Panasonic has announced a batch of 16 heat pump water heaters that will save energy and keep your water temperature constant by using a human presence sensor. The mechanism is able to reduce power consumption by up to 35% in winter, which is when you use the most.
If you’re in Japan, you can get one by July 10. Just don’t expect it to be affordable. The HE-KU37CQS model has a tank capacity and hot water supply pressure of 370L and 280kPa and retails for about $8,211. Seems like a cruel joke, but at that price they are selling you the remote control separately.