A study done by law firm "Heslin Rothenberg Farley & Mesiti P.C." has found that in the first quarter of '08 clean energy patent approval had dipped a little. In the first quarter there were 220 patents as compared to 228 approved in the first quarter and 227 in the last quarter of '07.
This study found that wind, tidal/wave and geothermal patent approvals are on the rise while solar, hybrid/electrical vehicle patents are dipping.
Honda Motors had the most "clean air" patents with 16 issued followed by General Electric and General Motors with 11 issued. The study found that auto companies claimed 6 of the study's top ten spots.