La Silla, Lit by the Sun and Stars

Published on Friday, 19 February 2016

An astronomical paradise lies in the Atacama Desert in northern Chile. In this arid location, situated literally between the sea and the stars, the sky is so dark that on a clear moonless night you can see your own shadow, cast by the light of Milky Way alone.

The mountainous area stretches from the Pacific coast to the Andes. It is in Cerro La Silla – 2,400 metres above sea level and 600 kilometres north of Santiago, near the city of La Higuerra, in the Coquimbo region – that ESO (the European Southern Observatory) built its first observatory in 1964. ESO is an international organisation for astronomical research in the Southern hemisphere, that was founded in 1962 and today includes 15 member countries.

ESO operates several observatories in the South American country. That of La Silla is the first world-class observatory to have received an ISO 9001 certification. And soon, all of its research activities will also become green.

Through its subsidiary EGP Chile, Enel has begun construction of an innovative 1.7 MW photovoltaic plant, which will provide energy to the observatory and to the Chilean electricity grid.

Once operational, the plant will generate approximately 4.75 GWh of electricity each year, equivalent to the electricity needs of approximately 2,000 households and more than 50 percent of the observatory’s annual power consumption. The energy generated at La Silla will avoid the emission of over 2,000 tonnes of CO2.

Observation of the Milky Way will become even more efficient and the cutting-edge telescopes at La Silla will significantly contribute to the research and discovery of exoplanets (planets located outside of the solar system), interstellar dust and gamma ray bursts. Just a few days ago – while the media confirmed the existence of gravitational waves, detected by the US facility LIGO (Laser Interferometer Gravitational-Wave Observatory) – the MPG/ESO 2.2-metre telescope in La Silla captured a snapshot of the birth of a star, through a reflection nebula called IC 2631. This telescope, which hosts a 67-million pixel WFI (Wide Field Imager), allows astronomers to take spectacular pictures of celestial bodies.

The astronomical equipment at the La Silla also features a 3.58-metre New Technology Telescope (NTT), the first in the world to have a computer-controlled main mirror (active optics). The telescope is now home to what has been defined as “the world’s foremost extrasolar planet hunter”: HARPS (High Accuracy Radial velocity Planet Searcher), a high-precision spectrograph capable of picking up distant signals.

At Enel, we share the same continuous search for innovation as ESO in its activities in La Silla, through all of the new projects that we are conducting in the countries in which we operate. Our strategies are driven by the search for innovation and sustainability, in order to develop the best renewable energy production technologies and transfer them to the territories in which we are present.

We have created an innovative system in La Silla, which will combine advanced technology, with bifacial and smart PV panels. The plant will be the first industrial sized solar-powered facility to combine the two technologies and to test their performance. The smart modules are equipped with microchips that optimise the production of each panel, thus allowing them to feed electricity into the grid in case of malfunction, whereas traditional modules would affect the production of the entire plant in the event of a malfunction.

Bifacial modules capture solar energy from both sides, including the surface that is not exposed to direct sunlight. In order to capture the light’s reflection, they are typically installed at a 45-degree angle, thereby reducing the accumulation of sand and dirt on the module’s surface, especially in arid and dusty areas.

The use of this innovative technology should help increase the generating capacity by 5 to 10 percent, compared to a traditional PV plant of the same size.

The new facility allows expert astronomers to observe the universe by using renewable energy, and to search for planets and distant stars, without emitting CO2 and helping keep the skies of the Atacama desert clean, lit only by the stars.