Replacing pump motor

[mas985]

Which type of motor is more energy efficient (uses less KW or Amps to run a pool, Cost less)
VFD or ectro-mechanical hi-E 2-speed?

A VS will always be more efficient and cost less to run but it may not be enough to pay for the extra cost of the pump.

And does the ImPower have the same efficient as a VFD? The specs say that the ImPower has max 1.25 Output (1 HP up-rate) and 3 speeds (3450, 2600, 1725)

The ImPower would probably be more efficient than the same size two speed motor but not as efficient as a true VS. A VS has the ability to optimize the speed for the particular job, where as the IMPower is a fixed three speed, so there is less flexibility.

The cost savings for any of these options will depend on how the pump is used. With solar, you will be using the pumps at high(er) speed most of the time so may see only a small change in your power bill. However, the VS would allow you to set the speed for just enough flow rate to keep the vacuum release closed and minimize energy use.