The city of Geneva has been at the epicenter of global governance and decision-making for nearly 100 years and is a prime example of local level implementation of innovative solutions to global challenges, such as sustainable urban transportation and energy systems. Taking stock of the global impact of climate change over the past few years, cities have been increasingly stepping up to the plate to take on a leading role in creating sustainable urban futures for their citizens, including Geneva. In just the last 8 years Geneva has been able to design and implement a novel urban energy infrastructure that will help the City achieve its goal of being a true sustainable city infrasystem that operates on 100% renewable energy.

Geneva, where sustainable city meets urban innovation

Known both as the “smallest of big cities”, or the “city of peace”, Geneva, among other things, is home to the European headquarters of the United Nations Organization. Furthermore, the city has far greater international influence than any other city of 200,000 inhabitants. Today, Switzerland’s second largest city is home to around twenty international organizations[i].

Geneva has experienced a steady demographic growth over the years, which has resulted in increased demand for of natural resources in order to provide heating and cooling in buildings in addition to electricity for homes, offices and public transportation services. This increase in population alongside the increased demand for energy-intensive services like building heating or cooling and public transportation forced Geneva’s urban infrastructure managers to address questions such as how to decrease the city’s dependence on fossil fuels, how to meet the energy demand of new buildings, houses and transportation, and what would be the impact of increased energy flows on the sustainability of the city?

These questions led the City of Geneva to adopt a strategic plan of sustainable development for 2011-2014, which contained 13 measurable priority objectives. Of the 13 objectives, energy, climate and transportation were at the top of the list. This program was implemented through the collaboration of different departments and in line with the Canton’s own strategic agenda for sustainable development, Agenda 21. The six strategic areas of the Cantonal Climate Plan are: to reduce dependence on fossil fuels and buildings to promote renewable energy; promote low-carbon mobility; promote clean, efficient modes of energy production and consumption; consider climate change in territorial development; protect people from the adverse effects of climate change; water protection, biodiversity, agriculture and forestry to climate change[ii].

As a result, the city of Geneva’s approach to its urban energy infrastructure management has gravitated towards the promotion of sustainable and healthy urban living. The City of Geneva set a goal to be “100% renewable and zero emissions in 2050.” The main objective is to disengage the City from fossil fuels, while reducing the need to facilitate the transition to renewable energy.  Today, 80% of city projects already fall in line with the “100% renewable in 2050” target[iii]. This energy concept applies specifically for each building construction and renovation as the city is working to improve insulation and implement technologies utilizing renewable energy.

Energy Infrasystem Transformation

Historically, Switzerland’s longest-serving and most important source of renewable energy has been hydropower due to its topography and high levels of annual rainfall, which present ideal conditions for the utilization of hydropower[iv]. The City of Geneva, however, has become a pioneer for Switzerland in the renewable energy sphere by innovating with hydro-thermal energy given its prime location on Lake Geneva and the interconnectivity of the buildings within the metro region.

Taking stock of both the Cantonal Agenda 21 Strategic Climate Action Plan and the City of Geneva Sustainable Development Agenda, in 2008 the State of Geneva, the City of Geneva, FIPOI (Building Foundation for International Organizations) and SIG came together to create the thermal Geneve Lac Nation (GLN) project which supplies heat and cooling facilities to numerous companies in the Sécheron district and has helped near-surface geothermal energy to advance. Additionally, the United Nations Commission for Sustainable Development supported this project as it enabled Geneva-based International Organizations to follow sustainable imperatives through the use of 100% renewable energy and the replacement of oil by gas for heating needs, in accordance with the Kyoto Protocol[v].

The GLN project functions through the principal of piping deep lake water (which acts as a heat sink) to the climate control systems in participating buildings. This system also provides heating in newly-constructed buildings via the installation of high-performance heat pumps. The GLN project was the first network distribution of “direct” cold water for air conditioning, heating, and the watering of green spaces in a neighborhood[vi].

