THREE element electric hot water heaters, with the bottom element controlled by the utility (to manage and use excess off-peak grid power rather than dumping that power.)
Load management/demand-response is becoming a really hot topic among grid operators looking for higher grid reliability and handling intermittent zero-marginal-cost sources outside of their direct control such as wind power and solar. There have been instances in the past year when the wholesale price of electricity has gone NEGATIVE during off peak hours in places like Iowa or parts of Texas with higher penetrations of wind power, forcing baseload generators to pay to keep putting power on the grid, which really messes with their business model. Widely distributed power-dumps like hot water heaters would lower the cost of power further in those places, and make better use of the overall power generation mix on the local grids.
Subsidizing these smart-heaters to take on excess power when available to the extent that it's cheaper than building & operating low capacity-factor peak generators, and everybody on the grid wins financially.
Load management/demand-response is becoming a really hot topic among grid operators looking for higher grid reliability and handling intermittent zero-marginal-cost sources outside of their direct control such as wind power and solar. There have been instances in the past year when the wholesale price of electricity has gone NEGATIVE during off peak hours in places like Iowa or parts of Texas with higher penetrations of wind power, forcing baseload generators to pay to keep putting power on the grid, which really messes with their business model. Widely distributed power-dumps like hot water heaters would lower the cost of power further in those places, and make better use of the overall power generation mix on the local grids.
Subsidizing these smart-heaters to take on excess power when available to the extent that it's cheaper than building & operating low capacity-factor peak generators, and everybody on the grid wins financially.