GREET is a full life-cycle model sponsored by the Argonne National Laboratory

Argonne National Laboratory

Argonne National Laboratory is the first science and engineering research national laboratory in the United States, receiving this designation on July 1, 1946. It is the largest national laboratory by size and scope in the Midwest...

 (U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy

Office of Energy Efficiency and Renewable Energy

The Office of Energy Efficiency and Renewable Energy is an office within the United States Department of Energy that invests in high-risk, high-value research and development in the fields of energy efficiency and renewable energy technologies...

). It fully evaluates energy and emission impacts of advanced and new transportation fuels, the fuel cycle from well to wheel and the vehicle cycle through material recovery and vehicle disposal need to be considered. It allows researchers and analysts to evaluate various vehicle and fuel combinations on a full fuel-cycle/vehicle-cycle basis.

Content

For a given vehicle and fuel system, GREET separately calculates the following:

• Consumption of total energy (energy in non-renewable and renewable sources), fossil fuel
  Fossil fuel
  Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
  
  s (petroleum, fossil natural gas, and coal together), petroleum, coal and natural gas;
• Emissions of CO₂-equivalent
  Carbon dioxide equivalent
  Carbon dioxide equivalent and Equivalent carbon dioxide are two related but distinct measures for describing how much global warming a given type and amount of greenhouse gas may cause, using the functionally equivalent amount or concentration of carbon dioxide as the reference.- Global warming...
  
   greenhouse gases - primarily carbon dioxide (CO₂), methane
  Methane
  Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
  
   (CH₄), and nitrous oxide
  Nitrous oxide
  Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
  
   (N₂O); and
• Emissions of six criteria pollutants: volatile organic compound
  Volatile organic compound
  Volatile organic compounds are organic chemicals that have a high vapor pressure at ordinary, room-temperature conditions. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and...
  
  s (VOCs), carbon monoxide
  Carbon monoxide
  Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
  
   (CO), nitrogen oxide
  Nitrogen oxide
  Nitrogen oxide can refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:* Nitric oxide, also known as nitrogen monoxide, , nitrogen oxide* Nitrogen dioxide , nitrogen oxide...
  
   (NOx), particulate matter with size smaller than 10 micrometre
  Micrometre
  A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
  
   (PM10]), particulate matter with size smaller than 2.5 micrometre (PM2.5),and sulfur oxide
  Sulfur oxide
  Sulfur oxide refers to one or more of the following:* Lower sulfur oxides * Sulfur monoxide * Sulfur dioxide * Sulfur trioxide *Higher sulfur oxides Sulfur oxide (SOx) refers to one or more of the following:* Lower sulfur oxides (SnO, S7O2 and S6O2)* Sulfur monoxide (SO)* Sulfur dioxide (SO2)*...
  
  s (SOx).

GREET includes more than 100 fuel production pathways and more than 70 vehicle/fuel systems.

Michael Wang, a Senior Scientist in the Energy Systems Division is the primary developer of GREET.