 Pernick and Wilder identify six major forces , which they call the six C ’ s , that are pushing clean technology into the mainstream and driving rapid growth and expansion : costs , capital , competition , China , consumers , and climate . 
 Pernick and Wilder identify six major forces , which they call the six C ’ s , <a href='null_relcl' title='1'><mark>that</mark></a>are pushing clean technology into the mainstream and driving rapid growth and expansion : costs , capital , competition , China , consumers , and climate . 
Pernick and Wilder identify six major forces , which they call the six C ’ s , are pushin clean technology into the mainstream and drivin rapid growth and expansion : costs , capital , competition , China , consumers , and climate .