Wind Energy Potential

Wind sites are rated by class (from 1–7) which represents some average wind power density (in units of watts per square meter). In general, wind speeds at height 100 meters above the ground are 20-30% higher than at ground level. Generally speaking, wind farms would be located in Class 3 sites and above. The table below summarizes the various attributes as a function of class.

Broad averages for the US are shown below:

Some features about the US distribution of wind source are the following:

The American West has many large-scale regions of Class 4 and higher. Detailed wind resource maps for individual states are below.
North Dakota has the highest wind resource, per state, in the US.
Northern Texas has significant resource and that is where most of the 5000 MW of installed capacity is located.
The American Southeast has poor wind resource (which is one reason that there is consistent air quality problems in this region).
Arizona is a dead wind resource (but, of course, abundant in solar resources).
Oregon has large areas of Class 4 wind resource (see more below), but note that the Willamette Valley is mostly all Class 1.

Another way to visualize the resource is to examine the percentage of land, on a state by state basis, that is rated at Class 3 and above. The red areas in the map below are clear indicators of where to plant wind farms:

Class 3 sites and above:

Alaska also has a serious wind resource:

Well, it's not enough to know that the wind can blow hard in some location. The bigger question is related to the reliability of the wind source (Is it blowing all of the time? Some of the time? or just a little while ...?). The following is the wind reliability map for all Class 3 and higher sites, rated on this kind of qualitative scale. Again, red colors are the best and there are many large scale areas in red:

The Medford area in Southern Oregon
The Interstate 80 East West area in Southern Wyoming
A large U-shaped band in Eastern Montana
Much of Nebraska/Kansas
Eastern half of Iowa
Mountain ridgelines in Pennsylvania
The Southern Gulf Coast of Texas
Much of Alaska

Alaska is good:

One of the more interesting natural wind alleys in the world is on the Island of Maui. The broad lowland "valley" separating the two halves of Maui has steady 20-30 mph winds blowing through it. Maui could easily create enough electricity to power the entire island by developing this resource:

Below are gridded maps that show the wind class site per grid for various states. These are important for identifying present and future wind deployment. However, in the US, the current rate of wind deployment is limited by access to extant transmission line infrastructure. This is the single biggest reason for why the robust wind resource in the Aleutian Islands and in North Dakota is currently being harvested with 0% efficiency. There is simply no access to the grid at these locations. Therefore, unless we get more creative in the future about extending the grid, or using hydrogen produced on site and then transported (through pipeline, train, whatever) as a carrier of electricity, we will never properly develop the innate wind resource in the US.

Oregon