CSCS: national supercomputing on Lake Lugano

From Manno to Cornaredo

The Swiss National Supercomputing Centre (Centro Svizzero di Calcolo Scientifico, CSCS) was founded in 1991 as a unit of ETH Zurich, which still operates it.¹ Its first seat was in Manno, a municipality in the Vedeggio valley north-west of Lugano, where it occupied rented premises for two decades.² The placement of a national research infrastructure of this kind in Ticino gave the canton a federal institution of international standing at a time when it still had no university, since USI opened only in 1996. The motives for the choice of Manno are not documented in the sources consulted for this chapter. It can be read as an early instance of the wish to give the Italian-speaking region a share of national institutions, which later decisions such as the seat of the Federal Criminal Court in Bellinzona (described in Chapter J.II) also reflect.³

By the late 2000s the premises in Manno had become too small for the growing machines and their power and cooling requirements. In July 2008 the Board of the Swiss Federal Institutes of Technology selected a site in the Cornaredo district of Lugano, in the area of the municipality of Porza, in preference to an alternative site in Caslano.⁴ The City of Lugano provided a plot of 8,790 square metres, the former depot of the Lugano public transport company, under a forty-year building right and paid the demolition costs. The Confederation financed the building through the ETH domain with CHF 67.5 million, while the supercomputer itself was budgeted separately at about CHF 70 million. In November 2009 the Ticino Grand Council approved a cantonal contribution of up to CHF 5 million, earmarked for the advanced cooling technology of the new building. The parliamentary report expected the number of staff to grow from about 40 to about 55.⁵

The new centre was inaugurated on 31 August 2012 by Federal Councillor Alain Berset, in the presence of Fritz Schiesser, president of the ETH Board, and Ralph Eichler, president of ETH Zurich. Berset described the investment as "a long-term commitment to cutting-edge research". The building was designed for an operating life of forty years, with a modular structure that would allow successive generations of computers to be installed. In 2012 the centre distributed 325 million computing hours to its users, and requests for computing resources had almost doubled since 2010.⁶

Cooling with lake water

The most distinctive technical feature of the Lugano centre is its cooling system. Supercomputers convert almost all the electricity they consume into heat. The cost and environmental impact of cooling are among the main constraints on their operation. The CSCS draws water from Lake Lugano at a depth of 45 metres near the mouth of the Cassarate river and pumps it through a pipeline of 2.8 kilometres to the centre in Cornaredo. The water arrives at about 6 degrees Celsius. The system can move up to 760 litres per second and returns the warmed water to the lake at a maximum temperature of 25 degrees, using the "free cooling" principle without energy-intensive compressors.⁷ The parliamentary report of 2009 described a double pipeline from the area of Parco Ciani and the return of the heated water at a depth of about 20 metres, so as to avoid a thermal impact on the Cassarate.⁸ The centre reports a power capacity of 11 megawatts, expandable to 25 megawatts, and a backup supply of 960 batteries.⁹

The use of the lake connects the supercomputer with the geography described in Chapter A.I. The lakes that once carried the trade of Como and Lugano now cool the computers on which Swiss climate models, materials simulations and artificial intelligence models are calculated. The arrangement also has a legal side, since the use of public waters for cooling and the return of heated water require concessions and environmental permits under cantonal and federal water protection law.¹⁰

Notes

1. Swiss National Supercomputing Centre, CSCS: Il Centro Svizzero di Calcolo Scientifico (brochure, 2024), https://www.cscs.ch/fileadmin/user_upload/contents_publications/factsheets/brochure/ CSCS_DI2024_IT_FINAL_LR.pdf. ↩
2. Gran Consiglio della Repubblica e Cantone Ticino, Rapporto 6281 R della Commissione della gestione e delle finanze (17 November 2009), https://www4.ti.ch/fileadmin/POTERI/GC/allegati/rapporti/9034_6281r.pdf (CSCS in Manno). The founding in Manno in 1991 is also stated in Wikipedia, "Swiss National Supercomputing Centre", https://en.wikipedia.org/wiki/Swiss_National_Supercomputing_Centre (consulted as a last resort). ↩
3. CSCS brochure 2024 (above) (founded in 1991); USI, "History" (above) (first classes on 21 October 1996). The reading of the choice as part of a regional distribution of national institutions is the author's interpretation. ↩
4. Rapporto 6281 R (above). ↩
5. Rapporto 6281 R (above). ↩
6. CSCS, media release on the inauguration of the new building (31 August 2012), https://www.cscs.ch/fileadmin/user_upload/contents_publications/press_releases/strategy/ Medienmitteilung_CSCS_Inauguration_IT.pdf. ↩
7. CSCS brochure 2024 (above). ↩
8. Rapporto 6281 R (above). ↩
9. CSCS brochure 2024 (above). ↩
10. Federal Act on the Protection of Waters of 24 January 1991 (Water Protection Act, WPA), SR 814.20, Art. 6 and 9 (discharge of substances) and Art. 29–30 (authorization of water withdrawals), headings at https://www.droit-bilingue.ch/de-fr/8/81/814.20-index.html; cantonal concession law for the use of public waters. ↩

For general information only. This article does not constitute legal or tax advice, does not replace advice on an individual case and creates no lawyer-client relationship. It reflects the legal position as of October 2026.