In March this year, a swimming pool in Devon, UK, was the unlikely setting for the most widely covered data center story (so far) of 2023.  A small immersion-cooled high-performance computing module from Deep Green is giving its heat to the swimming pool, saving Exmouth Leisure Centres £20,000 ($24,000) per year. It's not the first time data center waste heat has been harnessed. It's not even the first time it has heated a swimming pool. But Deep Green CEO Mark Bjornsgaard tells us that, this time, all the pieces are in place to make the idea mainstream.  In the future, he asks, why should the heat from any computing be wasted? Put it another way: if all our heating needs were produced by GPUs and CPUs, that would provide way more computing power than we currently know how to use.