The Federal Hydrogen Hub Community Guide

Specific Types of Hydrogen Hub Projects That Could Impact Your Community

Learn about potential community and climate impacts, and environmental approvals

The Hillcrest neighborhood near “Refinery Row” in Corpus Christi, TX, on May 2, 2022. (Eddie Seal for Earthjustice)

The Hillcrest neighborhood near "Refinery Row" in Corpus Christi, TX. About 60% of current U.S. hydrogen demand comes from crude oil refineries. (Eddie Seal for Earthjustice)

This resource is part of the Federal Hydrogen Hub Community Guide.

Each Hydrogen Hub will include a wide range of projects — from facilities that produce hydrogen, to facilities that use hydrogen, to projects that transport or store hydrogen or CO₂ generated during hydrogen production.

Potential harms and benefits from specific projects will vary significantly.

Threats from a hydrogen buildout

Hydrogen is highly flammable and prone to leaking (it’s the smallest molecule in the universe).
Pumping hydrogen through existing gas pipelines risks leaks and explosions.
When hydrogen leaks into the atmosphere, its climate-warming impact is nearly 12 times greater than CO₂’s.
Producing hydrogen requires a massive amount of energy. Unless that energy comes from renewables that meet strict criteria, hydrogen production will increase pollution.
When hydrogen is burned, it emits health-harming nitrogen oxides^‡.
When hydrogen is used where we can directly electrify instead, hydrogen risks delaying the clean energy transition and making it more expensive.

This section covers types of Hydrogen Hub projects that communities are likely to face based on Hubs’ publicly announced plans and identifies potential community and climate impacts from each. As more Hub details are made available, this section will be updated.

Projects that Produce Hydrogen

Hydrogen can be produced from multiple sources, like water, fossil fuels, or biomass^‡, using different kinds of technologies, like electrolysis^‡ or methane reforming.

These different production methods can have substantially different community-level and climate impacts, and they are often characterized by colors, like green^‡, pink^‡, gray^‡, or blue hydrogen^‡. We discuss each of these types of hydrogen below.

Projects that Produce Hydrogen from Fossil Fuels

Impacts | Environmental Approvals

Most of the Hydrogen Hubs have announced projects that would produce hydrogen from fossil methane^‡.

Hydrogen that is produced from fossil methane is often called “gray” or “blue” hydrogen.

Gray hydrogen is made from fossil methane most often using one of two technologies: steam methane reforming (SMR)^‡ or autothermal reforming (ATR)^‡. Most hydrogen produced in the U.S. today — about 10 million metric tons — is gray hydrogen produced by gas companies and oil refineries.
Blue hydrogen is also made from fossil methane through either SMR or ATR technologies. The difference between gray and blue hydrogen is that blue hydrogen includes carbon capture^‡ technology.

According to publicly available information, all Hub projects that produce hydrogen from fossil fuels will be blue hydrogen projects, meaning they will include carbon capture technology.

A blue hydrogen facility is a large, industrial facility, similar to a refinery, with piping and smokestacks transporting and emitting gases.

The following table shows the community-level and climate impacts of blue hydrogen projects.

Community-Level Impact

Some existing facilities that are retrofitted with carbon capture technology may upgrade their controls for other pollutants, like sulfur dioxide and particulate matter, so that their carbon capture technology can function efficiently, which would reduce emissions of these other pollutants.

Community-Level Impact

Blue hydrogen facilities emit substantial health-harming pollution, including NO_x^‡, sulfur dioxide^‡, particulate matter^‡, carbon monoxide^‡, and volatile organic compounds^‡.

Carbon capture technology alone does not capture pollution other than CO₂. Additionally, capturing carbon requires a lot of energy, which often comes from burning fossil fuels, further increasing air pollution in most cases.

Community-Level Impact

Because blue hydrogen facilities use methane^‡ from fossil fuels, new fossil methane pipelines may be built and connected to the facility.

Community-Level Impact

Blue hydrogen facilities require large amounts of water, which could strain local water resources. Depending on the type of carbon capture technology, it may also create water pollution.

Community-Level & Climate Impact

Blue hydrogen facilities might also transport CO₂ captured from their processes to a storage site.

The CO₂ would likely be transported by pipeline to an off-site location, in which case all the impacts of CO₂ pipelines apply along the pipeline route, as well as the impacts of CO₂ storage at the storage site.

→ In this Guide: CO₂ Pipelines and CO₂ Storage

Climate Impact

Blue hydrogen facilities emit substantial climate-warming pollution, like CO₂ and methane. Carbon capture technology does not capture all CO₂ emissions.

Only a few blue hydrogen facilities operate today, and their CO₂ capture rates are between 40 and 70%. It also does not capture other greenhouse gas emissions, such as methane.

Climate Impact

Extracting fossil methane and transporting it to the production site produces methane emissions.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

A blue hydrogen facility will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

A blue hydrogen facility might need:

An environmental impact review under federal NEPA and/or similar state laws
A Section 404 permit if the facility is constructed near a waterway or wetland, as well as state 401 permits under the Clean Water Act
Land use approvals
Permits under the Rivers and Harbors Act if dredging and/or filling of watered areas is needed
A Class VI permit for injecting CO₂ into wells for underground storage
Approvals under the Endangered Species Act
Approvals under the National Historic Preservation Act
Approvals if it plans to seek other federal subsidies, like federal tax credits for producing “clean” hydrogen or for capturing and storing CO₂, or state or local subsidies
Depending on the state, additional permits beyond those required by the federal government

Each of these permits and approvals could have its own public comment period, legal requirements, decision-makers, and appeal process. See details in Federal, State, and Local Permits and Approvals in the section Tools for Communities.

