Carbon Dioxide Pipelines 101

Pipelines are critical infrastructures that move essential resources, such as water, oil, natural gas and other materials, from where they are produced or gathered to locations where they can be used or stored. Pipelines are everywhere. They are found beneath our highways, through our cities and communities. If you have a gas stove or plumbing, you have a pipeline in use at home. Today, there are over 5,300 miles of carbon dioxide (CO2) pipelines in the United States.

For over 50 years, pipelines have transported CO2 safely, quickly, efficiently and in large volumes. This experience makes pipelines uniquely equipped to facilitate the deployment of carbon management technologies such as carbon capture, utilization and storage (CCUS) and direct air capture (DAC). 

Carbon management technologies drive clean energy innovation and job creation at home, while strengthening U.S. global competitiveness and energy leadership abroad. The U.S. government has already invested billions in carbon management technologies, and from 2022 through mid-2024, the private sector announced over $26 billion in investments in these technologies. 

Today, more than 270 carbon management projects have been announced that are at various stages of development or are operational in the U.S. These projects make pipeline infrastructure essential. When CO2 is captured, it’s often not located near an available storage or use site and has to be transported to another location. Over half of cement plants in the U.S. are located outside a 100-mile radius of the nearest CO2 storage site. Pipelines are the best and safest way to move CO2 to these storage sites and other locations.

In this 101, you will learn about CO2 pipelines, including the importance of pipelines for U.S. energy security, how CO2 pipelines are regulated, why they are safe, and most importantly, policies that can enable the build-out of this infrastructure.  

Recommendations include:

What are Carbon Dioxide Pipelines?

CO2 pipelines move carbon dioxide – a non-flammable, odorless and stable gas – to locations where it can enhance energy production, make valuable products or be safely stored. CO2 is usually transported in a liquid or “supercritical” state, which is the easiest, most efficient way to transport CO2. A supercritical state means the CO2 is pressurized to the point it exhibits properties of both a liquid and gas.

Like most pipelines, CO2 pipelines are primarily located underground and out of sight. They are made with high-grade steel paired with anti-corrosive coatings and typically have a diameter of 4 to 24 inches – which is roughly between the length of a cell phone and a carry-on suitcase.

Where are Carbon Dioxide Pipelines in the U.S.?

CO2 pipelines have been safely operating in the U.S. for the last half-century. Historically, most CO2 pipelines in the U.S. have transported CO2 for enhanced oil recovery (EOR) operations. EOR is a highly engineered, well-understood process where CO2 is injected into the reservoirs of an existing oil field to increase oil recovery from depleting wells. During these operations, CO2 can remain underground, keeping it out of the atmosphere.

Of the 5,300 miles of CO2 pipelines across the U.S., most are in Texas, New Mexico, Wyoming, Oklahoma, Louisiana, North Dakota, Mississippi and Colorado. According to the U.S. Department of Energy, an estimated 30,000 - 96,000 miles of CO2 pipelines will be needed by 2050 to reach our emissions reduction goals. To put these numbers in perspective, this is only 1-3% the length of our existing 3,000,000 miles of oil and gas pipelines in the U.S. today.

Illustrative 2050 CO2 Pipeline Network

Sources include ClearPath analysis, National Carbon Sequestration Database Saline basins, and Princeton’s Net-Zero America spur and trunk line transmission expansions for the high-electrification scenario.

How are Carbon Pipelines Regulated?

Similar to other pipelines and linear infrastructure projects, CO2 pipelines are subject to several layers of regulations at the local, state and federal levels:  

Safety 

The Pipelines and Hazardous Materials Safety Administration (PHMSA), a federal agency within the U.S. Department of Transportation, regulates the safety of U.S. pipeline infrastructure and provides national standards for the safe and responsible design, construction, maintenance and operation of pipelines. In some cases, a state may assume regulatory authority over the safety of intrastate CO2 pipelines if it adopts rules that are as stringent as, or more stringent than, PHMSA’s minimum standards.

Environment, Water and Land

CO2 pipelines are subject to strict state and federal regulations that seek to protect water sources, agricultural land, the local environment and wildlife. These include the Clean Water Act, National Environmental Protection Act (NEPA), Endangered Species Act and more. Local and tribal communities are also engaged throughout these permitting processes. 

Siting and Construction 

Before building a CO2 pipeline, an operator must receive regulatory approval for the location and construction of the project. Unlike interstate natural gas pipelines, which are regulated by the Federal Energy Regulatory Commission (FERC), there is currently no option to site an interstate CO2 pipeline solely using a federal process. The siting and construction of both interstate and intrastate CO2 pipelines are largely regulated at the local and state levels, creating a patchwork of regulatory approaches and standards across the country. 

When siting and constructing a CO2 pipeline, each developer is subject to the unique eminent domain laws of each state, and many states lack clear eminent domain policies for these pipelines. Eminent domain, a last resort option for building major infrastructure projects, is a process by which the government can permit a company to use private property without the express permission of the landowner. This can only occur if the government determines that a property owner is fairly compensated and the project benefits the public. Eminent domain has been used to build roads, develop water supplies, construct pipelines and more. This process isn’t new, but it is rare. In fact, between 2008 and 2018, less than 2 percent of easements for interstate natural gas pipelines involved eminent domain. 

Rate Regulation

Rate regulation refers to a process by which an authority can regulate the price pipeline operators can charge for transporting a material (e.g., natural gas, oil). Unlike interstate natural gas and oil pipelines, there is no federal ratemaking authority for carbon pipelines. Today, the majority of carbon pipelines are private access and do not require rate regulation. However, this is poised to change as the carbon pipeline network grows and more entities require access to carbon transportation via common carrier or open-access pipelines.

Regulatory Landscape for Carbon Dioxide Pipelines

*PHMSA regulates interstate CO2 pipelines. PHMSA also regulates intrastate CO2 pipelines if a state does not have a certified safety program. If a state has a certified safety program, the state can only regulate intrastate pipelines, not interstate.

