Eau Claire Area Study Northern MAPP Subregional Planning Group January 11, 2007 Daniel Kline

3 Outline  Description of Area  Various Load Serving Problems  Study Methodology & Initial Alternatives  Final Alternatives  Final Recommendation  Questions

4 Description of Area  Located in West-Central Wisconsin  Eau Claire & Chippewa Counties  About an hour east of Twin Cities on I-94  Area fed by 345 and 161 kV sources and 69 kV transmission  Load belonging to NSPW and DPC  Lines belonging to NSPW and DPC

5 Description of Area  Area NSPW Sources:  Eau Claire Substation  Seven Mile Substation  Wheaton Substation  Chippewa River Generation  Area DPC Sources (2011):  Elk Mound Substation

6 Description of Area  Area NSPW Loads (2011):  Jeffers Road (27 MW)  Truax (41 MW)  Otter Creek (35 MW)  London (42 MW)  Hallie (31 MW)  Area DPC Loads (2011):  Seymour (4 MW)  Elco (4 MW)  Equity (3 MW)  Washington (3 MW)  Brunswick (2 MW)

7 Description of Area

8 Description of Problems  Eau Claire transmission system is designed to rely upon Eau Claire 69 kV bus  Eau Claire 161/69 kV transformers are heavily loaded and cannot endure loss of parallel bank  Eau Claire substation is crowded and not enough space exists to increase the size of the existing 161/69 kV banks  Increasing size of banks would require moving to non-standard bank sizes

9 Description of Problems  During peak load conditions, 69 kV system to north overloads  DPC system served out of Seven Mile overloads for various contingencies  High load growth throughout area  Interconnection requests at Hallie Substation requrie auto-transfer scheme to be turned off  Area transmission system highly susceptible to fluctuations in Chippewa River generation

10 Study Methodology  2006 MAPP Series Cases  2011 Near-Term  2016 Out-Year  Worked with DPC through Joint Planning Process

11 Study Methodology  Assumptions and Adjustments made  Assumed Chisago Line Project not in service in 2011 (In-service in 2016)  Included New Richmond Area Load Serving Study projects  Assumed Monroe County – Council Creek 161 kV line in service in 2011  Moved Riverview load to Hallie

12 Study Methodology

13 Study Methodology  Base Case Results

14 Initial Ideas  Reconductor double-circuit 69 kV corridor between Eau Claire and Chippewa Falls  Convert 69 kV double-circuit corridor to 161 kV  Add circuit breakers at Otter Creek  Shift load from 69 kV system to 161 kV system

15 Final Alternatives  Alternative 1  Convert entire 69 kV corridor from Eau Claire to Chippewa Falls to 161 kV  Convert all 69 kV load along corridor to 161 kV operation  Alternative 2  Extend 161 kV from Presto Tap to Hallie Substation  Place US Rubber on loop from Eau Claire Substation  Place Chippewa Falls on loop from Wissota Substation

16 Final Alternatives  Alternative 3  Convert double-circuit 69 kV corridor to single- circuit 161 kV  Convert Hallie to 161 kV operation  Place US Rubber on loop from Eau Claire Substation

17 Final Recommendation  Alternative 3 Recommended  Reterminate Wheaton to Presto Tap 161 kV line at Eau Claire Substation  Tear down existing 69 kV double-circuit line between Eau Claire and the point where line intersects with Hydro Lane – Red Cedar 161 kV line  Construct 161/69 kV substation (50 th Avenue Substation) where double-circuit 69 kV line intersects Hydro Lane – Red Cedar 161 kV line  Construct single circuit 161 kV line from Eau Claire to 50 th Avenue Substation  Convert Hallie Substation to 161 kV operation

18 Final Recommendation

19 Final Recommendation  Very robust service provided to area north of Eau Claire  Off-loading of Eau Claire 161/69 kV transformers buys approx. 12 years of life expectancy  Strong corridor to support Chippewa River generation  Increased Load-serving north of Jim Falls

20 Next Steps  Funding requested for 2007 budget process  Continuing to investigate ways to off-load 69 kV network out of Eau Claire  Eau Claire Area Long-Term Study to be completed with DPC during Summer 2007