Hydrogendecarbonization
pathways
A life-cycle assessment
January 2021

Published in January 2021 by the Hydrogen Council. Copies of this document are available uponrequest or can be downloaded from our website: www.hydrogencouncil.com.
This report was authored by the Hydrogen Council with analytical support from Ludwig-BölkowSystemtechnik GmbH (LBST) and McKinsey & Company.
The authors of this report confirm that:
1. There are no recommendations and/or any measures and/or trajectories within the report that
could be interpreted as standards or as any other form of (suggested) coordination between theparticipants of the study referred to within the report that would infringe EU competition law; and2. It is not their intention that any such form of coordination will be adopted.
While the contents of the report and its abstract implications for the industry generally can be
discussed once it has been prepared, individual strategies remain proprietary, confidential and the
responsibility of each participant. Participants are reminded that, as part of the invariable practiceof the Hydrogen Council and the EU competition law obligations to which membership activities are
subject, such strategic and confidential information must not be shared or coordinated – including aspart of this report.

Contents

Introduction and methodology

4Life-cycle emissions are coming into focus with scaling-up of hydrogen

4

Methodology of the LCA study

4

Various hydrogen production pathways can achieve very low life-cycle emissions

5

The move towards a carbon-neutral electricity mix will benefit hydrogen production
across the board

7

Water consumption and other environmental damage can be minimized in the
production of hydrogen

8

Eight illustrative pathways for hydrogen use in the global energy transition

10

Hydrogen is a versatile carrier for decarbonized energy

11

Eight pathways illustrate how hydrogen can support the energy transition11

1. Long-distance passenger cars

13

2. Ships14

3. Industrial heat15

4. Power generation

16

5. Fertilizer feedstock17

6. Buses18

7. Heavy-duty transport trucks

19

8. Steel production

20

Conclusions

21

Hydrogen decarbonization pathways
A life-cycle assessment

3

Introduction and methodology

Life-cycle emissions are coming into focus with scaling-up
of hydrogen
Hydrogen is one of the keys to the energy transition, a facilitator to sector integration, and thebasis for decarbonizing hard-to-abate applications. To deliver on the sustainability promise, it istherefore not only important to make it economically viable, but also maximize its decarbonization
potential and minimize its impact on resources, such as water. The European hydrogen strategy
and the targets of many EU member states are geared to place most of their support on renewablehydrogen production, while countries such as China, Korea, and Japan are supporting otherlow-carbon hydrogen routes as well. Countries with abundant renewable and/or fossil and CCS
resources are looking to optimize the value of these attributes in destination markets, such as
Australia, the MENA region, and Southern Latin America. In all cases, the decarbonization potentialof hydrogen is critical, including understanding potential contributions from the manufacturingof plants for primary energy supply, hydrogen production, transport, distribution, and use. An
evaluation of the carbon-saving potential of hydrogen over the life cycle is therefore an importantpiece of the Hydrogen Council’s perspective.

Methodology of the LCA study— This report is an assessment that uses an LCA approach for greenhouse gas (GHG) emissions
regarding “well-to-supply” and “well-to-use”, including end-of-life/recycling; it is, however, not adetailed LCA study.
— The assumptions for the LCA analysis have been reviewed by the 23 member companies of theHydrogen Council LCA project team, as well as by an independent group of experts, including
Michael Wang, Manager Systems Assessments at ANL, Stephanie Searle, Fuels Program Director
at ICCT, and Dolf Gielen, Director Innovation and Technology at IRENA.
— The analysis includes GHG emissions related to energy supply and use, as well as capex
emissions, i.e., “grey emissions” related to the manufacturing of energy conversion assets.
— Fugitive gas emissions, such as methane slip across gas production and supply or hydrogen
losses from flushing procedures, have been considered in the assessments assuming best
available technology and operational practices for a given regional energy source or route.
— Production and manufacturing conditions can vary significantly from producer to producer andregion to region, resulting in a wide range of capex-related impacts. Global assumptions have been
applied for a generalized LCA assessment, such as for the grid mix1 and recycling shares2.
— To capture the picture for different hydrogen value chains, the primary energy used for hydrogen
supply as well as for eight “well-to-use” illustrative pathways in this report have been regionalized.
— For coherence, technology data for the different elements in hydrogen value chains have beentaken from previous Hydrogen Council studies. Where needed, this has been updated andenriched with data based on current literature, including own calculations.

1

Global grid mix assumed with 68% and 90% low-carbon contribution from renewable and nuclear sources in 2030 and 2050
derived from [IRENA 2020], resulting in carbon-intensities of 229 g CO2eq/kWhe and 61 g CO2eq/kWhe, respectively.

2

Recycling shares of 80%, going up to over 90%, assumed for selected metals in 2030 and 2050, respectively, based on [UNEPIRP 2011] and expert input from the Hydrogen Council member pool.

