Montana Wind Power Map
The Montana wind power map shows areas that are predicted to have high wind
speeds and therefore high amounts of wind power. This map is better used to
identify high potential areas for wind prospecting than for actually siting
turbines. The data set on wind power was provided by the National Renewable Energy Laboratory
(NREL) and the map was prepared by Montana's Natural Resources Information
System (NRIS). The map is a 2.3 MB .pdf file.
Montana Wind Power Map
More details
The wind resource estimates were developed in 2002 using MesoMap, a wind mapping
system developed by TrueWind Solutions. MesoMap combines two models, MASS, a
mesoscale atmospheric simulation model similar to a weather forecasting model,
and WindMap, a simples wind flow model. The results were validated by NREL and
independent meteorologists using historical data. Wind speeds shown are
estimated to be within about +/-5% accuracy, and wind power density values
(which are related to the cube of the speed) are estimated to be within about
+/-15% accuracy. This means that the actual wind speed should be within 5% of
the predicted at two-thirds of the locations on the map, and should be within
10% of the actual at about 95% of the locations, assuming that the measurements
are taken in well exposed areas, with minimal obstructions, and following wind
industry measurement guidelines.
The two models work together, but at different scales. MASS operates on a
spatial grid resolution of 2.6 km (1.6 miles), whereas WindMap operates on a
resolution of 400 meters (1312 ft, or one-quarter mile), which is the final
scale of the maps. While WindMap can simulate the acceleration of winds over
small hills and ridges, many other terrain effects require the more
sophisticated MASS. Such effects include channeling through valleys or passes
(such as Judith Gap or Livingston Pass) and downslope flows (e.g., Blackfeet
area). To the extent these effects are at work, the accuracy of the maps is
limited by the spatial grid resolution of MASS. To be resolved completely, a
terrain feature must be larger than about 3-4 grid cells. Therefore, for
instance, a valley that is less than about 7-10 km wide will not be fully
"seen" by the MASS model, and if there is any channeling through that
gap, it will be underestimated or entirely missed in the map. Likewise, detailed
aspects of a downslope flow, including its intensity and full extent, will not
be resolved better than the scale of the MASS simulations.
The wind speed and wind power data sets are available from NRIS.