**CO2 pipelines are subject to various regulatory requirements pertaining to the environment, water, and wildlife under federal legislation such as the National Environmental Protection Act, Clean Water Act, Endangered Species Act, and more. Different federal agencies may have jurisdiction over permits and assessments required under these laws, such as the Army Corps of Engineers, the Fish and Wildlife Service, the Department of Energy and more.

Safety and Health

CO2 pipelines have a strong safety record. Over the last 20 years, zero fatalities have resulted from the few pipeline incidents that have occurred. CO2 is stable, non-flammable, and non-combustible. In fact, CO2 is used in fire extinguishers to put out flames. We also breathe CO2 in and out every day.

On the ground, pipeline operators take measures to ensure the safety and integrity of pipeline infrastructure. In addition to monitoring the integrity of the pipelines and conducting regular maintenance, operators mitigate corrosion by limiting the amount of water and other contaminants that enter a CO2 pipeline. For example, before CO2 enters a carbon capture system, contaminants must be removed, and before being placed into a pipeline, the CO2 is dehydrated to reduce the presence of water. 

A leak is the unintentional release of a substance or material from a pipeline. The overall CO2 leaked from pipelines is limited – approximately 0.001 - 0.005% of the total volume of CO2 that is transported through pipelines annually. To mitigate leaks, PHMSA requires new and refurbished CO2 pipelines to utilize remotely controlled or automatic shut-off valves, thus reducing safety risks and allowing first responders to act swiftly.

Operators regularly implement procedures to prevent and mitigate the impact of incidents, and PHMSA requires operators to communicate safety-related information with the public. CO2 pipelines are a vital part of American infrastructure, and operators are committed to working with PHMSA and other regulatory authorities to ensure robust safety standards for all pipelines.

What are the Benefits of CO₂ Pipelines?

CO2 pipelines benefit the public by boosting local economies, providing direct financial benefits for landowners, strengthening energy and national security and helping to lower carbon emissions:

Policy Recommendations

Establish Efficient Permitting Processes — A decentralized regulatory structure for siting interstate carbon pipelines has led to significant uncertainty for project developers who require access to pipeline infrastructure. An unpredictable regulatory environment can result in delays, increased project costs, and, in some cases, the cancellation of projects altogether. These challenges underscore the need for a more predictable, transparent and cohesive regulatory framework to support the safe and efficient deployment of interstate carbon pipeline infrastructure. The federal government – with agencies such as FERC – can play a critical role in supporting the coordinated and effective siting and permitting of carbon pipelines. Congress could consider establishing an optional federal siting pathway for interstate CO2 pipelines, allowing project developers the flexibility to choose a federal permitting process. 

Expand Research, Development and Deployment (RD&D) – Dedicated RD&D is critical to building out CO2 pipelines at the scale that is needed and enabling the commercialization of advanced materials and technologies for this infrastructure. Pipeline RD&D should focus on, among other areas, enhanced geohazard monitoring, advanced leak detection and monitoring, advanced pipeline materials and integrity, retrofitting natural gas pipelines for CO2 transport and more. Increased coordination between the Department of Energy (DOE) and other federal agencies, such as PHMSA, the National Institute for Standards and Technology (NIST) and FERC will also be key to expanding critical RD&D efforts for CO2 pipeline infrastructure. 

A key opportunity for Congress is to reintroduce and advance the bipartisan Next Generation Pipelines Research and Development Act, which passed the House of Representatives during the 118th Congress. This legislation would modernize our pipeline system by authorizing the U.S. Department of Energy’s research and development programs focused on various pipeline technologies and uses, including the transportation of carbon dioxide. 

Reauthorize PHMSA – PHMSA’s three-year authorization in the bipartisan PIPES Act of 2020 expired in September 2023. Reauthorizing and providing updated funding profiles for PHMSA’s activities and programs are critical for ensuring a safe and reliable pipeline network across the United States. During the 118th Congress, PHMSA reauthorization legislation, the PIPES Act of 2023, led by Chairman Sam Graves (R-MO), passed the House Committee on Transportation and Infrastructure with strong bipartisan support. This Congress, policymakers could reintroduce this legislation, which would mandate that the agency finalize updated CO2 pipeline safety rules.

By building CO2 pipeline infrastructure, we are not only building our capacity to reduce emissions and protect our environment, we’re also creating jobs, bolstering local economies and continuing to use the energy sources that make our country strong. In America, we’re not afraid to build — it’s what we do.

Coastal Blue Carbon 101

Blue carbon is the term used to describe the “watery” nature of carbon captured by the ocean and coastal ecosystems. Coastal blue carbon ecosystems refer to biomass-based coastal habitats, such as salt marshes, mangroves and seagrass meadows, that store carbon dioxide through photosynthesis. These ecosystems are a major carbon sink - storing about 50 percent of the Earth’s carbon, despite occupying less than 5 percent of global land area and less than 2 percent of the ocean. In addition to their carbon storage potential, these ecosystems create flood-resilient communities, provide economic benefits by supporting fisheries, enhance property values and improve nutrient cycling. However, the loss and degradation of coastal blue carbon ecosystems reduce future carbon sequestration potential and can emit carbon dioxide (CO2) back into the atmosphere. Therefore, the restoration, maintenance and conservation of these areas are essential to achieving global emissions reduction goals. Together, this makes coastal blue carbon ecosystems among the world's greatest natural tools to address climate-related challenges today. In fact, the Intergovernmental Panel on Climate Change (IPCC) has recognized coastal blue carbon as a necessary pathway to harness the resiliency of nature and naturally remove excess carbon from the atmosphere.  

This Coastal Blue Carbon 101 provides an overview of this promising natural carbon removal solution and policies that may bolster additional deployment across coastal states. Recommendations include:

What is Coastal Blue Carbon?

