In today’s rapidly growing and changing business landscape, understanding the intricacies of the renewable energy sector is crucial for achieving sustainability and emissions reduction goals. Whether you’re just starting your understanding of the renewable energy market or a seasoned professional, knowing and understanding these key terms can impact your organization’s environmental efforts. The glossary below includes terms that are fundamental to understanding renewable energy practices, policies and technology, and understanding these will enable you to effectively integrate environmental, social and governance (ESG) principles into your organization’s overall strategy. 
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Anaerobic Digestion
A process where bacteria break down organic matter such as food waste in the absence of oxygen. This process takes place in a reactor, which can be designed to fit various site and feedstock conditions. Reactors contain microbial communities that “digest” the waste and produce biogas and digestate.

Bcf
Stands for Billion cubic feet. This is a standard unit of measurement for natural gas. 1,000,000 mmBtu is equal to 1 Bcf. 

Biogas
Biogas is a gaseous fuel comprised of methane and other components that is produced by fermentation and decomposition of organic matter. Biogas can be found at landfills, wastewater treatment plants and farms. It can be used to create renewable natural gas (RNG), renewable electricity and can be employed for direct-use applications. RNG projects work by capturing biogas and upgrading it to pipeline-grade methane that can be used to displace conventional natural gas and transportation fuels. 

Biomethane
See RNG.

Carbon Dioxide
Carbon dioxide (CO₂) is a greenhouse gas (GHG) that is both found in nature and can develop as a result of the extraction and burning of fossil fuels like coal and oil. Carbon dioxide is the most common GHG and when it is in the atmosphere, it prevents heat from escaping and consequently warms the Earth. Annual carbon dioxide emissions hit an all-time high in 2023, and the annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases.¹

Reducing carbon emissions is one way companies can work toward their ESG goals. Companies can reduce their carbon emissions by increasing their energy efficiency, switch to using renewable energy like RNG, utilizing electric vehicles for fleets, adopt sustainable manufacturing processes such as using eco-friendly materials, and implementing carbon offset projects like reforestation. 

Carbon Intensity / Carbon Intensity Score
Carbon intensity refers to the amount of carbon dioxide (CO₂) emissions produced per unit of energy or economic output. Carbon intensity scores help measure the environmental impact of different activities in different sectors. Fuels are assigned a carbon intensity score which is measured in grams of carbon dioxide equivalent per megajoule of energy (gCO2e/MJ). These carbon intensity scores are then used to administer programs such as California’s Low Carbon Fuel Standard.  

Carbon Negative
Carbon negative refers to the state where the amount of carbon dioxide and other GHG removed from the atmosphere is greater than the amount emitted. Since it is impossible to emit a negative amount of carbon, being carbon negative refers to the net emissions an organization creates. Carbon negative can be achieved through reforestation, carbon capture, transitioning to renewable fuels like RNG and utilizing sustainable transportation practices. 

Clean Fuel Standards (CFS)/Low Carbon Fuel Standard (LCFS)
These are policies and regulations that aim to reduce GHG emissions from transportation fuels. These standards require fuel providers to reduce the carbon intensity of their fuel mix by blending in lower-carbon alternatives. Trucking companies can leverage RNG to lower their emissions.

The Low Carbon Fuel Standard was created to push companies in California’s transportation sector to decrease their carbon emissions and encourage the use of renewable fuel alternatives, such as RNG. The LCFS target is to hit 20% reduction from its 2010 reporting, by 2030. The LCFS program has been successful so far, as California has been hitting yearly reduction goals ahead of schedule. As of spring of 2024, Oregon, Washington and New Mexico are the only three other states to have implemented their own programs; other states are working toward making their own versions of the LCFS.² 

Clean Heat Standards (CHS)
Clean Heat Standards are policies that set requirements for the use of low-carbon heating technologies. It aims to reduce GHG emissions by promoting the adoption of cleaner heating systems that use renewable energy sources, heat pumps or efficient electric heating. Clean Heat Standards encourage transitioning away from heating methods powered by fossil fuels. Utilities can use RNG as a sustainable solution to help reduce their GHG emissions. 

Compressed Natural Gas (CNG)
CNG is a fuel gas made up mostly of methane that is compressed to less than 1% of the volume it occupies at standard atmospheric pressure. CNG is used in natural gas vehicles and is a safer and cleaner alternative to gasoline and diesel. 

Dekatherm
A dekatherm is equal to one million British thermal units or ten therms. This measures the actual heating value of a specific volume of natural gas. 

