United States
Hydrogen Station Location Planning via Geodesign in Connecticut: Comparing Optimization Models and Structured Stakeholder Collaboration
Nov 2021
Publication
Geodesign is a participatory planning approach in which stakeholders use geographic information systems to develop and vet alternative design scenarios in a collaborative and iterative process. This study is based on a 2019 geodesign workshop in which 17 participants from industry government university and non-profit sectors worked together to design an initial network of hydrogen refueling stations in the Hartford Connecticut metropolitan area. The workshop involved identifying relevant location factors rapid prototyping of station network designs and developing consensus on a final design. The geodesign platform which was designed specifically for facility location problems enables breakout groups to add or delete stations with a simple point-and-click operation view and overlay different map layers compute performance metrics and compare their designs to those of other groups. By using these sources of information and their own expert local knowledge participants recommended six locations for hydrogen refueling stations over two distinct phases of station installation. We quantitatively and qualitatively compared workshop recommendations to solutions of three optimal station location models that have been used to recommend station locations which minimize travel times from stations to population and traffic or maximize trips that can be refueled on origin–destination routes. In a post-workshop survey participants rated the workshop highly for facilitating mutual understanding and information sharing among stakeholders. To our knowledge this workshop represents the first application of geodesign for hydrogen refueling station infrastructure planning.
Everything About Hydrogen Podcast: Rethinking Hydrogen Storage with H2GOPOWER
Sep 2019
Publication
For this episode we speak to Enass Abo-Hamed the CEO of H2GOPower about their cutting edge hydrogen storage technology. Below we have attached a few links to the content discussed on the show and some further background reading.
The podcast can be found on their website
The podcast can be found on their website
Modeling Hydrogen Refueling Infrastructure to Support Passenger Vehicles
May 2018
Publication
The year 2014 marked hydrogen fuel cell electric vehicles (FCEVs) first becoming commercially available in California where significant investments are being made to promote the adoption of alternative transportation fuels. A refueling infrastructure network that guarantees adequate coverage and expands in line with vehicle sales is required for FCEVs to be successfully adopted by private customers. In this paper we provide an overview of modelling methodologies used to project hydrogen refueling infrastructure requirements to support FCEV adoption and we describe in detail the National Renewable Energy Laboratory’s scenario evaluation and regionalization analysis (SERA) model. As an example we use SERA to explore two alternative scenarios of FCEV adoption: one in which FCEV deployment is limited to California and several major cities in the United States; and one in which FCEVs reach widespread adoption becoming a major option as passenger vehicles across the entire country. Such scenarios can provide guidance and insights for efforts required to deploy the infrastructure supporting transition toward different levels of hydrogen use as a transportation fuel for passenger vehicles in the United States.
Economic Value of Flexible Hydrogen-based Polygeneration Energy Systems
Jan 2016
Publication
Polygeneration energy systems (PES) have the potential to provide a flexible high-efficiency and low-emissions alternative for power generation and chemical synthesis from fossil fuels. This study aims to assess the economic value of fossil-fuel PES which rely on hydrogen as an intermediate product. Our analysis focuses on a representative PES configuration that uses coal as the primary energy input and produces electricity and fertilizer as end-products. We derive a series of propositions that assess the cost competitiveness of the modeled PES under both static and flexible operation modes. The result is a set of metrics that quantify the levelized cost of hydrogen the unit profit-margin of PES and the real option values of ‘diversification’ and ‘flexibility’ embedded in PES. These metrics are subsequently applied to assess the economics of Hydrogen Energy California (HECA) a PES currently under development in California. Under our technical and economic assumptions HECA’s levelized cost of hydrogen is estimated at 1.373 $/kgh. The profitability of HECA as a static PES increases in the share of hydrogen converted to fertilizer rather than electricity. However when configured as a flexible PES HECA almost breaks even on a pre-tax basis. Diversification and flexibility are valuable for HECA when polygeneration is compared to static monogeneration of electricity but these two real options have no value when comparing polygeneration to static monogeneration of fertilizers.
Everything About Hydrogen Podcast: Toyota's global hydrogen ambitions
Feb 2020
Publication
On this weeks episode the team are talking all things hydrogen with Craig Scott the Group Manager for Toyota North America a global automotive giant and a recognised pioneer in the field of fuel cell mobility. On the show we get into the story of Toyota’s roll out of fuel cell mobility solutions in North America the challenges and opportunities that fuel cell vehicles can offer in the hydrogen market and the challenges around infrastructure. Importantly we also dive into the scaling up work that Toyota is undertaking and some of its plans for next steps on the mission to become the world’s leader in fuel cell mobility solutions. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Everything About Hydrogen Podcast: Taking the Lead in the Hydrogen Economy
Sep 2021
Publication
On the season premier episode the EAH hosts are joined by the Governor of New Mexico Michelle Lujan Grisham. The State of New Mexico has the opportunity to lead the United States into the hydrogen era and the Governor and her team are poised to take the opportunity to make New Mexico the strategic center of the US hydrogen economy. The Governor is joined by New Mexico Environment Department Secretary James Kenney on the show to announce the forthcoming New Mexico Hydrogen Hub Act which her administration expects to drive investment in the state job growth in the energy sector and catapult New Mexico to top of the list of states driving the hydrogen revolution.
The podcast can be found on their website.
The podcast can be found on their website.
Spherically Expanding Flame Simulations in Cantera Using a Lagrangian Formulation
Sep 2021
Publication
A Lagrangian-based one-dimensional approach has been developed using Cantera to study the dynamics of spherically expanding flames. The detailed reaction model USC-Mech II has been employed to examine flame propagating in hydrogen-air mixtures. In the first part our approach has been validated against laminar flame speed and Markstein number data from the literature. It was shown that the laminar flame speed was predicted within 5% on average but that discrepancies were observed for the Markstein number especially for rich mixtures. In the second part a detailed analysis of the thermo-chemical dynamics along the path of Lagrangian particles propagating in stretched flames was performed. For mixtures with negative Markstein lengths it was found that at high stretch rates the mixture entering the reaction-dominated period is less lean with respect to the initial mixture than at low stretch rate. This induces a faster rate of chemical heat release and of active radical production which results in a higher flame propagation speed. Opposite effects were observed for mixtures with positive Markstein lengths for which slower flame propagation was observed at high stretch rates compared to low stretch rates."