A Nature-based Carbon Removal Solution –
Coastal blue carbon is considered a nature-based carbon dioxide removal (CDR) solution. Nature-based CDR solutions remove and store carbon from the atmosphere through naturally occurring processes - like photosynthesis, which takes sunlight and CO2 from the air to make water and sugar for the plant. Nature-based CDR solutions are recognized as a promising set of pathways to reduce emissions, with the global voluntary carbon market recording a 170% increase in the traded volume of nature-based carbon credits between 2017 and 2018.

The Most Efficient Natural Carbon Sink –
In the U.S., coastal blue carbon ecosystems sequester an estimated additional 6.7 million tons of carbon dioxide equivalents (MtCO2e) annually, as of 2022. This is equivalent to CO2 emissions from energy usage in over 960 thousand U.S. homes each year. Globally, coastal blue carbon ecosystems sequester 0.84 billion tons (Gt) CO2 per year. It has been estimated that coastal blue carbon can annually sequester carbon at a rate ten times greater than mature tropical forests while covering far less area, making them the most efficient natural carbon sinks in the world, all while providing multiple co-benefits. This is possible because coastal blue carbon ecosystems are made up of oxygen-depleted flooded soil, which slows down decomposition.

A Solution for Economic and Environmental Resiliency –
Harnessing coastal blue carbon pathways can improve resiliency and bolster the economies of coastal communities by creating solutions in the face of extreme weather and changes in marine ecosystems. These nature-based solutions can be integrated into community planning to provide (1) billions of dollars in savings during floods, (2) economic benefits by maintaining habitats for marine life used by fisheries that support economic activity and food supply, (3)  improved water quality for residents and wildlife and (4) protect dozens of military installments and training grounds from storm surge and coastal flooding.

Types of Coastal Blue Carbon

The three main types of coastal blue carbon ecosystems are salt marshes, mangrove forests and seagrass meadows. Salt marshes are coastal wetlands flooded and drained by salt water brought in by the tides and are dominated by plants such as grasses, reeds and sedges. Salt marshes can be found on the coasts of the United States, with about half of the nation’s salt marshes located along the Gulf Coast. Mangroves are salt-tolerant trees that grow where land and sea meet, typically along shores, rivers and estuaries. Mangrove forests in the U.S. are found throughout the Gulf of Mexico, although increases in water temperature may lead to their northward expansion Figure 1. Seagrass is aquatic grass found in shallow coastal waters around the world. Figure 2 shows that sea level determines the designation of these ecosystems. Tidal marshes and mangrove forests exist both above and below sea level, while seagrass is strictly underwater. Table 1 provides a comparison between these three coastal blue carbon ecosystems.

Water level determines the location of coastal blue carbon ecosystems

Source: Nature Reviews, Earth & Environment

Comparison of coastal blue carbon ecosystems

Sources: 1. Louisiana mangrove projects, 2. Louisiana salt marsh project, 3. Florida seagrass project

Estimated ranges of coastal blue carbon in the U.S. from the Commission for Environmental Cooperation. Estimated carbon sequestration rates of coastal blue carbon pathways from the National Academies of Sciences, Engineering, and Medicine.

Mangroves

Mangroves are salt-tolerant trees that grow where land and sea meet, typically along shores, rivers and estuaries. Mangrove forests cover 33-49 million acres around the world, which is on average the size of the state of Iowa. A majority of mangrove forests in the U.S. can be found on the Gulf Coast, primarily in Florida and Louisiana, due to warmer temperatures. An estimated 500,000 acres of mangroves in the coastal areas of Central and South Florida.

Mangrove carbon sequestration –
Mangrove forests store more than 11.7 Gt of carbon globally, which is equivalent to 22% of 2023 global emissions. The restoration of all feasible mangrove regions in the world has been estimated to sequester up to an additional 688 Mt of carbon over a 40-year period, a greater carbon storage potential than afforestation. With optimal market incentives in place, 20% of global mangrove forests can be restored and contribute to the removal of 29.8 MtCO2e each year. The mangrove forests in Florida’s Everglades National Park can store carbon valued at nearly $3 billion. 

Benefits of mangrove restoration and protection –
Mangroves make up resilient coastal ecosystems that withstand damage from storms, preventing over $11 billion in property damage globally every year. For example, during Hurricane Irma in Florida, mangroves averted $1.5 billion in storm damages and protected over half a million people. Mangrove forests also provide key ecosystem benefits, including (1) serving as a habitat and nursery for many marine species, (2) providing economic opportunity for coastal communities and (3) supplying seafood for millions of people. They are also valuable for fisheries, with an annual median value of over $15,000 per acre for fisheries in the Gulf of California.

Salt Marshes

Salt marshes are coastal grassland ecosystems that are regularly flooded by seawater. North America is home to around 40% of global salt marshes. The U.S. has approximately 3.8 million acres of salt marshes, about a quarter larger than the state of Connecticut. A vast interconnected 1 million acres stretches from North Carolina to Florida. Louisiana accounts for up to 40% of the coastal salt marshes in the contiguous U.S.

Salt marsh carbon sequestration –
Globally, salt marshes store an estimated 1.4-2.4 Gt of carbon, which is equivalent to removing over 571 million vehicles from the road each year. Restored marshes could result in approximately 13 to 207 Mt of additional CO2 accumulation per year, equivalent to removing over 49 million vehicles from the road each year. This would offset 0.51% of global energy-related CO2 emissions, a substantial amount considering that salt marshes make up less than one percent of Earth’s surface. As of 2013, Louisiana’s marshes were estimated to bury and store 4.3 million tons of carbon per year, which was 47% of the capacity of North America and 5-21% of the global capacity for carbon in tidal wetlands. North Carolina’s salt marshes currently hold around 64 million tons of carbon and sequester an additional 250,000 tons each year.

Benefits of salt marsh restoration and protection –
Salt marshes play an important role in coastal flood protection, fisheries support and biodiversity enhancement. Salt marshes protect coastal communities from natural disasters that can cause infrastructural storm and flooding damage, preventing over $23 billion in storm protection services annually in the United States. Salt marshes, and the estuaries that support them, also provide habitat for more than 75% of commercial and recreational fish species in the U.S. including white shrimp, blue crab, redfish and flounder.

