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A Quantitative Assessment of the Hydrogen Storage Capacity of the UK Continental Shelf
Nov 2020
Publication
Increased penetration of renewable energy sources and decarbonisation of the UK's gas supply will require large-scale energy storage. Using hydrogen as an energy storage vector we estimate that 150 TWh of seasonal storage is required to replace seasonal variations in natural gas production. Large-scale storage is best suited to porous rock reservoirs. We present a method to quantify the hydrogen storage capacity of gas fields and saline aquifers using data previously used to assess CO2 storage potential. We calculate a P50 value of 6900 TWh of working gas capacity in gas fields and 2200 TWh in saline aquifers on the UK continental shelf assuming a cushion gas requirement of 50%. Sensitivity analysis reveals low temperature storage sites with sealing rocks that can withstand high pressures are ideal sites. Gas fields in the Southern North Sea could utilise existing infrastructure and large offshore wind developments to develop large-scale offshore hydrogen production.
The Role of Hydrogen in Heavy Transport to Operate within Planetary Boundaries
Jul 2021
Publication
Green hydrogen i.e. produced from renewable resources is attracting attention as an alternative fuel for the future of heavy road transport and long-distance driving. However the benefits linked to zero pollution at the usage stage can be overturned when considering the upstream processes linked to the raw materials and energy requirements. To better understand the global environmental implications of fuelling heavy transport with hydrogen we quantified the environmental impacts over the full life cycle of hydrogen use in the context of the Planetary Boundaries (PBs). The scenarios assessed cover hydrogen from biomass gasification (with and without carbon capture and storage [CCS]) and electrolysis powered by wind solar bioenergy with CCS nuclear and grid electricity. Our results show that the current diesel-based-heavy transport sector is unsustainable due to the transgression of the climate change-related PBs (exceeding standalone by two times the global climate-change budget). Hydrogen-fuelled heavy transport would reduce the global pressure on the climate change-related PBs helping the transport sector to stay within the safe operating space (i.e. below one-third of the global ecological budget in all the scenarios analysed). However the best scenarios in terms of climate change which are biomass-based would shift burdens to the biosphere integrity and nitrogen flow PBs. In contrast burden shifting in the electrolytic scenarios would be negligible with hydrogen from wind electricity emerging as an appealing technology despite attaining higher carbon emissions than the biomass routes
An Investigation into the Change Leakage when Switching from Natural Gas to Hydrogen in the UK Gas Distribution Network
Sep 2021
Publication
The H21 National Innovation Competition project is examining the feasibility of repurposing the existing GB natural gas distribution network for transporting 100% hydrogen. It aims to undertake an experimental testing programme that will provide the necessary data to quantify the comparative risk between a 100% hydrogen network and the natural gas network. The first phase of the project focuses on leakage testing of a strategic set of assets that have been removed from service which provide a representative sample of assets across the network. This paper presents the work undertaken for Phase 1A (background testing) where HSE and industry partners have tested a range of natural gas pipework assets of varying size material age and pressure-rating in a new bespoke open-air testing facility at the HSE Science and Research Centre Buxton. The assets have been pressurised with hydrogen and then methane and the leakage rate from the assets measured in both cases. The main finding of this work is that the assets tested which leak hydrogen also leak methane. None of the assets were found to leak hydrogen but not methane. In addition repair techniques that were effective at stopping methane leaks were also effective at stopping hydrogen leaks. The data from the experiments have been interpreted to obtain a range of leakage ratios between the two gases for releases under different conditions. This has been compared to the predicted ratio of hydrogen to methane volumetric leak rates for laminar (1.2:1) and turbulent (2.9:1) releases and good agreement was observed.
