Depending on your electric company / coop the instant heaters can cost more than their labels suggest. My coop has announced that they are looking for ways to charge not only by what month you use the electricity in and the time of day it was used, but now they are wanting to charge more for instant high usage. Their main example was the tiny water heaters that only heat water as it is needed. Some how the tiny heaters suck up lots of energy at one time and none most of the time. Supposedly that sudden usage costs more than the gradual usage. I'm not buying it. I guess I think it a wise idea to contact your electrical supplier and see what they have planned for the instant water heaters.
Over all I like the idea of saving space and not running out of hot water.
Over all I like the idea of saving space and not running out of hot water.