As Greg Gaudet explains, the water heaters are made by Marathon and are super insulated, allowing water to be heated to 77 degrees C under the control of Summerside’s smart grid. The water heaters lose only one-quarter of a degree per hour and have mixing valves on top to mix the super hot water with cold water to ensure the home gets hot water that’s not too hot to use, about 60 degrees C. Photo David Dodge, GreenEnergyFutures.ca