Projects that Produce Hydrogen from Water

Impacts | Environmental Approvals

All of the Hydrogen Hubs have announced some projects that would produce hydrogen by using energy to extract it from water.

Hydrogen that is produced from water is often called “green” or “pink” hydrogen.

Green hydrogen^‡ is made using 100% renewable electricity — like solar and wind — to split hydrogen from water molecules through a process called electrolysis^‡, using a technology called an electrolyzer.
Pink hydrogen is the same as green, except that nuclear energy^‡ is used to power the electrolyzer instead of renewable electricity.

Unlike the technologies used to produce gray or blue hydrogen (SMR/ATR), which produce substantial pollution from dirty feedstocks, an electrolyzer produces only hydrogen and oxygen and the feedstocks are water and electricity.

Truly Clean Hydrogen Production

Producing hydrogen from water through electrolysis requires an immense amount of energy. Green^‡ or pink hydrogen^‡ can only be produced without massive CO₂ emissions and other pollution if it uses sources of clean energy that are “new, now, and near.” These criteria are often called the “three pillars” of clean hydrogen production:

New — The electrolyzer^‡ is powered by new, not existing, renewable sources of energy. This requirement is often called “additionality” or “incrementality.” Some would propose that this requirement is met when an electrolyzer is powered by a nuclear plant that increases its energy production rather than new renewables. In that case, the impacts of increased nuclear energy production^‡ must be considered.
Now — Those new renewable sources produce electricity during the same hours that the electrolyzer is running. This requirement is often called “hourly matching” or “temporal matching.”
Near — Those new renewable sources are located near the electrolyzer and can deliver power to the process. This requirement is often called “deliverability.”

Without these three pillars, green or pink hydrogen production will divert enormous amounts of zero-carbon electricity that is already in use. Making up for this loss will require more electricity from fossil fuel power plants. This is true even if the hydrogen project claims it will run its electrolyzer on only zero-carbon electricity.

Additionality ensures that we don’t divert existing zero-carbon electricity from the grid or other uses to power hydrogen production.
Hourly matching and deliverability account for the fact that the emissions impact of running an electrolyzer depends on time and location.

Some parts of our grid get more electricity from fossil fuel power plants than other parts. Likewise, our electric grid depends more on fossil fuel power plants at certain hours of the day. Hourly matching and deliverability ensure that electrolyzers only run when and where zero-carbon resources are actually providing zero-carbon electricity to the grid.

A green or pink hydrogen facility will mostly consist of a warehouse-like building housing one or more electrolyzers. The electricity produced to power the electrolyzer(s) may be located on or off-site.

A major concern with green and pink hydrogen is whether the zero-carbon electricity used to power the electrolyzer is diverted from the electric grid. Zero-carbon energy diverted from the grid has to be replaced, and most often it is replaced with dirty fossil energy, increasing community-level and climate pollution in the communities that host fossil fuel power plants. In this case, hydrogen produced from water is not clean. A related concern is the highly inefficient use of zero-carbon electricity to produce green or pink hydrogen for uses that can be electrified instead.

Community-Level Impact

Green hydrogen can be made without causing community-level pollution only if it is truly clean hydrogen — meaning the production process is powered by sources of clean energy that are “new, now, and near.”^‡

Community-Level Impact

If it is not truly clean hydrogen^‡, green hydrogen production would cause dirty fossil fuel power plants to run longer and/or more frequently, significantly increasing local air pollution around those plants.

Community-Level Impact

Pink hydrogen production will involve all the potential local health risks of nuclear energy production and will cause the same indirect impacts as green hydrogen unless it is powered by sources of clean energy that are “new, now, and near.”

Community-Level Impact

Producing hydrogen from water requires large amounts of water, which could strain local water resources.

Climate Impact

Green and pink hydrogen production will cause significant increases in CO₂ pollution unless they are powered by sources of clean energy that are “new, now, and near.”

Climate Impact

Green and pink hydrogen production risks wasting large amounts of zero-carbon electricity.

Electrolysis requires a tremendous amount of electricity, and it is always more efficient to directly use zero-carbon electricity where possible than to use it to produce hydrogen.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

A green or pink hydrogen facility might need:

An environmental impact review under NEPA and/or similar state laws
Land use approvals
Approvals if it plans to seek other federal subsidies, like federal tax credits for producing “clean” hydrogen, or state or local subsidies

Projects that Produce Hydrogen from Biomass

Impacts | Environmental Approvals

The Appalachian Hydrogen Hub (ARCH2) in West Virginia, Ohio, and Pennsylvania and the California Hydrogen Hub (ARCHES) propose to produce hydrogen from biomass^‡.

According to DOE, biomass includes:

agriculture crop residues,
forest residues,
crops grown specifically for energy use,
organic municipal solid waste, and
animal waste.

