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3.1.1 Geographic Sources
In the United States, we observe increasing inventive activity in the clean energy sector
over the last several decades along with increasing geographic concentration (Table 1).
California is a dominant geography for energy inventive activity across all technology
areas, especially solar, which is likely based on the concentration of the semiconductor
and venture capital industries there. High patenting activity is also observed in Texas,
Massachusetts, Colorado, and New York. Pennsylvania shows active patenting across all
traditional energy technologies, perhaps due to geographic choices in the early oil
industry. And not surprisingly, Texas shows strong oil-related patenting activity due to
the strength of the industry there. Because of the dominance of California,
Massachusetts, New York, and Texas and the high levels of activity in Colorado, we
focus our analysis on breakthroughs in those states. In the future, we can extend this
analysis for all states—and similarly, any feature of interest that we identified—and run
comparisons between them.

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