Seagrass

Seagrass meadows are underwater coastal ecosystems composed of aquatic grasses. Globally, the documented area of seagrass coverage is accepted by researchers to be an underestimate at 43.7 million acres, equivalent to nearly the size of the state of Oklahoma. This is an underestimate because many seagrass meadows have not been fully charted. Models that consider uncharted areas indicate a three times greater area of seagrass meadows at 148 million acres, or similar to the size of the state of Texas.

Seagrass Carbon Sequestration –
Globally, seagrass meadows could store as much as 8.5 Gt of carbon, equivalent to energy emissions from over 1.1 billion homes in the U.S. each year. This is as much as salt marshes and mangroves combined, primarily due to more global acreage. Seagrass habitat throughout the Mississippi River Delta stores up to 35 Mt of carbon, a greater storage capacity than any other terrestrial or marine area and even higher than seagrass habitats in other locations.

Benefits of seagrass restoration and protection –The 1 million acres of salt marshes within the South Atlantic states (Florida, Georgia, South Carolina and North Carolina) shield over a dozen military installations and training grounds from storm surges and coastal flooding. Economically, seagrass meadows contribute over $20 billion each year to Florida by providing habitat for commercially and recreationally important fish. For instance, a single acre of seagrass meadow can be home to 40,000 fish and 50 million invertebrates. Additionally, coastal tourism and recreation in seagrass ecosystems along Florida’s coast generates $250 million annually across 8,000 jobs and 500 companies.

Policy

Research and Development (R&D) — Continued support for coastal blue carbon R&D initiatives, as carried out by Federal research agencies like the National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA), Department of Energy (DOE), U.S. Geological Survey (USGS) and the National Science Foundation (NSF), will be important to understand the carbon sequestration and storage potential of coastal blue carbon projects. R&D initiatives could include long-term research studies examining the impact of (1) different coastal ecosystems, (2) plant species and (3) changes in climate or management during the maintenance of projects. R&D will also be needed to improve the consistency and accuracy of measurement, monitoring, reporting and verification (MMRV) of emissions from coastal blue carbon projects by improving remote sensing measurement tools and methods, including for satellites and aircraft. 

Data Collaboration and Coordination — A collaborative and coordinated effort between federal agencies to map current and future coastal blue carbon ecosystems is necessary to determine geographic areas with the greatest potential for increasing blue carbon stocks. This collaborative data resource could expand on existing projects to include information on ongoing and planned coastal blue carbon projects. A project that could be expanded is the NASA-USGS National Blue Carbon Monitoring System, which integrates nationally available data sets, satellite data and field data to refine models used to measure carbon stocks and fluxes in changing coastal wetlands. 

Wide-scale Deployment —  To support the wide-scale deployment of coastal blue carbon pathways, coastal restoration and creation projects could design their planning processes with carbon removal and sequestration built-in. An existing projects that could implement this is the Department of Defense’s Readiness and Environmental Protection Integration Program (REPI), which preserves natural habitats near military installations through stakeholder partnerships. Market incentives and technology-inclusive regulatory pathways may be helpful in encouraging the incorporation of carbon removal into coastal restoration planning processes. Market incentives could look like tax incentives aimed at encouraging the incorporation of carbon measurements into projects, and purchase prizes, such as DOE’s Commercial CDR Purchase Pilot Prize, which aims to demonstrate how technology-neutral CDR purchase contracts can catalyze innovation. Streamlined permitting and regulatory processes that reflect the value of coastal blue carbon projects could also increase deployment and carbon removal.

Advanced Nuclear Fuel 201

Congratulations! If you have read our Nuclear Fuel 101, you are already well on your way to understanding the importance of the nuclear fuel supply chain. This second installation goes a bit further, discussing what happens after fuel is used, innovations in nuclear fuel and why new types of fuel are important for new reactor designs. 

Innovative Reactors Demand Innovative Fuel

Most new advanced reactor designs incorporate passive and inherent safety features (like heat transfer) that remove the need for active, engineered safety systems (like a pump or valve). This allows designs to shut down naturally and safely in case of an event, like a total loss of power.

Advanced reactors are designed to be smaller, more affordable, safer, and more fuel efficient. Like other types of new reactors – fast reactors – can harness the energy from used fuel. This could reduce proliferation risks and decrease the volume of high-level nuclear waste by around 85%. Currently, the U.S. safely stores used nuclear fuel at more than 80 sites across 35 states.

Used Fuel Storage and Recycling: The Back End of The Nuclear Fuel Cycle

After nuclear fuel is used in nuclear reactors, there are a few options for managing the fuel.

Storage. When removed from any type of reactor, nuclear fuel continues to emit both radiation and heat. Once the fuel has reached the end of its useful life, the assembly is loaded into a nearby storage pool to allow the heat and radiation levels to decrease. After several years, the fuel may be transferred to naturally-ventilated storage, typically in dry casks like the ones shown below at the Comanche Peak Nuclear Power Plant.

The Comanche Peak Nuclear Plant has provided jobs for 1,300 workers since 1990 and supplies Texans with 2,425 MWe, enough to power 500,000 homes.

Recycling. One factor that makes nuclear energy so unique is the ability to reprocess and recycle used fuel. In a reactor, uranium splits into two new atoms (or elements). Over time, these new atoms build up like dirt on a windshield until the fuel is no longer usable. Used fuel reprocessing removes that “dirt,” giving the remaining uranium a second life. Even after several years in a reactor, the fuel retains more than 90% of its potential energy. Globally, in 2019, recycled fuel replaced the need for more than 2,200 tons of new natural uranium, despite reprocessing capacity being limited to France, the U.K., Russia, Japan and India.

