A new energy graph is very cool! It would be even cooler to get cost graphs next 
It would be so helpful for any kind of optimizations in case of multiple or changing tariffs. In our energy market very cheap price often means surplus production and more consumption helps to keep grid stable. Optimizing only for kWh consumption is a way wrong for the whole system.
Many users here have quite smart setups for car charges, heating and water boiler automation and so on based on energy price but HA still miss good built-in overview to visualize the final cost/saving.