The document discusses a new product called the Green Tub that generates renewable energy from wasted hot water in bathrooms. It notes that while people invest heavily in other green energies like wind and solar, hot water from showers and baths is often wasted. The Green Tub aims to give water a second life by reusing this hot water to create energy through a smart system that doesn't require changes to habits. The company's goals are to have everyone benefit from this technology initially and potentially power entire cities through water-generated energy in the future.