Assessing the Prospective Environmental Performance of Hydrogen from High Temperature Electrolysis Coupled with Concentrated Solar Power
Jul 2022
Publication
Hydrogen is currently being promoted because of its advantages as an energy vector its potential 12 to decarbonise the economy and strategical implications in terms of energy security. Hydrogen 13 from high-temperature electrolysis coupled with concentrated solar power (CSP) is especially 14 interesting since it enhances the last two aspects and could benefit from significant technological 15 progress in the coming years. However there is a lack of studies assessing its future 16 environmental performance. This work fills this gap by carrying out a prospective life cycle 17 assessment based on the expected values of key performance parameters in 2030. The results 18 show that parabolic trough CSP coupled with a solid oxide electrolyser is a promising solution 19 under environmental aspects. It leads to a prospective hydrogen carbon footprint (1.85 kg CO2 20 eq/kg H2) which could be classified as low-carbon according to current standards. The 21 benchmarking study for the year 2030 shows that the assessed system significantly decreases the 22 hydrogen carbon footprint compared to future hydrogen from steam methane reforming (81% 23 reduction) and grid electrolysis (51%) even under a considerable penetration of renewable energy 24 sources.
A 1000 MWth Boiler for Chemical-looping Combustion of Solid Fuels – Discussion of Design and Costs
May 2015
Publication
More than 2000 h of solid-fuel CLC operation in a number of smaller pilot units clearly indicate that the concept works. A scale-up of the technology to 1000 MWth is investigated in terms of mass and heat balances flows solids inventories boiler dimensions and the major differences between a full-scale Circulating Fluidized-Bed (CFB) boiler and a Chemical-Looping Combustion CFB (CLC–CFB). Furthermore the additional cost of CLC–CFB relative to CFB technology is analysed and found to be 20 €/tonne CO2. The largest cost is made up of compression of CO2 which is common to all capture technologies. Although the need for oxygen to manage incomplete conversion is estimated to be only a tenth of that of oxy-fuel combustion oxygen production is nonetheless the second largest cost. Other significant costs include oxygen-carrier material increased boiler cost and steam for fluidization of the fuel reactor.
Simulation-Assisted Determination of the Start-Up Time of a Polymer Electrolyte Fuel Cell
Nov 2021
Publication
Fuel starvation is a major cause of anode corrosion in low temperature polymer electrolyte fuel cells. The fuel cell start-up is a critical step as hydrogen may not yet be evenly distributed in the active area leading to local starvation. The present work investigates the hydrogen distribution and risk for starvation during start-up and after nitrogen purge by extending an existing computational fluid dynamic model to capture transient behavior. The results of the numerical model are compared with detailed experimental analysis on a 25 cm2 triple serpentine flow field with good agreement in all aspects and a required time step size of 1 s. This is two to three orders of magnitude larger than the time steps used by other works resulting in reasonably quick calculation times (e.g. 3 min calculation time for 1 s of experimental testing time using a 2 million element mesh).
Conceptual Study and Development of an Autonomously Operating, Sailing Renewable Energy Conversion System
Jun 2022
Publication
With little time left for humanity to reduce climate change to a tolerable level a highly scalable and rapidly deployable solution is needed that can be implemented by any country. Offshore wind energy in international waters is an underused resource and could even be harnessed by landlocked countries. In this paper the use of sailing wind turbines operating autonomously in high seas to harvest energy is proposed. The electrical energy that is generated by the wind turbine is converted to a renewable fuel and stored onboard. Later the fuel will be transferred to shore or to other destinations of use. The presented idea is explored at the system level where the basic subsystems necessary are identified and defined such as energy conversion and storage as well as propulsion subsystems. Moreover various operating possibilities are investigated including a comparison of different sailing strategies and fuels for storage. Existing ideas are also briefly addressed and an example concept is suggested as well. In this paper the proposed sailing renewable energy conversion system is explored at a higher level of abstraction. Following up on this conceptual study more detailed investigations are necessary to determine whether the development of such a sailing renewable energy conversion system is viable from an engineering economic and environmental point of view.
