United Kingdom
Premier, Progress and Prospects in Renewable Hydrogen Generation: A Review
May 2023
Publication
Renewable hydrogen production has an opportunity to reduce carbon emissions in the transportation and industrial sectors. This method generates hydrogen utilizing renewable energy sources such as the sun wind and hydropower lowering the number of greenhouse gases released into the environment. In recent years considerable progress has been made in the production of sustainable hydrogen particularly in the disciplines of electrolysis biomass gasification and photoelectrochemical water splitting. This review article figures out the capacity efficiency and cost-effectiveness of hydrogen production from renewable sources effectively comparing the conventionally used technologies with the latest techniques which are getting better day by day with the implementation of the technological advancements. Governments investors and industry players are increasingly interested in manufacturing renewable hydrogen and the global need for clean energy is expanding. It is projected that facilities for manufacturing renewable hydrogen as well as infrastructure to support this development would expand hastening the transition to an environment-friendly and low-carbon economy
Assessment of Hydrogen Gas Turbine-fuel Cell Powerplant for Rotorcraft
Jul 2023
Publication
Conventional turboshaft engines are high power density movers suffering from low efficiency at part power operation and producing significant emissions. This paper presents a design exploration and feasibility assessment of a hybrid hydrogen-fueled powerplant for Urban Air Mobility (UAM) rotorcraft. A multi-disciplinary approach is devised comprising models for rotorcraft performance tank and subsystems sizing and engine performance. The respective trade-offs between payload-range and mission level performance are quantified for kerosene-fueled and hybrid hydrogen tilt-rotor variants. The effects of gas turbine scaling and fuel cell pressurization are evaluated for different hybridization degrees. Gas turbine scaling with hybridization (towards the fuel cell) results in up to 21% benefit in energy consumption relative to the non-scaled case with the benefits being more pronounced at high hybridization degrees. Pressurizing the fuel cell has shown significant potential as cell efficiency can increase up to 10% when pressurized to 6 bar which translates to a 6% increase in overall efficiency. The results indicate that current fuel cells (1 kW/kg) combined with current hydrogen tank technology severely limit the payload range capability of the tilt-rotor. However for advanced fuel cell technology (2.5 kW/kg) and low ranges hybrid powerplant show the potential to reduce energy consumption and reduce emissions footprint.
HyDeploy2 Project: Winlaton Trial Report
Sep 2022
Publication
The HyDeploy project seeks to address a key issue for UK customers and UK energy policy makers: how to reduce the carbon emitted from heating homes. The UK has a world class gas distribution grid delivering heat conveniently and safely to over 83% of homes. Emissions can be reduced by lowering the carbon content of gas through blending with hydrogen. This delivers carbon savings without customers requiring disruptive and expensive changes in their homes. It also provides the platform for deeper carbon savings by enabling wider adoption of hydrogen across the energy system. HyDeploy has previously delivered a successful trial demonstrations of repurposing existing UK distribution gas networks (Keele University) to operate on a blend of natural gas and hydrogen (up to 20% mol/mol) showing that carbon savings can be made through the gas networks today whilst continuing to meet the needs of gas consumers without introducing any disruptions.<br/>The ultimate objective of the HyDeploy programme is to see the roll-out of hydrogen blends across the GB gas distribution network unlocking 35 TWh pa of low carbon heat - the equivalent of removing 2.5 million fossil-fuelled cars off the roads. To achieve this the next phase of the programme is to address the remaining evidence gaps that had not been covered by the trial demonstration programmes.<br/>The demonstrations have focussed on the low and medium pressure tiers of the gas distribution network (i.e. injecting into a 2 bar gauge pressure network and distributing the blended gas down to the low pressure network and into people’s homes and commercial buildings and businesses) and predominantly serving domestic appliances.<br/>The remainder of the HyDeploy2 programme will generate an evidence base for GB’s gas distribution network which includes demonstrating the suitability of using hydrogen blended gas in the fields of industrial and commercial users and the performance of materials assets and procedures on the higher pressure tiers (i.e. 7 bar gauge operation and above).<br/>This report captures the details of the Winlaton trial and provides a future look to how the UK can transition from successful hydrogen blending trials to roll-out.
