Probably, Yes, & No
Meaning, some sort of cellular manipulation, genetic engineering, or other biological magic could probably do this.
If it was done, the chloroplasts would generate energy for the being in which they resided and through the same mechanisms that they generate energy for plants (e.g. they'd produce sugars).
Unfortunately, the amount of energy chloroplasts produce is pitifully small compared to what we need.
Consider that it takes a corn plant, roughly the dimensions of a human being, 2-3 summer months to produce 1-3 corn cobs. How much energy do these corn cobs possess in terms of keeping a human active, a couple of hours?
Or looked at another way, it takes a minimum of an acre of intensive plant farming to generate enough energy to keep a human alive. A human body has roughly $ 1.7 m^2 $ of surface area, only 1/2 ($ 0.85 m^2 $) pointed in one horizontal direction or another. However, due to our body orientation, the Sun mostly shines down on our heads which presents a much smaller surface area available for absorbing energy (estimated at $ 0.25 m^2 $). Meanwhile an acre of crops covers about $ 4050 m^2 $.
By that comparison, the chloroplasts might produce 0.06 % of what a human body needs for survival.
There is a reason that plants aren't mobile. They don't produce enough energy to move.