The types of projects able to sell offset credits on the offset market are defined by methodologies (also called protocols). Most of these are from these offset project registries: Climate Action Reserve, American Carbon Registry, Clean Development Mechanism, Verra, and California Air Resources Board.
The following list provides some sense of the wide range of project types generating carbon credits on the voluntary market, including a sampling of methodologies. A more comprehensive list of methodologies can be found at each registry’s website listed above.
- Building/home energy efficiency, including weatherization, refrigerators, air conditioners, solar water heating, household appliances, space heating, lighting and lighting controls (see CDM and Verra
- Carbon capture and storage [ACR]
- Cookstoves [improved stove efficiency] [switch from non-renewable biomass]
- Electricity generation
- Renewable energy generation (many protocols under the CDM including: CDM)
- Cogeneration
- Forests and land use
- Agriculture
- Energy efficiency and fuel switching measures for agricultural facilities and activities [CDM]
- Energy efficient pump-set for agriculture use [CDM]
- Nitrogen management (improved nitrogen use efficiency on agricultural lands) [ACR][CAR]
- Rice cultivation [ACR][CAR]
- Forest
- Grasslands
- Avoided conversion of grasslands [ACR] [CAR]
- Compost additions to grasslands [ACR] [CAR]
- Biochar additions to grasslands [CAR]
- Livestock [CAR][CAR Mexico]
- Methane digesters at livestock facilities (livestock protocol) [ACR]
- Grazing and other livestock management improvements [ACR]
- GHG reductions from manure management systems [CDM]
- Wetland restoration (several Verra protocols)
- Fuel switching (many protocols)
- Fuel switching from coal or petroleum fuel to natural gas [CDM]
- Natural gas substitution by biogenic methane produced from the anaerobic digestion of organic waste [CDM]
- Industrial efficiency in a range of industries, including cement, paper, brick manufacturing, data centers, and boilers (see CDM and Verra)
- Methane capture or reduction
- Other high potency GHGs include protocols for N2O, ozone-depleting substances and CF4s. Here’s a sample of available protocols for non-CO2 high potency GHGs..
- Reduction of N2O emissions generated as a byproduct of nitric acid production [CAR]
- Destruction of ozone depleting substances that would otherwise have been vented to the atmosphere [ACR] [CAR][CAR Mexico]
- CF4 emission reduction in a semiconductor manufacturing facility [CDM]
- Transportation
- Truck stop electrification [ACR]
- Fuel switch from gasoline to ethanol in flex-fuel vehicle fleets [Verra]
- Transportation energy efficiency activities using retrofit technologies [CDM]
- Carpooling [Verra]
- Electric vehicle charging systems [Verra]
- Mass rapid transit [CDM]
- Water
- Treatment of wastewater [CDM]
- Distribution of zero energy water purification systems for safe drinking water [CDM]
- Installation of low-flow water devices [Verra]