H-Mat Hydrogen Compatibility of NBR Elastomers
Sep 2021
Publication
The H2@Scale program of the U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office (HFTO) is supporting work on the hydrogen compatibility of polymers to improve the durability and reliability of materials for hydrogen infrastructure. The hydrogen compatibility program (H-Mat) seeks “to address the challenges of hydrogen degradation by elucidating the mechanisms of hydrogen-materials interactions with the goal of providing science-based strategies to design materials (micro)structures and morphology with improved resistance to hydrogen degradation.” Previous work on ethylene propylene diene indicated hydrogen interaction with plasticizer increased its migration to the surface and coalescing within the elastomer compound. New research on nitrile butadiene (NBR) has found hydrogen and pressure interactions with a series model rubber-material compounds to behave similarly in some compounds and improved in other compounds that is demonstrated through volume change and compression-set differences in the materials. Further studies were conducted using a helium-ion microscope (HeIM) which revealed significant morphological changes in the plasticizer-incorporating compounds after static exposure and pressure cycling as evidenced by time-of-flight secondary ion mass spectrometry. Additional studies using x-ray chromatography revealed that more micro-voids/-cracks developed after gas decompression in unfilled materials than in filled materials; transmission electron microscopy (TEM) probed at the nano-meter level showing change in filler distribution and morphology around Zinc-based particles.
Everything About Hydrogen Podcast: Reaching for the Stars
Mar 2023
Publication
Today Everything About Hydrogen had a chance to speak with Paul Barrett the CEO of Hysata and dig into what makes this electrolysis company different.
The podcast can be found on their website.
The podcast can be found on their website.
Thermodynamic and Emission Analysis of a Hydrogen/Methane Fueled Gas Turbine
May 2023
Publication
The importance of hydrogen in the effort to decarbonize the power sector has grown immensely in recent years. Previous studies have investigated the effects of mixing hydrogen into natural gas for gas turbine combustors but limited studies have examined the resulting effects hydrogen addition has on the entire system. In this work a thermodynamic model of a gas turbine with combustion chemical kinetics integrated is created and the effects hydrogen addition (0-100 volume percent addition) has on the system performance emissions and combustion kinetics are analyzed. The maximum system performance is achieved when the maximum turbine inlet temperature is reached and the resulting optimal fuel/air equivalence ratio is determined. As hydrogen is added to the fuel mixture the optimal equivalence ratio shifts leaner causing non-linearity in emissions and system performance at optimal conditions. An analysis of variance is conducted and it is shown that isentropic efficiencies of the turbine and compressor influences the system performance the most out of any system parameter. While isentropic efficiencies of the turbine and compressor increase towards 100% an operating regime where the optimal system efficiency cannot be achieved is discovered due to the lower flammability limit of the fuel being reached. This can be overcome by mixing hydrogen into the fuel.
Experimental Investigation of Stress Corrosion on Supercritical CO2 Transportation Pipelines Against Leakage for CCUS Applications
Nov 2022
Publication
Carbon Capture Utilization and Storage (CCUS) is one of the key technologies that will determine how humans address global climate change. For captured CO2 in order to avoid the complications associated with two-phase flow most carbon steel pipelines are operated in the supercritical state on a large scale. A pipeline has clear Stress Corrosion Cracking (SCC) sensitivity under the action of stress and corrosion medium which will generally cause serious consequences. In this study X70 steel was selected to simulate an environment in the process of supercritical CO2 transportation by using high-temperature high-pressure Slow Strain Rate Tensile (SSRT) tests and high-temperature high-pressure electrochemical test devices with different O2 and SO2 contents. Studies have shown that 200 ppm SO2 shows a clear SCC sensitivity tendency which is obvious when the SO2 content reaches 600 ppm. The SCC sensitivity increases with the increase of SO2 concentration but the increase amplitude decreases. With the help of advanced microscopic characterization techniques such as scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) through the analysis of fracture and side morphology the stress corrosion mechanism of a supercritical CO2 pipeline containing SO2 and O2 impurities was obtained by hydrogen embrittlement fracture characteristics. With the increase of SO2 content the content of Fe element decreases and the corrosion increases demonstrating that SO2 plays a leading role in electrochemical corrosion. This study further strengthens the theoretical basis of stress corrosion of supercritical CO2 pipelines plays an important role in preventing leakage of supercritical CO2 pipelines and will provide guidance for the industrial application of CCUS.
Process of Transformation to Net Zero Steelmaking: Decarbonisation Scenarios Based on the Analysis of the Polish Steel Industry
Apr 2023
Publication
The European steel industry is experiencing new challenges related to the market situation and climate policy. Experience from the period of pandemic restrictions and the effects of Russia’s armed invasion of Ukraine has given many countries a basis for including steel along with raw materials (coke iron ore electricity) in economic security products (CRMA). Steel is needed for economic infrastructure and construction development as well as a material for other industries (without steel factories will not produce cars machinery ships washing machines etc.). In 2022 steelmakers faced a deepening energy crisis and economic slowdown. The market situation prompted steelmakers to impose restrictions on production volumes (worldwide production fell by 4% compared to the previous year). Despite the difficult economic situation of the steel industry (production in EU countries fell by 11% in 2022 compared to the previous year) the EU is strengthening its industrial decarbonisation policy (“Fit for 55”). The decarbonisation of steel production is set to accelerate by 2050. To sharply reduce carbon emissions steel mills need new steelmaking technologies. The largest global steelmakers are already investing in new technologies that will use green hydrogen (produced from renewable energy sources). Reducing iron ore with hydrogen plasma will drastically reduce CO2 emissions (steel production using hydrogen could emit up to 95% less CO2 than the current BF + BOF blast furnace + basic oxygen furnace integrated method). Investments in new technologies must be tailored to the steel industry. A net zero strategy (deep decarbonisation goal) may have different scenarios in different EU countries. The purpose of this paper was to introduce the conditions for investing in low-carbon steelmaking technologies in the Polish steel market and to develop (based on expert opinion) scenarios for the decarbonisation of the Polish steel industry.
Artificial Intelligence/Machine Learning in Energy Management Systems, Control, and Optimization of Hydrogen Fuel Cell Vehicles
Mar 2023
Publication
Environmental emissions global warming and energy-related concerns have accelerated the advancements in conventional vehicles that primarily use internal combustion engines. Among the existing technologies hydrogen fuel cell electric vehicles and fuel cell hybrid electric vehicles may have minimal contributions to greenhouse gas emissions and thus are the prime choices for environmental concerns. However energy management in fuel cell electric vehicles and fuel cell hybrid electric vehicles is a major challenge. Appropriate control strategies should be used for effective energy management in these vehicles. On the other hand there has been significant progress in artificial intelligence machine learning and designing data-driven intelligent controllers. These techniques have found much attention within the community and state-of-the-art energy management technologies have been developed based on them. This manuscript reviews the application of machine learning and intelligent controllers for prediction control energy management and vehicle to everything (V2X) in hydrogen fuel cell vehicles. The effectiveness of data-driven control and optimization systems are investigated to evolve classify and compare and future trends and directions for sustainability are discussed.