The Nuclear Fuel Cycle

Source: World Nuclear Association

Innovations in Nuclear Fuel

There are a number of innovations in nuclear fuel that are currently in early stage use or research, development and demonstration (RD&D) phases. 

Recycling Innovation: MOX fuel is recycled fuel for existing reactors.

Mixed oxide fuel (MOX) is the second, third, fourth and even fifth life of the low-enriched uranium (LEU) from light water reactors (LWRs). Programs that leverage MOX fuel exist in Europe, Russia, and Japan. MOX fuel has been used commercially since the 1980s, and currently fuels about 10% of France’s nuclear plants. 

Making MOX fuel requires mixing depleted uranium with plutonium. Depleted uranium is the less-valuable coproduct from uranium enrichment. Plutonium is produced naturally in the reactor’s fuel during operation and can be extracted from used fuel during reprocessing. 

MOX fuel can be used in qualified existing reactors alongside fresh fuel. They decrease the overall amount of waste produced per megawatt, reduce the consumption of natural uranium by about 20% with each recycle and can be recycled up to five times.

Fuel Form Innovation: TRISO pellets are the safest form of fuel for advanced reactors. 

Tri-structural isotropic fuel (TRISO) is an innovation in fuel form that makes it impossible for the fuel to meltdown. The idea behind TRISO fuel is to give each piece of nuclear fuel, no bigger than the tip of a pen, its own containment and pressure vessel, two vital safety features in a full-sized plant. This feature makes the fuel durable even at very high temperatures. TRISO particles remain securely intact up to 3250°F, a temperature that exceeds even worst-case conditions in a reactor. For context, high-temperature reactors operate between 1350 and 1750°F, well below the melting threshold for TRISO. The U.S. Department of Defense and NASA both use TRISO fuel for their upcoming reactor programs because of its exceptional safety features.

Fuel Composition Innovation: Thorium-based fuel could be used in addition to uranium. 

Thorium as an alternative source of nuclear fuel has been a promising innovation over the past decade. Thorium occurs naturally as thorium-232. It is slightly radioactive, is about three times more abundant than uranium, and has a half-life that is three times the age of the Earth. In a reactor, it is possible to create more thorium than is used, although economic and technical hurdles remain. 

India has established the long-term goal of a three-stage, thorium-based, closed-loop fuel cycle. Stage one involves pressurized water reactors fueled by natural uranium. In stage two, the used fuel from stage one will be reprocessed to recover plutonium, which will be used to fuel India’s fast reactors. Finally, stage three would involve fueling advanced heavy water reactors with thorium-plutonium fuel. Using thorium-based fuel could help diversify the fuel cycle, however thorium is expensive to extract, and additional RD&D is needed to capture its full potential.

Fuel Composition Innovation: Natural uranium can reduce waste and proliferation risk.

Another potential composition for nuclear fuel is natural uranium (i.e., unenriched uranium) fuel pellets. Natural uranium does not require enrichment, and enrichment infrastructure is required for making nuclear weapons; therefore, if a country wants to reduce proliferation risk, it can opt to use natural uranium as a fuel source. 

Two schools of reactors can take advantage of natural uranium: heavy water reactors and fast reactors. The most famous heavy water reactor design is the Canadian CANDU reactor which first went online in 1977. Canada has exported CANDU reactors to Argentina, China, India, Pakistan, Romania and South Korea. There are 30 CANDU reactors in operation globally. British-designed Magnox reactors also use natural uranium fuel, and have been in operation since 1956. Because natural uranium is unenriched, the storage and reprocessing is more simple and less expensive than for enriched uranium fuel. 

Fast reactors are designed to operate with high-energy, fast neutrons (imagine neutrons moving 9000 miles per second). Fast reactors are less common today than CANDU reactors but dominate the field of advanced reactors because they are up to 60 times more fuel efficient than today’s LWRs.

Recycling Innovation: Fast reactor fuel is more efficient and consumes waste. 

Fast reactors were some of the first nuclear reactors built in the U.S. because they can extract more energy from fuel than traditional LWRs, and can use energy from material that would be considered “waste” in traditional LWRs. The Experimental Breeder Reactor (EBR-I and EBR-II) test facilities were operational from 1951 to 1964 and 1965 to 1994, respectively. EBR-I was the world’s first plant to generate electricity from atomic energy, and the combined test facilities successfully demonstrated a complete breeder reactor cycle with on-site fuel reprocessing. 

France also took an early interest in recycling fuel in fast reactors. France’s Phénix prototype reactor, which operated from 1973 to 2009, was designed to maximize fuel utilization and recycle all of the plutonium it produced. The recycling facility, the Marcoule Pilot Plant has reprocessed a total 25 tons of fuel from the Phénix reactor. 

Because some of the fuel was reprocessed multiple times, France was able to illustrate a closed-loop fuel cycle and demonstrate the value of the fast breeder reactor system.

What's in Fuel

Source: Japan Nuclear Fuel Limited

Why it Matters

Fuel form, composition and enrichment level create many combinations of fuel types that could service remote communities, military installations and massive metropolitan centers. Nuclear batteries power our space missions and nuclear reactors power our submarines, but the individual technologies taking advantage of that energy look drastically different. 

Completely carbon-free, nuclear energy powers nearly 20% of U.S. electricity consumption using variations of the same fuel developed in the 1940s. More than 80 years later, new advanced reactor designs are gaining momentum and we could see them in the marketplace this decade. The fuels in development for these new designs enable the recycling of used fuel and prevent the reactor from melting down. Although the U.S. does not currently recycle any used nuclear fuel, in 2022 the Department of Energy awarded $38 million for twelve projects aimed at developing domestic recycling capacity. 

Asking everyone to have a complete understanding of nuclear fuel is unnecessary, but it is important that people understand the magnitude of its potential to provide reliable, clean and affordable energy to our power grid.

