You can charge your residential or utility battery storage from the imported hydro or solar depending on spot prices, no need to consume immediately at that time.

Transmission is crucial for flexibility in balancing generation and consumption, as well as optimizing storage utilization. You can also assume there will be times you’ll throw away (curtail) clean energy as it’s cheaper than it would’ve been to store and then deliver it, but you still need that capacity available at other times (seasonal variability).