ESO’s Paranal Observatory starts receiving energy from the largest solar plant in Chile dedicated to astronomy

After nine months of work, ESO and the Saesa Group inaugurated the Paranal-Armazones photovoltaic plant, which will supply renewable energy to ESO’s Paranal Observatory and, soon, to the construction and operation of ESO’s Extremely Large Telescope (ELT), the largest optical telescope in the world.

After its inauguration, the plant became the largest solar complex in Chile supplying renewable energy to an astronomical observatory. With 18 565 panels, distributed over 7.2 hectares of land, it will harvest 9 megawatts of electric power. This will make it possible to cover 100% of the energy needed to operate ESO’s facilities, such as the Very Large Telescope and the ELT, during a day, the period with the greatest energy demand due to the telescopes’ cooling systems.

“This milestone is a dream that becomes reality! Today we are closing an endeavour that started more than ten years ago, when the Chilean Ministry of Energy together with the National Energy Commission engaged to help ESO in looking for the best available options to generate and supply clean energy to the biggest telescope in the world,” said ESO’s ELT Programme Manager Roberto Tamai during the plant’s inauguration ceremony, which gathered authorities with members of Saesa Group and ESO.

“We are very happy to expand our presence in Antofagasta, supplying renewable energy to ESO’s ELT and, at the same time, injecting clean energy into the system. For years we have been providing clean, efficient, and reliable energy solutions to the southern regions, so offering them to the north of the country is a source of pride and motivation for us and we can continue contributing to the decontamination of cities and the improvement of quality of people’s lives. By operating this plant, which will be very important for the development of national astronomy, we are contributing another small grain of sand to achieve the carbon neutrality that Chile has proposed”, said Francisco Alliende, general manager of the Saesa Group.

Energy consumption represents one of ESO’s largest sources of CO2 emissions. However, the emission of 1700 tons of CO2 per year, will be avoided thanks to the power plant, which is located 130 km south of Antofagasta in Chile’s Atacama Desert and is a key part of ESO’s strategic sustainability plan.

“The opening of this photovoltaic plant is a milestone because it connects and boosts the activities we want for the country we are trying to build: science, astronomy, and clean energy. From the Atacama Desert, we will learn about the origins of the Universe, promoting climate action to face the challenge of climate change,” said Maisa Rojas, Minister for the Environment of Chile.

This new plant will also contribute solar energy to the country’s energy system. Thanks to the Armazones substation and its transmission lines, all the energy not used in scientific operations will be injected into the Chilean energy grid.

“The scientific infrastructure must be at the service of society. This also implies actively taking on the current challenges in matters of sustainability. This plant brings us one step closer to the development of science in a way that is friendly to the environment”, said Luis Chavarría, ESO representative in Chile, during the ceremony.

“We are grateful for ESO’s commitment to the region, which is reflected by changing their energy matrix to a 100% clean and renewable supply. These projects are aligned with Chilean President Gabriel Boric’s Ecological Government’s objective, as well as the Climate Change Framework Law. Therefore, the solar matrix that will supply clean energy to the Observatory is noteworthy, as it contributes to the country’s goal of being carbon neutral by 2050,” said Dafne Pino, Ministerial Regional Secretary of Energy in Antofagasta.

The photovoltaic complex has state-of-the-art technology to efficiently collect the photons emitted by the Sun. It has double-sided panels capable of generating electricity from direct sunlight and light reflected by the ground of the Atacama Desert. Additionally, the panels were installed in such a way that they can automatically rotate to follow the apparent movement of the Sun in the sky. This optimises power generation until the last seconds of the day.

The plant, the substation and the transmission lines are owned and operated by the Saesa Group. ESO provided the land use, along with administrative and legal support to bring the project to fruition.

Courtesy of European Southern Observatory