As digitalisation progresses, so does the flood of data. The Internet of Things, or 'Big Data’ requires ever more performance and storage space. And so, large data centres are becoming indispensable around the world – but they are massive energy guzzlers. Cloud&Heat shows how waste heat from a data centre in the former European Central Bank building in Frankfurt can be used for heating. The start-up’s patented hot-water direct-cooling system saves 160,000 euros in total costs and 560 tons of carbon dioxide – per year. An idea that intelligently combines digitalisation, economy, and sustainability.