A state-of-the-art solar power system has been installed at the Nordic Optical Telescope, on La Palma, Canary Islands. This marks a significant step towards sustainable science and commitment to environmentally responsible operations.
The Nordic Optical Telescope (NOT), located on top of the Roque de Los Muchachos in Garafía, La Palma, is co-owned by the University of Turku in Finland and Aarhus University in Denmark, and it is one of the world’s most productive medium-sized astronomical facilities.
“The Nordic Optical Telescope relies on a combination of precision engineering and advanced computing power to explore the depths of the universe. This includes, and requires, not only powering sophisticated electronics and data systems, but also managing the thermal environment inside the telescope dome during the day, a critical factor in ensuring high-quality night-time observations” says Professor Petri Väisänen, the Director of the Nordic Optical Telescope as well as the Finnish Centre for Astronomy with ESO based at the University of Turku.
Harnessing the power of the Sun to unlock the mysteries of the stars, the University of Turku announces the completion of a state-of-the-art solar power system at the NOT.
The system consists of 71 high-performance photovoltaic panels, strategically installed across the roof of the Telescope’s service building. Of these, 35 panels face east to capture the morning sun, while 36 panels face west, extending production into the late afternoon.
This dual orientation ensures that solar energy is harvested steadily throughout the day, rather than peaking only at midday. Despite the modest 14-degree tilt of the roof, the design achieves a balance between early and late-day solar exposure. Thanks to this setup, the system is expected to produce approximately 220 kilowatt-hours of electricity per day, covering nearly 40% of the Telescope’s continuous daily energy demand of 600 kWh.
This reduction translates into a carbon footprint decrease of up to 40% during daytime operations, and estimated annual energy savings exceeding 7,000€. This also means that the investment in the installation will be recovered in just a few short years.
This project reflects the commitment of the University of Turku to clean energy and responsible research practices, while fostering collaboration with local businesses on the Canary Islands. The installation of the solar panel system was entrusted to local companies in La Palma, therefore supporting the island’s economy and drawing on its wealth of local expertise.
Merging scientific discovery with ecological responsibility
The solar plant was inaugurated on 29 April 2025 by the Rector of the University of Turku, Professor Marjo Kaartinen.
“It is great how appreciated the Nordic Optical Telescope and the research conducted with it are all over the world. Astronomy has very long traditions in Turku and at the University of Turku. We conduct top research in the discipline. I am very happy that while we conduct this top research, we are also pioneers in using green energy,” says Rector Kaartinen.
“This initiative reflects our dedication to innovation, both in astronomy and in the way we work and do research”, says Professor Väisänen. “Utilising the power of our own star, the Sun, to study stars and the universe, also just feels very poetic. And more importantly, harnessing solar energy for our observations brings us closer, even in this small way, to a future where cutting-edge research and environmental protection go hand in hand.”
By merging scientific discovery with ecological responsibility, this solar energy project stands as a powerful example of how research institutions can lead the way toward a more sustainable and energy-conscious future. The University of Turku is proud to contribute to this transformation — exploration of the cosmos and the care for our planet can be pursued together.
The project was funded by the Research Council of Finland, through an Infrastructure Grant (FIRI2023) managed by the University of Turku, it was designed by Industrial Technical Engineer Rubén García Batista, and coordinated on behalf of the NOT by Peter Melgaard Sørensen.
Main photo: Urs Leutenegger / Nordic Optical Telescope