4

Hydrogen decarbonization pathways
A life-cycle assessment

— For life-cycle modeling and calculations, the LBST software E3database was used in accordancewith standard practices regularly applied to life-cycle assessments for clients such as the Joint
Research Centre of the European Commission, EUCAR, Concawe, and other industry as well as
environmental interest groups.
— Data quality and the availability of data to calculate capex-related GHG emissions is generally
poor – therefore, to the extent possible, this study attempts to shed light on their potential
magnitude of impact.
— GHG emissions are the focus of this report. Unless stated otherwise, “carbon” and “carbon
dioxide” includes all relevant GHGs, according to the latest 5th IPCC Assessment Report (AR5) andenergy values refer to the lower heating value (LHV, Hi).
— Water footprint calculations take gross water demand into account3.
— To give the full picture, different primary energies and conversion technologies for hydrogen supply
are presented, including renewable power, fossil (with and without carbon sequestration), as wellas nuclear-based primary energies.

Various hydrogen production pathways can achieve very low lifecycle emissions
There are various ways of producing hydrogen. The most common way of producing hydrogen today
is by reforming natural gas into hydrogen and CO24, which is often referred to as “grey hydrogen” if
the CO2 is emitted into the atmosphere, or “blue hydrogen” if the CO2 is captured and permanently
sequestrated. If sustainable biomass is gasified and the resulting biogas is reformed or pyrolyzed, thehydrogen is considered “green,” and carbon-negative if the CO2 is sequestrated.
Water electrolysis uses electricity to split water into hydrogen and oxygen. If renewable sources areused, the hydrogen produced is often referred to as “green”. Other pathways include the gasificationof coal into hydrogen and carbon monoxide (which can be captured and sequestrated) or thepyrolysis of natural gas into hydrogen and solid carbon.
The emission intensity varies between these pathways, but also within pathways: for instance, due
to different energy mixes and efficiency of production operations, hydrogen derived from natural gas
produced in Norway has different emissions than natural gas produced in Russia and transported tocenters of consumption.
Exhibit 1 summarizes the results. Overall, we find that:
Electrolysis using 2030 global average grid electricity (11.1 kg CO2eq/kg H2)5 and SMR without CCS
with Russian natural gas transported over 5,000 km (11.0 kg CO2eq/kg H2) show the highest GHG

3

For gross water demand, green and blue water are taken into account in this study, i.e., water from precipitation and abstraction,
respectively. Grey water demand has not been differentiated in this study for reasons of data availability. Grey water refers towater contaminated continuously (effluent water) and/or incidents (e.g., oil spills) and is understood to be of less relevance in thepathways analyzed in this study.

4

Mainly using steam methane reforming (SMR). Autothermal reforming (ATR), another technology available for producing hydrogenfrom natural gas, is today mainly used for the production of synthesis gas, a mixture of H2 and CO, e.g., for methanol synthesis.

5

GHG emissions are expressed in kgCO2eq/kg H2 here and include CO2 equivalents of other emissions with climate impacts.
Multiply by 30 to convert kg CO2eq/kg H2 to g CO2eq/kWh H2.

Hydrogen decarbonization pathways
A life-cycle assessment

5

emissions for 2030 of pathways analyzed here. In the case of water electrolysis, this is mostly due
to the 16% coal power share in the global grid mix assumed. SMR fed with Norwegian natural gas
and 1,700 km transport has slightly lower GHG emissions (9.2 kg CO2eq/kg H2). For comparison, thefossil comparator in the European Renewable Energy Directive is 94 g CO2eq/MJ of final fuel, i.e.,
11.28 kg CO2eq/kg H2eq, in the case of transportation fuel, 183 g CO2eq/MJ of electricity in the case ofelectricity generation, and 80 g/MJ of heat in the case of heat generation. Furthermore, the guarantees
of origin system CertifHy has defined a fossil fuel comparator for hydrogen of 10.92 kg CO2eq/kg H2.
Among the CCS pathways for blue hydrogen supply, coal gasification with CCS using Chinese coalshows high GHG emissions of 11.8 kg CO2eq/kg H2 due to methane and CO2 emissions from uncontrolledcoal-seam fires. Sweet natural gas sources in combination with high carbon capture rates and transportdistances in the low thousand kilometers can reduce GHG emissions substantially: for example, inthe case of SMR with a carbon capture rate of 90%6 and natural gas from Norway transported overa distance of 1,700 km to the German or Dutch North Sea coast, GHG emissions amount to
1.5 kg CO2eq/kg H2, and to 2.7 kg CO2eq/kg H2 in the case of an SMR with a CO2 capture rate of 75%7.
It should be noted that a 90% carbon capture rate does not reduce emissions by 90%, as additionalenergy is needed to power the capture and sequestration process, and GHG emissions occur overthe natural gas supply chain. Both these emission sources are reflected in our analysis.

Exhibit 1: Carbon-equivalent emissions by hydrogen production pathways, 2030 and 2050
(resulting figures refer to virgin material use); energy production refers to GHG emissions from the
supply of the main input into the H2 plant (natural gas, coal, electricity), while H2 production refers to
direct GHG emission of H2 plant, including from plant auxiliary electricity use+ capex-related emissions - virgin materials

H2 production+ capex-related emissions - recycled materials

Energy production

GHG emissions, kg/kgH2, LHV
resulting figures refer to virgin material use
2030
2050
Grid electricity + PEM

11.1

NG (5000 km) + SMR

11.0

Grid electricity electrolysis

3.1
11.0

Fossil without CCS

NG (1700 km) + ATR

9.3

8.8

Fossil without CCS

NG (1700 km) + SMR

9.2

9.2

Fossil without CCS

Coal + Coal gasification (CCS)

