IBM, together with Honda and the California utility Pacific Gas & Electric, is about to start trialling a smart-charging system to charge a fleet of electric vehicles without disrupting the grid.

The electricity grid already has the capacity to accommodate millions of plug-in vehicles. The problem arises if there is a concentration of electric vehicles charging at the same time. Even as few as four or five vehicles charging at the same time in nearby locations could cause local stability problems.

IBM’s smart-charging system monitors a car’s battery charge state along with the grid load. Consumers indicate when they want their car to be fully charged  – say by 6 a.m. The system then schedules the charging, taking into account other loads on the grid, to have the car ready by the specified time.

The project will also test smartphone and web-based apps for consumers, giving them an estimate of charge time and the location of charging stations,. and will provide utilities with information about consumers’ charging patterns and requirements..