Heat pump water heater cost savings – GreenBuildingAdvisor

Hi GBA Community,

I am trying to help a client determine if a heat pump water heater or a standard electrical water heater is best for their budget / long term savings.  Part of this discussion is the payback period on the HPWH up charge versus the energy savings.  I know the unit and install cost difference between the two. Now I need to determine the estimated energy cost savings of HPWH.

Can someone help me with the calculation for annual electrical energy operating cost for a typical family?

Here is what I know:

-The HPWH has a UEF of up to 3.45

-The electric WH has a UEF of 0.92

– The current average electrical rate here in Portland, OR is $0.20 KWH

The two units we are comparing are:

– State HPX50DHPTNE 50gal Heat pump water heater 63″ x 22″

– STATE 50GAL EE6-50-DURT TALL ELECTRIC WATER HEATER

What is the calculation I should be using?

Thanks in advance for the help!