The US State of Minnesota has issued a "comprehensive, quantitative assessment of integration costs and reliability impacts of 1500 MW of wind generation in the Xcel Energy control area in Minnesota in the year 2010, when the peak load is projected to be just under 10,000 MW". The full report, available here as a pdf file, is highly technical and dry. Nonetheless, we found a few nuggets. Like this one: "Many of the earlier concerns and issues related to the possible impacts of large wind generation facilities on the transmission grid have been shown to be exaggerated or unfounded by a growing body of research, studies, and empirical understanding gained from the installation and operation of over 6000 MW of wind generation in the United States". The key finding seems to be that integration costs will be "moderate," much of which involves grid expansion costs that will have to be met to bring 1,500 MW in wind power to the local market.