Sustainable Ammonia Production Processes
Mar 2021
Publication
Due to the important role of ammonia as a fertilizer in the agricultural industry and its promising prospects as an energy carrier many studies have recently attempted to find the most environmentally benign energy efficient and economically viable production process for ammonia synthesis. The most commonly utilized ammonia production method is the Haber-Bosch process. The downside to this technology is the high greenhouse gas emissions surpassing 2.16 kgCO2-eq/kg NH3 and high amounts of energy usage of over 30 GJ/tonne NH3 mainly due to the strict operational conditions at high temperature and pressure. The most widely adopted technology for sustainable hydrogen production used for ammonia synthesis is water electrolysis coupled with renewable technologies such as wind and solar. In general a water electrolyzer requires a continuous supply of pretreated water with high purity levels for its operation. Moreover for production of 1 tonne of hydrogen 9 tonnes of water is required. Based on this data for the production of the same amount of ammonia through water electrolysis 233.6 million tonnes/yr of water is required. In this paper a critical review of different sustainable hydrogen production processes and emerging technologies for sustainable ammonia synthesis along with a comparative life cycle assessment of various ammonia production methods has been carried out. We find that through the review of each of the studied technologies either large amounts of GHG emissions are produced or high volumes of pretreated water is required or a combination of both these factors occur.
Performance and Failure Analysis of a Retrofitted Cessna Aircraft with a Fuel Cell Power System Fuelled with Liquid Hydrogen
Jan 2022
Publication
Proton-Exchange Membrane-Fuel Cells (PEM-FC) are regarded as one of the prime candidates to provide emissions-free electricity for propulsion systems of aircraft. Here a turbocharged Fuel Cell Power System (FCPS) powered with liquid H2 (LH2) is designed and modelled to provide a primary power source in retrofitted Cessna 208 Caravan aircraft. The proposed FCPS comprises multiple PEM-FCs assembled in stacks two single-stage turbochargers to mitigate the variation of the ambient pressure with altitude two preheaters two humidifiers and two combustors. Interlinked component sub-models are constructed in MATLAB and referenced to commercially available equipment. The FCPS model is used to simulate steady-state responses in a proposed 1.5 h (∼350 km) mission flight determining the overall efficiency of the FCPS at 43% and hydrogen consumption of ∼28 kg/h. The multi-stack FCPS is modelled applying parallel fluidic and electrical architectures analysing two power-sharing methods: equally distributed and daisy-chaining. The designed LH2-FCPS is then proposed as a power system to a retrofitted Cessna 208 Caravan and with this example analysed for the probability of failure occurrence. The results demonstrate that the proposed “dual redundant” FCPS can reach failure rates comparable to commercial jet engines with a rate below 1.6 failures per million hours.
Hydrogen Refuelling Station Calibration with a Traceable Gravimetric Standard
Apr 2020
Publication
Of all the alternatives to hydrocarbon fuels hydrogen offers the greatest long-term potential to radically reduce the many problems inherent in fuel used for transportation. Hydrogen vehicles have zero tailpipe emissions and are very efficient. If the hydrogen is made from renewable sources such as nuclear power or fossil sources with carbon emissions captured and sequestered hydrogen use on a global scale would produce almost zero greenhouse gas emissions and greatly reduce air pollutant emissions. The aim of this work is to realise a traceability chain for hydrogen flow metering in the range typical for fuelling applications in a wide pressure range with pressures up to 875 bar (for Hydrogen Refuelling Station - HRS with Nominal Working Pressure of 700 bar) and temperature changes from −40 °C (pre-cooling) to 85 °C (maximum allowed vehicle tank temperature) in accordance with the worldwide accepted standard SAE J2601. Several HRS have been tested in Europe (France Netherlands and Germany) and the results show a good repeatability for all tests. This demonstrates that the testing equipment works well in real conditions. Depending on the installation configuration some systematic errors have been detected and explained. Errors observed for Configuration 1 stations can be explained by pressure differences at the beginning and end of fueling in the piping between the Coriolis Flow Meter (CFM) and the dispenser: the longer the distance the bigger the errors. For Configuration 2 where this distance is very short the error is negligible.
