Xcel Energy said Tuesday it will purchase another wind farm being developed in North Dakota, the fourth wind power project the Minneapolis-based utility has announced in the past month.

The company said the 150-megawatt Border Winds Project near the U.S.-Canadian border will save customers $45 million over its lifetime because its entire cost over 20 years is less than the cost of purchasing natural gas and burning it in existing power plants.

It will be one of four new wind farms in Xcel’s Upper Midwest service territory, bringing a total of 750 megawatts in new wind power, roughly the output of a large power plant, and saving customers $220 million over 20 years, the company said.

“Wind energy is a valuable, low-cost substitute for natural gas and other fuels right now,” Dave Sparby, Xcel’s Minnesota-region CEO, said in a statement. “These projects will reduce customer costs by providing a valuable hedge to rising and volatile fuel prices well into the future.”

RES America Developments Inc. will develop the project in Rolette County in north central North Dakota, Xcel said.

In July, Xcel Energy asked Minnesota utility regulators to approve three planned wind projects in the region: power purchase agreements with the 200-megawatt Odell Wind Farm near Windom, Minn., and the 200-megawatt Courtenay Wind Farm near Jamestown, N.D., and the purchase from RES America of the 200-megawatt Pleasant Valley Wind Project near Austin, Minn. Those three wind farms and the latest announced project are scheduled to be in service by the beginning of 2016.