Temporal trends in energy patents.

<p>(A.) Time series for US energy patents published during the period 1974-2009 show rapid growth over the last decade (upper panel), with the greatest increases in renewables patents. Public funding (lower panel) for energy R&D (1974-2008) increased dramatically in the 70s and 80s but then remained relatively constant. (B.) A similar trend in patenting (1974-2008) is seen when aggregating globally (upper panel). Funding for public R&D (1974-2008) among IEA countries (lower panel) shows only modest increases in recent years.