Note that the above hypothesis assumes that nuclear fission is taking place in the corona of the Sun, and possibly in the chromosphere and photosphere as well.
Nuclear fission is an exothermic reaction for all elements heavier than iron, and quite possibly for lighter elements as well.
This means that energy is added to the external environment through fission of heavy elements. The Sun is an electrical accelerator. It has a greater output of electric energy than its input.
This in turn explains where the cosmic currents come from. The source of the currents that power our Sun is other stars.