Electricity grids in some United States cities may require upgrades to handle increasing numbers of electric cars, according to a new study from the United States Department of Energy’s Pacific Northwest National Laboratory (PNNL). “While we don’t know exactly when the tipping point will happen, fleets of fast-charging vehicles are going to change…Electricity grids in some United States cities may require upgrades to handle increasing numbers of electric cars, according to a new study from the United States Department of Energy’s Pacific Northwest National Laboratory (PNNL). “While we don’t know exactly when the tipping point will happen, fleets of fast-charging vehicles are going to change…Electricity grids in some United States cities may require upgrades to handle increasing numbers of electric cars, according to a new study from the United States Department of Energy’s Pacific Northwest National Laboratory (PNNL). “While we don’t know exactly when the tipping point will happen, fleets of fast-charging vehicles are going to change…Electricity grids in some United States cities may require upgrades to handle increasing numbers of electric cars, according to a new study from the United States Department of Energy’s Pacific Northwest National Laboratory (PNNL). “While we don’t know exactly when the tipping point will happen, fleets of fast-charging vehicles are going to change…