The Water Heater as Grid Battery, Version 2.0
The Water Heater as Grid Battery, Version 2.0
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...adding an extra heating element at the bottom of the tank, where the cold water sits, allows utilities the ability to turn it on and off at will, while leaving the hot water at the top of the tank at a stable temperature, he said.
That solves four key challenges, he said -- How do we give the utility company the timing, how do we keep it safe, how do we keep water hot, and how do we keep it simple?
These are challenges that have limited todays water heater demand response programs. Traditional water heaters have some pretty strict limits on how often they can be turned off, and for how long, before the water gets cold enough to be noticed by homeowners. Likewise, programs that use water heaters to absorb excess power -- for example, to make use of wind power that would otherwise be curtailed for lack of demand -- can only crank up the heat so much before it starts to get dangerously hot, threatening homeowner safety and the integrity of the water heater itself.
This new design, by contrast, allows utilities to extend the capacity -- and take over 100 percent of the timing, Flohr said. Heres a chart illustrating how a utility using one of Sequentrics water heaters is able to use that lower heating element in ways that drive significant ups and downs in the lower, colder portion of the tank, while keeping water temperature at the top of the tank stable:
From Real-Time Grid Support to Long-Range Wind Energy Storage
What can be done with a utility-controlled water heater with this kind of range and flexibility? A new ...
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