Hydrogen 101

Hydrogen is the smallest atom in the universe. Yet, this tiny molecule has enormous potential to unlock some of our most significant energy challenges – electricity grid resilience, energy storage and clean manufacturing. Hydrogen, in its natural state, is really two hydrogen atoms linked together, and in that link is where energy is stored. Like an electron flowing through a transmission line, hydrogen holds energy that moves between the electricity, transportation and manufacturing sectors. Watch a video that further explains how hydrogen functions here.

Hydrogen is used widely today as a chemical in agriculture, chemical production and oil refining. The United States produces around 10 million metric tons of hydrogen, enough to power 2.4 million transcontinental flights for a Boeing 747. By 2050, hydrogen has the potential to decrease 7 Gt of global CO2 emissions each year. However, only a fraction of U.S. hydrogen production today is considered low-emissions. 

The innovation potential of hydrogen lies in its use as energy in new markets, such as energy storage, heavy-duty vehicles and manufacturing applications. Recent legislation, like the bipartisan Investment Infrastructure and Jobs Act of 2021 (IIJA) $8 billion Regional Clean Hydrogen Hubs, has helped accelerate the demonstration and deployment of low-emissions hydrogen while securing American leadership. To meet our clean energy goals, emissions reduction in the existing hydrogen infrastructure and significant new deployment of low-emissions hydrogen must be realized to meet the demand of new markets. 

How it works

Hydrogen Production (“the hydrogen rainbow”)

Hydrogen, in reality, is a colorless gas, but it is talked about widely using six color classifications: grey, blue, turquoise, brown, green and white. Today, adding carbon capture to existing hydrogen production facilities, a kind of blue hydrogen, is the least-expensive, nearest-term option to decarbonize existing production.

Production Methods - Hydrogen Rainbow

Source: DOE Pathway to Commercial Liftoff: Clean Hydrogen

Grey and Blue hydrogen are made by heating a natural gas and steam mixture, which produces CO2 as a byproduct. The grey hydrogen process allows CO2 to escape into the atmosphere, but the blue hydrogen process captures, utilizes or stores CO2. Carbon capture is already commercial, with facilities capturing millions of tons of CO2 worldwide – including in the United States. 

Turquoise hydrogen is produced through either gasification or pyrolysis with carbon capture.  Gasification means that biomass, such as used paper or waste from crops, is heated to release hydrogen gas and produces CO2 as a byproduct. The other process, pyrolysis, heats methane (i.e., natural gas) in a container without oxygen to separate the hydrogen and carbon atoms. Because there is no oxygen in the mix, carbon in the pyrolysis process does not turn into CO2. Instead, it becomes carbon black, a solid used to manufacture tires, mascara, water filters and more. One innovative American company producing hydrogen through pyrolysis is Monolith, which received a $1.04 billion conditional commitment from LPO to expand its facility in Nebraska.

Brown hydrogen is produced through the gasification of coal, which means that coal is heated with oxygen and steam to release hydrogen gas. This process also releases CO, CO2 and particulate matter as byproducts.

Green hydrogen is produced through electrolysis, which uses electricity to separate the oxygen and hydrogen atoms in water and is powered by low-emissions electricity sources. Producing hydrogen from electrolysis is possible regardless of the electricity source. Still, hydrogen is considered green only if the electricity is produced from a low-emissions energy source, such as nuclear, geothermal, hydropower or renewable energy. 

White hydrogen naturally occurs and is found in underground deposits. The process that forms geologic hydrogen is called serpentinization, during which water reacts with iron-rich mantle rocks at high temperatures to make hydrogen. Typically, other gasses are present in the hydrogen deposits, with N2, CH4, He and other noble gasses being the most common. In February 2024, the DOE’s Advanced Research Projects Agency-Energy (ARPA-E) selected 16 projects to receive a total of $20 million in funding to research the production of geologic hydrogen through stimulated mineralogical processes, meaning that there is potential to stimulate the production of white hydrogen.

 

Hydrogen Storage and Delivery

Storage

There are multiple ways to store hydrogen. One method is underground hydrogen storage, limited to excavated salt caverns and lined hard rock storage near production sites. Luckily, storage regions tend to overlap with production regions. This increases the viability of this storage method. Additionally, gaseous and liquid storage containers are currently used for industrial applications. Research, development, and deployment (RD&D) are needed to reduce costs, improve efficiency, and increase scalability for hydrogen storage.

Delivery

Currently, there are four main methods to deliver hydrogen:

Comparison of Hydrogen Delivery Methods

Source: DOE Pathways to Commercial Liftoff: Clean Hydrogen

Although smaller amounts of hydrogen in natural gas pipelines are considered safe, experts say blending larger ratios requires further research for feasibility. Natural gas infrastructure is more readily impacted by embrittlement and leakage when hydrogen is in the mix.

 

Hydrogen Utilization 

Regardless of how hydrogen is produced, it can be used in many applications, including as a feedstock for industry, a fuel for vehicles or power plants, or burned for heat.                                                                                                                              

Industry

Hydrogen has been used in American industries since the 1950s and is most widely used in refining (55%), ammonia and methanol (35%), and metals (8%). Ammonia, a component of fertilizer, is synthesized using hydrogen. Refineries use hydrogen to reduce the sulfur content in diesel fuel. It is also being developed as a feedstock to reduce CO2 emissions from the steel production process, making it an alternative to metallurgical coal. Also, hydrogen can be burned as a high-temperature heat source in heavy industry applications like cement and concrete manufacturing.

Natural Gas Blending

Today, hydrogen can be blended with natural gas in small quantities and used in many similar applications, such as home heating, high-grade heat for industry, and turbines for power generation. Turbine manufacturers design products that can co-fire hydrogen and natural gas or burn 100 percent hydrogen. Duke Energy will build and operate the U.S.’ first system capable of producing, storing and combusting 100% clean hydrogen in a combustion turbine. 

Fuel Cells

Fuel cells work the opposite of electrolyzers and use hydrogen to make water and electricity. Small fuel cells can be used in vehicles, and large ones can be used for reliable electricity, such as a hospital or data center backup generator. 

