Xcel Energy subsidiary Southwestern Public Service has completed a major transmission project in Texas and New Mexico, part of a multibillion effort to expand and modernize the region’s grid.

The $400 million, three-year project came in 9% under budget and involved the construction of 240 miles of 345-kV transmission lines from SPS’ TUCO substation north of Abernathy, Texas, to the China Draw substation southeast of Carlsbad, N.M.

The TUCO-China Draw project is part of Xcel’s Power for the Plains initiative, designed to update the region’s grid to improve reliability, meet demand and provide new renewable energy outlets. SPS’ network comprises more than 7,000 miles of high-voltage lines that cover the Panhandle and South Plains regions in Texas, portions of eastern and southeastern New Mexico, and also reach into the Oklahoma Panhandle and southwestern Kansas.

Xcel said much of the initiative’s work has focused on strengthening its connections with SPP, enabling it to tap abundant and economical sources of electricity that have lowered purchased power costs by as much as $60 million annually. The investments have quadrupled Xcel’s import capabilities and boosted the region’s power supply during peak demand months, the company said.

“Xcel Energy is committing a large amount of capital as a sign of our faith in the economies of eastern New Mexico and West Texas,” said David Hudson, president of Xcel’s New Mexico and Texas operations. “We are focusing resources on projects that will not only provide our communities the safe, clean, abundant and affordable power they require for development but also keep the cost of electricity at or below the rate of inflation. The Power for the Plains transmission enhancement program is a foundational aspect of that strategy.”

The region’s energy and agriculture economies are expected to expand in the coming years, though the crash in oil prices has dampened some of those projections.

Xcel said it has invested more than $3 billion in grid and power generating improvements in Texas and New Mexico since 2011. That includes an expansion of wind resources that puts the company on track for an 80% reduction in carbon emissions by 2030.