NREL study finds that managing EV charging complements grid-connected renewables

The transportation sector is the largest source of carbon emissions for our country, which is why the National Renewable Energy Lab (NREL) is conducting transportation decarbonization research on many fronts, including the ways in which the grid of the future can benefit from EV managed charging.

EV managed charging coordinates charging based on people’s travel needs, electricity supply, and grid conditions. This flexibility could be especially valuable for the grid as it transitions to high shares of variable renewable (VRE) generation, like solar and wind.

An NREL team recently completed a literature review on the potential value of EV managed charging, the findings of which are published in an Energy & Environmental Science article.

Understanding that the large-scale adoption of EV charging can have large-scale consequences for energy and electricity systems, including great opportunities for significant load growth. NREL reports that it found that unmanaged EV charging can stress existing grid infrastructure, possibly leading to operational, reliability, and planning challenges.. A solution is effective charging management, which offers significant benefits including support for power system planning and operations during normal and extreme conditions.. The report acknowledges that the costs of enabling these services must be weighed against the benefits they provide.

The report discusses the value of demand-side flexibility in the evolving power system and it states that it’s often more efficient to have demand match supply than the more traditional approach of making supply match demand. Managed EV charging can provide the flexibility needed in a distributed response (DR) system.

Any form of EV managed charging requires communication between the utility and the vehicles. In some approaches, the communication is one-directional and less frequent. More complex implementations require two-way dynamic communication.

“Managed charging can be a tremendous resource for the grid but there are trade-offs to solutions at different levels of commercial readiness,” said Matteo Muratori, NREL analyst and principal investigator of the study. “Some solutions offer a wider range of grid services and value streams but require increasingly complex communication and control technology and demands on users, which come with a cost.”

Managed charging complements variable renewables

NREL researchers found significant benefits of EV managed charging, including decreased emissions, improved reliability, supporting large-scale deployment of variable generation (such as wind and solar), and lower power system costs. Managed charging is valuable in systems with high levels of variable renewables because it provides the flexibility to match supply and demand. Overall the report found that managed EV charging can support and complement the expected large-scale VRE deployment, with implications for long-term planning.

The value of managed charging will change over time and additional data are needed to estimate future needs and constraints.