GREET (
Greenhouse gases, Regulated Emissions, and Energy use in Technologies) is a full life-cycle model sponsored by the
Argonne National Laboratory (
U.S. Department of Energy's
Office of Energy Efficiency and Renewable Energy
The Office of Energy Efficiency and Renewable Energy (EERE) is an office within the United States Department of Energy. Formed from other energy agencies after the 1973 energy crisis, EERE is led by the Assistant Secretary of Energy Efficiency an ...
). 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
A materials recovery facility, materials reclamation facility, materials recycling facility or Multi re-use facility (MRF, pronounced "murf") is a specialized plant that receives, separates and prepares recyclable materials for marketing to end-u ...
and
vehicle disposal. It allows researchers and analysts to evaluate various vehicle and fuel combinations on a full fuel-cycle/vehicle-cycle basis.
The GREET model is specified in the
Inflation Reduction Act of 2022
The Inflation Reduction Act of 2022 (IRA) is a landmark United States federal law which aims to curb inflation by reducing the deficit, lowering prescription drug prices, and investing into domestic energy production while promoting clean en ...
§4
as the methodology to calculate the lifecycle greenhouse gas emissions "through the point of production (well-to-gate)" when determining the level of tax credit for clean
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
production until a successor is approved by the
Secretary of the Treasury
The United States secretary of the treasury is the head of the United States Department of the Treasury, and is the chief financial officer of the federal government of the United States. The secretary of the treasury serves as the principal a ...
.
The basic implementation of the model was made using Excel spreadsheets. However a more practical and easy to use software developed with
.NET and with a fully graphical toolbox is also availab
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 fuels (petroleum, fossil natural gas, and coal together), petroleum, coal and natural gas;
*Emissions of
CO2-equivalent greenhouse gases - primarily carbon dioxide (CO
2),
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Ea ...
(CH
4), and
nitrous oxide
Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has ...
(N
2O); and
*Emissions of six criteria pollutants:
volatile organic compound
Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...
s (VOCs),
carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
(CO),
nitrogen oxide (NOx),
airborne particulate matter
Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...
with sizes smaller than 10
micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
(PM10]), particulate matter with sizes smaller than 2.5 micrometre (PM2.5), and
sulfur oxide
Sulfur oxide refers to many types of sulfur and oxygen containing compounds such as SO, SO2, SO3, S7O2, S6O2, S2O2, etc.
Sulfur oxide (SO''x'') refers to one or more of the following:
* Lower sulfur oxides (S''n''O, S7O2 and S6O2)
* Sulfur mono ...
s (SOx).
GREET includes more than 100 fuel production pathways and more than 70 vehicle/fuel systems.
Michael Wang a Senior Scientist in th
Energy Systems Divisionis the primary developer of GREET.
External links
* http://greet.es.anl.gov/
References
{{Reflist
Vehicle emission controls
Emission standards
Transport and the environment
Standards of the United States