I want to thank Secretary Chu for his dedicated service on behalf of the American people. As a Nobel Prize-winning scientist, Steve brought to the Energy Department a unique understanding of both the urgent challenge presented by climate change and the tremendous opportunity that clean energy represents for our economy. And during his time as Secretary, Steve helped my administration move America towards real energy independence. Over the past 4 years, we have doubled the use of renewable energy, dramatically reduced our dependence on foreign oil, and put our country on a path to win the global race for clean energy jobs. Thanks to Steve, we also expanded support for our brightest engineers and entrepreneurs as they pursue groundbreaking innovations that could transform our energy future. I am grateful that Steve agreed to join in my Cabinet, and I wish him all the best in his future endeavors.
Barack Obama, Statement by the President on the Resignation of Steven Chu as Secretary of Energy Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/303555