MAPLE GROVE (AP) - Minnesota's second-largest electricity producer is increasing wholesale rates for the seventh consecutive year.

Great River Energy's board of directors approved an average increase of 4 percent for its 28 local power cooperatives -- including Stearns Electric -- which serve 645,000 customers.

The Maple Grove electric power producer's chief financial officer, Larry Schmid, says the main reason for the 2013 increase is maintenance at two of the cooperative's coal-fired power plants in North Dakota, estimated to cost $30 million.

Schmid also cited a drop in power demand as a reason for the increase. Co-op officials say the rate increase will cost a typical residential customer an additional $2 to $3 a month.

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