Reduction in Greenhouse Gas and Other Emissions from Ship Engines: Current Trends and Future Options
Nov 2022
Publication
The impact of ship emission reductions can be maximised by considering climate health and environmental effects simultaneously and using solutions fitting into existing marine engines and infrastructure. Several options available enable selecting optimum solutions for different ships routes and regions. Carbon-neutral fuels including low-carbon and carbon-negative fuels from biogenic or non-biogenic origin (biomass waste renewable hydrogen) could resemble current marine fuels (diesel-type methane and methanol). The carbon-neutrality of fuels depends on their Well-to-Wake (WtW) emissions of greenhouse gases (GHG) including carbon dioxide (CO2) methane (CH4) and nitrous oxide emissions (N2O). Additionally non-gaseous black carbon (BC) emissions have high global warming potential (GWP). Exhaust emissions which are harmful to health or the environment need to be equally removed using emission control achieved by fuel engine or exhaust aftertreatment technologies. Harmful emission species include nitrogen oxides (NOx) sulphur oxides (SOx) ammonia (NH3) formaldehyde particle mass (PM) and number emissions (PN). Particles may carry polyaromatic hydrocarbons (PAHs) and heavy metals which cause serious adverse health issues. Carbon-neutral fuels are typically sulphur-free enabling negligible SOx emissions and efficient exhaust aftertreatment technologies such as particle filtration. The combinations of carbon-neutral drop-in fuels and efficient emission control technologies would enable (near-)zero-emission shipping and these could be adaptable in the short- to mid-term. Substantial savings in external costs on society caused by ship emissions give arguments for regulations policies and investments needed to support this development.
Everything About Hydrogen Podcast: Plotting the Course for a Decarbonized Global Maritime Industry
Jan 2023
Publication
On this episode of EAH we sat down with Dr. Bo Cerup-Simonsen Chief Executive Officer of the Maersk Mc-Kinney Møller Center for Zero Carbon Shipping. Bo holds a PHD in Naval Architecture and Mechanical Engineering and spent seven years as a research engineer at MIT.
Bo explains the Center's work and we discuss decarbonization of shipping using hydrogen derived green fuels.
The podcast can be found on their website.
Bo explains the Center's work and we discuss decarbonization of shipping using hydrogen derived green fuels.
The podcast can be found on their website.
Electric Aircraft Fueled by Liquid Hydrogen and Liquefied Natural Gas
Jul 2021
Publication
The paper is a review of the opportunities and challenges of cryogenic power devices of electric aircraft and the ongoing research and development efforts of the government agencies and the industry. Liquid Hydrogen (LH2) and Liquefied Natural Gas (LNG) are compared to support high temperature superconducting (HTS) and normal metal devices respectively. The power devices were assumed to operate at the normal boiling point of the fuel used. The efficiencies of the electrical devices are estimated based on state-of-the-art technology. The mass flow rates and total fuel requirements for both the cryogenic fuels required to maintain the operating temperatures of the devices were simulated using thermal network models. A twin-aisle 300 passenger aircraft with a 5.5 h flight duration was used for the models. The results show that the required masses of LH2 and LNG are 744 kg and 13638 kg respectively for the cooling requirement. The corresponding volumes of LH2 and LNG required are 9760 and 30300 L respectively. In both cases the estimated mass of the fuel needed for the aircraft is more than what is needed to maintain the cryogenic environment of the power devices. It was concluded that an electric aircraft with LNG cooled normal metal devices is feasible. However an aircraft with HTS devices and cooled with LH2 is more attractive if the ongoing R&D efforts on HTS devices and LH2 infrastructure are successful. The emission reductions would be substantially higher with LH2 particularly when H2 is produced using renewable energy sources.
Everything About Hydrogen Podcast: Manufacturing the Components of a Hydrogen Economy
Dec 2022
Publication
On today’s episode Alicia Chris and Patrick are chatting with Vonjy Rakajoba UK Managing Director at Robert Bosch. The Bosch Group is a leading global supplier of technology and services and employs roughly 402600 associates worldwide. Its operations are divided into four business sectors: Mobility Solutions Industrial Technology Consumer Goods and Energy and Building Technology. Bosch believes that hydrogen has a bright future as an energy carrier and is making considerable upfront investments in this area. From 2021 to 2024 the company plans to invest around 600 million euros in mobile fuel-cell applications and a further 400 million euros in stationary ones for the generation of electricity and heat. Vonjy is here with us to discuss more about what Bosch’s expansion into the hydrogen energy sector will look like and how the company expects the market to grow moving forward.
The podcast can be found on their website.
The podcast can be found on their website.
Deep Decarbonisation Pathways of the Energy System in Times of Unprecedented Uncertainty in the Energy Sector
May 2023
Publication
Unprecedented investments in clean energy technology are required for a net-zero carbon energy system before temperatures breach the Paris Agreement goals. By performing a Monte-Carlo Analysis with the detailed ETSAPTIAM Integrated Assessment Model and by generating 4000 scenarios of the world’s energy system climate and economy we find that the uncertainty surrounding technology costs resource potentials climate sensitivity and the level of decoupling between energy demands and economic growth influence the efficiency of climate policies and accentuate investment risks in clean energy technologies. Contrary to other studies relying on exploring the uncertainty space via model intercomparison we find that the CO2 emissions and CO2 prices vary convexly and nonlinearly with the discount rate and climate sensitivity over time. Accounting for this uncertainty is important for designing climate policies and carbon prices to accelerate the transition. In 70% of the scenarios a 1.5 ◦C temperature overshoot was within this decade calling for immediate policy action. Delaying this action by ten years may result in 2 ◦C mitigation costs being similar to those required to reach the 1.5 ◦C target if started today with an immediate peak in emissions a larger uncertainty in the medium-term horizon and a higher effort for net-zero emissions.
Risk of the Hydrogen Economy for Atmospheric Methane
Dec 2022
Publication
Hydrogen (H2) is expected to play a crucial role in reducing greenhouse gas emissions. However hydrogen losses to the atmosphere impact atmospheric chemistry including positive feedback on methane (CH4) the second most important greenhouse gas. Here we investigate through a minimalist model the response of atmospheric methane to fossil fuel displacement by hydrogen. We find that CH4 concentration may increase or decrease depending on the amount of hydrogen lost to the atmosphere and the methane emissions associated with hydrogen production. Green H2 can mitigate atmospheric methane if hydrogen losses throughout the value chain are below 9 ± 3%. Blue H2 can reduce methane emissions only if methane losses are below 1%. We address and discuss the main uncertainties in our results and the implications for the decarbonization of the energy sector.
