I like this idea because it can be an answer to the question "What can I do?" posed by a concerned individual. Too often the response to this question is something like "Don't run your dishwasher until it is full". Most proposed solutions tend to be industrial scale or global level concepts that most of us feel powerless to implement. Devices such as Gerry is investigating may not be useful for everyone in the most extreme climates, but for many others they could be practical.