These waste streams can be converted into hydrogen via various chemical processes, depending on the starting material.

Solid biomass (like forest residues) will typically undergo a gasification^‡ or pyrolysis process that requires high heat and pressure.
Gaseous waste streams (e.g., landfill, sewage, or animal waste biogas^‡) can be upgraded (e.g. cleaned of impurities) before undergoing SMR^‡ or ATR^‡ just like fossil methane.

→ In this Guide: Projects that produce hydrogen from fossil fuels

A biomass hydrogen facility is large and looks like a refinery, with piping and smokestacks transporting and emitting gases that are part of the process.

Community-Level Impact

Biomass-to-hydrogen facilities will emit health-harming pollution because they process carbon-based fuels at high temperatures and pressures to create hydrogen.

The exact pollutants and amount of emissions will depend on the biomass used and control technologies^‡ implemented at the facility. Pollutants may include but are not limited to NO_x^‡, particulate matter^‡, and carbon monoxide^‡.

Community-Level Impact

Transporting biomass to the hydrogen production facility will likely involve increased trucking in the area, which will increase local air and noise pollution, and may have impacts on traffic and quality of life.

Community-Level Impact

Pre-processing of biomass^‡ to prepare it for use in a hydrogen production facility may create significant local air and water pollution. This may occur at the production site or a separate site.

Community-Level Impact

If the facility uses carbon capture^‡ technology, there may be additional air pollution impacts because the technology requires a lot of energy, which often comes from burning more fossil fuels. Carbon capture technology also increases water use and may increase water pollution.

Community-Level & Climate Impact

Biomass-to-hydrogen facilities might also transport CO₂ captured from their processes to a storage site. The CO₂ would likely be transported by pipeline to an off-site location, in which case all the impacts of CO₂ pipelines apply along the pipeline route, as well as the impacts of CO₂ storage^‡ at the storage site.

→ In this Guide: CO₂ Pipelines and CO₂ Storage

Climate Impact

All biomass-to-hydrogen facilities will directly emit climate-warming pollution, like CO₂ and methane.

Climate Impact

Biomass-to-hydrogen production often causes indirect climate-warming emissions through the production of biomass^‡. This is true of the production of landfill, sewage, and animal waste biogas^‡. Appropriate waste and manure management practices lead to small amounts of unavoidable waste biogas that are most effectively used directly as fuel rather than to power hydrogen production.

The production of hydrogen from crop and forest residues can increase climate-warming emissions if it causes harmful land use changes, such as deforestation.

Biogas and biomethane supply chains have also been shown to leak at much higher rates than even the fossil methane supply chain. If biogas or biomethane is intentionally produced (e.g. from poor manure management practices), then net leakage could offset the climate benefit of replacing fossil methane. Avoiding the creation of methane^‡ in the first instance is the best option

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

A biomass-to-hydrogen facility will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

A biomass-to-hydrogen facility might need:

An environmental impact review under federal NEPA and/or similar state laws
A Section 404 permit if the facility is constructed near a waterway or wetland, as well as state 401 permits under the Clean Water Act
Land use approvals
Permits under the Rivers and Harbors Act if dredging and/or filling of watered areas is needed
A Class VI permit for injecting CO₂ into wells for underground storage
Approvals under the Endangered Species Act
Approvals under the National Historic Preservation Act
Approvals if it plans to seek other federal subsidies, like federal tax credits for producing “clean” hydrogen or for capturing and storing CO₂, or state or local subsidies
Depending on the state, additional permits beyond those required by the federal government

Projects that Use Hydrogen

Projects that use hydrogen can also impact communities and the climate in a variety of ways.

This section describes potential impacts — positive and negative — from various hydrogen uses that have been proposed by the Hydrogen Hubs.

Power Generation

Power Plants

Impacts | Environmental Approvals

All of the Hydrogen Hubs are proposing to use hydrogen to generate electricity at power plants.

Generating power from hydrogen likely involves burning hydrogen or a mix of hydrogen and methane^‡.

These facilities will likely be existing power plants that already use fossil methane as a fuel, where some portion of the fossil methane will be substituted with hydrogen. New hydrogen-fueled power plants might also be proposed as part of the Hubs.

Community-Level Impact

Burning hydrogen in a power plant will increase NO_x^‡ emissions.

Currently, pollution control technologies^‡ can minimize, but not eliminate, this increase. One industry study found that burning a 50/50 mix of hydrogen and methane could increase NO_x emissions by 35%.

A recent air permit for a proposed hydrogen-fueled power plant in Indiana suggests emissions could be even higher; that permit set NO_x limits for hydrogen combustion 3x higher than the limits for burning methane.

NO_x emissions can aggravate respiratory diseases, particularly asthma.

Community-Level Impact

Transporting hydrogen to a power plant might increase trucking in the area, which will increase local air and noise pollution.

It might also require new pipelines, in which case all impacts from hydrogen pipelines would apply.

→ In this Guide: Hydrogen Pipelines

Community-Level Impact

Depending on how it is produced, hydrogen can be expensive compared to other fuels and thus combusting hydrogen at power plants may increase local energy bills.

Climate Impact

Power plants that burn hydrogen can produce CO₂ emissions.

