The smart money in green building has usually been on tankless, on-demand hot water heaters that only go on when needed, but they only work really well when gas-fired, and even then can be problematic. Most people still have hot water tanks, which are pretty dumb, firing up when the water runs and the temperature in the tank drops.
The Aquanta is a water heater controller that, of course, connects via wifi to your smart phone so can see what's happening in your tank and control it from your phone. It's from Sunnovations, an company that has been in the solar hot water biz for a while and is based on their existing solar hot water control technology, so it is not a technical stretch like many Kickstarters.
Installing right on your existing water heater, Aquanta will learn your hot water usage patterns and, if enabled by you, control your water heater to match those patterns and save energy. Aquanta will give you unprecedented insight into your water heating energy and hot water use, alert you to maintenance issues, and enable its control – right from your smart device or home networking platform.
Depending on how good its insulation is, a hot water heater normally is firing all the time to keep the water at the same temperature. However a smart heater will learn that nobody takes showers at three in the morning and that there is a big rush at 7AM when everyone is getting ready for work. There is a lot of thermal lag in an hot water tank, so there are probably limits to how smart it can get about adjusting to demand, but there are obvious patterns that can be learned. We are, after all, creatures of habit.
There are new efficiency standards for water heaters coming into force next April 15 that will make both gas and electric water heaters a lot more efficient- and expensive. Gas heaters will probably all have condensing burners like high efficiency furnaces, and electric heaters will probably all be heat pump based. $ 150 spent on the Aquanta might be a more cost-effective way to go. Interesting idea with a ways to go on Kickstarter.