Great Green Fleet = Great Green Fleet = The Great Green Fleet is the popular nickname of the carrier strike group serving as the US Navy ' s proving ground for the strategic and tactical viability of biofuels . The name is an homage to the Great White Fleet of the early 20th century . Overview . The United States has only 4 % of the world ' s population , but consumes a quarter of its oil . The Department of Defense is the single largest consumer of oil within the US , constituting about 80 % of the federal governments usage profile . It is with that in mind that the US military is seeking to change the profile of its energy usage . While each branch of the military has its own goals and plans , the Navy ' s goals are particularly lofty : The Navy ' s efforts are highlighted by the Great Green Fleet , which first sailed in July 2012 during the RIMPAC exercise . The carrier , the USS Nimitz , was nuclear powered , but everything else , including the Nimitz ' s strike aircraft , ran on a 50 : 50 mix of petroleum and biofuel derived from cooking oil and algae . Set to fully deploy in 2016 , the fleet will combine advances in fuels , equipment , and navigation all in an effort to deploy the most energy efficient , and modern fleet anywhere in the world . " The Great Green Fleet will signal to the world America ' s continued naval supremacy , unleashed from the tether of foreign oil . " - Ray Maybus , Secretary of the Navy Fleet Composition . The fleet is composed of the aircraft carrier USS Nimitz ( CVN 68 ) , the cruiser USS Princeton ( CG 59 ) , the two destroyers USS Chafee ( DDG 90 ) and USS Chung Hoon ( DDG 93 ) , and the fuel tanker USNS Henry J . Kaiser ( T - AO - 187 ) . Concerns . There are reservations from some politicians , as well as military officials that the transition to alternative fuel sources would be too costly . Beyond the strict fuel costs , there are also concerns about the time and resources which would be required to create the necessary support structure to produce the volume of fuel sufficient for the military ' s needs . Benefits . The Navy ' s goals will further their own objectives , but will also have far - reaching effects in the US and beyond . Reducing U . S reliance on foreign petroleum has numerous strategic advantages , and could work to avert future conflicts centered around the acquisition of petroleum stores . The call for alternative fuels has already begun to drive innovation , with companies striving to create efficient processes to bring biofuel availability to the necessary scale the military requires . Energy companies Solazyme ( CA ) and Dynamic Fuels ( LA ) are working towards numerous fuels and competing for the contracts offered by the U . S Department of Defense , and continued studies by military and civilian researchers will build momentum in both the scientific community , as well as the energy marketplace . Studies have also shown a decrease in particulate emissions from the use of algal biofuels versus naval diesel fuel . Crossover and cooperation with the civilian marketplace is already underway with comparable studies and efforts underway in civilian aviation and maritime fleets . As all these efforts come together , we will see public acceptance for biofuels grow , and a demand for cleaner , more efficient fuels from populations across the globe .