Although burning 100% hydrogen does not produce CO₂ emissions, power plants won’t burn pure hydrogen, at least in the short term. Instead, they will burn a blend of hydrogen and methane.

A plant that burns methane will continue to produce CO₂. There is not a 1:1 relationship between the amount of hydrogen burned and CO₂ reduced.

In order to reduce a power plant’s CO₂ emissions by 50%, that plant would need to burn at least 75% hydrogen.

Climate Impact

Using renewable electricity directly is much more efficient than using renewable electricity to create hydrogen, and then burning that hydrogen for power.

For example, roughly 2/3 of energy is lost when renewable electricity is used to produce hydrogen that is burned in a power plant.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

A hydrogen-fueled power plant will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

A hydrogen-fueled power plant might need:

An environmental impact review under federal NEPA and/or similar state laws
A Section 404 permit if the facility is constructed near a waterway or wetland, as well as state 401 permits under the Clean Water Act
Land use approvals
Approvals under the Endangered Species Act
Approvals under the National Historic Preservation Act
Approvals from the state agency overseeing electric utilities, often called the Public Service Commission or Public Utility Commission
Additional approvals if it plans to seek other federal, state, or local subsidies

If a Hydrogen Hub proposes to use hydrogen at an existing power plant, some requirements may be addressed by existing permits.

Power Generation

Heating for Buildings

Like hydrogen mixed with methane^‡ at power plants, hydrogen could be mixed with methane in systems that use boilers to heat homes or commercial buildings. This could cause many of the same impacts as burning hydrogen at a power plant — such as increased NO_x^‡ emissions — except that people would experience those impacts in their homes and other buildings.

Just as generating electricity from renewable resources like wind and solar is more efficient than generating electricity from hydrogen-fueled power plants, electric heat pumps^‡ are more efficient, cleaner, and safer than burning hydrogen for heat. It takes about five times more electricity to heat a home with green hydrogen^‡ than it takes to heat the same home with an efficient heat pump.

Power Generation

Fuel Cells

Impacts | Environmental Approvals

Hydrogen fuel cells produce electricity by combining hydrogen and oxygen atoms.

The hydrogen and oxygen react across an interface, similar to a battery, and produce electricity, water, and small amounts of heat.
Unlike using hydrogen in power plants to generate electricity or in boilers to heat homes, where hydrogen is burned, hydrogen used in fuel cells is not burned.

Fuel cells range in size.

Some are small enough to fit inside of a car,
Some are big enough to power a single home, and
Others may be big enough to power the equivalent of hundreds of homes.

Community-Level Impact

Unlike using hydrogen in power plants or boilers, using hydrogen in fuel cells is a way to store clean energy without producing air pollution since fuel cells do not burn hydrogen.

Community-Level Impact

Like power plants, hydrogen fuel cells will need a steady stream of hydrogen to feed their operations.

Transporting hydrogen to a power plant might increase trucking in the area, which will increase local air and noise pollution.
It might also require new pipelines, in which case all impacts from hydrogen pipelines would apply.

→ In this Guide: Hydrogen Pipelines

Climate Impact

The climate impacts of hydrogen fuels cells will depend on how the hydrogen is delivered to the site (e.g. pipeline, truck), and how much hydrogen leaks into the atmosphere.

Climate Impact

Using renewable energy directly is more efficient than using renewable energy to create hydrogen, and then converting the hydrogen back to electricity in a fuel cell.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

Hydrogen fuel cells might need:

Land use approvals
Additional approvals if the project developer plans to seek other federal, state, or local subsidies

Industrial Sector

Some hydrogen hub projects will use hydrogen to make other fuels or end products.

Industrial Sector

Oil Refineries

Impacts | Environmental Approvals

Today, oil refineries use hydrogen to lower the sulfur content of diesel fuel. In fact, about 60% of current U.S. hydrogen demand comes from crude oil refineries.

Some oil refineries produce hydrogen on-site from fossil methane, while others get it delivered (e.g. by pipeline or truck) from off-site production facilities.

Community-Level Impact

For oil refineries that produce hydrogen on-site, replacing hydrogen made from fossil fuels (gray^‡ or blue hydrogen^‡) with hydrogen made from water (green hydrogen^‡) will reduce refineries’ health-harming emissions, as long as the green hydrogen is truly clean^‡.

Climate Impact

Replacing gray or blue hydrogen production with green hydrogen production may reduce impacts from transporting fossil methane^‡ to the refinery site.

Climate Impact

For oil refineries that produce hydrogen on-site, replacing hydrogen made from fossil fuels (gray or blue hydrogen) with hydrogen made from water (green hydrogen) will reduce refineries’ climate-warming emissions, as long as the green hydrogen is truly clean^‡.

This type of replacement is an important piece of any decarbonization pathway for oil refineries.

Community-Level Impact

Oil refineries emit substantial health-harming pollution, including NO_x^‡, particulate matter^‡, SO₂^‡, and volatile organic compounds^‡.

Community-Level Impact

Transporting hydrogen to a refinery might increase trucking in the area, which will increase local air and noise pollution.

It might also require new pipelines, in which case all impacts from hydrogen pipelines would apply.

