At the Central State Archive, documents from public and private archives will be on display in an area of 600 square meters to recount the efforts made by the pioneers of the 19th and 20th centuries in order to achieve with solar energy the same things accomplished with fossil and nuclear fuels, i. e. heating and cooling buildings, illuminating day and night living and working spaces, powering farms, industries and other human activities.

Gaetano Vinaccia (1889-1971), an architect and city-planner, is the author of dozens of little known publications and articles on solar urbanism and architecture. Among them is the 385 page book “Il corso del sole in urbanistica ed edilizia” (“The path of the Sun in urban planning and building construction”), published in 1939 in which Vinaccia reviewed systemic architectural and city-planning aspects of the use of solar energy over the ages, in the conviction that the past has to be placed at the centre of any enterprise headed for the future [8][9].

Giovanni Francia (1911-1980), a mathematician and engineer, thought that solar heat, abundant at low density and temperature, needed to be collected at high temperatures in order to be useful in modern societies to run industries and power plants. He was the first person ever to apply the Fresnel Reflector Technology principle in real systems, linear, in Marseille in 1963, and point focus, in S. Ilario in 1965. He envisioned a modern city powered only with solar energy. In 1970, before the 1973 oil crisis, working with two young architects, Bruna Moresco and Karim Armifeiz, and other collaborators, Francia developed a visionary project for a model energy-independent city, with a population of about 100,000 that would rely on solar energy. He called it "The solar city — Hypothesis for a new urban structure [10][11]."

Francia was one of the first people in modern times, if not the very first, to propose the idea of the solar city so explicitly. It was precisely because of this pioneering intuition of Francia’s that GSES and CONASES decided to organize the 1st Solar Cities exhibition in Genoa, and to honour him with a 20-minute DVD [12]."

In Rome new documents and pictures on the Solar city project preserved in Brescia in the Francia Archive will be on display.

At the venue of the Central State Archive highly visible projects of solar buildings and cities headed for the future, selected either from Italy or from other countries, will be exhibited as well.

6. Conclusion

The "Italian Solar City Travelling Exhibition" is part of the “Italian National Solar Energy History Project” whose purposes are first and foremost cultural. It aims at changing the perception people have about solar energy and at envisioning that it is possible to combine the knowledge of the past, as recommended by Vinaccia, with the introduction of the most advanced solar technologies, as those pioneered by Giovanni Francia, on a large scale in a modern or future city [13].

The special symbolic environments offered by the Museum of Roman Civilization and the State Central Archive, should contribute in addressing the scientific challenges and research directions toward either the past or the future, in order to use the best of both as suggested by Norbert Lechner. The exhibition will show how to rethink our future energy infrastructure and its technological, organisational and cultural implications. How to supply solar-generated electricity, heating and cooling to homes, hospitals, schools, industries and offices, for transportation and other economic activities. It will especially focus on the importance of solar light and heat, as directly available in nature, for day lighting, heating and cooling buildings, that are the greatest consumers of energy in modern cities.

6. Acknowledgements

In writing this paper I had the benefit of accounts from and contacts with many people. I would like to thank in particular, C. F. Giuliani, M. Martelli, R. Merola, G. Nebbia, P. P. Poggio, L. Ungaro, U. Wienke and the heirs of G. Francia, and G. Vinaccia.

References

[1] K. Butti, J. Perlin, Solar Houses and Cities in the Ancient Mediterranean, Sapere 2006; www. gses. it 2008.

[2] C. Silvi, S. Los, The Italian Solar City Travelling Exhibition, Poster Presentation, Proceedings International Solar Cities Congress, Oxford, 2006; www. gses. it 2008.

[3] C. Silvi, Prima edizione a Genova della mostra su storia e futuro dell’energia solare nelle citta (First exhibition in Genoa on the history and future of solar energy in cities), Scienza e Tecnica, December 2006; www. gses. it.

[4] Videoclip, Le citta solari al Festival della Scienza di Genoa (Solar Cities at the Genoa Science Festival), You Tube 2006; www. gses. it/conases/genova. php.

[5] N. Lechner, The Future of Architecture: Sustainable Architecture, Lecture delivered in China in 2007 (private communication).

[6] L. Ungaro, Perche una mostra su mostra sull’energia solare al Museo della Civilta Romana: sinergie possibili (An Exhibition on Solar Energy at the Museum of Roman Civilization; Possible Synergies),

Seminar “I pionieri dell’energia solare incontrano le nuove generazioni (Solar energy pioneers meet new generations)”, Rome (Italy), April 4, 2008; www. gses. it 2008.

[7] C. F. Giuliani, Evidenze archeologiche e fonti storiche per la riscoperta dell’uso dell’energia solare in alcuni ambienti costruiti nell’antichita (Archeological Evidence and Historical Sources for Rediscovering Sun’s Energy Use in the Built Environment in Antiquity), Seminar “I pionieri dell’energia solare incontrano le nuove generazioni (Solar energy pioneers meet new generations)”, Rome (Italy), April 4, 2008; www. gses. it 2008.

[8] G. Vinaccia, Per la citta di domani (For the City of Tomorrow), Fratelli Palombi Editori, Volume II, Roma, 1943 — 1952.

[9] C. Silvi, The work of Italian solar energy pioneer Giovanni Francia (1911 — 1980), Proceedings ISES SWC 2005, Orlando, Florida (USA); www. gses. it 2008.

[10] Nice-Matin, L’utilization industrielle de la ‘houille d’or’ premier pas vers les (futuriste) villes del soleil, Vendredi 9 Octobre 1970.

[11] G. Francia, Solar City Project — Hypothesis for an Urban Structure, Proceedings COMPLES meeting, Marseilles, Bulletin 19, April 1971.

[12] C. Silvi, R. Torti, L. Francia, DVD ‘Giovanni Francia’s Contribution to the Idea of a Solar City’, Oct. 2006.

[13] C. Silvi, The Italian National Solar Energy History Project, Poster presentation, Proceedings of ISES Solar World Congress 2007, Bejing (China), Sept. 18-21, 2007.