Since 2004, Chu has been director of the Berkeley lab, the oldest of the Energy Department's national laboratories, with its 4,000 employees and a budget of $650 million. The laboratory does only unclassified work and under Chu has been a center of research into biofuels and solar energy technologies. He is a former head of the physics department at Stanford University.
Chu has been a vocal advocate for more research into alternative energy, arguing that a shift away from fossil fuels is essential to combat global warming.
Chu, a Chinese-American, has in recent years campaigned to bring together a cross-section of scientific disciplines to find ways to counter climate change.
Chu as energy secretary would head a department with a $25 billion budget and 14,000 employees and more than 193,000 contract workers. Two-thirds of its budget involves activities related to nuclear weapons research and maintenance.