BOSTON (AP) — Boston University says it will buy power from a South Dakota windfarm to offset its carbon emissions in Massachusetts.

The school announced Tuesday it will buy wind power for 15 years starting in 2020 as part of a plan to reduce its carbon emissions to zero by 2040.

Although the power will be used in the Midwest, the school will receive legal credits proving it bought renewable power.

University President Robert Brown says it's "a major step" in the school's plan to become more environmentally friendly.

The school's "climate action plan" approved last year also calls for $141 million in capital improvements over 10 years to cut greenhouse gas emissions.

Officials say supporting renewable power in the upper Midwest is helpful because its power grid relies more on fossil fuels.