Prediction of Transient Hydrogen Flow of Proton Exchange Membrane Electrolyzer Using Artificial Neural Network
Aug 2023
Publication
A proton exchange membrane (PEM) electrolyzer is fed with water and powered by electric power to electrochemically produce hydrogen at low operating temperatures and emits oxygen as a by-product. Due to the complex nature of the performance of PEM electrolyzers the application of an artificial neural network (ANN) is capable of predicting its dynamic characteristics. A handful of studies have examined and explored ANN in the prediction of the transient characteristics of PEM electrolyzers. This research explores the estimation of the transient behavior of a PEM electrolyzer stack under various operational conditions. Input variables in this study include stack current oxygen pressure hydrogen pressure and stack temperature. ANN models using three differing learning algorithms and time delay structures estimated the hydrogen mass flow rate which had transient behavior from 0 to 1 kg/h and forecasted better with a higher count (>5) of hidden layer neurons. A coefficient of determination of 0.84 and a mean squared error of less than 0.005 were recorded. The best-fitting model to predict the dynamic behavior of the hydrogen mass flow rate was an ANN model using the Levenberg–Marquardt algorithm with 40 neurons that had a coefficient of determination of 0.90 and a mean squared error of 0.00337. In conclusion optimally fit models of hydrogen flow from PEM electrolyzers utilizing artificial neural networks were developed. Such models are useful in establishing an agile flow control system for the electrolyzer system to help decrease power consumption and increase efficiency in hydrogen generation.
Numerical Simulation of Hydrogen Diffusion in Cement Sheath of Wells Used for Underground Hydrogen Storage
Jul 2023
Publication
The negative environmental impact of carbon emissions from fossil fuels has promoted hydrogen utilization and storage in underground structures. Hydrogen leakage from storage structures through wells is a major concern due to the small hydrogen molecules that diffuse fast in the porous well cement sheath. The second-order parabolic partial differential equation describing the hydrogen diffusion in well cement was solved numerically using the finite difference method (FDM). The numerical model was verified with an analytical solution for an ideal case where the matrix and fluid have invariant properties. Sensitivity analyses with the model revealed several possibilities. Based on simulation studies and underlying assumptions such as non-dissolvable hydrogen gas in water present in the cement pore spaces constant hydrogen diffusion coefficient cement properties such as porosity and saturation etc. hydrogen should take about 7.5 days to fully penetrate a 35 cm cement sheath under expected well conditions. The relatively short duration for hydrogen breakthrough in the cement sheath is mainly due to the small molecule size and high hydrogen diffusivity. If the hydrogen reaches a vertical channel behind the casing a hydrogen leak from the well is soon expected. Also the simulation result reveals that hydrogen migration along the axial direction of the cement column from a storage reservoir to the top of a 50 m caprock is likely to occur in 500 years. Hydrogen diffusion into cement sheaths increases with increased cement porosity and diffusion coefficient and decreases with water saturation (and increases with hydrogen saturation). Hence cement with a low water-to-cement ratio to reduce water content and low cement porosity is desirable for completing hydrogen storage wells.
Solar Water Splitting by Photovoltaic-electrolysis with a Solar-to-hydrogen Efficiency over 30%
Oct 2016
Publication
Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.
Techno-economic Feasibility of Hybrid PV/wind/battery/thermal Storage Trigeneration System: Toward 100% Energy Independency and Green Hydrogen Production
Dec 2022
Publication
With the clear adverse impacts of fossil fuel-based energy systems on the climate and environment ever-growing interest and rapid developments are taking place toward full or nearly full dependence on renewable energies in the next few decades. Estonia is a European country with large demands for electricity and thermal energy for district heating. Considering it as the case study this work explores the feasibility and full potential of optimally sized photovoltaic (PV) wind and PV/wind systems equipped with electric and thermal storage to fulfill those demands. Given the large excess energy from 100% renewable energy systems for an entire country this excess is utilized to first meet the district heating demand and then to produce hydrogen fuel. Using simplified models for PV and wind systems and considering polymer electrolyte membrane (PEM) electrolysis a genetic optimizer is employed for scanning Estonia for optimal installation sites of the three systems that maximize the fulfillment of the demand and the supply–demand matching while minimizing the cost of energy. The results demonstrate the feasibility of all systems fully covering the two demands while making a profit compared to selling the excess produced electricity directly. However the PV-driven system showed enormous required system capacity and amounts of excess energy with the limited solar resources in Estonia. The wind system showed relatively closer characteristics to the hybrid system but required a higher storage capacity by 75.77%. The hybrid PV/wind-driven system required a total capacity of 194 GW most of which belong to the wind system. It was also superior concerning the amount (15.05 × 109 tons) and cost (1.42 USD/kg) of the produced green hydrogen. With such full mapping of the installation capacities and techno-economic parameters of the three systems across the country this study can assist policymakers when planning different country-scale cogeneration systems.
Repurposing Pipelines for Hydrogen: Legal and Policy Considerations
Nov 2022
Publication
As the world looks to implement the Energy Transition repurposing existing fossil fuel infrastructure to produce or distribute “clean” energy will be critical. The most promising is using natural gas pipelines for moving hydrogen. This is the cheapest and fastest method of transport and reducing the cost of transporting hydrogen is a key step in making it economically viable. However while there are technical challenges the greater challenge is in the legal arena. This paper seeks to outline the numerous legal — treaty statutory and contractual — and regulatory obstacles to repurposing natural gas pipelines for hydrogen transport. Gas pipelines exist in a complex microclimate of international public and private law and domestic law and contracts. Ownership is often layered and tangled; financing doubly so; and myriad state interests compound the private interests including national security concerns energy supply imperatives and geopolitical balance. State aid — investment subsidies and tax breaks — may encumber the project with additional legal obligations. And the contracts that control the development of a pipeline project may inject further legal complexity such as dispute mediation procedures and fora and applicable law. This paper seeks to map all the likely areas of future conflict or difficulty so that work on developing the requisite legal regime and remedies to permit use of natural gas pipelines for hydrogen transport can begin now. For policy and lawmakers as well as the private sector evaluating these known unknowns is a good starting point for reconsidering legislation regulation contracts and project risk in preparation for the future probability of hydrogen pipelines.
Grid Ancillary Services using Electrolyzer-based Power-to-Gas Systems with Increasing Renewable Penetration
Nov 2023
Publication
Increasing penetrations of renewable-based generation have led to a decrease in the bulk power system inertia and an increase in intermittency and uncertainty in generation. Energy storage is considered to be an important factor to help manage renewable energy generation at greater penetrations. Hydrogen is a viable long-term storage alternative. This paper analyzes and presents use cases for leveraging electrolyzer-based power-to-gas systems for electric grid support. The paper also discusses some grid services that may favor the use of hydrogenbased storage over other forms such as battery energy storage. Real-time controls are developed implemented and demonstrated using a power-hardware-in-the-loop(PHIL) setup with a 225-kW proton-exchange-membrane electrolyzer stack. These controls demonstrate frequency and voltage support for the grid for different levels of renewable penetration (0% 25% and 50%). A comparison of the results shows the changes in respective frequencies and voltages as seen as different buses as a result of support from the electrolyzers and notes the impact on hydrogen production as a result of grid support. Finally the paper discusses the practical nuances of implementing the tests with physical hardware such as inverter/electrolyzer efficiency as well as the related constraints and opportunities.
