Before revision:  Our analysis demonstrates that 1) LCETs rely increasingly on science, 2) Solar PVand Nuclear fusion depend heavily on science, while Hydro energy does not, 3) renewable and nuclear energy technologies rely on a strikingly different kind of science, and 4) there is a remarkable convergence of scientific knowledge bases of renewables over recent decades. These findings suggest a need for technology-specific research policies, although targeted research in renewables is likely to cross-fertilize a wider range of LCETs.
After revision:  In recent years, Solar PV, Nuclear fusion and Biofuels (including energy from waste) have 35-65