Energy Storage

Hydrogen is an emerging option for long-duration energy storage. Like natural gas, it can be stored for long periods and transported over distances. PG&E, in partnership with Energy Vault, is building the most extensive clean hydrogen long-duration energy storage system in the U.S., which can power about 2,000 electric customers for up to 48 hours.  

Major Federal Programs

The vast hydrogen ecosystem has the potential to decarbonize many clean energy technologies. Supporting these many decarbonization pathways requires significant coordination across offices in the DOE and other federal agencies. The DOE released the Pathways to Commercial Liftoff: Clean Hydrogen report and the U.S. National Clean Hydrogen Strategy and Roadmap in 2023. These strategies have common veins: the production cost of low-emissions hydrogen must be lowered to be cost-competitive, and successful demonstrations are important to scale these technologies.

Hydrogen Interagency Taskforce (HIT)

In August of 2023, the Hydrogen Interagency Taskforce (HIT), which is a partnership led by the Hydrogen and Fuel Cells Technology Office (HFTO), was announced to enact a coordinated approach for the advancement of clean hydrogen. The HIT consists of three working groups: “Supply and Demand at Scale,” “Infrastructure, Siting, and Permitting,” and “Analysis and Global Competitiveness.” The DOE will focus on RD&D, bolstering supply chains, developing a domestic and international market, and financing hydrogen projects as authorized by the IIJA. Non-energy agencies are also involved. The DOD, DOE and Homeland Security are developing an advanced fuel cell truck prototype, dubbed H2@Rescue, to provide zero-emissions power, heat and water to disaster sites. 

Regional Clean Hydrogen Hubs (H2Hubs) Program

In October 2023, the DOE preliminarily selected seven public-private partnerships to receive awards for the H2Hub program authorized by the IIJA. If implemented and supported properly, the $8 billion program will help launch the nascent hydrogen industry forward and decrease the cost of clean hydrogen.

States Awarded Hydrogen Hubs

Map of states selected for the DOE H2Hub’s award negotiations. Negotiations are expected to be completed in Q2 of 2024.

Source: DOE H2Hubs Press Release

Other IIJA Clean Hydrogen Programs

The IIJA also authorized $1 billion for the Clean Hydrogen Electrolysis Program, in which the DOE will establish an RD&D program to improve electrolyzers' efficiency, durability, and cost and bring them to commercialization. A complementary program, Clean Hydrogen Manufacturing and Recycling RD&D Activities, was authorized for $500 million in the IIJA for the DOE to create innovative approaches to increasing the reuse and recycling of clean hydrogen technologies. The DOE released a Request for Information (RFI) in February of 2022, asking stakeholders for ideas on program structure and thoughts on the current electrolyzer landscape. The DOE selected both programs' first tranche of projects simultaneously in March of 2024. The $750 million in joint funding will go to 52 projects across 24 states to support electrolyzer manufacturing, supply chains and components; fuel cell manufacturing and supply chains; and a recycling consortium. 

Policy Opportunity

Hydrogen has the potential to be an innovative solution to decarbonize the power and manufacturing sectors while making American energy cleaner, more secure and reliable. However, the simultaneous development of the hydrogen value chain (i.e., production, storage, end-use) is a barrier to deployment due to varying technological readiness levels, lack of long-term offtake and the need for dedicated hydrogen infrastructure. To meet emissions reduction goals, the following policies are needed to reach the widespread adoption of hydrogen.

  1. Technology-neutral policy — Develop policies to encourage and incentivize diverse, low-emissions hydrogen production methods regardless of the feedstock.
  2. Support infrastructure deployment — Advance policies that further expand and decrease the cost of midstream and end-use infrastructure. 
  3. Research and development — Develop regulations in preparation for a mature and scaled industry while advancing the commercialization of clean hydrogen technologies.
  4. Wide-scale deployment — Improve cost-competitiveness of clean hydrogen and support reliable offtake for hydrogen producers.

Fertilizer Innovations 101

The U.S. agricultural productivity boom in the mid-20th century resulted from innovative fertilizer technologies. Novel technologies like synthetic fertilizers helped revolutionize fuel, food, fiber and feed production. Synthetic fertilizers are also directly linked to U.S. economic growth and prosperity and reduced reliance on other countries. Today, the U.S. continues to lead the world in finding new ways to enhance agricultural productivity and efficiency while producing clean and reliable ammonia for fertilizer production and reducing agricultural sector emissions. 

Fertilizer provides essential plant nutrients to maximize productivity

Agricultural resources like crops and other feedstocks grow and produce food, fuel, fiber and feed through photosynthesis, which uses water, sunlight and CO2 from the atmosphere. Nutrients like nitrogen, phosphorus and potassium are needed to ensure the health and productivity of these resources to optimize growth and yields, similar to how people need a diverse, nutritious diet to stay healthy and grow. These essential nutrients can be found naturally in agricultural fields in varying amounts, depending on the location. However, for certain crops, fertilizers can optimize these conditions. For example, long-term research in Iowa showed that corn yields averaged 60 bushels per acre without fertilizer, and corn fertilized with nitrogen easily yields 200 bushels per acre. Fertilizers for crops are like food for humans, supplying essential nutrients to plants. Fertilizer can be stored, transported and applied in various forms (i.e., liquid, solid). The type of fertilizer used depends on the plant being grown and environmental conditions, similar to how the food intake for a marathon runner will differ from that of a weightlifter.

Figure 1. Fertilizers for Crops Is Like Food for Humans

The Haber-Bosch process, invented in 1913, is a crucial scientific discovery, and the technological innovations that came from it revolutionized the world. The Haber-Bosch process is the main industrial method of producing ammonia. The most prominent innovation from the process is the creation of synthetic nitrogen fertilizer. This spurred the rapid growth in crop productivity beginning in the mid-1900s and supported the growing global population. Long-term field studies across the U.S. dating back before the development and use of synthetic fertilizers have shown the positive impact of fertilizer use on crop yield. A review of crop production across 362 crop growing seasons showed that synthetic fertilizers are responsible for at least 30-50 percent of crop yields. Location-specific research done on the Magruder Plots in Oklahoma, the oldest continuous soil fertility research plots in the Great Plains region of the U.S., found that, on average, over 71 years, nitrogen and phosphorus fertilization was responsible for 40% of wheat yield in America (Figure 2).

