I came accross this data the other day and thought I would share it with the forum. The California Energy Commission in conjunction with PG&E, a power company in California, has collected energy efficiency data on pool pumps from various suppliers. The methodology used allows pumps from different manufactures to be compared directly. Each pump is tested under the same effective plumbing configuration. Currently, there are two curves which represent two different plumbing configurations and by my estimates, they represent the following:
Curve-A is equivalent to a 2.0" suction & 1.5" return plumbing system with 60' runs (high head loss)
Curve-B is equivalent to a 1.5" plumbing system with 250' foot runs (really high head loss)
Because the current curves represent very poor plumbing designs, pump manufactures have requested a third plumbing system which reflects a more reasonable head loss for better designed pools. I will keep an eye out for that version.
Anyway, Curve-A is probably reasonable to compare pumps and the column of most interest is labeled as Curve-A Energy Factor (CAEF). This is simply the gallons pumped per Watt-Hour so the higher the number the better and it provides a direct efficiency comparison of various pumps.
In addition, you can use the CAEF to determine the watts per turnover for any pool although keep in mind that it will be somewhat pessimistic because of the high head loss assumption but at least it will be an upper bound.
This should make it much easier to compare the energy efficiency of pumps.
[EDIT] One disturbing point on this data is that some of the test points do not lie on the published head curves which could mean that either the test data is inaccurate or the published head curves are inaccurate.
[EDIT2] The CEC recently removed the ability to directly download the Excel spreadsheet. You now have to do a web query and then export that to a spreadsheet. From what I understand, they will be adding Curve C which is more inline with a typical 2" plumbing system.