4th SESSION – Roadmap for the realization of an eco-district, including development of medium-depth geothermal energy in urban areas

4th session Lausanne


Slot 1: Roadmap for the realization of an eco-district

The City of Lausanne has the ambition to realize the Plaines-du-Loup eco-district. The roadmap starts with the realization of an energy concept, which shows that for heat generation, the most promising option is the implementation of heat pumps connected to deep geothermal probes (800 m). Then, organization of an urban planning competition. Its objective was to select a masterplan project offering sufficient flexibility to integrate the technical and social evolutions that would have taken place over the period until 2030. It was essentially to develop a process of people participation, to lay favourable framework conditions to the anticipated appropriation of this neighbourhood by citizen. The winner has been entrusted with the mandate to implement the master plan, which sets the principles of urbanization, landscape and mobility, and formalizes the energy concept, which is accompanied by an environmental paper. From the master plan, 4 partial assignment plans were adopted, defining the rights to be built. The first of these plans as well as its principles of urban planning and landscaping has been adopted. A call for tender made it possible to select 18 investors, grouped into 5 companies, one per Urban block. Each company’s mission is to organize an architectural competition on its territorial scope. A first winner has been nominated.

Speaker: Maria Riera Project manager in building management. Apprehend the transversality of sus-tainnable construction, deepened themes such as the heritage, the quality of the living environment, city planning, etc.

Sector: Energy

Stakeholders: Town planner (Public and private), Engineer (Public and private), Lawyer (Public, private and civic society), Communication specialist (Public) Architect (Private) and Investors (Entrepr/Act).


Slot 2: Development of medium-depth geothermal energy in urban areas

Before embarking on the realization of a neighbourhood, it was necessary to develop the technology and validate the economic aspects of a similar pilot project in terms of density and geology. The pilot project allowed:

  • to make possible the use of heat pumps with geothermal probes in a compact urban environment with a coefficient of performance approaching the value of 5;
  • to develop a protocol allowing the use of standard drills planned for depths of 200 meters, which makes it possible to obtain a competitive cost compared to installations using fossil fuels;
  • to develop, in collaboration with the driller, a coaxial probe model making it possible to limit the heat losses encountered at great depths with a conventional double-U type geometry;
  • to equip geothermal probes with optical fibers to be able to continuously measure the temperatures according to the depth;
  • to produce a software for processing the mass of data generated, making it possible to visualize the evolution of the temperature at hourly, daily or monthly averages; to validate the calculation models used to simulate deep geothermal probe fields, with a difference of 3% with the measured values.

Speaker: Francesco Barone Engineer. Deep geothermal probes: theory and design

Sector: Energy

Stakeholders: Engineer (Public) and  Geologist Driller (Entrepr/Act)


Slot 3: Energy efficiency program

In 2016, the City of Lausanne launched an energy efficiency program call Equiwatt with the objective of saving energy for individuals and businesses and raising awareness of energy consumption. This program is financed over seven years by the Energy Efficiency Fund of the City. In order to reach all target audiences, the program has implemented various action plans, including:

  • A collaboration with the biggest store chain and other partners made possible to offer 50% discount LED bulbs
  • Four eco-social operations took place in different districts of the City where efficient equipment was offered and behaviour change explained to the inhabitants of subsidised housing
  • A incentive is offered to companies undertaking renovation of lighting systems or cooling system
  • When changing refrigerators, Equiwatt offers a subsidy for the purchase of new high-performance equipment
  • An awareness module has been put in place to allow company collaborators to understand the impact of their everyday behaviour on the energy consumption.

Speaker: Baptiste Antille (Public) Engineer. Conduct and coordination of energy optimization projects.Monitoring and analysis of energy. performance

Sector: Energy

Stakeholders: Citizens (Civic society) and SMEs (Entrepr/Act)