to its operation and maintenance. By promoting the sustainable use of natural resources, the Kirchberg Fund is committed to offering the best possible quality of life to the future residents of the neighbourhood. "

The neighbourhood is based on an innovative energy system, combining 21 decentralised and autonomous geothermal hubs, reinforced by an aerothermal power plant, all connected via a low-temperature network. This modular, flexible and interconnected system provides thermal energy for heating and domestic hot water and for cooling in the summer months thanks to geocooling, while regenerating the geothermal probes. Hybrid solar panels (thermal and photovoltaic) complete the system by recharging the subsoil to ensure optimal, balanced operation over the long term. Thanks to the solar panels on site, most of the electricity is produced on site, ensuring a high degree of autonomy.

With 6 MW of power supplied by the aerothermal power plant and 6 MW by the 21 decentralised hubs, this circular architecture embodies carbon neutrality by combining performance, energy efficiency and comfort throughout the year.

Thanks to this innovative combination of geothermal, aerothermal and hybrid solar energy, the Kuebebierg district covers almost all of its heating needs using renewable energy, perfectly illustrating how a new-generation heating network can combine urban comfort with climate responsibility.

Finally, such a network allows for control and predictability of energy production costs, making them largely independent of the electricity market. This approach thus offers the possibility of reducing heating costs for future residents, which is all the more important in a neighbourhood where 30% of the housing will be affordable.