→ In this Guide: Hydrogen Pipelines

Climate Impact

Oil refineries release substantial climate-warming pollutants like CO₂ and methane^‡.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

Oil refineries will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

Oil refineries might need:

An environmental impact review under federal NEPA and/or similar state laws
Land use approvals
Additional approvals if planning to seek other federal, state, or local subsidies

If a Hydrogen Hub proposes to retrofit a refinery with hydrogen infrastructure, some requirements may be addressed by existing permits.

Industrial Sector

Ammonia Production

Impacts | Environmental Approvals

Ammonia^‡ is used primarily in agriculture as fertilizer. More recently, ammonia has been discussed as a possible marine shipping fuel.

Much existing hydrogen production takes place at ammonia production facilities, which look like large, industrial facilities with piping and smokestacks transporting and/or emitting the different gases that are part of the process.

At large scales, ammonia (NH₃) is produced from hydrogen and nitrogen through a chemical reaction. The reaction runs at high temperature and pressure and requires a lot of energy.

Climate Impact

For ammonia production facilities that make hydrogen on-site, replacing hydrogen made from fossil fuels (gray^‡ or blue hydrogen^‡) with hydrogen made from water (green hydrogen^‡) will reduce climate-warming emissions, as long as the green hydrogen is truly clean^‡.

Community-Level Impact

The ammonia production facility will emit health-harming air pollutants when it burns fossil fuels to create the high temperature and pressure needed for the chemical reaction that produces ammonia.

Community-Level Impact

If the ammonia production facility also makes hydrogen from fossil fuels on-site, then all the impacts associated with producing hydrogen from fossil fuels apply.

Community-Level Impact

These facilities also emit large amounts of health-harming ammonia.

Exposure to ammonia can irritate the nose, throat, and respiratory tract, which can also lead to respiratory issues.
Chronic exposure increases risk of respiratory irritation, asthma symptoms, and impaired lung function.
Studies suggest that exposure to high levels of ammonia may adversely affect the liver, kidney, and spleen. Ammonia also transforms into secondary PM_2.5 (ammonium sulfate, ammonium nitrate, and ammonium chloride), causing the same health effects associated with exposure to particulate matter^‡.

Community-Level Impact

Transporting hydrogen to a power plant might increase trucking in the area, which will increase local air and noise pollution.

It might also require new pipelines, in which case all impacts from hydrogen pipelines would apply.

→ In this Guide: Hydrogen Pipelines

Climate Impact

The chemical reaction that produces ammonia does not directly emit CO₂.

However, the ammonia production facility will emit CO₂ when it burns fossil fuels to create the high temperature and pressure needed for the chemical reaction that produces ammonia.

Climate Impact

Ammonia production requires nitrogen. Nitrogen may be produced on-site, which would require an energy-intensive air separation unit that will have its own environmental and climate impacts.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

Ammonia production facilities will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

Ammonia production facilities might need:

An environmental impact review under federal NEPA and/or similar state laws
Land use approvals
Additional approvals if planning to seek other federal, state, or local subsidies

If a Hub project proposes to retrofit an existing ammonia production facility, some requirements may be addressed by existing permits.

Industrial Sector

Methanol Production

Impacts | Environmental Approvals

Proposed uses for methanol include engine fuel and marine shipping fuel, among others.

Under the right conditions, hydrogen and carbon oxides (CO^‡, CO₂) can react to form methanol (CH₃OH).

Today, methanol is produced almost exclusively using gray hydrogen^‡.

Hub projects might produce methanol using blue hydrogen^‡. This type of methanol is often called “blue” methanol.
It is also possible that Hub projects will produce so-called “green” methanol (or e-methanol). While it has not yet been done at large scale, some are proposing to produce e-methanol using green hydrogen^‡ and CO₂ captured from facilities that burn fossil fuels. E-methanol is one of several e-fuels discussed as a possible alternative to fossil fuels. None of these e-fuels have been produced at scale.

Methanol production facilities look like large, industrial facilities with piping and smokestacks transporting and/or emitting the different gases that are part of the process.

Climate Impact

For methanol production facilities that make hydrogen on-site, replacing hydrogen made from fossil fuels (gray^‡ or blue hydrogen^‡) with hydrogen made from water (green hydrogen^‡) will reduce climate-warming emissions, as long as the green hydrogen is truly clean^‡.

Community-Level Impact

If the methanol production facility also makes hydrogen from fossil fuels on-site, then all the impacts associated with producing hydrogen from fossil fuels apply.

The facility may also emit methanol and VOCs^‡, especially if the liquid methanol is stored on-site before transport.

Community-Level Impact

Transporting hydrogen to a power plant might increase trucking in the area, which will increase local air and noise pollution.

It might also require new pipelines, in which case all impacts from hydrogen pipelines would apply.

→ In this Guide: Hydrogen Pipelines

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

Methanol production facilities will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

Methanol production facilities might need:

An environmental impact review under federal NEPA and/or similar state laws
Land use approvals
Additional approvals if planning to seek other federal, state, or local subsidies

If a Hub project proposes to retrofit an existing methanol production facility, some requirements may be addressed by existing permits.