9.2

7.9

Fossil with CCS
Fossil with CCS

NG (5000 km) + SMR (CCS 90%)

3.9

Coal + Coal gasification (CCS)

3.5

3.1

Fossil with CCS

Bio-CH4 (energy crops) + SMR

3.3

2.8

Biomass

3.9

Wood chips + Biomass gasification

1.7

1.5

BiomassNG (1700 km) + SMR (CCS 90%)

1.5

1.5

Fossil with CCS

NG (1700 km) + ATR (CCS 98%)

1.2

0.8

Fossil with CCS

Bio-CH4 (waste) + SMR

1.0

0.4

Biomass

Solar 1500 h/a + PEM

1.0

0.6

Renewable electrolysis

Nuclear power + PEM

0.6

0.5

Nuclear electrolysis

Wind onshore 2400 h/a + PEM

0.5

0.5

Renewable electrolysis

Hydro 5000 h/a + PEM

0.3

0.3

Renewable electrolysis

Source: Hydrogen Council, LBST

6

Reference: Amec Foster Wheeler; IEAGHG: Techno-Economics of Deploying CCS in a SMR Based Hydrogen Production using
NG as Feedstock/Fuel; IEAGHG Technical Report, February 2017.

7

Reference: Hydrogen Council: Path to Hydrogen Competitiveness: A Cost Perspective, 2020.

6

Hydrogen decarbonization pathways
A life-cycle assessment

Electrolysis can achieve very low emissions if powered with renewable energy or nuclear power. Solar
power achieves 1.0 kg CO2eq/kg H2 and wind 0.5 kg CO2eq/kg H2 in 2030, the difference resulting fromthe higher embedded capex emissions for solar panels8 (due to global grid mix9 assumed for thepanel manufacture). Electrolysis with run-of-river hydropower can achieve even lower emissions of
0.3 kg CO2eq/kg H2. Nuclear power comes in at 0.6 kg CO2eq/kg H2, but it is also important to note inthis context that it leads to 0.115 g of radioactive waste per kg of hydrogen10.
Capex-related emissions based on global average grid mix (66% renewable power in 2030) for asset
manufacturing are very low across hydrogen production pathways. For fossil, nuclear, and mostrenewable power sources, capex-related emissions are in the single-digit g CO2e/kWh range only,
and a very low double-digit number in the case of photovoltaics (PV).
Applying recycling rates of 80% and more for different metals at end of life versus using virginmaterials reduces GHG emissions by 0.1 to 0.3 kg CO2eq/kg H2 (equivalent to about 1 to 3% of thefossil comparator, i.e., Norway natural gas steam methane reforming without sequestration).

The move towards a carbon-neutral electricity mix will benefithydrogen production across the board
Towards 2050, in order to achieve a net-zero emission economy, the global power supply has to belargely decarbonized. This will also impact hydrogen emissions – as shown in Exhibit 1. Most notably,
electrolysis with grid electricity becomes viable compared to 2030’s global average grid mix whichstill remains carbon intensive.
For blue hydrogen, decarbonization of the power supply (for 2050, we assume 86% renewable share,
90% including nuclear) also allows for significant emissions reduction: hydrogen from natural gas with
98% CCS capture rate using ATR technology will achieve life-cycle emissions comparable to 100%
solar powered electrolysis when the ATR is powered with fully decarbonized energy.
In a world striving for low to net carbon-negative emissions, recycling11 plays an important role in thecontext of a circular economy with a sensitivity towards additional sustainability aspects, such as
resource consumption (abiotic depletion), i.e., the use of resources that are nonrenewable in humanrelevant timeframes.
For wind and hydropower combined with water electrolysis, the numbers for 2030 and 2050
are approximately the same if virgin materials are used because conventional blast furnacetechnology has been assumed for steel production. If recycling is taken into account, the GHG
emissions for hydrogen from wind power decreases from about 9 g CO2eq/kWh of hydrogen in
2030 to about 7 g CO2eq/kWh in 2050 (or 0.31 kg/kgH2 in 2030 to 0.24 kg/kgH2). Recycling ofsteel is carried out via electric arc furnaces (EAFs) where the electricity mix influences the GHG
footprint. Some GHG emissions for the manufacturing of wind and hydropower plants result fromthe production of concrete, for which GHG intensity has not been assumed to change between
2030 and 2050.

8

Based on a GHG-intensity of 20 and 13 g/kWh for PV electricity at 1,500 heq/a for 2030 and 2050, respectively.

9

Based on scenario in [IRENA, Global Renewables Outlook 2020, April 2020] for 2030: 20% wind, 15% PV, 6% biomass,
15% hydro, 1% geothermal, 11% nuclear, 16% natural gas, 16% coal.

10

Based on spent nuclear fuel of 0.0021 to 0.0027 g/kWh of electricity.

11

For metals, we have assumed for this study an 80% and above 90% recycling share for 2030 and 2050, respectively, whichtoday is achieved with selected industrial products.

