Here are eleven Greenshift and/or Winsness; Davis; Barlage; Cantrell; Krablin; Kreisler patents:
http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=0&f=S&l=50&d=PG01&OS=AN%2F%22gs+cleantech%22+or+%22Barlage%3B+Gregory%22+or+%22Cantrell%3B+David%22+or+%22winsness%22&RS=%28%28%28AN%2F%22gs+cleantech%22+OR+%22Barlage%3B+Gregory%22%29+OR+%22Cantrell%3B+David%22%29+OR+%22winsness%22%29&TD=11&Srch1=%28%28%28%28%2522gs+cleantech%2522.AS.%29+OR+%2522Barlage%253B+Gregory%2522%29+OR+%2522Cantrell%253B+David%2522%29+OR+%2522winsness%2522%29&StartNum=&Refine=Refine+Search&Query=AN%2F%22gs+cleantech%22++or+%22winsness%22
The first one listed is the same one featured in the blog below.
SkunK