Industrial Sector

Sustainable Aviation Fuel (SAF) Production

Impacts | Environmental Approvals

Sustainable Aviation Fuel is a general term for alternative jet fuels made from a variety of carbon-based feedstocks such as:

agricultural and forestry residue
organic municipal solid waste
fats, oils, and greases from cooking waste and meat production
algae
industrial carbon monoxide^‡ or CO₂ waste gas

Of these, hydrogen only plays a major role in CO₂ waste gas, when carbon captured from industrial facilities is used as the carbon-based feedstock.

Under high temperatures and pressures, which could come from burning fossil fuels, carbon-based feedstock and hydrogen can react to produce jet fuels, sometimes called eSAF.

Facilities that produce eSAF will likely look like industrial facilities with piping and smokestacks transporting and/or emitting the different gases that are part of the process.

Community-Level Impact

eSAF production will require a steady stream of CO₂ and hydrogen, both of which may be delivered to a site via new pipelines, in which case all the impacts from hydrogen and CO₂ pipelines apply.

→ In this Guide: Hydrogen Pipelines and CO₂ Storage

Both gases could also be transported to the facility by truck, which might increase trucking in the area, and with it, increase local air and noise pollution.

eSAF production requires high temperatures and pressures which may require burning fossil fuels, which emits various health-harming pollutants.

Climate Impact

eSAF production is an emerging industry and its total climate impacts are unclear. However, as with other hydrogen projects, hydrogen leaks from these facilities will contribute to climate change, because hydrogen is an indirect greenhouse gas.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

eSAF production facilities will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

eSAF production facilities might need:

An environmental impact review under federal NEPA and/or similar state laws
A Section 404 permit if constructing the facility would take place near a waterway or wetland
Land use approvals
Approvals under the Endangered Species Act
Approvals under the National Historic Preservation Act
Additional approvals if planning to seek other federal, state, or local subsidies

Industrial Sector

Steel Production

Impacts | Environmental Approvals

Steel production accounts for about 1% of total U.S. greenhouse gas emissions and is widely considered to be hard to decarbonize due to the high heat required throughout the production process.

Hydrogen may be used to replace fossil fuels at some steel mills as a means of lowering greenhouse gas emissions.

Community-Level Impact

Replacing fossil fuels like coal and fossil methane at steel mills with hydrogen made from water (green hydrogen) will reduce mills’ health-harming emissions, as long as the green hydrogen is truly clean^‡.

Community-Level Impact

Replacing fossil fuels with green hydrogen^‡ may reduce impacts from transporting fossil fuels to the site.

Climate Impact

To the extent steel mills replace fossil fuels with green hydrogen^‡ that is truly clean^‡, then they will reduce their climate-warming emissions.

This type of replacement is an important piece of any decarbonization pathway for steel manufacturing.

Community-Level Impact

Steel mills emit substantial health-harming pollution, including NO_x^‡, particulate matter^‡, SO₂^‡, and volatile organic compounds^‡.

Community-Level Impact

Transporting hydrogen to a steel mill might increase trucking in the area, which will increase local air and noise pollution.

It might also require new pipelines, in which case all impacts from hydrogen pipelines would apply.

→ In this Guide: Hydrogen Pipelines

Climate Impact

Steel mills release substantial climate-warming pollutants like CO₂ and methane^‡.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

Steel mills will need:

Air permits to address air pollution (both an operating permit and either a construction or modification permit)
An NPDES permit for discharging polluted water

Steel mills might need:

An environmental impact review under federal NEPA and/or similar state laws
Land use approvals
Additional approvals if planning to seek other federal, state, or local subsidies

If a Hub project proposes to retrofit a steel mill with hydrogen infrastructure, some requirements may be addressed by existing permits.

Projects that Transport or Store Hydrogen or CO₂

Transport Hydrogen

Hydrogen Pipelines

Impacts | Environmental Approvals

While four of the seven Hydrogen Hubs have announced plans to build new hydrogen pipelines, it is likely that all Hubs will need hydrogen pipeline infrastructure.

Regulation of hydrogen pipelines

Hydrogen pipelines are very limited. There are only about 1,600 miles of hydrogen pipelines in the U.S. today, mostly clustered in Southern California and along the Gulf Coast in Texas and Louisiana, compared to millions of miles of methane pipelines across the country. Unchecked, a hydrogen economy could lead to a massive buildout of new hydrogen pipelines.

Regulation of hydrogen pipelines must be strengthened to adequately protect communities. The U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) oversees hydrogen pipeline safety and has acknowledged challenges and uncertainties regarding the safe transport of hydrogen by pipeline. PHMSA has indicated that it's evaluating its hydrogen pipeline regulations but has not committed to strengthening them.

Hydrogen pipelines function like methane^‡ pipelines, but there are substantial differences between methane and hydrogen that must be accounted for in these new pipelines.

Hydrogen is a smaller, lighter, and more reactive molecule than methane, which makes it more prone to leaking out of pipelines than methane.
Hydrogen can also cause embrittlement issues in some pipeline materials used to transport methane (meaning hydrogen creates small cracks in the metal that can lead to more significant cracking).

It is important that hydrogen pipelines use different materials that address these leakage and embrittlement risks.

New pipelines would need to be built if hydrogen is to be transported safely. Existing methane pipelines will not be effective.

Community-Level Impact

Hydrogen behaves very differently than fossil methane and is more prone to leaking, exploding, and burning.