Safety Design and Engineering Solution of Fuel Cell Powered Ship in Inland Waterway of China
Oct 2021
Publication
From the perspective of risk control when hydrogen fuel and fuel cells are used on ships there is a possibility of low-flash fuel leakage leading to the risk of explosion. Since the fuel cell space (cabin for fuel cell installations) is an enclosed space any small amount of leakage must be handled properly. In ship design area classification is a method of analyzing and classifying the areas where explosive gas atmospheres may occur. If the fuel cell space is regarded as a hazardous area all the electrical devices inside it must be explosion-proof type which will make the ship’s design very difficult. This paper takes a Chinese fuel cell powered ship as an example to analyze its safety. Firstly the leakage rates of fuel cell modules valves and connectors are calculated. Secondly the IEC60079-10-1 algorithm is used to calculate the risk level of the fuel cell space. Finally the ship and fuel cells are optimized and redesigned and the risk level of the fuel cell space is recalculated and compared. The result shows that the optimized fuel space risk level could be reduced to the level of the non-hazardous zone.
Effect of Mechanical Ventilation on Accidental Hydrogen Releases - Large Scale Experiments
Sep 2021
Publication
This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces like underground garages. The purpose was to find the mass flow rate limit hence the TPRD diameter limit that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard outlet 315 mm diameter. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzle from different hydrogen reservoir pressures. Both types of mass flow: constant and blowdown were included in the experimental matrix. The analysis of hydrogen concentration of created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step.
Everything About Hydrogen Podcast: Hydrogen 101
Aug 2019
Publication
A 10-minute tour of hydrogen industry technology and terminology for those who are new to the sector or who would simply like a quick review of the basics behind this burgeoning energy source.
Podcast can be found on their website
Podcast can be found on their website
Everything About Hydrogen Podcast: Ending on a Hy Note
Jul 2021
Publication
This week's show is the last episode of Season 2! To celebrate we invited our friend and colleague Markus Wilthaner partner at McKinsey & Company to come speak with us. Markus has been a leader in the hydrogen space for the past ten years and has drafted a number of the Hydrogen Council's reports since its founding including the newly released - and highly anticipated - Hydrogen Insights 2021 (link below). In this episode we speak with Markus about the state of the market and the innovation he has seen in the last couple of years that make hydrogen a critical part of the energy transition. We had a lot of fun recording this interview and it was the perfect way to end a fantastic EAH season!
The podcast can be found on their website
The podcast can be found on their website
Life Cycle Assessments on Battery Electric Vehicles and Electrolytic Hydrogen: The Need for Calculation Rules and Better Databases on Electricity
May 2021
Publication
LCAs of electric cars and electrolytic hydrogen production are governed by the consumption of electricity. Therefore LCA benchmarking is prone to choices on electricity data. There are four issues: (1) leading Life Cycle Impact (LCI) databases suffer from inconvenient uncertainties and inaccuracies (2) electricity mix in countries is rapidly changing year after year (3) the electricity mix is strongly fluctuating on an hourly and daily basis which requires time-based allocation approaches and (4) how to deal with nuclear power in benchmarking. This analysis shows that: (a) the differences of the GHG emissions of the country production mix in leading databases are rather high (30%) (b) in LCA a distinction must be made between bundled and unbundled registered electricity certificates (RECs) and guarantees of origin (GOs); the residual mix should not be applied in LCA because of its huge inaccuracy (c) time-based allocation rules for renewables are required to cope with periods of overproduction (d) benchmarking of electricity is highly affected by the choice of midpoints and/or endpoint systems and (e) there is an urgent need for a new LCI database based on measured emission data continuously kept up-to-date transparent and open access.
