Getting electric vehicles recharged

By Greg Whiting

Where's the electricity for electric vehicles going to come from? Why has California recently asked people to stop charging electric cars and, at the same time, changed regulations so that only electric cars will be sold there in 2035?

As EVs grow to a larger fraction of the vehicle population, they can be expected to help, not hurt, both power availability and grid stability.

Most electricity for EVs can be produced simply by running existing power plants more. During non-peak hours, generation capacity is available, but not used. For example, in the northwest, about 200 "peak" electric-use hours for the 8,760-hours in a year have historically occurred during early mornings on winter days, when heaters are running and people start turning appliances and lights on. In Florida, the peak may only occur for about 40 hours a year, during heat waves when most air conditioners run at the same time. EVs can be charged by using that unused generation capacity. EVs reduce energy costs, energy use and carbon emissions relative to gas and diesel vehicles even when coal and gas are part of the electric generation mix.

To the extent additional generation capacity will be needed, power plants of any type can be built. The financial justification for new power plants will include the increased electricity sales for EVs. Electric utilities will make money by taking market share away from gas stations. Power plants added to increase capacity for EVs will increase capacity for other electric uses.

On-peak charging can be addressed through market-based demand management programs. Such programs have been proven via several decades of experience in the southeast, where utilities use financial incentives to get customers to voluntarily help control air conditioning demand peaks.

Systems are being tested to enable utilities to use EVs to supplement peak hour electric supplies via reverse charging, i.e., supplying energy to the grid from voluntarily participating EVs. "Vehicle to grid" payment rates would be structured, just as current utility conservation programs are, to reduce costs for all utility customers, not just EV owners.

For transmission and distribution (T&D), EVs will use the existing grid. They will not require a completely new grid. A Level 2 (240 Volt) EV charger is, electrically, about the same as a clothes dryer. Utilities easily accommodated those when they were introduced.

Required T&D investments will include chargers at homes and in public areas and some transformers. New transmission lines will be developed along with new power plants they will serve. The private sector can fund most of this. Utilities can fund their part by selling energy for EVs. Some government funding is likely, e.g., for fast chargers in remote locations. This is comparable to funding paved roads before everyone in the country had a car.

Independent of EV growth, California, Texas and all other states, are working on generation and T&D upgrades. These upgrades will address system resilience, population changes and increased electricity use. Recent conservation requests in California and Texas have not been for all hours, but for short-term local system peak hours, which have been exacerbated by hot weather and by fire safety considerations in California. EVs are likely to make situations like these better, not worse, by helping to finance new generation capacity and by providing utilities with new peak management tools.