 Pernick and Wilder define " clean tech " as " any product , service , or process that delivers value using limited or zero non @-@ renewable resources and / or creates significantly less waste than conventional offerings . " They highlight eight major clean technology sectors : solar power , wind power , <unk> , green buildings , personal transportation , the smart grid , mobile applications ( such as portable fuel cells ) , and water filtration . The authors explain how investors , entrepreneurs , and individuals can profit from technological innovation in these areas . Pernick and Wilder identify some specific clean technologies , companies , and regions that are leading the way . 
