Growth and Reliability

Increases in residential and agricultural growth throughout the region have caused the existing transmission infrastructure to reach its limit, requiring investments to increase capacity into and out of southern Colorado.

The existing transmission lines in Colorado's San Luis Valley include a 230-kV line and a 115-kV line. Both of those lines originate about 60 miles to the north of Alamosa near Poncha Springs. Since both lines are in close proximity to each other, the resulting radial configuration is less than optimal from a reliability standpoint. Because of the single source nature of the existing transmission system, it does not provide the reliability benefits of redundant service.

"Without the addition of new transmission lines in the near future, voltage collapse could affect many potato producers' ability to efficiently operate their farms, and perhaps even limit potato production in the valley."
- Colorado Potato Administrative Committee

Common utility practice is to maintain continuous service to customers, even when there is an outage or failure of a single transmission element. Studies show that if there is an outage on the existing 230-kV line, Tri-State and PSCo customers are at risk of losing service. Continued residential and irrigation growth increases the overall risk.

Since the proposed project would provide another source of power to the San Luis Valley, and implement a second transmission corridor for power delivery, a significant improvement to reliability would be assured.

The additional transmission connections between Pueblo and Walsenburg also benefit northeastern New Mexico. Currently, customers can lose service there in the case of an outage of the 230 kV line between Pueblo and Walsenburg.

Southern Colorado Transmission Improvements will help improve system reliability, meet increased electric loads due to valley growth and provide improved transmission support to the surrounding region.

Growth and Reliability

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