Though the metaphor creates the image of something ethereal, the cloud is of course a very physical thing. Amazon Web Services, Microsoft Azure, and Google Cloud Platform all run on physical data centres that need electricity and generate lots of heat and often have energy-hungry cooling systems.
Data centres alone now account for around 2% of global energy use – about the same as the aviation industry. If it weren’t for ever-greater efficiencies that figure would be much higher, but with the advent of the Internet of Things and Artificial Intelligence the amount of energy consumed by compute is still due to increase.
While some of the bigger companies occasionally find novel ways to reuse the heat from their computing operations, these are the exception rather than the rule, and definitely don’t constitute standard practice. However, over the last few years, a new wave of companies are looking to utilise the waste heat from ever-increasing computing demands to heat homes and buildings.
Cloud = heat
There are four companies looking to take the cloud, put it in your home or building, and then use the excess heat to warm either the building itself or the water: The Dresden-based Cloud∅Heat (previously AOTerra), Dutch startup Nerdalize, as well as two French companies in Qarnot and Stimergy.