Question

why sodium is not used to produce electricity or be a source of energy

Answer 1

Hey here is your answer!!!!
There are a few reasons why synchronous generators are used to supply electric power

Constant Voltage.
Constant frequency.
Capability to deliver active as well as reactive power.

Appropriate synchronization between all alternators to an infinite bus bar (V=1<0 p.u constant).
Hope this helps you ✌️

Answer 2

Sodium is highly reactive.It is even explosive when reacting with water.So its not safe to use sodium for energy purposes.