Hi Kevin; Welcome to Permies!
Well Kevin, I'm not understanding correctly what your thinking/hoping for here?
I'll give you my thoughts and we will see how close I get.
I could be wrong about this but, a spa motor is a
water pump correct?
It uses 110 or 220 power to turn impellers that pressurize the water coming out of the jets.
It does not produce electricity as it turns.... but instead uses electricity too turn .
What were you hoping for ?