Community-Level Impact

Pipelines rely on compressor stations to maintain flow, which can cause air pollution near these stations, depending upon how they are fueled.

Community-Level Impact

Pipeline installation can cause habitat and farmland destruction and can involve taking private property without public benefit.

Climate Impact

Hydrogen is an indirect greenhouse gas.

Through a series of chemical reactions, hydrogen increases the amount of greenhouse gases, like methane, in the atmosphere. Scientists have estimated that hydrogen has nearly 12 times the warming impact of CO₂ over a 100-year period.

Any substantial hydrogen pipeline leaks would have climate implications.

Environmental Approvals

The construction and/or operation of a hydrogen pipeline might need some or all of the following approvals, depending on its location and whether it crosses state lines:

An environmental impact review under federal NEPA and/or similar state laws
Clean Air Act approvals if the pipeline relies on compressor stations powered by fossil fuels. A compressor station is an industrial facility that maintains the flow of gas through a pipeline.
A Section 404 permit if constructing the pipeline would take place near a waterway or wetland
Land use approvals
Approvals under the Endangered Species Act
Approvals under the National Historic Preservation Act
Permits and approvals required under state law

Store Hydrogen

Hydrogen Storage and Fueling Stations

Impacts | Environmental Approvals

Each Hydrogen Hub will need to store some amount of hydrogen, either as a gas or liquid.

Storage facilities can vary widely, ranging from tanks to the few geologic salt caverns in the U.S. that have been proposed for underground storage of hydrogen.

Different types of hydrogen storage present different challenges, such as high costs, inadequate space (storing gaseous hydrogen requires large amounts of space), and inefficiencies (converting hydrogen to a liquid, then back to a gas, results in energy loss).
Some storage methods are in the very early stages of research and development and a lot is still unknown about their reliability and potential impacts.

Electric vehicles vs. fuel cell vehicles

Battery-electric vehicles are generally a better option for decarbonizing our transportation sector than hydrogen fuel cell vehicles.

Only about 25% of renewable electricity used to produce hydrogen makes it to the wheels of a hydrogen fuel cell vehicle, compared to 75% in a battery-electric vehicle.

While hydrogen fuel cells could help decarbonize our heaviest duty trucks with the longest routes, battery electric vehicles are a more efficient option for most other types of road transportation.

Hubs have provided limited information on their hydrogen storage plans. However, four of the seven Hydrogen Hubs include building new hydrogen fueling stations, and six of seven Hubs propose to use hydrogen in the transportation sector, which will likely also require hydrogen fueling stations. Hydrogen fueling stations are essentially a type of hydrogen storage.

The potential impacts of hydrogen fueling stations are described in the below table.

Community-Level Impact

Existing fueling stations that switch from fueling diesel vehicles to fueling hydrogen vehicles could reduce local air pollution.

It is important to consider whether electric vehicles are also an option and, if so, to evaluate whether battery-electric vehicles would provide greater community-level (and climate) benefits than hydrogen fuel cell vehicles.

Climate Impact

Replacing diesel with hydrogen at fueling stations could reduce greenhouse gas emissions, depending on how the hydrogen is produced and transported to the fueling station.

Community-Level Impact

New hydrogen fueling stations could increase truck traffic in communities, which would increase local air and noise pollution.

Community-Level Impact

Hydrogen is more prone to leaking, exploding, and burning than many other liquid fuels, including methane^‡ and propane.

Climate Impact

Because hydrogen is an indirect greenhouse gas, hydrogen leaks from these facilities will contribute to climate change.

→ In this Guide: Hydrogen Pipelines

Environmental Approvals

A hydrogen fueling station may need land use approvals. An existing fueling station that switches to hydrogen fuel is less likely to need approvals.

Transport CO₂

CO₂ Pipelines

Impacts | Environmental Approvals

The four Hydrogen Hubs that plan to produce hydrogen from fossil fuels using carbon capture^‡ technology (blue hydrogen^‡) will likely need to build and operate pipelines to transport CO₂ captured from the blue hydrogen facility.

As of 2022, approximately 5,000 miles of CO₂ pipelines exist in the U.S. — far fewer than the over 220,000 miles of pipelines that carry other hazardous liquids.

Existing CO₂ pipelines generally serve enhanced oil recovery operations — which is when CO₂ is used to pump more oil out of the ground — and these pipelines are only loosely regulated.
The Pipeline and Hazardous Materials Safety Administration (PHMSA) has committed to updating CO₂ pipeline regulations, but the proposed rule is not yet public.

Existing CO₂ pipelines mostly transport CO₂ produced from underground sources, rather than CO₂ produced by burning fossil fuels. It may be difficult to remove all impurities when CO₂ is captured from processes that burn fossil fuels, and these impurities could create risks within pipelines.

Community-Level Impact

CO₂ leaks could be harmful because CO₂ is an asphyxiant, meaning it displaces oxygen and can cause suffocation.

It is heavier than air, so it stays close to the ground, and can travel large distances at high concentrations from a ruptured pipeline.

CO₂ leaks can also prevent combustion vehicles (as opposed to battery-electric vehicles) from operating, which can impede efforts to respond to a leak.

Community-Level Impact

Pipelines rely on compressor stations to maintain flow, which can cause air pollution near these stations, depending on how they are fueled.