Cost of Long-Distance Energy Transmission by Different Carriers
Nov 2021
Publication
This paper compares the relative cost of long-distance large-scale energy transmission by electricity and by gaseous and liquid carriers (e-fuels). The results indicate that the cost of electrical transmission per delivered MWh can be up to eight times higher than for hydrogen pipelines about eleven times higher than for natural gas pipelines and twenty to fifty times higher than for liquid fuels pipelines. These differences generally hold for shorter distances as well. The higher cost of electrical transmission is primarily due to lower carrying capacity (MW per line) of electrical transmission lines compared to the energy carrying capacity of the pipelines for gaseous and liquid fuels. The differences in the cost of transmission are important but often unrecognized and should be considered as a significant cost component in the analysis of various renewable energy production distribution and utilization scenarios.
Numerical Predictions of a Swirl Combustor Using Complex Chemistry Fueled with Ammonia/Hydrogen Blends
Jan 2020
Publication
Ammonia a chemical that contains high hydrogen quantities has been presented as a candidate for the production of clean power generation and aerospace propulsion. Although ammonia can deliver more hydrogen per unit volume than liquid hydrogen itself the use of ammonia in combustion systems comes with the detrimental production of nitrogen oxides which are emissions that have up to 300 times the greenhouse potential of carbon dioxide. This factor combined with the lower energy density of ammonia makes new studies crucial to enable the use of the molecule through methods that reduce emissions whilst ensuring that enough power is produced to support high-energy intensive applications. Thus this paper presents a numerical study based on the use of novel reaction models employed to characterize ammonia combustion systems. The models are used to obtain Reynolds Averaged Navier-Stokes (RANS) simulations via Star-CCM+ with complex chemistry of a 70%–30% (mol) ammonia–hydrogen blend that is currently under investigations elsewhere. A fixed equivalence ratio (1.2) medium swirl (0.8) and confined conditions are employed to determine the flame and species propagation at various operating atmospheres and temperature inlet values. The study is then expanded to high inlet temperatures high pressures and high flowrates at different confinement boundary conditions. The results denote how the production of NOx emissions remains stable and under 400 ppm whilst higher concentrations of both hydrogen and unreacted ammonia are found in the flue gases under high power conditions. The reduction of heat losses (thus higher temperature boundary conditions) has a crucial impact on further destruction of ammonia post-flame with a raise in hydrogen water and nitrogen through the system thus presenting an opportunity of combustion efficiency improvement of this blend by reducing heat losses. Final discussions are presented as a method to raise power whilst employing ammonia for gas turbine systems.
Analysis to Support Revised Distances between Bulk Liquid Hydrogen Systems and Exposures
Sep 2021
Publication
The minimum distances between exposures and bulk liquid hydrogen listed in the National Fire Protection Agency’s Hydrogen Technology Code NFPA 2 are based on historical consensus without a documented scientific analysis. This work follows a similar analysis as the scientific justification provided in NFPA 2 for exposure distances from bulk gaseous hydrogen storage systems but for liquid hydrogen. Validated physical models from Sandia’s HyRAM software are used to calculate distances to a flammable concentration for an unignited release the distance to critical heat flux values and the visible flame length for an ignited release and the overpressure that would occur for a delayed ignition of a liquid hydrogen leak. Revised exposure distances for bulk liquid hydrogen systems are calculated. These distances are related to the maximum allowable working pressure of the tank and the line size as compared to the current exposure distances which are based on system volume. For most systems the exposure distances calculated are smaller than the current distances for Group 1 they are similar for Group 2 while they increase for some Group 3 exposures. These distances could enable smaller footprints for infrastructure that includes bulk liquid hydrogen storage tanks especially when using firewalls to mitigate Group 3 hazards and exposure distances. This analysis is being refined as additional information on leak frequencies is incorporated and changes have been proposed to the 2023 edition of NFPA 2.
The NREL Sensor Laboratory: Status and Future Directions for Hydrogen Detection
Sep 2021
Publication
The NREL Hydrogen Sensor Laboratory was commissioned in 2010 as a resource for the national and international hydrogen community to ensure the availability and proper use of hydrogen sensors. Since then the Sensor Laboratory has provided unbiased verification of hydrogen sensor performance for sensor developers end-users and regulatory agencies and has also provided active support for numerous code and standards development organizations. Although sensor performance assessment remains a core capability the mission of the NREL Sensor Laboratory has expanded toward a more holistic approach regarding the role of hydrogen detection and its implementation strategy for both assurance of facility safety and for process control applications. Active monitoring for detection of unintended releases has been identified as a viable approach for improving facility safety and lowering setbacks. The current research program for the Sensor Laboratory addresses both conventional and advanced developing detection strategies in response to the emerging large-scale hydrogen markets such as those envisioned by H2@Scale. These emerging hydrogen applications may require alternative detection strategies that supplement and may ultimately supplant the use of traditional sensors for monitoring hydrogen releases. Research focus areas for the NREL Sensor Laboratory now encompass the characterization of released hydrogen behavior to optimize detection strategies for both indoor and outdoor applications assess advanced methods of hydrogen leak detection such as hydrogen wide area monitoring for large scale applications implement active monitoring as a risk reduction strategy to improve safety at hydrogen facilities and to provide continuing support of hydrogen safety codes and standards. In addition to assurance of safety detection will be critical for process control applications such as hydrogen fuel quality verification for fuel cell vehicle applications and for monitoring and controlling of hydrogen-natural gas blend composition.
Everything About Hydrogen Podcast: Catching up on the State of Scale in PEM Electrolysis
Feb 2022
Publication
This episode of EAH is a chance for the team to catch up with one of our early guests on the show Graham Cooley - CEO of ITM Power. For the past twenty years ITM Power PLC has been designing and manufacturing electrolyser systems that generate hydrogen based on proton exchange membrane (PEM) technology. As the first hydrogen related company to be listed on the London Stock Exchange ITM are globally recognised experts in the field of electrolysis. In 2021 the company opened its first Gigafactory in Bessemer Park Sheffield: the world’s largest electrolyser production factory.
