Studies and Reports > 2009 MN Biennial Report > WC Planning Zone > Needs: 6.4.16 Wakefield –Paynesville—Maple Lake Area

To inquire about this project, click here.

6.4.16 Wakefield –Paynesville—Maple Lake Area

Tracking Number. 2009-WC-N5

Utility. Great River Energy

Inadequacies: The Wakefield – Paynesville – Maple Lake area includes a 34.5 kV and 69 kV transmission system that serves the area from the Wakefield and Dickinson 115/69 kV sources and Paynesville 115/34.5 kV source.

Studies including GRE’s latest long range plan show that this area will experience low voltage problems around Watkins and transmission line loading issues on the Maple Lake to Watkins 69 kV system. The area between Wakefield and Watkins experiences low voltage problems for the loss of the Wakefield 115/69 kV transformer or the Wakefield Fairhaven Tap 69 kV line. These outages also cause the Maple Lake to Annandale 69 kV line to overload in the short term. The Maple Lake to Watkins 69 kV system is also known to have reliability problems due to age.

A map of this area is shown following the discussion.

Alternatives: Four alternatives were considered to address the low voltage and line overload problems in this area. The following are the alternatives:

1) Establish a 115/69 kV, 70 MVA source at Watkins

2) Construct a new 69 kV line from Paynesville to Watkins

3) Rebuild the Maple Lake to Watkins 69 kV line with 477 ACSR conductor

4) Distributed Generation

Analysis: All three alternatives were evaluated and were found to alleviate the low voltage and line loading issues in the area. Alternative 1 establishes a 115/69 kV source at Watkins, tapping the Wakefield to Big Swan 115 kV line. While this source addresses the low voltage problems in the Watkins area, it will not address the low voltage problems in the Kingston area that will arise in the long term for the loss of the Watkins to Kingston Tap 69 kV line.

Alternative 2, construction a new 69 kV line from Paynesville to Watkins, introduces the Paynesville source to the Watkins area and provides opportunities for 34.5 kV radial distribution substations, such as the Meeker Electric Cooperative (MEC) Paynesville Substation and Xcel Energy’s Eden Valley Substation, to be upgraded to 69 kV when an upgrade is required. Similar to Alternative 1, this alternative doesn’t address the long term voltage problems in the Kingston area that will be caused by the loss of the Watkins to Kingston Tap 69 kV line.

The Maple Lake to Watkins 69 kV system is old, has high impedance conductors, and has had reliability concerns. The high impedance conductors on this line cause a considerable voltage drop along the line. Alternative 3 includes rebuilding this line with a 477 ACSR conductor in multiple phases with Phase I being the rebuild of the Maple Lake to Annandale 69 kV line portion. Unlike the other two alternatives, this option improves the reliability of the Maple Lake to Watkins 69 kV line and provides a better voltage profile for the Kingston area during the loss of the Watkins to Kingston Tap 69 kV line. This option, however, doesn’t address the long term reactive power needs of the Watkins area. Thus, as these options have different benefits to the area, a combination of the above alternatives is preferred to address the transmission deficiencies of the area.

Distributed generation is not a desirable option in this area since the existing 69 kV system from Maple Lake to Watkins is aging and has reliability concerns. This line needs to be rebuilt to improve reliability and voltage of the 69 kV system regardless.

Schedule: Xcel Energy plans to reconductor the Maple Lake to Watkins line starting in 2010. The work will occur in different phases. Phase 1 of this project rebuilds the Maple Lake to Annandale 69 kV line. Reconductoring of the rest of the line from Annandale to Watkins will be carried on based on budget availability and need for voltage improvement in the area. GRE will start building a new 69 kV line from Paynesville to Meeker Electric Cooperative’s new 69 kV distribution substation called Rice Lake. The existing 34.5 kV Paynesville distribution substation will be moved about 1 mile north in the 2012 timeframe and will be called Rice Lake distribution substation. This substation will serve all loads that are currently served from the Paynesville 34.5 kV substation. GRE anticipates that the rest of the 69 kV line from Rice Lake to Watkins will be constructed in the 2020 timeframe. According to GRE’s latest long range plan, the Watkins 115/69 kV source will be required in the area in the 2030 timeframe. Re-study of the long term 69 kV constructions, including need for the Watkins 115/69 source, may be needed depending on changes in the load growth of the area.

Click here or on map below to download high resolution PDF map.