California power is awesome. Until recently, it was almost all nuclear. Those reactors take 6 hours to spin up and wind down. As demand went up for the day, they'd supplement their systems by buying power from BC. As the demand went down at night faster than the nuclear could wind down, they would pay BC to take their excess. You need to use you excess load or you blow up your grid. So BC was making money providing AND taking power at different points throughout the day.

Now, thanks largely to solar, California is generating so much power they have to pay people to take the excess during peak hours. Such an incredibly fast transformation. They still buy a bit at night, but California is quickly freeing itself from dependence on other systems.

So while they still import a bit of Hydro power, they'll be fully autonomously renewable really soon.