Electric Renewable Identification Numbers (eRINs)
eRINs are credits that were originally proposed to be a part of the 2023 update to the Renewable Fuel Standard. eRINs aimed to spur electric vehicle adoption and would be produced when qualifying biogas is used to generate renewable electricity for the charging of electric vehicles. Similar to Renewable Identification Numbers (RINs), eRINs could be purchased to help refiners or importers of gasoline or diesel fuel to meet their renewable volume obligations (RVO). 

Environmental, Social, Governance (ESG)
This refers to a set of standards used to measure an organization’s environmental and social impact. It is typically used in the context of investments. 

• Environmental: the company’s attitude and stewardship toward climate change, GHG emissions, carbon emissions, waste management and pollution. 
• Social: the company’s impact on people, culture and communities through diversity, inclusivity and human rights. 
• Governance: the company’s directors and how it looks at corporate governance factors like executive compensation, succession planning, board management practices and shareholder rights. 
• Using renewable, lower-carbon fuels can help your company’s environmental commitment when it comes to ESG. 

Feedstock
A feedstock refers to the raw material or source from which something is produced. RNG feedstocks include landfills, wastewater sludge and animal manure. 

Greenhouse Gas (GHG)
A gas that contributes to the greenhouse effect by absorbing infrared radiation. Gases including carbon dioxide, methane and nitrous oxide absorb radiation and keep the Earth warmer than it would be without them. These gases create what we call a “greenhouse effect.” In the world of transportation and energy, greenhouse gases can come from fleet trucks, electricity and industrial processes, along with biogas from landfills, dairy farms and wastewater treatment plants. 

GHG emissions are categorized into three scopes. Scope 1 emissions are also referred to as direct emissions; these are emissions that your company is directly responsible for, such as kilns and dryers used to manufacture products or vehicles used for product distribution. Scope 2 emissions are indirect emissions from sources such as consumed electricity. Scope 3 emissions are indirect emissions that are not directly produced by your company. The emissions from a flight for business travel would be considered Scope 3 emissions for your company, but Scope 1 emissions for the airline. 

Inflation Reduction Act (IRA)
The Inflation Reduction Act is a federal law that aims to curb inflation by investing in clean energy among other sectors. This law was passed in 2022 and is considered one of the most aggressive actions of tackling the climate crisis in American history. 

Landfill gas (LFG)
Landfill gas is a byproduct of decomposing organic materials in landfills. LFG is comprised mainly of methane and carbon dioxide and small amounts of other organic compounds. LFG is captured through wells, which can be transferred to an RNG project at the landfill, which creates RNG. Using LFG to create RNG helps reduce GHG emissions, mitigate odors and can bring in more revenue to the landfill. LFG can also be used to produce renewable electricity, and can be used in direct applications, such as supplying power to a manufacturing plant’s processes. 

Lifecycle analysis
Lifecycle analysis is used to assess the overall GHG impact of a fuel, including each stage of its production and use. The Environmental Protection Agency’s (EPA) lifecycle analysis includes significant indirect emissions as required by the Clean Air Act (CAA). 

Liquefied Natural Gas (LNG)
LNG is a natural gas that has been cooled to its liquid state for shipping and storage. Natural gas is smaller in its liquid state than its gaseous state in a natural pipeline. Natural gas pipelines cannot reach everywhere, so transporting natural gas as a liquid makes it possible for these hard-to-reach areas to access natural gas. In order to be used, LNG must be regasified. 

Methane
Methane is a GHG that is both naturally occurring and produced by human activities. It is the primary component of natural gas and can be used as a fuel source. Methane accounts for about 16% of global emissions and is about 28 times more potent than carbon dioxide.³ Because methane is so powerful and short lived compared to carbon dioxide, methane reduction would have a significant effect on atmospheric warming potential. Landfills, wastewater treatment plants and agriculture operations can work with an RNG developer to capture methane to generate renewable energy, increase revenue and decrease emissions. 

mmBtu
mmBtu stands for 1 million British Thermal Units and is a unit of measurement for natural gas. A thermal unit represents the amount of energy needed to heat a pound of water by one degree Fahrenheit at or near 39.2 degrees Fahrenheit, and mmBtu is frequently used in natural gas financial contracts.