GLN water pump (SIG)

GLN water pump (SIG)


Student tour of GLN pump station (Author’s photo)

Student tour of GLN pump station (Author’s photo)

Motivated by the success of the GLN project, in April 2016, Geneva canton and city officials, in partnership with SIG, launched the Genilac project, which uses lake water for cooling in summer and heating in winter homes and businesses buildings, similar to GLN but with an energy power to the order of 10x that of the GLN network[vii]. This new hydro-thermal network will cover the city center and the airport area by 2022, building upon the connections in place from the GLN project. With the realization of the GLN implementation, SIG has proven the reliability of an innovative thermal system. By extending this heating system in the town center district by 2017 and the airport by 2022, SIG and its partners (state universities, Canton and City officials) will be able to demonstrate that the lake water is a renewable resource that can be used widely[viii].

Served areas of the completed network extension (SIG)

Served areas of the completed network extension (SIG)

In line with the City and Cantonal sustainable development agendas, the Genilac Project will be a beneficial solution for the environment through creating a sharp reduction in electricity consumption (~80% reduction by 2020), no use of refrigerant greenhouse gases, and a reduction of CO2 emissions thanks to the coupling of heat pumps to cold networks (~80% reduction)[ix]. Furthermore, this energy system does not damage the natural environment as water is pumped from the lake at a depth of 45 meters at a stable temperature year-round. After the water is used for heating or cooling in residences or buildings, the water is returned to the lake in original form at similar temperature, in-line with the water cycle.

Systemic illustration of the Genilac project (SIG)

Systemic illustration of the Genilac project (SIG)

To date, this urban energy transition through the GLN and GeniLac network is considered a success and is currently being studied by city officials from Boston and Chicago, amongst others, as a model for an integrated urban energy infrasystem transformation. Additionally, these projects demonstrated the success of a public-private partnership involving the United Nations, the Canton of Geneva, the City of Geneva and SIG.

Challenges and opportunities

Technological challenges

The main technology challenges posed are those related the new interconnections and interoperability of the continuation in connecting of more buildings in the Greater Geneva region to the Genilac network. The urban infrastructure managers of Geneva will need to assess the capacity to which connecting more buildings to the network is possible and if new infrastructure needs to be added to existing ones in order to connect from farther distances. And if new infrastructure does need to be added, how much will it cost both financially and time-wise? These are questions that will need to be addressed in the future as the Genilac network evolves.

The Energy Future of Geneva

In 2014, Geneva won for the 2nd time in a row the Gold European Energy Award (EEA) for its visionary energy policies. Considered the most prestigious distinction of its kind for European cities and issued every four years, the award recognized Geneva’s performance with a top rating of 82% of renewable energy initiatives. The EEA’s Gold award is only granted to cities that have achieved 75% or more of their urban energy development goals. It is this forward-thinking shift of mindset from the City and Cantonal officials of Geneva alongside SIG that has charted a path for Geneva to be a pioneer in the new sustainable urban age. Through ambitious policies and action plans (soft infrastructure), alongside the construction of the GLN and Genilac network (hard infrastructure), Geneva has been able to transition to a sustainableresilient and efficient urban energy infrasystem that will continue to evolve in order to continue decreasing fossil fuel dependence, promoting local renewable energy, and creating a healthy city for its citizens.

University of Geneva 2016 Summer School GLN pump tour (Author’s photo)

University of Geneva 2016 Summer School GLN pump tour (Author’s photo)



[i] Ville de Geneve 2016. Energy Policy. Available at:

[ii] Canton of Geneva 2015. Agenda 21 – Cantonal Climate Strategy, Available at:

[iii] Ville de Geneve 2013. The city of Geneva on the way to 100% renewable energy by 2050, Available at:

[iv] Swiss Federal Office of Energy 2016. Hydropower, Available at:

[v] Viquerat, P. 2008. Utilization of a deep lake water direct coling network (DLWDC) for cooling of a large administrative district. Energy and Environmental demonstration and follow-up. CUEPE, University of Geneva, Switzerland

[vi] SIG 2015. Geneva Lac Nations: a step ahead in the use of local resources, Available at:

[vii] Geneva Network of Industrial Ecology 2015. Genilac: A major and sustainable energy innovation in Geneva, Available at:

[viii] SIG 2016. Genilac: participate in new development projects with the thermal resource of the Lake, Available at:

[ix] SIG 2016. Genilac: Your renewable heat solution at the forefront of innovation. Available at:

This piece is the original writing of the author(s). The view points in the post is the author’s personal opinions and do not reflect IGLUS/EPFL’s viewpoints. The author(s) is the sole responsible person regarding the accuracy of the information presented in the post and will be liable for any potential copyright infringements.

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