In general a third party provider may use alternative energy sources. It’s heavily implied that Eversource is increasing prices because of the increased price of natural gas making electric generation more expensive for them.

But, if you have a nuke (to pick one) heavy provider, theoretically they’re decoupled from that cost. They could keep their prices lower in an effort to gain market share (or jack them up too because increase shareholder value.

(I did some analysis specifically on Constellation earlier…)