To recap, I replaced my 1.5 hp single speed whisperflo motor with a two speed in April. I'm attaching a comparison of my electric consumption and billed amounts of last year compared to this year. This is by no means a best case scenario because I run my pump substantially longer than I need to - I want the water moving anytime someone is home. It probably only needs to run 5 or 6 hours a day; I used to run it about 9 hrs a day in summer, and around 5 hours in the winter. With the 2 speed, I now run it 13 hrs a day - 12 hrs on low and 1 hr on high. Here's the result - differences since April I attribute to the pump motor since not much else has changed:
This summer has been pretty hot, so the a/c has probably run a bit more than last. I was also on vacation June of last year, which is why I imagine my consumption was slightly higher this year.
Since April, we've consumed 1659 fewer kWh; at $.12 per, the new pump has saved me at least $200, or around $40 / month... Probably it is a little more, since my sense is that we're using more air conditioning this summer, but since I can't measure how much more it's running, it would be pointless to guess.
When school starts in a couple of weeks, I'll likely start cutting back on run time since the kids won't be home all day to use the pool. The new motor, timer and gasket/seal kit should be paid for in the next 2 months with the savings; beyond that, it is gravy for me Any of you questioning whether it pays to switch to a two speed can see the graphs and judge for yourselves.