With the increasing adoption of electric vehicles (EVs), the energy impact on the grid is less about the overall availability of energy to charge vehicles than it is about the ability to meet demand at the local level – where clustering of EVs could overstress local transformers.
Pike research predicts that by 2015, there will be 1 million charge points in the United States alone, but that drivers will still prefer the convenience of charging their cars primarily at home. They also forecast that utilities will see revenues from EV charging increase from $3 million in 2010 to $200 million by 2015. As such, the market has huge growth potential, but growth must be managed so that the supply of power at the local level is delivered reliably. This has utilities looking at ways to serve customers by tracking vehicle sales and offering customer billing programs in order to comfortably distribute the load into off-peak hours. But that still requires estimates of demand to be made, and therefore entails a certain degree of unpredictability.
However, a system developed by Southampton University in the UK demonstrates that the number of cars that can be charged overnight in a neighborhood of 200 homes may be increased by as much as 40%, while being designed specifically to prevent the overloading of a local network at any given moment. This is achieved by employing an online auction protocol.