The podcast can be found on their website
The podcast can be found on their website
Safety and Other Considerations in the Development of a Hydrogen Fueling Protocol for Heavy-duty Vehicles
Sep 2021
Publication
Several manufacturers are developing heavy duty (HD) hydrogen stations and vehicles as zeroemissions alternatives to diesel and gasoline. In order to meet customer demands the new technology must be comparable to conventional approaches including safety reliability fueling times and final fill levels. For a large HD vehicle with a storage rated to 70 MPa nominal working pressure the goal to meet liquid fuel parity means providing 100 kg of hydrogen in 10 minutes. This paper summarizes the results to date of the PRHYDE project efforts to define the concepts of HD fueling which thereby lays the groundwork for the development of the safe and effective approach to filling these large vehicles. The project starts by evaluating the impact of several different assumptions such as the availability of static vehicle data (e.g. vehicle tank type and volume) and station data (e.g. expected station precooling capability) but also considers using real time dynamic data (e.g. vehicle tank gas temperature and pressure station gas temperature etc.) for optimisation to achieve safety and efficiency improvements. With this information the vehicle or station can develop multiple maps of fill time versus the hydrogen delivery temperature which are used to determine the speed of fueling. This will also allow the station or vehicle to adjust the rate of fueling as the station pre-cooling levels and other conditions change. The project also examines different steps for future protocol development such as communication of data between the vehicle and station and if the vehicle or station is controlling the fueling.
Addressing the Low-carbon Million-gigawatt-hour Energy Storage Challenge
Nov 2021
Publication
The energy system of the United States requires several million gigawatt hours of energy storage to meet variable demand for energy driven by (1) weather (heating and cooling) (2) social patterns (daily and weekday/weekend) of work play and sleep (3) weather-dependent energy production (wind and solar) and (4) industrial requirements. In a low-carbon world four storage options can meet this massive requirement at affordable costs: nuclear fuels heat storage hydrocarbon liquids made from biomass and hydrogen. Because of the different energy sector characteristics (electrical supply transportation commercial and industrial) each of these options must be developed. Capital costs associated with electricity storage at this scale using for example batteries and hydroelectric technologies are measured in hundreds of trillions of dollars for the United States alone and thus are not viable.
Everything About Hydrogen Podcast: Digging into the Mining Industry
Jan 2021
Publication
On this episode of Everything About Hydrogen Jan Klawitter Head of International Policy for Anglo American speaks with Andrew Chris and Patrick about Anglo American's strategy for decarbonizing its mining operations and how they plan to use hydrogen and fuel cell technologies as a key part of their approach.
The podcast can be found on their website
The podcast can be found on their website
Deep Decarbonization of the Indian Economy: 2050 Prospects for Wind, Solar, and Green Hydrogen
May 2022
Publication
The paper explores options for a 2050 carbon free energy future for India. Onshore wind and solar sources are projected as the dominant primary contributions to this objective. The analysis envisages an important role for so-called green hydrogen produced by electrolysis fueled by these carbon free energy sources. This hydrogen source can be used to accommodate for the intrinsic variability of wind and solar complementing opportunities for storage of power by batteries and pumped hydro. The green source of hydrogen can be used also to supplant current industrial uses of grey hydrogen produced in the Indian context largely from natural gas with important related emissions of CO2. The paper explores further options for use of green hydrogen to lower emissions from otherwise difficult to abate sectors of both industry and transport. The analysis is applied to identify the least cost options to meet India’s zero carbon future.
A Brief History of Process Safety Management
Sep 2021
Publication
Common root causes are often to be found in many if not most process safety incidents. Whilst largescale events are relatively rare such events can have devastating consequences. The subsequent investigations often uncover that the risks are rarely visible the direct causes are often hidden and that a ‘normalization of deviation’ is a common human characteristic. Process Safety Management (PSM) builds on the valuable lessons learned from past incidents to help prevent future recurrences. An understanding of how PSM originated and has evolved as a discipline over the past 200 years can be instructive when considering the safety implications of emerging technologies. An example is hydrogen production where risks must be effectively identified mitigated and addressed to provide safe production transportation storage and use .
Everything About Hydrogen Podcast: The Oracle of Hydrogen
Oct 2019
Publication
Nel Hydrogen is one of the largest electrolysis companies in the world with an array of Alkaline and PEM solutions that have been used in an array of energy and industrial applications. On the show we ask Bjørn Simonsen Vice President of Investor Relations and Corporate Communication at Nel Hydrogen to talk through how Nel has seen the green hydrogen market evolve and where Nel fits into this sector transition.
The podcast can be found on their website
The podcast can be found on their website
Hydrogen Wide Area Monitoring of LH2 Releases at HSE for the PRESLHY Project
Sep 2021
Publication
The characterization of liquid hydrogen (LH2) releases has been identified as an international research priority to facilitate the safe use of hydrogen as an energy carrier. Empirical field measurements such as those afforded by Hydrogen Wide Area Monitoring can elucidate the behavior of LH2 releases which can then be used to support and validate dispersion models. Hydrogen Wide Area Monitoring can be defined as the quantitative three-dimensional spatial and temporal profiling of planned or unintentional hydrogen releases. The NREL Sensor Laboratory developed a Hydrogen Wide Area Monitor (HyWAM) based upon a distributed array of hydrogen sensors. The NREL Sensor Laboratory and the Health and Safety Executive (HSE) formally committed to collaborate on profiling GH2 and LH2 releases which allowed for the integration of the NREL HyWAM into the HSE LH2 release behavior investigation supported by the FCH JU Prenormative Research for the Safe Use of Liquid Hydrogen (PRESLHY) program. A HyWAM system was deployed consisting of 32 hydrogen measurement points and co-located temperature sensors distributed downstream of the LH2 release apparatus developed by HSE. In addition the HyWAM deployment was supported by proximal wind and weather monitors. In a separate presentation at this conference “HSE Experimental Summary for the Characterisation Dispersion and Electrostatic Hazards of LH2 for the PRESLHY Project” HSE researchers summarize the experimental apparatus and protocols utilized in the HSE LH2 releases that were performed under the auspices of PRESLHY. As a supplement to the HSE presentation this presentation will focus on the spatial and temporal behavior LH2 releases as measured by the NREL HyWAM. Correlations to ambient conditions such as wind speed and direction plume temperature and hydrogen concentrations will be discussed in addition to the design and performance of the NREL HyWAM and its potential for improving hydrogen facility safety.
