From CBS San Francisco:

Port of Oakland officials said Friday they are encouraging more vessels to plug into the power grid while berthed to reduce emissions.

By plugging in, ships can turn off their diesel engines while at berth. More than 70 percent of ships visiting the port use shore power, but Lytle said in a statement that “our goal is to plug in every vessel.”

He said port officials are trying to identify reasons why some ships don’t plug in, such as ill-equipped ships or a lack of electrical vaults on shore.

More at CBS San Francisco