Community-Level Impact

CO₂ forms carbonic acid in the presence of water, which can eat away at certain types of pipeline material, increasing rupture risk.

Community-Level Impact

Pipeline installation can cause habitat and farmland destruction and can involve taking private property without public benefit.

Climate Impact

CO₂ is a greenhouse gas and can leak from pipelines.

Climate Impact

Fossil fuel-powered compressor stations emit climate-warming pollution.

Environmental Approvals

CO₂ pipelines might need the following approvals, depending on its location and the design of the pipeline component.

State siting or routing permits or eminent domain permissions, including an environmental impact review under state NEPA laws where such laws exist.
Clean Air Act approvals if the pipeline relies on compressor stations powered by fossil fuels. A compressor station is an industrial facility that maintains the flow of gas through a pipeline.
Clean Water Act Section 404 individual permit, including a NEPA environmental impact review, and state Clean Water Act Section 401 certification or authorization to proceed under Nationwide Permit 58
Land use approvals

Store CO₂

CO₂ Storage

Impacts | Environmental Approvals

While two of the seven Hydrogen Hubs have announced plans to permanently store CO₂, every Hub that produces hydrogen from fossil fuels using carbon capture^‡ technology (blue hydrogen^‡) will likely store CO₂.

Similar to CO₂ pipeline projects, CO₂ storage projects only exist at a small scale in the U.S. today.

The potential risks of CO₂ storage are not fully understood, and any potential site requires rigorous and comprehensive geophysical evaluations to ensure it can contain CO₂ effectively.

Community-Level Impact

When CO₂ is stored underground, it can leak and dissolve in shallow groundwater, making the groundwater acidic and potentially impacting drinking water.

Community-Level Impact

Pressure changes from CO₂ storage can displace underground salt water (brines), which could then mix with and impact fresh groundwater resources.

Community-Level Impact

Injecting CO₂ underground can increase the frequency of earthquakes (seismicity).

Community-Level Impact

CO₂ injection wells that are abandoned after use can create significant leakage risks.

Climate Impact

CO₂ is a greenhouse gas and may leak from storage sites and be released into the atmosphere.

Environmental Approvals

A project that involves injecting CO₂ into wells for underground storage will need:

Land use approvals
A Class VI permit for injecting CO₂ into wells for underground storage

A project that involves injecting CO₂ into wells for underground storage might need:

An environmental impact review under federal NEPA and/or similar state laws
A Section 404 permit if constructing the injection well would take place near a waterway or wetland
Approvals under the Endangered Species Act
Approvals under the National Historic Preservation Act
Additional approvals if it plans to seek other federal subsidies, like federal tax credits for capturing and storing CO₂, or state or local subsidies
Permits and approvals required under state law

Next: Glossary

^‡Exposure to nitrogen oxides causes asthma and respiratory infections. See full definition.

^‡Biomass refers to materials that come from living things, such as leaves or stems, or animal manure. See full definition.

^‡Electrolysis is the process of using electricity to drive a chemical reaction. See full definition.

^‡Methane is a potent greenhouse gas. See full definition.

^‡SMR is a chemical process in which methane and water vapor are reacted to produce a synthetic gas. See full definition.

^‡ATR is a chemical process in which methane and water vapor are reacted in pure oxygen to produce a synthetic gas. See full definition.

^‡Carbon capture refers to a set of industrial technologies designed to reduce CO₂ emissions at the source (i.e., smokestack) of a facility and prevent on-site CO₂ emissions from entering the atmosphere. See full definition.

^‡Exposure to NO_x causes asthma and respiratory infections. See full definition.

^‡Sulfur dioxide can harm the human respiratory system. See full definition.

^‡Exposure to particulate matter can cause early death due to stroke. See full definition.

^‡Carbon monoxide reduces the ability of blood to carry oxygen. See full definition.

^‡Exposure to volatile organic compounds can harm the respiratory and central nervous systems. See full definition.

^‡CO₂ storage, also known as sequestration, can refer to different things. When discussed in this guide, CO₂ storage refers to storage in saline aquifers, which are deep underground and filled with salty water (brine).

^‡Nuclear power can pose health risks to communities and the environment, largely due to the risk of an accident. See full definition.

^‡Biomass can be processed and used in ways that lead to meaningful decarbonization, but also in ways that increase carbon emissions.

^‡Gasification is a process through which complex carbon-based materials are converted into syngas, a gas mixture composed of carbon oxides and hydrogen gas. See full definition.

^‡Biogas is a particular type of biomass. See full definition.

^‡Facilities that emit air pollution often must use control technology systems to keep their emissions below state or federal standards. See full definition.

^‡Pre-processing of biomass feedstocks: Often, biomass feedstocks must be processed before they can be used for hydrogen production. See full definition.

Updated on October 11, 2024

Maps and graphics by Casey Chin / Earthjustice. Basemap data sources: Esri, HERE, Garmin, FAO, NOAA, USGS, EPA.

This guide is intended for informational purposes only and does not constitute legal advice. The information contained herein is not a substitute for professional legal counsel. Please consult with an attorney to discuss your specific legal needs.

Questions? For questions or feedback on this Guide, please contact us at webmaster@earthjustice.org

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