I am eager to share proof of projected 40% electricity savings, in replacement of an ordinary resistance electric water heater, with a beautiful heat pump water heater, HPWH. The installation was reported in post an exemplary heat pump water heater.
I have the unusual resource of a chart going back 22 years. This chart through December 2021 includes a full year since the water heater replacement. Savings are very evident, seeming to be the expected 40%:
From 2012 to 2018, there was remarkably little need of electricity, me living alone. Demand might have been met with a modest photovoltaic array but for neighboring trees to South, and adverse West facing of the major roof surface. For the past four years, occupancy and electricity demand have doubled, with two wonderful renters in this 1955 home now fully weatherized and modern, radon-free. It is a rare rental opportunity, managed with some originality. All utility costs are auto-paid by me. The renters pay a fixed total of $200 per month for electricity, natural gas, water/ sewer and trash/ recycling, balanced annually against actual payments. Where I see the costs and share pain, I am moved to do all possible to reduce costs; thus the HPWH.
I believe charts showing control of somewhat-voluntary expenses, can be rewarding and inspiring. And, yes, they can be dispiriting if not achieved. We wonder why monthly utility bills include charts such as this of the October 2021 electricity bill:
There are many variables of weather, behavior and occupancy, in monthly bars. Why a December spike? Visitors? October comparisons pre- and post-HPWH 278 kwh vs 390 kwh, a drop of 29%, is as expected, but probably under-states actual savings accumulated. Is that really 40%, as hoped? Sometimes the trends in this bar charting, are concrete.
From my Excel file:
See annual savings of about : ($680 - $460.) $220, a 32% reduction of annual total dollars. With $220 per year savings, $18 per month on average, the material total cost of $577 (plus my free labor) is repaid in fhree years. If the water heater serves twenty years, the present value of the annual savings, applying my Perpetuity Math, is $24,000. What a good deal!
In January 2022, find the deal quite diminished for a new investor. My $399 purchase in November 2020 was of: Rheem Professional Prestige ProTerra Hybrid Electric Water Heater PROPH65 T2 RH375-SO
Offered today at homedepot,com, $1199 after $500 discount:
Local distributor General Pacific offers this unit is $1658 minus $500 = $1158, not a compellingly better deal. Equivalent models from Rheem and from AO Smith, cost the same,
Energy Trust of Oregon in its public web site doesn't bother to promote the heat pump water heaters it subsidizes with public funds, while subsidizing flimsy LED light bulbs with far less savings potential, I think the HPWH promotion is very muddled and.is probably not working, The better bargain two years ago was a missed opportunity too, I suppose. We should be moving these by hundreds of thousands, involving DIY home owners as well as contractor allies of Energy Trust..Maybe slow motion is a factor in ballooning cost.
Failed promotion of heat pump water heaters is a big disappointment to me as an advocate of affordable rental living (my house as exemplary). I am so happy for what I have done. Who else even thinks of this?
Here post updates of the monthly electricity usage tracking, ever more clearly the dramatic savings with the HPWH. Hot water is much more nearly "free", not proportional to the number of house residents, perhaps more free than with some rooftop solar collector, that would be badly oriented, shaded by a neighboring tall Douglas Fir.
For a house that could "go solar", a heat pump water heater must be key in being solar-ready.
1 comment:
Nice article with concrete figures. Interested to see the year end numbers.
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