Green ESO — Environmental Sustainability at ESO

Green ESO logo


Globally we are facing many significant environmental challenges, including climate change, pollution and waste. ESO — as the foremost intergovernmental astronomy organisation in the world — has a role to play: by addressing the environmental impact of its activities and operations; by ensuring it is well-informed in its decisions and actions; and by contributing to sustainable solutions towards a greener planet.

ESO carries out the design, construction and operation of the most powerful ground-based observing facilities, providing astronomers with the best tools to enable the most important scientific discoveries. But this work places significant demands on resources, including energy.

Several green initiatives have been developed in consultation with ESO staff, through which the organisation aims to tackle the environmental impacts of its operations.

Overall ESO has the following green aims:

  1. To ensure that all the main aspects of our activities, including operations, IT and resource management, are efficient and protective of the environment.
  2. As part of our overall strategy to increase operating efficiency, we are considering environmental stewardship and energy consumption as administrative parameters.
  3. To maintain a public commitment to meaningful and achievable green goals.
  4. To promote energy conservation and environmental stewardship across all activities.
  5. To have a strategy that supports reducing costs, lowering complexity, and increasing operating and energy efficiency.
  6. To look for ways to improve IT operations to generate more computing performance without increasing power consumption.
  7. To develop verifiable energy conservation and renewable energy initiatives that proactively address energy and climate challenges.
  8. To pursue the development of energy and environmental strategies and policies.

Green Initiatives at ESO

ESO Headquarters (Garching)

ESO HeadquartersThe ESO Headquarters comprises the scientific, technical and administrative centre of the organisation and thus is reliant on a high-quality IT infrastructure and, particularly for its academic work, high-powered computing. All computer rooms are equipped with efficient air circulation cooling devices of the newest standards and all old cooling units were recently replaced. During the winter months, the cold outside air is used to cool the computer rooms to reduce power consumption. All pumps in the heating system, as well as all control units of the ventilation system, have also been replaced with new models to save energy.

ESO is committed to separate waste and recycling of glass, cardboard and paper, metals, plastics, electronic materials, domestic waste, batteries, fluorescent tubes, electronic waste, coffee cups, hazardous material, glass, copper and other metals and more. Environmental friendly, wood-free printing paper is used.

ESO HeadquartersESO supports Stadtradeln — a competition and campaign to support climate protection and promote cycling in Germany.

The ESO sites are very geographically dispersed (ESO has more than a dozen small and large facilities and sites in Germany and Chile) and makes extensive use of video conferencing facilities to reduce travel and the consequent environmental damage. Likewise, ESO encourages astronomers to make use of “service mode observations” whenever feasible, eliminating the need for them to visit the observatories and thereby reducing carbon footprints.

The energy consumption of both the new Headquarters Extension (eso1350) building and the new technical building is significantly lower than typical for buildings of their size. This is achieved by efficient insulation and state of the art heating and cooling concepts. Offices in the office building are cooled and heated by concrete core activation using a heat pump and ground water supported by geothermally-generated district heat and are vented naturally. Common areas (meeting rooms, auditorium, Council room and cafeteria) utilise a mechanical ventilation system with heat recovery. Floor-to-ceiling triple glazing in both buildings, as well as automatically operated blinds control the amount of sun into the rooms, meaning less heat in the summer and less heat loss in winter. Chillers with free cooling systems are being used for the technical building and the IT infrastructure and laboratories.

ESO Supernova visitor centreGreen measures are incorporated into the design of the building that will house the ESO Supernova — Planetarium & Visitor Centre. The facility is aiming for a DGNB (Deutsche Gesellschaft für Nachhaltiges Bauen or German Sustainable Building Council) certification for sustainability with respect to its "green economical, socio-cultural, technical and ecological aspects".


Heading to ArmazonesThe remoteness of the Atacama Desert presents significant challenges to ESO’s operations at its ALMA and Paranal observing sites as they currently have no connection to the Chilean power grid, relying instead on their own supply of energy. This is known as "island operation" mode. Also food, water and other consumables have to be either produced on site or trucked in from nearby cities.

Despite the addition of the VISTA survey telescope and VLT Survey telescope (VST), power use has remained stable over the past few years at Paranal. While power saving has been a paramount objective at Paranal, the power requirements for the considerable amount of high-tech equipment remains high. Numerous steps have been taken to reduce power consumption, but with some natural limitations. Therefore, only renewable energy can be a real step forward to make the observatory independent from fossil energy: Photovoltaics, wind energy and solar thermal solutions have the potential to be implemented in the future and the connection to the electric grid is essential to make this economically attractive. One of the small but significant initiatives is a new, more modern laser guide star system which has been installed at Paranal, effectively reducing the power consumption to less than a tenth of that required by the old laser. This is naturally only a small fraction of the observatory’s power consumption, but since more lasers are planned for the Very Large Telescope in a near future, and on the European Extremely Large Telescope (E-ELT) in the medium term, it is an important step.

With the construction of the E-ELT at Cerro Armazones, 22 kilometres east of Cerro Paranal, the increased power requirements warrant an electric grid connection at both sites. For more than two years staff have worked with the authorities and companies to connect the remote Paranal-Armazones observatory to the Chilean power grid, which will reduce in its carbon footprint as the grid electricity is produced with a lower percentage of fossil primary energy.

Green energy is strongly supported by the Chilean government, who aims to increase the Chilean green energy component to 25% in 2020, with a possible target of 30% by 2030. This improves the energy mix.

La Silla Observatory

Over the years ESO has managed to successfully reduce its power consumption at La Silla.

A solar farm is being built and installed at La Silla, effectively exploiting solar energy by the use of crystalline photovoltaic modules (solar panels) in a project by the Chilean company, Astronomy and Energy (a subsidiary of the Spanish LKS Group). These will cover an area of more than 100 000 square metres on the site.

ESO’s sites offer astronomers more than 320 clear nights per year; the clear daytime sky also provides abundant sunshine. But only very recently, however, the much-improved efficiency of solar cells has meant they have become a viable alternative to exploit solar energy. Solar cells of the latest generation are considered to be very reliable and almost maintenance-free, characteristics that contribute to a high availability of electric power, as required at astronomical observatories.


ESO Vitacura

ESO has implemented recycling containers in its main and satellite buildings at Vitacura for recycling of glass, cardboard and paper, plastics, batteries and more.

Rainwater is collected in a water well and this natural water is used for watering the park, which is quite large with thousands of plants, trees and large grass areas.




The Dark Sky — Our Universal Heritage

Protection of the dark sky is relevant not only for astronomers, but for everyone. More than half of the world’s population now lives in cities, where the night sky is barely visible due to light pollution. The dark sky is part of our universal heritage and visibility of the stars and the Milky Way is a privilege that should be preserved for future generations.

ESO’s observatories are located under the pristine Chilean skies, but there are signs that light pollution is becoming a serious problem even there. ESO is an active supporter of light pollution control. Since 1999, Chile has made laws to protect the skies in northern Chile. ESO is also a partner in Chile’s Office for the Protection of the Night Sky Quality, along with other international observatories and Chile’s Ministry of Environment.

Protection of the night sky is everyone’s responsibility. With small changes in how we illuminate our homes and streets we can save energy, reduce the effects of light pollution on people and wildlife, and contribute to the protection of the night sky.