| This seems like the sort of claim that can only be checked with math, not intuition. Without further ado: https://colab.research.google.com/drive/1fcwuNd2XANIXmKGPRN_... Basically, I got some raw data by tracing the graph in Wikipedia[0], as well as the current amount of hydroelectricity generated per day. I made the (highly pessimistic) assumption that aside from hydro, solar would be the sole energy supply for the grid by scaling the production numbers in the graph until the area under the solar curve matched the area under the total, minus the production of hydro. I don't actually know that anybody is seriously advocating for pure solar + hydro, but I wanted to run the numbers. The result, assuming cars with 85kWh batteries that can be 70% available for grid balancing (leaving ~80-100 miles of range for driving and such) is that California would need 4.3 million cars acting as grid balancing. For reference, that is just under 30% of the number of cars currently in California, where electrics made up 7% of new car sales last year. Ultimately, I think the bigger problem is battery degradation, not battery capacity. Being used this heavily for grid balancing would at least double total battery usage on a car, and apart from Tesla with their million-mile drivetrain, no other manufacturer seems to be over-designing their batteries enough to support that. Perhaps that will change if the economics of feeding power back into the grid become compelling enough. [0]: https://apps.automeris.io/wpd/ |