The Upper Peninsula of Michigan is a unique landform protruding from Wisconsin into three of the five Great Lakes. It is bordered on the north by Lake Superior and on the south by Lake Michigan and Lake Huron. The western Upper Peninsula includes a second smaller peninsula, the Keweenaw, which extends into Lake Superior providing a long western coastline.

The land hosts an interesting array of hills, valleys, and moraines.  In the Precambrian times, massive lava flows in this region caused the earth’s crust to sag under their immense weight. This sagging formed the synclinal basin presently occupied by Lake Superior. This immense body of water allows wind to reach the western shores of the Upper Peninsula basically undisturbed and moving at good speeds. The Keweenaw Peninsula was uplifted by folding and faulting and its rock bends below Lake Superior and reappears as Isle Royale to the northwest. This folding and faulting has created a ridgeline along the western edge of the Keweenaw that disturbs the wind’s access to areas further inland, thus decreasing inland wind potential. 

Intense glacial action is also evident in the area, resulting in steep slopes along some ridges. These high terrain features can accelerate the flow of wind. An approaching air mass is often squeezed into a thinner layer, causing it to speed up as it crosses the summit. Maximum acceleration occurs when the wind blows perpendicular to the ridgeline. Isolated hills and mountains may accelerate the wind less than ridges because more of the air tends to flow around the sides. The downward, or lee, side of high terrain features is not a particularly good place for a wind turbine due to the presence of high wind turbulence.

Weather patterns in the western U.P. are largely determined by the Alberta Clipper, a wind system that flows from the upper northwest of North America and across the northern United States. This means that wind reaching the western U.P. generally flows across the western portion of Lake Superior.

The area's high average annual snowfall is mainly due to lake effect snow generated when cold air blowing toward the area encounters the rising moisture of Lake Superior.  The average monthly temperatures recorded in the area range from a high of 83.1 degrees (F) to a low of 14 degrees (F). The highest recorded temperature was 112 degrees (F) and the lowest recorded temperature was minus 51 degrees (F).

The western Upper Peninsula is heavily forested, presenting major challenges to the development of large commercial wind farms.  To avoid the turbulence caused by the tree line, wind farms with many turbines would require that large tracts of wooded land be cleared.  Even though hills, plateaus, and bluffs provide high ground on which to raise a wind turbine, many of these sites are also heavily wooded.  Also, due to the small amount of agricultural land in the western U.P., there are very few, if any, areas where a wind farm with large numbers of turbines could be located with clearing some wooded land.

For small wind farms, employing no more than a few turbines, appropriate sites are more available.  In addition, there are many areas appropriate for smaller scale residential turbines, which allow individuals to generate their own electricity.

A water surface is much smoother than land cover, so air flowing over water encounters very little friction. The best shoreline sites are those where the prevailing wind direction is perpendicular to the shore.  Therefore, given the west-to-east direction of prevailing winds, the highest wind potential in the area exists along the western shore of the U.P. This shore borders Lake Superior and runs from Copper Harbor in the north to Little Girl’s Point in the south.

In addition, when regional winds are light, as they might be on a sunny summer day, local winds known as lake breezes can develop because the land and water surfaces heat up at different rates. Given that land heats up more quickly than water, the warm rising air over the land is replaced by the cooler air from over the water. This produces an on-shore breeze that is typically 8 to 12 mph or more. At night the breeze stops or reverses direction, as the land cools more quickly.

Development of an offshore wind farm in Lake Superior is possible, but the the expense of constructing towers and maintaining turbines in deep water would affect feasibility. Currently, offshore wind farms are probably not commercially feasible.

Although the U.P. occupies one-third of Michigan ’s total land area, it is home to only 3% of its population. With only 300,000 people living in the entire U.P., the area is quite sparsely populated. With so much land and so few people, towns are not very large and are well spread out.  When coupled with the heavily forested land cover, it allows for many areas that are out of sight.

The mining and timber industries are what brought the first wave of non-native people to the area, including immigrants from many different countries. Each has left a bit of their culture on the area. Today, tourism is a main industry in the western portion of the Upper Peninsula, with both summer and winter recreational opportunities being an important draw.

Wind Power in the Western Upper Peninsula