the evidence indicates that the rate of innovation has accelerated for many of these technologies coinciding approximately with the passage of the kyoto protocol this is particularly true of those technologies that were closest to being competitive ie wind power some solar power biofuels geothermal and hydro patent activity for other technologies ie carbon capture and storage showed declines even in comparison with the rate of patenting in general and for other energy technologies hascic et al but some indicators emerge as particularly relevant from a policy perspective and one of them is public investment in research