Short answer: Thermodynamics dictates that the energy you use moving this heat will always be less than the useful work you can get from it, and that’s before you get into all the inefficiencies that exist in a real process.

Slightly longer answer: According to the second law of thermodynamics, you can never create any kind of machine (or group of machines) such that you can move heat from a cold spot to a hot spot without doing work. Now if you could use your air conditioner to generate energy in the way you describe, you would be able to use that energy to run the air conditioner, generating energy ad infinitum without ever inputting work from outside the system. This contradicts the second law of thermodynamics, so you can’t do it; the power you get from your air conditioner contraption will always ve less than the power it requires to run.