Additive Manufacturing for Proton Exchange Membrane (PEM) Hydrogen Technologies: Merits, Challenges, and Prospects
Jul 2023
Publication
With the growing demand for green technologies hydrogen energy devices such as Proton Exchange Membrane (PEM) fuel cells and water electrolysers have received accelerated developments. However the materials and manufacturing cost of these technologies are still relatively expensive which impedes their widespread commercialization. Additive Manufacturing (AM) commonly termed 3D Printing (3DP) with its advanced capabilities could be a potential pathway to solve the fabrication challenges of PEM parts. Herein in this paper the research studies on the novel AM fabrication methods of PEM components are thoroughly reviewed and analysed. The key performance properties such as corrosion and hydrogen embrittlement resistance of the additively manufactured materials in the PEM working environment are discussed to emphasise their reliability for the PEM systems. Additionally the major challenges and required future developments of AM technologies to unlock their full potential for PEM fabrication are identified. This paper provides insights from the latest research developments on the significance of advanced manufacturing technologies in developing sustainable energy systems to address the global energy challenges and climate change effects.
The Bio Steel Cycle: 7 Steps to Net-Zero CO2 Emissions Steel Production
Nov 2022
Publication
CO2 emissions have been identified as the main driver for climate change with devastating consequences for the global natural environment. The steel industry is responsible for ~7–11% of global CO2 emissions due to high fossil-fuel and energy consumption. The onus is therefore on industry to remedy the environmental damage caused and to decarbonise production. This desk research report explores the Bio Steel Cycle (BiSC) and proposes a seven-step-strategy to overcome the emission challenges within the iron and steel industry. The true levels of combined CO2 emissions from the blast-furnace and basic-oxygen-furnace operation at 4.61 t of CO2 emissions/t of steel produced are calculated in detail. The BiSC includes CO2 capture implementing renewable energy sources (solar wind green H2 ) and plantation for CO2 absorption and provision of biomass. The 7-step-implementation-strategy starts with replacing energy sources develops over process improvement and installation of flue gas carbon capture and concludes with utilising biogas-derived hydrogen as a product from anaerobic digestion of the grown agrifood in the cycle. In the past CO2 emissions have been seemingly underreported and underestimated in the heavy industries and implementing the BiSC using the provided seven-steps-strategy will potentially result in achieving net-zero CO2 emissions in steel manufacturing by 2030.
Underground Hydrogen Storage to Balance Seasonal Variations in Energy Demand: Impact of Well Configuration on Storage Performance in Deep Saline Aquifers
Mar 2023
Publication
Grid-scale underground hydrogen storage (UHS) is essential for the decarbonization of energy supply systems on the path towards a zero-emissions future. This study presents the feasibility of UHS in an actual saline aquifer with a typical dome-shaped anticline structure to balance the potential seasonal mismatches between energy supply and demand in the UK domestic heating sector. As a main requirement for UHS in saline aquifers we investigate the role of well configuration design in enhancing storage performance in the selected site via numerical simulation. The results demonstrate that the efficiency of cyclic hydrogen recovery can reach around 70% in the short term without the need for upfront cushion gas injection. Storage capacity and deliverability increase in successive storage cycles for all scenarios with the co-production of water from the aquifer having a minimal impact on the efficiency of hydrogen recovery. Storage capacity and deliverability also increase when additional wells are added to the storage site; however the distance between wells can strongly influence this effect. For optimum well spacing in a multi-well storage scenario within a dome-shaped anticline structure it is essential to attain an efficient balance between well pressure interference effects at short well distances and the gas uprising phenomenon at large distances. Overall the findings obtained and the approach described can provide effective technical guidelines pertaining to the design and optimization of hydrogen storage operations in deep saline aquifers.