Hydrogen decarbonization pathways
A life-cycle assessment

7

Water consumption and other environmental damage can be
minimized in the production of hydrogen
Water demand for hydrogen production via electrolysis, reforming or gasification is marginal. For
example, in the case of water electrolysis, about 9 kg of water per kg of hydrogen is needed12. The
one electricity-based technology for which it is significantly higher is electrolysis via nuclear electricity,which uses about 270 kg of cooling water per kg of hydrogen due to nuclear power production. For
SMR/ATR specific water demand is very low with 13-18 kg of water per kg of hydrogen. Nevertheless,gigawatt-scale projects can be a significant local water consumer. In regions prone to water supply
stress, sea water desalination is required. While this adds little incremental electricity use to powerto-X projects, it requires the environmentally benign management of the effluent brine.
Process cooling for thermal power generation typically is a major source of water demand
embodied in the energy conversion process (energy-water-nexus). Today, usually open cooling isused for large power plants which results in gross water demands in the order of several hundredsof kg water per kg of hydrogen. In arid regions and regions that are already under water stress, drycooling should be considered.
Gross water demand for bio pathways is much more significant and can be up to 1,000 times higher
than for other routes. Thus, bio feedstock is preferably used in water-rich regions with moderate
climatic conditions. Biowaste may also have a certain water demand, as illustrated in Exhibit 213.

Exhibit 2: Gross water demand for hydrogen production pathways+ capex-related water use, virgin materials+ capex-related water use, recycled materials

Water use w/o capex-related GHG H2 production
Water use w/o capex-related GHG energy production

Gross water demand, kg/kgH2, LHV
2030
7,427.6

Bio-CH4 (energy crops) + SMR
499.5

Wood chips + Biomass gasification
414.0

Nuclear power + PEM
85.9

Coal + Coal gasification (CCS)81.8

Grid electricity + PEM
41.0

Coal + Coal gasification (CCS)
Solar 1500 h/a + PEM

19.1

Bio-CH4 (waste) + SMR

18.0

NG (1700 km) + ATR (CCS 98%)

17.3

NG (1700 km) + ATR

17.3

NG (5000 km) + SMR

13.9

NG (1700 km) + SMR

13.6

NG (5000 km )+ SMR (CCS 90%)

13.5

NG (1700 km) + SMR (CCS 90%)

13.1

Wind onshore 2400 h/a + PEM

11.0

Hydro 5000 h/a + PEM

9.9

Source: Hydrogen Council, LBST

12

Net water demand from chemical reaction. Mehmeti et al. (2018) report approximately 18 kgH2O/kgH2 and 9 kgH2O/kgH2 for proton
exchange membrane (PEM) and solid oxide electrolyzer (SOEL), respectively.

13

In case of hydrogen from gasification of waste wood (forestry residues) rapeseed methylester (RME) is consumed by the gasifier
for syngas clean-up, which comes with a water demand burden.

8

Hydrogen decarbonization pathways
A life-cycle assessment

Another potentially relevant source of water demand is evaporation from an increased water surfaceof large hydropower dams. This is particularly an issue for countries in dry regions that largely
depend on surface water as a key source of water replenishment.
Water demand for coal mining and gas production varies significantly, subject to the local
geology and processes applied, such as underground stimulation of tight gas through hydraulicfracturing. Other environmental impacts may result from the mobilization of, e.g., heavy metals,
naturally occurring radioactive materials and other effluents that can impact water quality (grey water),air, soil, and the living environment.
On a methodology note, gross water demand in Exhibit 2 is depicted by the stage of use in theenergy process chain for a high-level comparison across main hydrogen value chains, i.e., a water
inventory that is neither making a reference to the water source nor a reference to potential impacts
from water use. In contrast, a full water footprint and impact assessment commonly differentiates
between different water sources and may also include “grey water”14. As water footprint results arehighly sensitive to process design and local conditions – such as the availability of rainfall – which isbeyond the scope for this study, we here refer to the gross water demand only.

14“Grey water” refers to water that is contaminated through continuous (effluent water) and/or incidents (e.g., oil spills). For thepathways analyzed here, it can be considered of less relevance under the assumption of best available technology and best
operational practice and is thus not included.

Hydrogen decarbonization pathways
A life-cycle assessment

9Eight illustrative
pathways forhydrogen use
in the global
energy transition

Hydrogen is a versatile carrier for decarbonized energy
Hydrogen is a uniquely versatile energy carrier. As the previous chapter showed, it can be produced
using different energy inputs and different production technologies. It can also be converted todifferent forms and distributed through different routes – from compressed gas hydrogen in pipelines
through liquid hydrogen on ships, trains or trucks, to synthesized fuel routes (see Exhibit 3).
Of course, hydrogen can also be used across a range of different applications – including the 36 enduse applications described in the Hydrogen Council´s “Path to Hydrogen Competitiveness” study.

Exhibit 3: Hydrogen pathways from production to use

Energyproduction

Solar
power

H2
production

Wind
power

HydropowerGridelectricity

Coal

AWE

Nuclear
power

Naturalgas

BiomassH2
conversion

PEM

SMR +
CCS

ATR +
CCS

ATR

Gasification

Methanepyrolysis

Liquefaction
(LH2)

SMR

Thermochemical
cyclesCompression(CGH2)
NH3
synthesis/
cracking

LOHC

SynfuelH2 storage,
distribution,
retailH2
applications1

End of life

StorageLight
vehiclesRemanufacturing

H2
pipeline

CGH2/
LH2
refueling

CGH2/
LH2/LOHC
trucking
LH2/NH3/
LOHCshipping

Trucks /
Buses

Ship
propulsion

Rail

Steel
(DRI)

Heat
(boilers)

Recycling

Energy/recoveryAmmonia
feedstock

Grey emissions from capex (incl. raw materials)
2

Emissions from energy use/losses

1 Including repair, maintenance, lubes, etc.
2 Included on a best-effort basis, depending on data availability

The GHG emissions (carbon intensity) of each individual brick has been calculated, parameterized
in key aspects such as the capacity rate (renewable power production) or shipping distances(H2 transport), and compiled in a simplified LCA tool. This tool also comprises the eight illustrative
pathways laid out in this report as default data, including key assumptions. The simplified LCA tool
allows the footprint of hundreds of different pathways to be estimated.