Net Zero
This refers to the state where the amount of GHG emissions produced is equal to the amount of greenhouse gases removed from the atmosphere. The goal is to achieve a balance between emissions and removals, resulting in no net increase in the concentration of GHG. Companies can achieve net zero by utilizing carbon offsetting, implementing energy efficiency measures, transitioning to renewable fuels like RNG and transitioning their transportation fleets to natural gas or electric vehicles. According to The Intergovernmental Panel on Climate Change’s sixth assessment report, GHG emissions will need to drop by almost 50% by 2030 in order for the world to reach net zero.⁴ 

Nitrous Oxide
Nitrous oxide is emitted during agricultural activities, land use and industrial processes. This is emitted when fossil fuels and solid waste combust. Nitrous oxide accounts for about six percent of all GHG emissions from human activities. 

Renewable Energy Certificates (RECs)
RECs are the accepted legal instrument to track and verify the production and use of renewable energy.  RECs represent the environmental and social benefits of generating electricity from renewable sources, like landfill biogas. When a renewable energy facility generates electricity, it also generates RECs, which can be bought and sold separately from the actual electricity. When a company purchases RECs, they support renewable energy production and can claim they are using renewable energy even if their electricity comes from the grid.

Renewable Fuel Standard (RFS)
This is a program that requires a certain volume of renewable fuel to be used to replace or reduce the quantity of fossil fuel in transportation fuel, home heating oil or jet fuel. The RFS program was created in 2005 and aims to reduce GHG emissions, enhance energy security and promote the renewable fuels industry. Compliance is tracked through RINs, which monitor the production and usage of these fuels.

Renewable Identification Numbers (RINs)
RINs are credits that refiners and importers of gasoline or diesel fuel acquire to demonstrate compliance with the Renewable Fuel Standard. RINs are created when RNG is used as a transportation fuel. 

Renewable Natural Gas (RNG)
Renewable natural gas, or RNG, is biogas that has been upgraded to a quality similar to natural gas that is sourced from fossil fuels. It is a lower-carbon energy alternative that can help organizations advance toward their environmental goals. RNG can power gas appliances, fuel fleet trucks, heat buildings, sustain manufacturing plants’ furnaces and dryers and can even create electricity to power electric vehicles. Currently, landfills account for over 90% of RNG production. RNG has a lower carbon intensity than diesel, which makes it a great fuel alternative for transportation fleets.  

Landfills – learn more about how you can feed the growing demand for RNG by downloading our RNG Guide.
 
Corporates – are you interested in using RNG? Let’s connect and work together to achieve your sustainability goals. 

Renewable Portfolio Standards (RPS)
Renewable Portfolio Standards are designed to increase the use of renewable energy sources. RPS programs require energy suppliers to provide customers with a minimum share of energy from eligible renewable resources. These standards help reduce emissions and promote renewable energy technology. Most states currently have or are working to implement their own versions of RPS programs.⁵ 

Renewable Volume Obligation (RVO)
RVO is the volume of renewable fuels a fuel company (fuel refiners, blenders and importers) is obligated to sell. That amount is based on a percentage of the company’s total fuel sales and is assigned through the RFS program. 

Standard Cubic Feet Per Minute (SCFM)
SCFM stands for standard cubic feet per minute and measures how much gas flows within a minute. Biogas sources include landfills, wastewater treatment plants, agricultural digesters and food waste digesters. 

U.S. Securities and Exchange Commission (SEC) SEC Disclosures
The U.S. Securities and Exchange Commission (SEC) is a government agency responsible for enforcing the law against market manipulation. Its main goal is to protect investors and maintain fair and efficient markets. The SEC plays a role in reducing emissions by requiring companies to disclose their climate-related risks and impacts. Through regulation and guidelines, the SEC promotes transparency and accountability regarding climate change and corporations’ efforts to reduce their carbon footprint. 

On March 6, 2024, the SEC adopted new rules that require climate-related disclosures to be included in public companies’ annual reports and registration statements.⁶ These required disclosures include the climate risk governance – in other words, who is in charge of strategy regarding greenhouse gas emissions at both board and management levels. 
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Mastering the terminology outlined in this glossary is a crucial step toward success in achieving ESG goals so you and your team can implement more effective and sustainable practices. Whether your landfill is looking to contribute to a greener future through renewable energy creation or your corporation is looking to reduce emission with RNG, feel free to bookmark this page to use this as a resource during your sustainability journey. 


Sources
1. Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov 
2. Revving Up: Eight States in Gear with Low-Carbon Fuel Standard Legislation (pillsburylaw.com) 
3. Importance of Methane | US EPA 
4. Sixth Assessment Report — IPCC 
5. State Renewable Portfolio Standards and Goals (ncsl.org)
6. SEC.gov | SEC Adopts Rules to Enhance and Standardize Climate-Related Disclosures for Investors