Review and Meta-analysis of Recent Life Cycle Assessments of Hydrogen Production
Apr 2023
Publication
The world is facing an urgent global climate challenge and hydrogen (H2) is increasingly valued as a carbon-free energy carrier that can play a prominent role in decarbonising economies. However the environmental impact of the different methods for hydrogen production are sometimes overlooked. This work provides a comprehensive overview of the environmental impacts and costs of a diverse range of methods for producing hydrogen. Ninety nine life cycle assessments (LCAs) of hydrogen production published between 2015 and 2022 are categorised by geography production method energy source goal and scope and compared by data sources and methodology. A meta-analysis of methodological choices is used to identify a subset of mutually comparable studies whose results are then compared initially by global warming potential (GWP) then low-GWP scenarios are compared by other indicators. The results show that the lowest GWP is achieved by methods that are currently more expensive (~US $4–9/kg H2) compared to the dominant methods of producing hydrogen from fossil fuels (~US $1–2/kg H2). The research finds that data are currently limited for comparing environmental indicators other than GWP such as terrestrial acidification or freshwater eutrophication. Recommendations are made for future LCAs of hydrogen production.
A Justice and Responsible Research and Innovation Exploration of Marine Renewables and Green Hydrogen in Island Communities
Oct 2022
Publication
Both marine renewables and hydrogen are being tested by the European Marine Energy Centre in the Orkney Islands Scotland. Given their emerging nature there is opportunity and risk pertaining to their development and deployment. This research will contribute conceptually and methodologically through the integration of energy justice and RRI conceptual frameworks strengthening justice analyses in relation to emerging energy technologies. This integrated model will be mobilized to critically scrutinize marine energy and green hydrogen as two future energy sources within the energy system. Following a technology-centered exploration of these technologies this work will then contextualise them into place-based considerations of Orkney’s just energy futures. Placing the technologies at the centre of the justice analysis insights will have the potential to inform their development and deployment in other locations. Exploring them within the local Orkney context will initiate an essential and important discussion of energy futures in this specific location. This presentation sets out the empirical and conceptual context for this work and presents a novel conceptual and methodological model combining energy justice and RRI frameworks. Moreover preliminary methods are discussed including methods and outcomes from co-creation workshops held at research design phase.
Recent Advances in Sustainable and Safe Marine Engine Operation with Alternative Fuels
Nov 2022
Publication
Pursuing net-zero emission operations in the shipping industry are quintessential for this sector to mitigate the environmental impact caused by hydrocarbon fuel combustion. Significant contributions to this are expected from the substitution of conventional marine fuels by alternative emission-free fuels with lower emission footprints. This study aims to conduct a comprehensive literature review for delineating the main characteristics of the considered alternative fuels specifically focusing on hydrogen methanol and ammonia which have recently attracted attention from both industry and academia. This study comparatively assesses the potential of using these fuels in marine engines and their subsequent performance characteristics as well as the associated environmental benefits. In addition the required storage conditions space as well as the associated costs are reviewed. Special attention is given to the safety characteristics and requirements for each alternative fuel. The results of this study demonstrate that the environmental benefits gained from alternative fuel use are pronounced only when renewable energy is considerably exploited for their production whereas the feasibility of each fuel depends on the vessel type used and pertinent storage constraints. Hydrogen ammonia and methanol are considered best-fit solutions for small scale shipping requiring minimal on-board storage. In addition the need for comparative assessments between diesel and alternative fuels is highlighted and sheds light on marine engines’ operational characteristics. Moreover using combinations of alternative and diesel fuels is identified as a direction towards decarbonisation of the maritime sector; intensifying the need for optimisation studies on marine engine design and operation. This study concludes with recommendations for future research directions thus contributing to fuel research concepts that can facilitate the shipboard use of alternative fuels.
