[steve86]

Well, if water usage is unlimited and BTUs are unlimited, sure.

[mrsmith]

But taking twice as long, one uses more energy. Unless the rate of using energy is half, or less.
And if the device has to be used twice... forgetabotit.

[Dr. Sivana]

Well, if water usage is unlimited and BTUs are unlimited, sure.

The manufacturers have had to put those big bright yellow stickers on dishwashers for a long time. The buyers can still get those dishwashers that take much longer, and sometimes need special extra expensive Calgon, if they choose. The electric bill will put a control on electricity abuse. Some of the new dishwashers are not only slower, but the dishes don't come out as clean, calling for a rewash.