Sorry, but that right there is funny.:D

In any discussion of cost for hot water, it should be considered that different usage patterns are crucial in determining the best heating method.

Chew on this one for awhile.

http://www.empowerdistribution.com/

How does it work?

Apparently, it's a simple heat pump. It takes heat from the surrounding area and transfers it to the water. The efficiency of taking heat from 70° ambient air and attempting to heat water to 130° is highly questionable. Think about the energy needed to take heat from a 70° room and dispose of it in a 90° room (outdoors). A simple 20° differential reduces the efficiency of the typical a/c unit to about 3:1. He's looking at a 60° differential............the efficiency isn't going to be better than 1:1.

Some folks at GE think they can do better than that.

Heat pump water heaters aren't in general a new idea, are they? They just haven't achieved wide popularity in the past.

I'll believe 2:1 with a 60° differential when I see it with my own two eyes.

http://www.aceee.org/consumerguide/waterheating.htm

No statement of differential in that article..........which is critical to the efficiency...........they could easily assume a 40° differential for the sake of a much better efficiency figure.

there's this thing called Kilowatt Hours....typically how they rate electrical device consumption. If you look carefully at your electronic devices you will, most likely, see a sticker that outlines the consumption of electricity.

so, to put it simple terms, say you have 10 80 watt bulbs lit up
right now in your house and kept them on 24 hours a day/night.

what you have here is 800 Kwh times 24 at roughly $.27 a Kwh
and I'd reckon it'd cost around 52 cents a day to keep 10 80
watt light bulbs on for 24 hours a day in your house. And
I'm paying high here......could be less...by a margain

Applied Energy Recovery Systems shows some data sheets that include graphs of their (claimed) coefficient of performance as a function of final tank temperature, with curves for different ambient temperatures. Here's the data sheet for one of their residential units.

I read that AERS was acquired by A. O. Smith not that long ago.

There's these fellows called "engineers" who will call you out when you put up a condescending post with factually incorrect information.

In your scenario, you're using 800 watts for 24 hours..........equating to 19.2 kwH which will cost you $5.18 per day.

They're claiming 3.4 for a 67° differential. If they actually make those figures I'd really be amazed.

The big fly in the ointment is the differential. As the water in the storage tank warms, the differential becomes less. Warming water at 100 deg to 125 deg will reduce efficiency, perhaps by a bunch.
I can see an intergrated system, where the removed heat from household cooling is transferred to the domestic hot water supply, as being cost effective-eventually. Simply returning conducted heat in the utility room to the hot water supply means the temperature of the utility room will be lower and heat transfer from the hot appliances will increase.

The big fly is the differential. But, you've got it reversed. The larger the differential, the lower the efficiency. However, you've got to be clear on the term "differential". It's the difference between the temperature of the air used as the supplier of the heat and the final temperature of the water in the tank.