The U.S. Department of Energy on Friday proposed energy efficiency standards on water heaters it said would save consumers $11.4 billion on energy and water bills annually.
The standards on residential water heater efficiency, which are required by Congress, have not been updated in 13 years. Water heating is responsible for roughly 13% of both annual residential energy use and consumer utility costs, the DOE said.
The proposal would require the most common-sized electric water heaters to achieve efficiency gains with heat pump technology and gas-fired water heaters to achieve efficiency gains through condensing technology.
The electric one is a pretty big design change.
Interesting what industry says on it:
A group including water heater maker Rheem, environmental group Natural Resources Defense Council and efficiency and consumer advocacy organizations issued a joint statement welcoming the new standards.
Tankless water heater maker Rinnai (5947.T), however, said the proposed standards for its products were "technologically impossible" and would reduce consumer choice.
PS if you want to reduce your hot water usage, turn off the shower while you're soaping. I've got my shower down to like 1 minute of running water. Wash clothes on cold.
When it’s on. When you aren’t using it, it draws zero. I’ve had a tankless electric for 8 years, and my power usage hasn’t changed much either up or down.
Storage water heaters can also capture off peak or curtailed energy (acting as 6-12kWh of diurnal storage), so they are more than 3x better in terms of emissions.
Heat pump water heaters already exist, but I think they're pretty expensive compared to gas/resistive heat.
I wouldn't be surprised if electric tankless water heaters are indeed infeasible under this mandate. Heat pumps generally aren't powerful, and tankless heaters require enormous amounts of power while in use.
Heat pump water heaters are pretty standard in large parts of the world. They are a bit expensive to install, but with today's electric prices, they pay off quite fast.