The Great Green Fleet

Great Green Fleet Logo
(U.S. Navy graphic)

The Great Green Fleet (GGF) is a year-long, Department of the Navy initiative that demonstrates the sea service’s efforts to transform its energy use. As one of the Secretary of the Navy’s key energy goals, the purpose of the GGF is to make our Sailors and Marines better warfighters, able to go farther, stay longer and deliver more firepower.

Secretary RayMabus chose the name Great Green Fleet to honor President Theodore Roosevelt’s Great White Fleet, which helped usher in America as a global power on the world stage at the beginning of the 20th Century. The GGF will usher in the next era of Dept. of Navy energy innovation.

The centerpiece of the Great Green Fleet is a Carrier Strike Group (CSG) that deploys on alternative fuels, including nuclear power for the carrier and a blend of advanced biofuel made from beef fat and traditional petroleum for its escort ships. These biofuels have been procured by DON at prices that are on par with conventional fuels, as required by law, and are certified as “drop-in” replacements that require no engine modifications or changes to operational procedures. The CSG also uses energy efficient technologies and operating procedures referred to as Energy Conservation Measures (ECMs) during the course of its normal operations.

Throughout 2016, other Dept. of Navy platforms including ships, aircraft, amphibious and expeditionary forces, as well as shore installations, will participate in the GGF by using energy efficient systems, operational procedures, and/or alternative fuel during the course of planned mission functions worldwide.

Ashore, DON installations have in procurement 1.1 gigawatts of renewable energy – or about one-half of overall DON power requirements as of January 2016. Renewable energy projects at our facilities can help increase resiliency by enabling them to continue operations in the event of a commercial grid disruption.

Energy Conservation Measure

A dedicated change in operational procedure or material configuration change undertaken for the specific purpose of increasing platform energy efficiency.

Such examples are Smart Voyage Planning Decision Aid, Stern Flaps, High Efficiency Small Capacity Chiller, Thermal Management Control System, Variable Speed Drive Port Use Fan, Shipboard Energy Dashboard, Hybrid Electric Drive, Gas Turbine Online Water Wash, Solid State Lighting, Energy Storage Module, short-cycle mission and recovery tanking (SMART), advanced propeller coatings, and combustion trim loop.

Great Green Fleet

 A composite term that may encompass multiple Carrier or Expeditionary Strike Groups (CSG, ESG) throughout the year, as opposed to a single CSG or ESG being designated the Great Green Fleet for its entire deployment.

Groups with participating ships or independent deployers meeting the participating ship criteria engaged in globally distributed maritime operations in 2016 will be designated as participants in the Great Green Fleet.

Drop-in Biofuels

Naval tactical fuels produced partly, or in whole, from non-petroleum based sources that have been qualified for use in Naval systems (aircraft, ships and ground vehicles), are procured through existing military and/or commercial fuel specifications (e.g. JP-5/F-44, JP-8/F-34, F-76, Jet A, Jet Al) and drop into existing infrastructure and function in a fashion indiscernible from petroleum derived fuels.

Some Energy Efficient Technologies

Solid State Lighting

 Use of light-emitting diodes (LEDs) to save energy, especially when replacing incandescent fixtures or in colored lighting applications. LEDs also last longer than an incandescent or fluorescent fixture, reducing maintenance.

Gas Turbine On-Line Water Wash

Allows compressors to be washed while the engine is running (normally, engines are shut down during this activity). This reduces maintenance, improves starter life, and reduces fuel consumption by keeping the compressor section of the gas turbine cleaner.

Shipboard Energy Dashboard

Provides real-time situational awareness of energy demand associated with equipment. This allows the crew to minimize a ship's energy consumption and increase its efficiency while meeting system performance and reliability requirements.

Smart Voyage Planning Decision Aid

Sends messages to ships with optimized routing plans for both ship safety and fuel savings.

Stern Flaps

Modifies the flow field under the hull to reduce drag, turbulence, and thus, reduce overall hull resistance.