Eight pathways illustrate how hydrogen can support the energy
transition
We selected eight illustrative pathways out of the large set of potential options to showcase howhydrogen can support the energy transition and the life-cycle emissions hydrogen generates
compared to alternative solutions (see Exhibit 4). The pathways were selected to cover a wide range
of geographies, production technologies, midstream transmission and distribution vectors, as well as
end-use applications, but are by no means comprehensive.

Hydrogen decarbonization pathways
A life-cycle assessment

11

The eight illustrative pathways are realistic examples for potential value chains, and several Hydrogen
Council members are working on projects similar to some of the pathways described. However,
the illustrative pathways do not reference any concrete projects, nor imply any preference to future
developments, and actual emissions may differ between our examples, which build on deepdecarbonization technologies within the green (wind, solar) and blue (ATR with 98% capture rate)technology portfolio, and any projects that are currently being implemented (given, e.g., high regionalvariations in the energy mix).

Exhibit 4: Eight illustrative pathways
OriginregionDestination
regionEnergyproduction

H2
production

H2
conversion

H2 transport,
distribution

H2
application

Alternatives

1

Australia

East Asia

Natural gas

ATR + CCS

LH2

LH2 shipping(9,000 km)

Light-duty vehicles(e.g., fleets)

Gasoline ICE
BEV

2Scandinavia

Scandinavia

Natural gas

ATR + CSS

LH2

LH2 trucking(100 km)Shipping(e.g., cruise ship)

Diesel ICE

3

North/West
EuropeNorth/West
EuropeNatural gas

ATR + CCS–

H2 pipeline
network

Industrial heat(e.g. boiler/furnace)

Natural gas

4

Middle East

East Asia

Natural gas

ATR + CCS

NH3synthesis

NH3 shipping(12,000 km)

Central power
generation

Natural gas

5

North
America

North
AmericaWind +
solar

Central EL

NH3synthesis

NH3 shipping(2,000 km)

Fertilizer

Natural gas

6

China

China

Solar

Central EL–

H2 pipeline(2,500 km)

Buses

Diesel ICE

7

USA

USA

Wind +
solar

On-site/Decentral EL–

RefuelingstationTrucksDiesel ICE

8

West/Central
EuropeWest/Central
EuropeOffshorewind

On-site/Decentral EL––

Steel plant(DRI + EAF)

Steel plant(BF + BOF)

Note: These pathways are the result of an exercise to adhere to a long list of pre-conditions. It is neither the intention to reflect actual projects nor to imply developments of any sort

The eight illustrative pathways are depicted in the following sections with some further backgroundinformation. The pathways presented include assumptions for recycling of metals at equipment endof life (as far as data was available). The excess heat (low temperature) from hydrogen production via
electrolysis has not been taken into account in the GHG balance, as this is subject to the availabilityof a low-temperature heating grid or the addition of a heat pump.

12

Hydrogen decarbonization pathways
A life-cycle assessment

1. Long-distance passenger cars

Exhibit 5: Long-distance passenger cars in East Asia, using imported blue hydrogen
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
g CO2eq/km
Gasoline HEV ICE(2030)

174

Reference (gasoline/BEV)
Fuel cell LDV (long distance)
H2 refueling station (LCGH2)

Gasoline HEV ICE(2050)

169

LH2 distribution
LH2 transport

H2 FCEV(2030)

H2 liquefaction
H2 production

H2 FCEV(2050)-77%

40

BEV (2030)

BEV (2050)

-61%

67

NG supply76

27

Source: LBST

Pathway description: For the use of hydrogen as in fuel cell electric vehicle (FCEV) powertrain,hydrogen is supplied from Australian natural gas with carbon capture using autothermal reformer witha capture rate of 98 %, which would then be stored in suitable disposal formations. The hydrogen isliquefied and transported via ship over a distance of 9,000 km to East Asia. The liquefied hydrogen is
distributed to refueling stations via truck. At the refueling station, the liquefied hydrogen is vaporized
and dispensed to the LDV.
Overall GHG reduction: This solution offers a reduction in GHG emissions of approximately 60% in
the short term, and a reduction of 75% in the long run, compared to a hybrid electric vehicle with aninternal combustion engine (ICE). GHG emissions of a battery-electric vehicle (BEV) of similar range
using the global grid mix are in the same order of magnitude as the FCEV.
Reference GHG: The hybrid reference vehicle improves marginally towards 2050 because of
improving vehicle capex-related GHG. The battery-electric alternative (BEV) improves significantlywith both capex-emissions and opex-related GHG emissions from reduced carbon-intensity of the
global grid mix. However, it has to be noted that there are applications where fast refueling, longer
driving ranges (over 300 km), or higher loads are required simultaneously, which cannot currently beachieved by BEV, especially in cases of very cold or very hot weather.
GHG reduction drivers in H2 pathways: Progress in GHG emission reductions in the FCEV wellto-wheel pathway mainly results from improved H2 liquefaction (higher per unit capacities, further
improved processes). It also benefits from much better global grid mix for auxiliary energy supply in
H2 production.

