As electric vehicle use rises, utilities need to adopt a flexible rate structure to avoid overtaxing the grid. : According to the Edison Electric Institute, seven million zero-emission vehicles will be on American roads by 2025. This could have significant impacts on the grid as charging one electric vehicle (EV) is nearly equivalent to adding three houses to the power system. Utilities must implement rate designs to efficiently manage electricity demand. Rate structure options include demand charges, time-of-use rates and dynamic pricing.