S. 535 · 114th Congress Energy Efficiency Improvement Act of 2015 StageSigned by the president SponsorRob Portman Introduced2015-02-23 Latest action2015-04-30 · Signed by President. Follow Summary Text Subjects Cosponsors (7) Votes (0) Actions Cosponsors (7) Kelly Ayotte Former member Senate NH Republican Michael Bennet Current member Senate CO Democrat Susan Collins Current member Senate ME Republican Al Franken Former member Senate MN Democrat Cory Gardner Former member Senate CO Republican Joe Manchin Former member Senate WV Independent Jeanne Shaheen Current member Senate NH Democrat