Battery and Hydrogen Energy Storage Control in a Smart Energy Network with Flexible Energy Demand Using Deep Reinforcement Learning
Sep 2023
Publication
Smart energy networks provide an effective means to accommodate high penetrations of variable renewable energy sources like solar and wind which are key for the deep decarbonisation of energy production. However given the variability of the renewables as well as the energy demand it is imperative to develop effective control and energy storage schemes to manage the variable energy generation and achieve desired system economics and environmental goals. In this paper we introduce a hybrid energy storage system composed of battery and hydrogen energy storage to handle the uncertainties related to electricity prices renewable energy production and consumption. We aim to improve renewable energy utilisation and minimise energy costs and carbon emissions while ensuring energy reliability and stability within the network. To achieve this we propose a multi-agent deep deterministic policy gradient approach which is a deep reinforcement learning-based control strategy to optimise the scheduling of the hybrid energy storage system and energy demand in real time. The proposed approach is model-free and does not require explicit knowledge and rigorous mathematical models of the smart energy network environment. Simulation results based on real-world data show that (i) integration and optimised operation of the hybrid energy storage system and energy demand reduce carbon emissions by 78.69% improve cost savings by 23.5% and improve renewable energy utilisation by over 13.2% compared to other baseline models; and (ii) the proposed algorithm outperforms the state-of-the-art self-learning algorithms like the deep-Q network.
The EU Hydrogen and Gas Decarbonisation Package: Help or Hindrance for the Development of a European Hydrogen Market?
Mar 2023
Publication
The European Commission has identified hydrogen as a key part of its decarbonisation strategy. The 2022 REPowerEU Strategy set a target of 20MT consumption of renewable hydrogen by 2030. The Commission is keen to promote a single European market in hydrogen similar to the current one for natural gas. To this end it has published proposals on the regulation of future European hydrogen infrastructure (pipelines storage facilities and import terminals). The European Council (representing Member States) and the European Parliament are finalising their amendments to the Commission proposals prior to ’trilogue’ negotiations and final agreement later this year. The paper ‘The EU Hydrogen and Gas Decarbonisation Package: help or hindrance for the development of a European hydrogen market?’ examines the European Commission proposals and their suitability for a developing hydrogen market.
Assessing the Pressure Losses during Hydrogen Transport in the Current Natural Gas Infrastructure Using Numerical Modelling
May 2023
Publication
The UK government aims to transition its modern natural gas infrastructure towards Hydrogen by 2035. Since hydrogen is a much lighter gas than methane it is important to understand the change in parameters when transporting it. While most modern work in this topic looks at the transport of hydrogen-methane mixtures this work focuses on pure hydrogen transport. The aim of this paper is to highlight the change in gas distribution parameters when natural gas is replaced by hydrogen in the existing infrastructure. This study uses analytical models and computational models to compare the flow of hydrogen and methane in a pipe based on pressure loss. The Darcy-Weisbach and Colebrook-White equations were used for the analytical models and the k- ε model was used for the computational approach. The variables considered in the comparison were the pipe material (X52 Steel and MDPE) and pipe diameters (0.01m–1m). It was observed that hydrogen had to be transported 250–270% the velocity of methane to replicate flow for a fixed length of pipe. Furthermore it was noted that MDPE pipes has 2–31% lower pressure losses compared to X52 steel for all diameters when transporting hydrogen at a high velocity. Lastly it was noted that the analytical model and computational model were in agreement with 1–5% error in their findings.
Future Energy Scenarios 2019
Jul 2019
Publication
Decarbonising energy is fundamental in the transition towards a sustainable future. Our Future Energy Scenarios aim to stimulate debate to inform the decisions that will help move us towards achieving carbon reduction targets and ultimately shape the energy system of the future.