CFD Simulation of Pressure Reduction Inside Large-scale Liquefied Hydrogen Tank
Sep 2021
Publication
Building the international hydrogen supply chain requires the large-scale liquefied hydrogen(LH2) carrier. During shipping LH2 with LH2 Carrier the tank is pressurized by LH2 evaporation due to heat ingress from outside. Before unloading LH2 at the receiving terminal reducing the tank pressure is essential for the safe tank operation. However pressure reduction might cause flashing leading to rapid vaporization of liquefied hydrogen liquid leakage. Moreover it was considered that pressure recovery phenomenon which was not preferred in terms of tank pressure management occurred at the beginning of pressure reduction. Hence the purpose of our research is to clarify the phenomenon inside the cargo tank during pressure reduction. The CFD analysis of the pressure reduction phenomenon was conducted with the VOF based in-house CFD code utilizing the C-CUP scheme combined with the hybrid Level Set and MARS method. In our previous research the pressure reduction experiments with the 30 m³ LH2 tank were simulated and the results showed that the pressure recovery was caused by the boiling delay and the tank pressure followed the saturation pressure after the liquid was fully stirred. In this paper the results were re-evaluated in terms of temperature. While pressure reduction was dominant the temperature of vapor-liquid interface decreased. Once the boiling bubble stirred the interface its temperature reached the saturation temperature after pressure recovery occurred. Moreover it was found that the liquid temperature during pressure reduction could not be measured because of the boiling from the wall of the thermometer. The CFD analysis on pressure reduction of 1250 m³ tank for the LH2 Carrier was also very could occur in the case of the 1250 m³ tank in a certain condition. These results provide new insight into the development of the LH2 carrier.
Everything About Hydrogen Podcast: Masters of Scale: How to Build the Hydrogen Infrastructure of the Future
Oct 2020
Publication
On this week's episode the EAH team speaks with Prof. Armin Schnettler CEO of New Energy Business at Siemens Energy to talk about where green hydrogen solutions fit into the path to decarbonisation how companies like Siemens are looking at those solutions and working to scale them to meet future demand timelines for deployment in different markets how governments can help the private sector and much much more.
The podcast can be found on their website
The podcast can be found on their website
Time‐Decoupling Layered Optimization for Energy and Transportation Systems under Dynamic Hydrogen Pricing
Jul 2022
Publication
The growing popularity of renewable energy and hydrogen‐powered vehicles (HVs) will facilitate the coordinated optimization of energy and transportation systems for economic and en‐ vironmental benefits. However little research attention has been paid to dynamic hydrogen pricing and its impact on the optimal performance of energy and transportation systems. To reduce the dependency on centralized controllers and protect information privacy a time‐decoupling layered optimization strategy is put forward to realize the low‐carbon and economic operation of energy and transportation systems under dynamic hydrogen pricing. First a dynamic hydrogen pricing mechanism was formulated on the basis of the share of renewable power in the energy supply and introduced into the optimization of distributed energy stations (DESs) which will promote hydro‐ gen production using renewable power and minimize the DES construction and operation cost. On the basis of the dynamic hydrogen price optimized by DESs and the traffic conditions on roads the raised user‐centric routing optimization method can select a minimum cost route for HVs to purchase fuels from a DES with low‐cost and/or low‐carbon hydrogen. Finally the effectiveness of the proposed optimization strategy was verified by simulations.
Optimal Integration of Hydrogen-Based Energy Storage Systems in Photovoltaic Microgrids: A Techno-Economic Assessment
Aug 2020
Publication
The feasibility and cost-effectiveness of hydrogen-based microgrids in facilities such as public buildings and small- and medium-sized enterprises provided by photovoltaic (PV) plants and characterized by low electric demand during weekends were investigated in this paper. Starting from the experience of the microgrid being built at the Renewable Energy Facility of Sardegna Ricerche (Italy) which among various energy production and storage systems includes a hydrogen storage system a modeling of the hydrogen-based microgrid was developed. The model was used to analyze the expected performance of the microgrid considering different load profiles and equipment sizes. Finally the microgrid cost-effectiveness was evaluated using a preliminary economic analysis. The results demonstrate that an effective design can be achieved with a PV system sized for an annual energy production 20% higher than the annual energy requested by the user and a hydrogen generator size 60% of the PV nominal power size. This configuration leads to a self-sufficiency rate of about 80% and without public grants a levelized cost of energy comparable with the cost of electricity in Italy can be achieved with a reduction of at least 25–40% of the current initial costs charged for the whole plant depending on the load profile shape.