Figure 2. Wheat yield attributable to nitrogen and phosphorus fertilizer in the Oklahoma State University Magruder plots (1930-2000)

Source: Better Crops

U.S. leadership in fertilizer innovation is needed now

Food security is national security. The U.S. food system is heavily reliant on fertilizer production from adversaries like Russia and China, which could limit fertilizer supply to the U.S. and reduce America’s ability to provide affordable food and fuel domestically and globally. For example, the Russia-Ukraine conflict resulted in fertilizer trade restrictions across the globe, driving up fertilizer prices and increasing grain prices. Therefore, U.S. leadership in fertilizer production is essential to reduce American dependence on international fertilizer production and to ensure American farmers have access to affordable and reliable fertilizer to fuel and feed the nation. 

As the U.S. leads in fertilizer innovation through initiatives like USDA’s Fertilizer Product Expansion Program (FPEP) that aims to expand the manufacturing and processing of fertilizer in the U.S., American ingenuity is also beginning to address the emissions impact of fertilizers, as the production and use of fertilizer accounts for approximately 5% of global emissions. Recent studies on the full life-cycle of fertilizers found that emissions could be reduced by 80% by 2050 without impacting productivity. Fertilizer production accounts for around one-third of synthetic fertilizer emissions, while the remaining two-thirds derive from fertilizer use. As a result, if we want to reduce emissions, we must find a way to both decarbonize fertilizer production and develop technologies and practices to reduce emissions from nitrogen fertilizer. Technological innovation will be key to ensuring that we do so in a manner that does not increase costs or decrease yields. 

Clean ammonia can reduce fertilizer production emissions

Ammonia production is a major global industry that accounts for 2% of total energy consumption and 1.3% of CO2 emissions. It is produced by combining nitrogen from the air and hydrogen through the Haber-Bosch process. Approximately 70 percent of ammonia produced is used for agricultural fertilizers. The U.S. has cleaner ammonia production compared to its international counterparts, with American ammonia being approximately 24% less carbon intensive than the global average. The U.S. is also twice as efficient at producing ammonia as China, the largest producer and consumer of chemicals. 
As the global population increases and becomes more affluent, demand for fertilizer will increase, resulting in the need for more ammonia. The U.S. is primed to lead in clean ammonia production as demand rises. To maintain America’s competitive advantage, the U.S. needs to support the research and development (R&D) of innovations that reduce emissions during ammonia production, such as electrolysis, methane pyrolysis and carbon capture and storage. Supporting R&D efforts can make American ammonia more affordable, reliable and cleaner and encourage the deployment and commercialization of viable technologies to reach net-zero goals by 2050.

Innovations to reduce agricultural nitrous oxide emissions

Nitrous oxide, like carbon dioxide, is a gas in the atmosphere that accounts for around 6 percent of U.S. greenhouse gas emissions. Nitrous oxide is also 300 times more effective at trapping heat than carbon dioxide. In agriculture, more than 70 percent of nitrous oxide comes from agricultural soil management. Nitrous oxide emissions result from natural microbial processes in the soil that convert nitrogen, an important nutrient for plants, to nitrous oxide. Multiple factors such as the amount of nitrogen in the soil, type and amount of fertilizer used, crop type and soil conditions (including type, pH, temperature and moisture level) can impact the amount of nitrous oxide emitted. As such, innovations to reduce nitrous oxide will differ based on location, crop type and nutrient management practices. Implementation of the 4R principles (right source, right rate, right time and right place) through the 4R Nutrient Stewardship Framework, developed by the fertilizer industry worldwide, is one way the agriculture sector is working to reduce emissions. Examples of innovations include enhanced efficiency fertilizers that control fertilizer release or prevent the biological process of nitrous oxide emissions, breeding and engineering crops with greater nitrogen use efficiencies and biostimulants (i.e., microbial fertilizers) that support plant growth and nutrient uptake.

U.S. agriculture is highly productive due to the historical adoption of innovations like enhanced seeds. Continued R&D that correlates reductions in nitrous oxide emissions with cutting-edge technologies could encourage more innovation deployment and more affordable implementation. 

Policy Opportunities 

Support for and utilization of policy levers can enhance fertilizer innovation in the U.S., further improving agricultural productivity and efficiency while reducing emissions from the agricultural sector. 

  1. Clean Ammonia Research, Development and Deployment — Support research and development of low-carbon ammonia production technologies to improve fertilizer affordability and reduce emissions. Encourage deploying viable technologies. 
  2. Nitrous Oxide Research and Development — Increase investments in research and development of innovations that reduce agricultural nitrous oxide emissions, such as through the support of targeted research programs like the Agriculture Advanced Research and Development Authority (AGARDA), more long-term, on-farm research trials and improvements to nitrous oxide measurements. 
  3. Fertilizer Innovation Demonstration and Deployment — Explore pathways to encourage deploying cutting-edge innovations for reducing nitrous oxide emissions, including through programs like the U.S. Department of Agriculture's Natural Resource Conservation Service’s Conservation Innovation Grants. 

Coordination between Relevant Federal Agencies — Enhance the coordination and collaboration among existing and future agriculture innovation research, such as between the USDA, DOE, NASA and NSF, to leverage resources across the federal government and streamline the innovation pipeline from research to deployment.

Nuclear Fuel 101

Agricultural Innovation 101

Ocean CDR Permitting and Regulations 101

Biomass Hybrid CDR Innovations 101

Pore Space 101: Carbon Capture Can't Rock and Roll Without Storage