"Water heaters use about 20 percent of the energy consumed by an average American household, making them the second largest energy user in the home, after space heating." -US Department of Energy
Water Heater represents the second largest energy consumer in American households. A typical 80 gallon electric hot water tank serving a family of four will consume approximately 150,000,000 (one hundred and fifty million) BTUs in its seven year lifetime. This will cost approximately US $3,600 (at US $0.08 per KWH), not accounting for fuel cost increases. Then it will be replaced by another one just like it.
The only digital thermostat programmable water heater controller in the market