Shopping malls could be in danger of losing their cachet as bastions of gratuitous consumerism and excess if they all go the route of the Ciudad de las Comunicaciones. Located in Madrid, this office complex sports an enormous array of 16,600 solar panels on its 1km long rooftop, giving it the capacity to generate 3 megawatts of energy. Result: savings of 15% on climate conditioning in winter, and 34% in summer, plus an unknown (but non-trivial) amount on lighting. Investment on the project was 21.8 million euros. [GT] Office complex - Ciudad de las Comunicaciones [via Metaefficient]