Hydrogen decarbonization pathways
A life-cycle assessment

132. Ships

Exhibit 6: Ships fueled with Norwegian blue hydrogen
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
g CO2eq/km
Diesel ICE(2030)

8,622

Diesel ICE(2050)

8,447

Reference (diesel ICE)
Ship
H2 refueling station (LH2)
LH2 distribution
H2 liquefaction

H2 FCEV(2030)

-75%

2,149

H2 production
NG supply

H2 FCEV(2050)

907-89%

Source: LBST

Pathway description: For the use of hydrogen as a transport fuel in fuel cell ship propulsion,hydrogen is supplied from Norwegian natural gas with carbon capture using an autothermal reformer
with a very high capture rate and storage in former offshore gas fields. The hydrogen is then liquefied
and distributed via trucks to bunker stations for ship fuel in Norway. In our example, a fuel-cellpowered Ro-Ro ferry with a capacity of 50-95 passenger is assumed.
Overall GHG reduction: Compared to the diesel reference, GHG emission reductions in the orderof 75% and almost 90% can be realized by 2030 and 2050, respectively.
Reference GHG: Marginal GHG emission reductions going forward can be observed in the fossil
reference pathway based on progress assumptions in the grid mix carbon intensity and increased
metal recycling efforts, i.e., both referring to improvements in capex-related GHG emissions only.
GHG reduction drivers in H2 pathways: Main GHG emission contributors in 2030 are ATR
operation and hydrogen liquefaction – as both consume significant amounts of auxiliary electricity
from global grid mix, the GHG intensity of which substantially improves towards 2050.

14

Hydrogen decarbonization pathways
A life-cycle assessment

3. Industrial heat

Exhibit 7: Industrial heat from blue hydrogen in Northern Europe
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
g CO2eq/kWhheat
Heat from NG

246

Reference (heat from NG)
Heat generation
H2 pipeline grid

Heat from H2(2030)

40-84%

H2 production
NG supply

Heat from H2(2050)

20-92%

Source: LBST

Pathway description: UK natural gas is split into hydrogen and CO2 via autothermal reforming (ATR)
using a 98% carbon capture rate. The CO2 is sequestered offshore. The hydrogen is transported via
a pipeline network to industry clusters in the UK, e.g., to produce industrial heat in boilers/furnaces.
Overall GHG reduction: Compared to the fossil reference (natural gas used in boiler or furnace),
GHG emission reductions of over 80% and over 90% can be realized by 2030 and 2050, respectively.
Reference GHG: From a GHG-emission balance perspective, differences between methane- andhydrogen-fed burners are marginal in terms of material intensity and conversion efficiency.
GHG reduction drivers in H2 pathways: Carbon capture via ATR requires significant auxiliaryelectricity to achieve the assumed high capture rate of 98%. The main GHG emission contributor in
the H2 value chain 2030 is grid mix for hydrogen production from natural gas, which more than halvesby 2050 due to substantial further improvements in the assumed global grid mix.

Hydrogen decarbonization pathways
A life-cycle assessment

15

4. Power generation

Exhibit 8: Blue hydrogen use in East Asian power generation
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
g CO2eq/kWheNG CCGT

369

Reference (NG CCGT)
Power station
NH3 transport

NH3 CCGT(2030)-64%

134

NH3 synthesis
H2 production

NH3 CCGT(2050)

59-84%

NG supply

Source: LBST

Pathway description: In this example, natural gas produced in Saudi Arabia is converted via
autothermal reforming with a 98% carbon capture rate. The CO2 is injected into old undergroundgas sources for permanent storage. Nitrogen is produced via air separation (using grid power) andsynthesized with hydrogen to create ammonia (NH3). The ammonia is transported in refrigerated
vessels that use dedicated ammonia for propulsion (boil-off gas to the extent available) over a
distance of about 12,000 km to East Asia. In the destination region, the ammonia is used to fire
central thermal power plants. In this case, a combined cycle gas turbine (CCGT) modified to run onammonia has been assumed, including selective catalytic reduction for exhaust gas treatment.
Overall GHG reduction: Compared to the fossil reference (natural gas used in CCGT power plants),
GHG emission reductions in the order of over 60% and over 80% are achieved by 2030 and 2050,
respectively.
Reference GHG: Differences between the methane and ammonia combustor unit are considerednegligible from a GHG emission point of view, both in terms of efficiency as well as in terms ofmaterial intensity. Already today, very high efficiency is achieved with large-scale combined-cycle gas
turbine (CCGT); hence, 2030 and 2050 efficiencies have been kept constant.
GHG reduction drivers in H2 pathways: Main GHG emission contributors in 2030 that could
significantly improve towards 2050 are hydrogen production, synthesis to ammonia, as well as
ammonia transport. GHG emissions from global grid mix serving the auxiliary electricity needs for
ATR hydrogen production significantly improve towards 2050, both with positive additional reductionsin ammonia synthesis and transport, respectively.

