A few points here to clear up Mark

(1) when your little little turbine is lifting the mass it is putting in some work to get that mass to a height, and the mass is gaining some energy; when the mass expresses its increased potential energy in its return to the bottom, it is losing that potential energy. In other words, the two energy terms you are referring to have opposite sign, so the overall sum of both of them is zero. However, that does not mean that your little turbine is not expressing any power; all it really means is that the 225 gram mass moving up and down is a "middle man" that does not really enter into energy calculations (until frictional dissipation and efficiency come into play)

(2) You seem unsure about the terms "power" and "energy" and the units "watt" and "joule". To clarify things a bit (I hope) "power" is the "energy" produced/dissipated per unit time.

Watt is a power unit, while joule is an energy unit. The watt is exactly the same as a joule per second.

(3) It is unclear exactly what setup you have there, but if we suppose that your little turbine is operating an ideal winch that is reeling in a suspended mass on a frictionless rope or pulley towards a skyhook, then the power is given by the increase in potential energy per second, which will in turn be determined by the mass suspended and its vertical velocity. In other words both of the energy-type terms you mention are really just the same energy looked at in two different ways.