The Prospects of Hydrogen in Achieving Net Zero Emissions by 2050: A Critical Review
May 2023
Publication
Hydrogen (H2) usage was 90 metric tonnes (Mt) in 2020 almost entirely for industrial and refining uses and generated almost completely from fossil fuels leading to nearly 900 Mt of carbon dioxide emissions. However there has been significant growth of H2 in recent years. Electrolysers' total capacity which are required to generate H2 from electricity has multiplied in the past years reaching more than 300 MW through 2021. Approximately 350 projects reportedly under construction could push total capacity to 54 GW by the year 2030. Some other 40 projects totalling output of more than 35 GW are in the planning phase. If each of these projects is completed global H2 production from electrolysers could exceed 8 Mt by 2030. It's an opportunity to take advantage of H2S prospects to be a crucial component of a clean safe and cost-effective sustainable future. This paper assesses the situation regarding H2 at the moment and provides recommendations for its potential future advancement. The study reveals that clean H2 is experiencing significant unparalleled commercial and political force with the amount of laws and projects all over the globe growing quickly. The paper concludes that in order to make H2 more widely employed it is crucial to significantly increase innovations and reduce costs. The practical and implementable suggestions provided to industries and governments will allow them to fully capitalise on this growing momentum.
The Role of Hydrogen in a Decarbonised Future Transport Sector: A Case Study of Mexico
Sep 2023
Publication
In recent years several approaches and pathways have been discussed to decarbonise the transport sector; however any effort to reduce emissions might be complex due to specific socio-economic and technical characteristics of different regions. In Mexico the transport sector is the highest energy consumer representing 38.9% of the national final energy demand with gasoline and diesel representing 90% of the sector´s total fuel consumption. Energy systems models are powerful tools to obtain insights into decarbonisation pathways to understand costs emissions and rate of deployment that could serve for energy policy development. This paper focuses on the modelling of the current Mexican transport system using the MUSE-MX multi-regional model with the aim to project a decarbonisation pathway through two different scenarios. The first approach being business as usual (BAU) which aims to analyse current policies implementation and the second being a goal of net zero carbon emissions by 2050. Under the considered net zero scenario results show potential deployment of hydrogen-based transport technologies especially for subsectors such as lorries (100% H2 by 2050) and freight train (25% H2 by 2050) while cars and buses tend to full electrification by 2050.
Hydrogen Storage for a Net-zero Carbon Future
Apr 2023
Publication
If a hydrogen economy is to become a reality along with efficient and decarbonized production and adequate transportation infrastructure deployment of suitable hydrogen storage facilities will be crucial. This is because due to various technical and economic reasons there is a serious possibility of an imbalance between hydrogen supply and demand. Hydrogen storage could also be pivotal in promoting renewable energy sources and facilitating the decarbonization process by providing long duration storage options which other forms of energy storage such as batteries with capacity limitations or pumped hydro with geographical limitations cannot meet. However hydrogen is not the easiest substance to store and handle. Under ambient conditions the extremely low volumetric energy density of hydrogen does not allow for its efficient and economic storage which means it needs to be compressed liquefied or converted into other substances that are easier to handle and store. Currently there are different hydrogen storage solutions at varying levels of technology market and commercial readiness with different applications depending on the circumstances. This paper evaluates the relative merits and techno-economic features of major types of hydrogen storage options: (i) pure hydrogen storage (ii) synthetic hydrocarbons (iii) chemical hydrides (iv) liquid organic hydrogen carriers (v) metal hydrides and (vi) porous materials. The paper also discusses the main barriers to investment in hydrogen storage and highlights key features of a viable business model in particular the policy and regulatory framework needed to address the primary risks to which potential hydrogen storage investors are exposed.
Hydrogen Embrittlement Characteristics in Cold-drawn High-strength Stainless Steel Wires
Mar 2023
Publication
Hydrogen uptake and embrittlement characteristics of a cold-drawn austenitic stainless steel wire were investigated. Slow strain rate testing and fracture surface analysis were applied to determine the hydrogen embrittlement resistance providing an apparent decrease in resistance to hydrogen embrittlement for a 50% degree of cold deformation. The hydrogen content was assessed by thermal desorption and laser-induced breakdown spectroscopy establishing a correlation between the total absorbed hydrogen and the intensity of near-surface hydrogen. The sub-surface hydrogen content of the hot-rolled specimen was determined to be 791 wt.ppm.
No more items...