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Hydrogen decarbonization pathways
A life-cycle assessment

5. Fertilizer feedstock

Exhibit 9: Ammonia fertilizer from green hydrogen
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
kg CO2eq per t NH3
2,171

NH3 from NG

Reference (NH3 from NG)
NH3 transport
NH3 synthesis

NH3 from RE H2(2030)

187-91%

H2 production
Wind+solar

NH3 from RE H2(2050)

90-96%

Source: LBST

Pathway description: Today, ammonia derived from natural gas is a main feedstock for the
production of synthetic fertilizer. In our example here, a mix of wind and solar power with production
conditions typically found in North America is used to produce hydrogen via water electrolysis andnitrogen via an air separation unit. Hydrogen and nitrogen are synthesized to create ammonia, whichis then transported to fertilizer production facilities via inland navigation (2,000 km).
Overall GHG reduction: Compared to the fossil reference, GHG emission reductions of more than
90% and close to 100% can be achieved by 2030 and 2050, respectively, when using renewable
power as the primary energy source.
Reference GHG: Ammonia production from natural gas is a long-established process. Main value
chain elements are shared between the fossil reference and alternative renewable pathway. Changes
in capex-related GHG emissions of the fossil reference through improving global average grid mix are
considered negligible against the bandwidth of process data available from several projects.
GHG reduction drivers in H2 pathways: Main GHG emission contributors in 2030 are capexrelated GHG emissions from the manufacturing of wind and solar power plants and ammonia
synthesis, both benefitting from the carbon-intensity improvements in the global grid mix.

Hydrogen decarbonization pathways
A life-cycle assessment

176. Buses

Exhibit 10: Buses fueled with green hydrogen
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
g CO2eq/km
Diesel ICE

1,370

Reference (diesel ICE)
Fuel cell HDV
H2 refueling station (CGH2)

H2 FCEV(2030)

151-89%

H2 pipeline grid
PV plant

H2 FCEV(2050)

73-95%

Source: LBST

Pathway description: Remote solar power installations in China are used to produce bulk greenhydrogen. The hydrogen is transported via gas pipeline over 2,500 km to consumption centers,
where it is used to refuel buses that can serve longer routes also under more challenging climaticconditions (heat, cold) by using hydrogen fuel cell electric powertrain (FCEV).
Overall GHG reduction: Compared to the diesel bus reference, GHG emission reductions of close
to 90% and 95% can be achieved for 2030 and 2050, respectively.
Reference GHG: The fossil comparator is diesel consumed by an ICE.
GHG reduction drivers in H2 pathways: Main GHG emission contributors in 2030 are longdistance pipeline transport (compression) and auxiliary energy supply for operating the H2 refuelingstation. From 2030 to 2050, GHG emissions from these are reduced significantly due to an improving
global grid mix.

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Hydrogen decarbonization pathways
A life-cycle assessment

7. Heavy-duty transport trucks

Exhibit 11: Heavy-duty trucks fueled with green hydrogen
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
g CO2eq/km
1,149

Diesel ICE

Reference (diesel ICE)
Fuel cell HDV
H2 refueling station (CGH2)1

H2 FCEV(2030)

122-89%

H2 production
Wind + Solar

H2 FCEV(2050)

62-95%

1 Using LH as a fuel for long-haul trucks, supplied to refueling stations from central production hubs, is another relevant supply option currently pursued by stakeholders in the value chain.
2

Source: LBST

Pathway description: Electricity from US wind (2,500 heq/a) and solar (1,500 heq/a) hybrid power
plants is fed into the grid with an assumed energy curtailment of 5%. Hydrogen is produced via waterelectrolysis on site at the H2 refueling station and dispensed to heavy-duty trucks15.
Overall GHG reduction: Compared to the diesel truck reference, GHG emission reductions of close
to 90% and well above 90% can be realized by 2030 and 2050, respectively.
Reference GHG: The fossil comparator is diesel consumed in an ICE.
GHG reduction drivers in H2 pathways: Main GHG emission contributors for the renewablehydrogen pathway in 2030 are capex-related GHG emissions for the manufacturing of wind and solar
power plants and auxiliary electricity demand for the operation of the H2 refueling station. These
already very low emissions can be approximately halved by improving the background energy system(global grid mix).

15

Using LH2 as a fuel for long-haul trucks, supplied to refueling stations from central production hubs, is another relevant supply
option currently pursued by stakeholders in the value chain.

Hydrogen decarbonization pathways
A life-cycle assessment

198. Steel production

Exhibit 12: Green steel production in Western Europe
Capex-related GHG emissions
included in the process steps(recycling taken into account)

Greenhouse gases (GHG)
kg CO2eq/tsteel
Blast furnace +BOF (2030)

1,858

Blast furnace +BOF (2050)

1,893

Reference (blast
furnace + BOF)
DRI plant + EAF
H2 production
Wind offshore

DRI + EAF
(2030)
DRI + EAF
(2050)

