Catalyst Summer 2017
Final Analysis

The Role of Electric Vehicles in a Modern Grid

Photo: Kristoffer Tripplaar/Alamy Stock Photo

By Peter O’Connor

Electric cars are good for the environment, fun to drive, and increasingly affordable to own. They are also a crucial piece of a more sustainable transportation system. But future widespread use of electric cars presents a challenge: what will happen to the electricity grid if drivers get home from work and want to charge their cars at the same time?

A key piece of the answer could be a practice called smart charging that would deploy a range of technological and regulatory advances that encourage charging when it is best for the grid. UCS is helping develop best practices for smart charging, identifying ways for states, utilities, automakers, and charging station providers and other companies to better integrate electric cars and renewable energy into the grid—with significant environmental and economic savings.

Smart charging systems can automatically vary the time or rate at which electricity flows into the vehicle. By coordinating electric vehicle charging with periods of cheap and abundant renewable energy, utilities can match supply and demand, and reduce system costs. In some areas this may mean charging cars in the middle of the day, when solar panels are most productive; in others, optimal charging may occur in the middle of the night, powered by the wind. In the future, two-way “vehicle-to-grid” power exchange could become more common, with vehicles being charged by renewable energy when it is abundant, and providing surplus electricity back to the grid when it is needed.

Some of the key findings from our work on smart charging: it’s a viable strategy, offering real-life benefits; pricing electricity based on supply and demand can help avoid costly peak-hour charging; and electric vehicles offer grid operators a realistic means of storing clean energy for times of high demand.

In short, smart charging of electric vehicles has a key role to play in grid modernization initiatives happening around the country. Where the timing and power of electric vehicle charging automatically adjust to meet drivers’ needs and grid needs, adding these vehicles to the grid can reduce total system costs and pollution.

For more details, view the report Charging Smart

Peter O’Connor is an energy analyst in the UCS Climate and Energy Program; he was formerly a Kendall Fellow at UCS focusingon the integration of solar power and electric vehicles into the electricity system. Read more from Peter on our blog, The Equation.