Yes, CAISO wholesale rates are much lower, but California also has the highest retail cost in the continental US, at over 28c/kWh. If any customer in the TVA paid that much for power there'd be riots.
Where does one even find wholesale rates for the various regional providers?
I -a complete ignoramous- spent like ten whole minutes poking around for wholesale rates. I could find documents about rates for several providers (including TVA) from many years back, complaints about rates increasing for many providers (but no actual mention of the new rates) and some governmental site that provided rates for a selected subset of all providers which included CAISO and one in Texas, but not TVA.
You'd think that this would be something that'd be very easy to find on -say- the DoE's website, but apparently you'd be totally wrong.
EIA doesn't carry TVA data because the TVA doesn't participate in open-market sales or report data to FERC. Wholesale power is auctioned in I(or R)SOs; TVA just sets rates directly during negotiations with power companies.