Water Electrolysis: From Textbook Knowledge to the Latest Scientific Strategies and Industrial Developments
May 2022
Publication
Replacing fossil fuels with energy sources and carriers that are sustainable environmentally benign and affordable is amongst the most pressing challenges for future socio-economic development. To that goal hydrogen is presumed to be the most promising energy carrier. Electrocatalytic water splitting if driven by green electricity would provide hydrogen with minimal CO2 footprint. The viability of water electrolysis still hinges on the availability of durable earth-abundant electrocatalyst materials and the overall process efficiency. This review spans from the fundamentals of electrocatalytically initiated water splitting to the very latest scientific findings from university and institutional research also covering specifications and special features of the current industrial processes and those processes currently being tested in large-scale applications. Recently developed strategies are described for the optimisation and discovery of active and durable materials for electrodes that ever-increasingly harness first principles calculations and machine learning. In addition a technoeconomic analysis of water electrolysis is included that allows an assessment of the extent to which a large-scale implementation of water splitting can help to combat climate change. This review article is intended to cross-pollinate and strengthen efforts from fundamental understanding to technical implementation and to improve the ‘junctions’ between the field’s physical chemists materials scientists and engineers as well as stimulate much-needed exchange among these groups on challenges encountered in the different domains.
Everything About Hydrogen Podcast: M&A in the Modern Hydrogen Economy
Sep 2021
Publication
This week we have Christopher Jackson in the hot seat as he catches up with BayoTech CEO Mo Vargas and BayoTech’s new President Michael Koonce to discuss the acquisition of IGX Group. Mergers & Acquisition activity has been growing in the hydrogen space with commentators suggesting the market is maturing faster than expected and customers seeking more integrated solutions. In this episode we look at the IGX acquisition by BayoTech and ask why the deal made sense what it means for the market and other participants and what listeners can learn from the deal to foreshadow future activity.
The podcast can be found on their website
The podcast can be found on their website
Is Hydrogen the Future of Nuclear Energy?
Jan 2008
Publication
The traditionally held belief is that the future of nuclear energy is electricity production. However another possible future exists: nuclear energy used primarily for the production of hydrogen. The hydrogen in turn would be used to meet our demands for transport fuels (including liquid fuels) materials such as steel and fertilizer and peak-load electricity production. Hydrogen would become the replacement for fossil fuels in these applications that consume more than half the world’s energy. Such a future would follow from several factors: (a) concerns about climatic change that limit the use of fossil fuels (b) the fundamental technological differences between hydrogen and electricity that may preferentially couple different primary energy sources with either hydrogen or electricity and (c) the potential for other technologies to competitively produce electricity but not hydrogen. Electricity (movement of electrons) is not fundamentally a large-scale centralized technology that requires centralized methods of production distribution or use. In contrast hydrogen (movement of atoms) is intrinsically a large-scale centralized technology. The large-scale centralized characteristics of nuclear energy as a primary energy source hydrogen production systems and hydrogen storage systems naturally couple these technologies. This connection suggests that serious consideration be given to hydrogen as the ultimate product of nuclear energy and that nuclear systems be designed explicitly for hydrogen production.
Everything About Hydrogen Podcast: Hydrogen from Waste
Mar 2021
Publication
On this episode of EAH the team is joined by Tim Yeo Chairman of Powerhouse Energy to talk about the work they are doing in the waste-to-energy space and how they see the sector evolving in the coming years.
The podcast can be found on their website
The podcast can be found on their website
Everything About Hydrogen Podcast: Is Small the Perfect Answer for SMRs?
Jun 2020
Publication
On this week’s episode the team discuss the appeal of modular reforming of biogas and natural gas with Mo Vargas from Bayotech. The company use a proprietary modular reformer technology to help provide low cost decentralise hydrogen production units for onsite demand at various scales using biogas waste gases and natural gas with carbon capture. With large scale steam methane reforming accounting for 95% of hydrogen production in major markets like the US and Europe today the team dive into the good the bad and the unusual considerations behind the growing international demand for modular methane reforming technologies and how Bayotech see the transition from a CO2 intensive process today to a net zero emission future. All this and more on the show!
The podcast can be found on their website
The podcast can be found on their website
Effect of Wind on Cryogenic Hydrogen Dispersion from Vent Stacks
Sep 2021
Publication
Liquid hydrogen vent stacks often release hydrogen for example due to pressure relief from an underutilized tank boiling off hydrogen or after hydrogen delivery and transfer (trucks often depressurize through the tank vent stack to meet pressure regulations for on-road transport).<br/>A rapid release of cryogenic hydrogen through a vent stack will condense moisture from the entrained air forming a visible cloud. It is often assumed that the extent of the cold hydrogen is concurrent with the cloud. In this work a laser-based Raman scattering diagnostic was used to map out the hydrogen location during a series of vent stack release experiments. A description of the diagnostic instrument is given followed by a comparison of hydrogen signals to the visible cloud for releases through a liquid hydrogen vent stack. A liquid hydrogen pump was used to vary the flowrate of hydrogen through the vent stack and tests were performed under low and high wind conditions as well as low and high humidity conditions. The hydrogen was observed only where the condensed moisture was located regardless of the humidity level or wind. These measurements are being used to validate models such as those included in Sanda’s HyRAM toolkit and inform safety codes and standards.
Everything About Hydrogen Podcast: Storage for the Future!
Jan 2022
Publication
For our first episode of 2022 we invited Jørn Helge Dahl Global Director of Sales&Marketing at Hexagon Purus to talk about hydrogen storage with the EAH podcast and to explain the types of solutions available today Hexagon's history and plans for the future alongside some commentary on US hydrogen strategy from the gang.
The podcast can be found on their website
The podcast can be found on their website
Optimization of Component Sizing for a Fuel Cell-Powered Truck to Minimize Ownership Cost
Mar 2019
Publication
In this study we consider fuel cell-powered electric trucks (FCETs) as an alternative to conventional medium- and heavy-duty vehicles. FCETs use a battery combined with onboard hydrogen storage for energy storage. The additional battery provides regenerative braking and better fuel economy but it will also increase the initial cost of the vehicle. Heavier reliance on stored hydrogen might be cheaper initially but operational costs will be higher because hydrogen is more expensive than electricity. Achieving the right tradeoff between these power and energy choices is necessary to reduce the ownership cost of the vehicle. This paper develops an optimum component sizing algorithm for FCETs. The truck vehicle model was developed in Autonomie a platform for modelling vehicle energy consumption and performance. The algorithm optimizes component sizes to minimize overall ownership cost while ensuring that the FCET matches or exceeds the performance and cargo capacity of a conventional vehicle. Class 4 delivery truck and class 8 linehaul trucks are shown as examples. We estimate the ownership cost for various hydrogen costs powertrain components ownership periods and annual vehicle miles travelled.
Everything About Hydrogen Podcast: Costs, Cost, Costs!
Aug 2020
Publication
On this week's episode of Everything About Hydrogen the team are celebrating the show's one year anniversary with Randy MacEwen the CEO of Ballard Power Systems. On the show the team ask Randy to explain the stunning rise of hydrogen over the last 12-24 months how the use cases for hydrogen are evolving and how the growing capitalisation of listed businesses like Ballard is driving a change in the investor base across the hydrogen & fuel cell sector. We also dive into the future for Ballard where the challenges and focuses for the business lie while the team reflect on what has been a very intense year for the show and the hydrogen industry. All this and more!
