Save electricity with a 2 speed pool pump
 

Great website, I'll try to contribute with what I know.
Swimming pools are awesome, but their upkeep requires a lot of power. Most pools are built with over sized pumps that use more power and waste energy because of head pressure and pipe resistance. For instance I have a 10,000 gallon pool it is common to see builders match up 1.5 hp motors for this size. I currently run a 3/4 hp pump that moves enough water for 4 return jets to break the surface of the water or move back the pool cover. In theory because I'm moving half water than the 1.5 hp I would need to double my run times. In practice I get by running the pump intermittently for 4 hours a day.

My current project is to replace my single speed 3/4 hp with a 2 speed 3/4. Low speed is 1/2 the rpm and flow but uses 1/8 electricity. This reduction is because the head loss from pipe resistance is minimal at lower speeds. I currently have a replacement motor on order, Ao Smith Century B2890. This motor line has a more efficient low speed than traditional motors. Price for the motor shipped is $270 and the energy savings should pay for itself within the first year.

That sounds like a good idea. How much electricity will that save you per day?

Last year I got this pump. On lowest setting it uses 65 watts it is 240 volt .
I run it on low power.
I now run it 12 hours a day but it has saved so much power.
Speck Pumps - Badu EcoM3V - Variable Speed
http://usa.speck-pumps.com/pdf/Techn...coM3V_tech.pdf

How many watts does Ao Smith Century B2890 use on low?
That is a good price on that motor.

Just power factor correcting the pump can save up to 30%.
But typical 220v motor setups see about a 5% savings.

PFC doesn't offer much benefit in residential.

Have you actually tested it?

I have seen new digital power meters with an "80% P.F." kwh counter.
So even if all my tests were wrong, some day we will all get a shinny new kwh meter and surely they will bill more for whats on the "80% P.F." counter.

This site has a very good operating cost comparison of various pumps and their operating wattage. It shows monthly costs between $8-$30
It also has some great info on pipe sizing and head loss.
A lot of other factors weigh in with pool pumps but traditionally 1 hp =745 watts. Which can give you an idea of the benefits of proper pump sizing vs oversizing.

Energy Efficient Swimming Pools
https://sites.google.com/site/maspooltools/spreadsheets

Multispeed PSC motors don't save as much money on "low" and buyign a smaller single speed pump. Currently running a 1/4HP pump on my own pool (uses 250W) for (2) 4hr shifts per day.

Has anyone thought about lifting the water with an over powered pump and then gravity feeding the water through the filter?
The pump will use just as much power as ever when its running but it will only have say 20 feet of pump head and it will run maybe 5 or 10% of the time. Controlled by a float switch. One switch turns it on, 2 turn it off (for backup).