Back in July the National Renewable Energy Labs (NREL) published a report titled U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis. Graphical Information System (GIS) data has become really popular. Thanks to satellites and the ability to handle massive amounts of image data, the world today is better mapped than previous generations could even dream about. Using available GIS data, the authors evaluated the potential for each of several different renewable sources of electricity in the US. Consider one resource -- rural utility-scale photovoltaic panels. The authors identified all of the land which met certain criteria (rural, sufficiently flat, not water, not in a national park, etc) and calculated how much power could be generated using today's PV technology if all of the identified land were used for that purpose.
The authors presented their results at the state level and used the data to produce maps like the one shown to the right. This particular map shows the potential for hydrothermal power, which is concentrated in the western states. But state level aggregation doesn't seem particularly helpful either. Western states are large, so energy sources can still be far from the population centers (as well as separated by the odd mountain range here and there). Western states vary enormously in terms of their population. California and Nevada may be in the same category in terms of hydrothermal potential; but because of the differences in their populations, Nevada's resource may be sufficient to meet all of Nevada's needs, while the same resource in California can provide only a small fraction of what is needed.
I'm seriously disappointed by the study, which I think adds very little value. We already knew that rural utility-scale PV could potentially produce far more power than we currently consume. I can think of a half-dozen things to do with the data that would have been much more useful. For example, for some (or all) of the 50 largest metro areas, how far and in what pattern would rural PV need to be deployed to meet the metro areas' power needs? Avoid mountain ranges; avoid areas that are heavily forested; avoid existing towns. Where do the patterns overlap? What happens if current crop land is excluded? There are enormous amounts of GIS data of various types available, and some of the ways that it can be used would be valuable. The results in this paper aren't one of those, unfortunately.