Experimental Study of Hydrogen Production Using Electrolyte Nanofluids with a Simulated Light Source
Dec 2021
Publication
In this research we conducted water electrolysis experiments of a carbon black (CB) based sodium sulfate electrolyte using a Hoffman voltameter. The main objective was to investigate hydrogen production in such systems as well as analyse the electrical properties and thermal properties of nanofluids. A halogen lamp mimicking solar energy was used as a radiation source and a group of comparative tests were also conducted with different irradiation areas. The results showed that by using CB and light it was possible to increase the hydrogen production rate. The optimal CB concentration was 0.1 wt %. At this concentration the hydrogen production rate increased by 30.37% after 20 min of electrolysis. Hence we show that using CB in electrolytes irradiated by solar energy could save the electrical energy necessary for electrolysis processes.
Modeling the Effects of Implementation of Alternative Ways of Vehicle Powering
Nov 2021
Publication
The trend to replace traditional fossil fuel vehicles is becoming increasingly apparent. The replacement concerns the use of pure biofuels or in blends with traditional fuels the use of hydrogen as an alternative fuel and above all the introduction of electric propulsion. The introduction of new types of vehicle propulsion affects the demand for specific fuels the needs for new infrastructure or the nature of the emissions to the environment generated by fuel production and vehicle operation. The article presents a mathematical model using the difference of two logistic functions the first of which describes the development of the production of a specific type of vehicle and the second the withdrawal of this type of vehicle from traffic after its use. The model makes it possible to forecast both the number of vehicles of each generation as a function of time as well as changes in energy demand from various sources and changes in exhaust emissions. The results of the numerical simulation show replacing classic vehicles with alternative vehicles increases the total energy demand if the generation of the next generation occurs earlier than the decay of the previous generation of vehicles and may decrease in the case of overlapping or delays in the creation of new vehicles compared to the course of the decay function of the previous generation. For electric vehicles carbon dioxide emissions are largely dependent on the emissions from electricity generation. The proposed model can be used to forecast technology development variants as well as analyze the current situation based on the approximation of real data from Vehicle Registration Offices.
Global Hydrogen Review 2021
Oct 2021
Publication
The Global Hydrogen Review is a new annual publication by the International Energy Agency to track progress in hydrogen production and demand as well as in other critical areas such as policy regulation investments innovation and infrastructure development.
The report is an output of the Clean Energy Ministerial Hydrogen Initiative (CEM H2I) and is intended to inform energy sector stakeholders on the status and future prospects of hydrogen while serving as an input to the discussions at the Hydrogen Energy Ministerial Meeting (HEM) organised by Japan. It examines what international progress on hydrogen is needed to help address climate change – and compares real-world developments with the stated ambitions of government and industry and with key actions under the Global Action Agenda launched at the HEM in 2019.
Focusing on hydrogen’s usefulness for meeting climate goals this Review aims to help decision makers fine-tune strategies to attract investment and facilitate deployment of hydrogen technologies while also creating demand for hydrogen and hydrogen-based fuels.
Link to International Energy Agency website
The report is an output of the Clean Energy Ministerial Hydrogen Initiative (CEM H2I) and is intended to inform energy sector stakeholders on the status and future prospects of hydrogen while serving as an input to the discussions at the Hydrogen Energy Ministerial Meeting (HEM) organised by Japan. It examines what international progress on hydrogen is needed to help address climate change – and compares real-world developments with the stated ambitions of government and industry and with key actions under the Global Action Agenda launched at the HEM in 2019.
Focusing on hydrogen’s usefulness for meeting climate goals this Review aims to help decision makers fine-tune strategies to attract investment and facilitate deployment of hydrogen technologies while also creating demand for hydrogen and hydrogen-based fuels.
Link to International Energy Agency website
On Board 70 MPA Hydrogen Composite Pressure Vessel Safety Factor
Sep 2021
Publication
The safety factor of a composite structure in relation to its mechanical rupture is an important criterion for the safety of a 70 MPa composite pressure vessel for hydrogen storage particularly for on-board applications (car bus truck train…). After an introduction of Type IV technology the contribution of carbon fibre composite material structure manufacturing process of pressure vessels and environmental effects on the safety factor are commented. Thanks to an experimental-based evaluation on composite material and H2 composite pressure vessel the safety margins are addressed.
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