The podcast can be found on their website
The podcast can be found on their website
Development of Risk Mitigation Guidance for Sensor Placement Inside Mechanically Ventilated Enclosures – Phase 1
Sep 2019
Publication
Guidance on Sensor Placement was identified as the top research priority for hydrogen sensors at the 2018 HySafe Research Priority Workshop on hydrogen safety in the category Mitigation Sensors Hazard Prevention and Risk Reduction. This paper discusses the initial steps (Phase 1) to develop such guidance for mechanically ventilated enclosures. This work was initiated as an international collaborative effort to respond to emerging market needs related to the design and deployment equipment for hydrogen infrastructure that is often installed in individual equipment cabinets or ventilated enclosures. The ultimate objective of this effort is to develop guidance for an optimal sensor placement such that when integrated into a facility design and operation will allow earlier detection at lower levels of incipient leaks leading to significant hazard reduction. Reliable and consistent early warning of hydrogen leaks will allow for the risk mitigation by reducing or even eliminating the probability of escalation of small leaks into large and uncontrolled events. To address this issue a study of a real-world mechanically ventilated enclosure containing GH2 equipment was conducted where CFD modelling of the hydrogen dispersion (performed by AVT and UQTR and independently by the JRC) was validated by the NREL Sensor laboratory using a Hydrogen Wide Area Monitor (HyWAM) consisting of a 10-point gas and temperature measurement analyzer. In the release test helium was used as a hydrogen surrogate. Expansion of indoor releases to other larger facilities (including parking structures vehicle maintenance facilities and potentially tunnels) and incorporation into QRA tools such as HyRAM is planned for Phase 2. It is anticipated that results of this work will be used to inform national and international standards such as NFPA 2 Hydrogen Technologies Code Canadian Hydrogen Installation Code (CHIC) and relevant ISO/TC 197 and CEN documents.
Everything About Hydrogen Podcast: Where Does Hydrogen Fit in the Global Energy Transition?
Apr 2022
Publication
On this episode the EAH team discusses the role of hydrogen in the energy transition with Michael Liebreich Chairman and CEO of Liebreich Associates. Michael is an acknowledged thought leader on clean energy mobility technology climate sustainability and finance. He is the founder and senior contributor to Bloomberg New Energy Finance a member of numerous industry governmental and multilateral advisory boards an angel investor a former member of the board of Transport for London and an Advisor to the UK Board of Trade.
The podcast can be found on their website
The podcast can be found on their website
Hydrogen is Essential for Sustainability
Nov 2018
Publication
Sustainable energy conversion requires zero emissions of greenhouse gases and criteria pollutants using primary energy sources that the earth naturally replenishes quickly like renewable resources. Solar and wind power conversion technologies have become cost effective recently but challenges remain to manage electrical grid dynamics and to meet end-use requirements for energy dense fuels and chemicals. Renewable hydrogen provides the best opportunity for a zero emissions fuel and is the best feedstock for production of zero emission liquid fuels and some chemical and heat end-uses. Renewable hydrogen can be made at very high efficiency using electrolysis systems that are dynamically operated to complement renewable wind and solar power dynamics. Hydrogen can be stored within the existing natural gas system to provide low cost massive storage capacity that (1) could be sufficient to enable a 100% zero emissions grid; (2) has sufficient energy density for end-uses including heavy duty transport; (3) is a building block for zero emissions fertilizer and chemicals; and (4) enables sustainable primary energy in all sectors of the economy.
Life-Cycle Greenhouse Gas Emissions Of Biomethane And Hydrogen Pathways In The European Union
Oct 2021
Publication
Gaseous fuels with low life-cycle emissions of greenhouse gases (GHG) play a prominent role in the European Union’s (EU) decarbonization plans. Renewable and low-GHG hydrogen are highlighted in the ambitious goals for a cross-sector hydrogen economy laid out in the European Commission’s Hydrogen Strategy. Renewable hydrogen and biomethane are given strong production incentives in the Commission’s proposed revision to the Renewable Energy Directive (REDII). The EU uses life-cycle analysis (LCA) to determine whether renewable gas pathways meet the GHG reduction thresholds for eligibility in the REDII. This study aims to support European policymakers with a better understanding of the uncertainties regarding gaseous fuels’ roles in meeting climate goals. Life-cycle GHG analysis is complex and differences in methodology as well as data inputs and assumptions can spell the difference between a renewable gas pathway qualifying or not for REDII eligibility at the 50% to 80% GHG reduction level. It is thus important for European policymakers to use robust LCA to ensure that policy only supports gas pathways consistent with a vision of deep decarbonization. For this purpose we conduct sensitivity analysis of the life-cycle GHG emissions of a number of low-GHG gas pathways including biomethane produced from four feedstocks: wastewater sludge manure landfill gas (LFG) and silage maize; and hydrogen produced from eight sources: natural gas combined with carbon capture and storage (CCS) coal with CCS biomass gasification renewable electricity 2030 EU grid electricity wastewater sludge biomethane manure biomethane and LFG biomethane. For each pathway we estimate the life-cycle GHG intensity using a default central case identify key parameters that strongly affect the fuel’s GHG intensity and conduct a sensitivity analysis by changing these key parameters according to the range of possible values collected from the literature. Figure ES1 summarizes the full range of possible GHG intensities for each gaseous pathway we analyzed in this study—biomethane is depicted in the top figure and hydrogen is shown in the bottom. The bars represent the GHG intensity of the central case and vertical error bars indicate the maximum and minimum GHG intensity of each pathway according to our sensitivity analysis. The dotted orange horizontal line illustrates the fossil comparator which is 94 grams of carbon dioxide equivalent per megajoule (gCO2e/MJ) for transport fuels in the REDII. The dotted yellow line represents the GHG intensity of a 65% GHG reduction goal for biomethane used in the transportation sector or 70% GHG reduction for hydrogen. Pathways are situated from left to right in increasing order of GHG intensity of the central case. Comparing the central cases of the four biomethane pathways the waste-based biomethane pathways generally have negative GHG intensity. However considering the uncertainty in these GHG intensities manure biomethane might have more limited carbon reduction potential in the 100-year timeframe if methane leakage from its production process is high. In contrast wastewater sludge biomethane and LFG biomethane even after accounting for uncertainties retain relatively low GHG emissions. On the other hand biomethane produced from silage maize can have much higher emissions; in the central case we find that silage maize biogas only reduces GHG emissions by 30% relative to the fossil comparator—the low carbon reduction potential is due to the significant emissions emerging from direct and indirect land use change involved in growing maize. Taking into account the variation in assumptions silage maize biomethane can be worse for the climate than fossil fuels.
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