249

103

-87%

-94%

Source: LBST

Pathway description: Electricity produced from offshore wind parks in the North or Baltic Seasis transported by a high-voltage direct current cable onshore from where it is further distributed toindustrial demand centers. Green hydrogen is produced via water electrolysis on site at a steelmaking
facility. In direct reduction of iron ore (DRI) using hydrogen, so-called sponge iron is produced, which
is further processed in an EAF to specified steel qualities.
Overall GHG reduction: Compared to the conventional primary iron production via blast furnaceand basic oxygen furnace process, GHG emission reductions in the order of 87% and 95% can berealized by 2030 and 2050, respectively, by using green hydrogen in a DRI and EAF configuration.
Reference GHG: The GHG emissions of the conventional steelmaking route marginally increase
from 2030 to 2050 as the carbon-intensity of the electricity mix decreases, leading to a lower credit
for the excess electricity (about 0.3 MWhe per ton of steel) from the blast furnace gas.
GHG reduction drivers in H2 pathways: Main GHG emission driver in the DRI and EAF
configuration is the auxiliary electricity consumption of the EAF. The attributed GHG emissions morethan halve from 2030 to 2050 as the global grid mix significantly improves.

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Hydrogen decarbonization pathways
A life-cycle assessment

Conclusions— Results from life-cycle assessments of GHG emission for hydrogen supply shows that natural
gas with CCS and renewable power for water electrolysis can achieve low and marginal well-touse GHG emissions, including end-of-life, respectively. For fossil primary energies with CCS, anumber of requirements must be met, namely sweet natural gas sources, highest capture rates(98% assumed in the eight illustrative pathways), as well as best available technologies andoperational practices.
— Biogenic feedstock for hydrogen production can result in a wide range of GHG emissions.
While energy crops are between natural gas-based and renewable electricity-based pathways,
GHG emissions from biogenic wastes can be as low as the best renewable power-to-hydrogen
pathways (or even negative in case of bio + CCS) but with waste streams somewhat limited at
global scale.
— Capex-related GHG emissions for the manufacturing of assets are low across the H2 supply
options compared to the carbon intensity of incumbent fossil pathways, and have been
calculated based on global average carbon intensities for energies used in manufacturing.
Some manufacturers already today excel beyond average by using renewable and low-carbon
energy sources for product manufacturing. GHG emissions of power-to-hydrogen pathways
are dominated by capex-related emissions, albeit at very low levels compared to fossil
references and alternatives. In this study, a global grid mix with decreasing carbon intensity
towards 2050 has been assumed for the capex-related emissions of energy production assets
and a number of hydrogen applications where data was available (here, data availability is
generally weak). The impact of selected recycling on the well-to-use GHG emission balanceis small compared to the fossil reference, most pronounced with solar and wind power
pathways, and of wider strategic relevance for deep decarbonization in the context of acircular economy.
— With a view to sustainability aspects other than GHG emissions, specific gross water demandhas been assessed for hydrogen supply pathways. Gross water demand is most pronouncedwith water needs for biomass cultivation and cooling of thermal power plants, hence, a focus onbiogenic waste streams and dry-cooling systems is recommended for regions prone to watersupply stress or already under supply risk. Gross water demand with photovoltaic (PV) andwind power for water electrolysis is very low. Power-to-X plants at gigawatt-scale neverthelesscan be a significant point-demand for water especially in arid regions. Site-specific watersupply and demand assessments are regular tasks in environmental impact assessments
prior to plant approvals. For large plants in dry regions, seawater desalination with adequate
effluent management is an option. Water desalination for Power-to-X plants requires marginal
additional energy.
— Eight illustrative pathways for hydrogen value chains from primary energies to hydrogen use havebeen laid out and GHG emissions calculated for 2030 and 2050. Thereof, four pathways describe
mobility and industry applications each. Half of the eight illustrative pathways each comprise green
and blue hydrogen value chains. Across the selected hydrogen pathways and applications, very
high (about 90% or higher) to high (about 60%) GHG emission reductions can be demonstratedusing green (solar, wind) and blue (98% carbon capture rate) hydrogen, respectively. GHG
emission reductions observed from 2030 to 2050 are largely capex related, assuming a strong
improvement to the global grid mix to reach Paris Agreement targets.
— On a sensitivity note, renewables and electrolysis show the strongest GHG reduction of thedifferent supply pathways assessed in this study, with the best-case blue pathway delivering a

Hydrogen decarbonization pathways
A life-cycle assessment

21

reduction in the same order of magnitude. Renewables + electrolysis and fossil + CCS do comewith different risks:— While all blue options considered in this study show a noticeable but wide range of GHG
reduction versus incumbent (grey) H2 production, blue pathways are connected with higher
GHG upwards sensitivities (not using sweet gas sources and best available technology as well
as operational practices)— Though they have not been analyzed in the study, we note that there are discussions about
long-term carbon storage and technology path dependencies, potentially impacting post-2050
emission reduction trajectories— Small differences in specific GHG emissions stack up to noticeable absolute emission volumes,
requiring larger shares from remaining carbon budgets to stay well below the 2°C target.
— H2 pathways derived from fossil resources can significantly improve carbon intensity if the auxiliary
energy required for primary energy supply or carbon capture is provided from dedicated renewablesources. This could also provide the opportunity to gain organizational knowledge, practicalexperience, and thus enable a seamless transition beyond 2050.
— Certification of origin and sustainability metrices are key for political support, social acceptance,and consumer willingness to pay the premium for low-carbon and renewable hydrogen supply
and applications.

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Hydrogen decarbonization pathways
A life-cycle assessment