Upper Midwest utilities have identified improvements needed in the region's high-voltage electricity transmission system to ensure they can deliver the renewable energy necessary to meet Minnesota's renewable energy milestones beginning in 2016.
Minnesota's 2007 Next Generation Energy Act requires that utilities increase renewables on their systems in increments and, by 2025, deliver 25% of their energy from renewable sources.
It is estimated that 4,000 MW to 6,000 MW of renewable energy will be needed to meet Minnesota's renewable portfolio standard. North Dakota, South Dakota and Wisconsin have 10% by 2015 renewable energy targets.
The utilities identified transmission needs in studies published this week. The studies confirmed that replacing a 60-year-old, 230 kV line that runs between Granite Falls and Shakopee with a double-circuit, 345 kV line would unlock up to 2,000 MW of transmission capacity from wind-rich areas in North Dakota, South Dakota and southern and western Minnesota.
The 125-mile line would cost an estimated $350 million, with an additional $110 million for underlying system improvements.
The studies also found that further upgrades in Minnesota and the Dakotas (beyond the 230 kV line upgrade) will not provide significant benefit prior to installation of a high-voltage transmission line between the La Crosse, Wis., area and the Madison, Wis., area.
Without a line to the east of Minnesota, the transmission system will reach a tipping point, where reliability is compromised, according to the studies. The studies also found that the combination of the new 345 kV, double-circuit line between Granite Falls and Shakopee and a new Wisconsin line would increase the transmission system transfer capability by 1,600 MW, for a total increase – with the 2,000 MW from the new 345 kV line in Minnesota – of approximately 3,600 MW.
A joint transmission planning study now under way by several utilities aims to determine the need for a new transmission line between La Crosse and Madison. The study is expected to be completed by 2010.
SOURCES: Great River Energy, Xcel Energy