United Kingdom

Water electrolysis is a process which converts electricity into hydrogen and is seen as a key technology in enabling a net-zero compatible energy system. It will enable the scale-up of renewable electricity as a primary energy source for heating transport and industry. However displacing the role currently met by fossil fuels might require a price of hydrogen as low as 1 $/kg whereas renewable hydrogen produced using electrolysis is currently 10 $/kg. This article explores how mass manufacturing of proton exchange membrane (PEM) electrolysers can reduce the capital cost and thus make the production of renewable power to hydrogen gas (PtG) more economically viable. A bottom up direct manufacturing model was developed to determine how economies of scale can reduce the capital cost of electrolysis. The results demonstrated that (assuming an annual production rate of 5000 units of 200 kW PEM electrolysis systems) the capital cost of a PEM electrolysis system can reduce from 1990 $/kW to 590 $/kW based on current technology and then on to 431 $/kW and 300 $/kW based on the an installed capacity scale-up of ten- and one-hundred-fold respectively. A life-cycle costing analysis was then completed to determine the importance of the capital cost of an electrolysis system to the price of hydrogen. It was observed that based on current technology mass manufacturing has a large impact on the price of hydrogen reducing it from 6.40 $/kg (at 10 units units per year) to 4.16 $/kg (at 5000 units per year). Further analysis was undertaken to determine the cost at different installed capacities and found that the cost could reduce further to 2.63 $/kg and 1.37 $/kg based on technology scale-up by ten- and one hundred-fold respectively. Based on the 2030 (and beyond) baseline assumptions it is expected that hydrogen production from PEM electrolysis could be used as an industrial process feed stock provide power and heat to buildings and as a fuel for heavy good vehicles (HGVs). In the cases of retrofitted gas networks for residential or industrial heating solutions or for long distance transport it represents a more economically attractive and mass-scale compatible solution when compared to electrified heating or transport solutions.

This review critically analyses various aspects of the most promising thermochemical cycles for clean hydrogen production. While the current hydrogen market heavily relies on fossil-fuel-based platforms the thermochemical water-splitting systems based on the reduction-oxidation (redox) looping reactions have a significant potential to significantly contribute to the sustainable production of green hydrogen at scale. However compared to the water electrolysis techniques the thermochemical cycles suffer from a low technology readiness level (TRL) which retards the commercial implementation of these technologies. This review mainly focuses on identifying the capability of the state-of-the-art thermochemical cycles to deploy large-scale hydrogen production plants and their techno-economic performance. This study also analyzed the potential integration of the hybrid looping systems with the solar and nuclear reactor designs which are evidenced to be more cost-effective than the electrochemical water-splitting methods but it excludes fossil-based thermochemical processes such as gasification steam methane reforming and pyrolysis. Further investigation is still required to address the technical issues associated with implementing the hybrid thermochemical cycles in order to bring them to the market for sustainable hydrogen production.

The effort to meet the ambitious targets of the Paris agreement is challenging many governments. The US and UK governments might have different approaches to achieving the targets but both will rely heavily on renewable energy sources such as wind and solar to power their economies. However these sources of power are unpredictable and ways will have to be developed to store renewable energy for hours days weeks seasons and maybe even years before it is used. As the disruptive and increasingly deadly impacts of climate change are being felt across the world the need to move to more sustainable sources of energy and to identify viable ways to store that energy has never been more important.<br/>This was the subject of the US–UK Science Forum on electrical storage in support of the grid which was held online from 17 – 18 March 2021. Co-organised by the Royal Society and the National Academy of Sciences it brought together a diverse group of 60 scientists policy makers industry leaders regulators and other key stakeholders for a wide-ranging discussion on all aspects of energy storage from the latest research in the field to the current status of deployment. It also considered the current national and international economic and policy contexts in which these developments are taking place. A number of key points emerged from the discussion. First it is clear that renewable energy will play an increasingly important role in the US and UK energy systems of the future and energy storage at a multi-terawatt hour scale has a vital role to play. Of course this will evolve differently to some extent in both countries and elsewhere according to the various geographical technological economic political social and regulatory environments. Second international collaboration is critical – no single nation will solve this problem alone. As two of the world’s leading scientific nations largest economies and per capita CO2 emitters with a long track record of collaboration the US and UK are well placed to play a vital role in addressing this critical challenge. As the discussion highlighted a wide range of energy storage technologies are now emerging and becoming increasingly available many of which have the potential to be critical components of a future net-zero energy system. A crucial next phase is in ensuring that these are technically developed as well as economically and political viable. This will require the support of a wide range of these potential solutions to ensure that their benefits remain widely available and to avoid costly ‘lock-in’. Scientists and science academies have a critical role to play in analysing technology options their combinations and their potential roles in future sustainable energy systems and in working with policymakers to incentivise investment and deployment.

This study presents a novel design and development of a 280000 m3 liquefied hydrogen tanker ship by implementing a set of 6 Flettner rotors as an assistance propulsion system in conjunction with a combined-cycle gas turbine fuelled by hydrogen as a prime mover. The study includes assessment of the technical and environmental aspects of the developed design. Furthermore an established method was applied to simulate the LH2 tanker in different voyages and conditions to investigate the benefits of harnessing wind energy to assist combined-cycle gas turbine in terms of performance and emission reduction based on engine behaviour for different voyages under loaded and unloaded normal as well as 6 % degraded engine and varying ambient conditions. The results indicate that implementing a set of 6 Flettner rotors for the LH2 tanker ship has the potential to positively impact the performance and lead to environmental benefits. A maximum contribution power of around 1.8 MW was achieved in the winter season owing to high wind speed and favourable wind direction. This power could save approximately 3.6 % of the combined-cycle gas turbine total output power (50 MW) and cause a 3.5 % reduction in NOx emissions.

A steady state analysis method was developed for gas networks with distributed injection of alternative gas. A low pressure gas network was used to validate the method. Case studies were carried out with centralized and decentralized injection of hydrogen and upgraded biogas. Results show the impact of utilizing a diversity of gas supply sources on pressure distribution and gas quality in the network. It is shown that appropriate management of using a diversity of gas supply sources can support network management while reducing carbon emissions.

This work studies the development of a sustainable hydrogen infrastructure that supports the transition towards a low-carbon transport system in the United Kingdom (UK). The future hydrogen demand is forecasted over time using a logistic diffusion model which reaches 50% of the market share by 2070. The problem is solved using an extension of SHIPMod an optimisation-based framework that consists of a multi-period spatially-explicit mixed-integer linear programming (MILP) formulation. The optimisation model combines the infrastructure elements required throughout the different phases of the transition namely economies of scale road and pipeline transportation modes and carbon capture and storage (CCS) technologies in order to minimise the present value of the total infrastructure cost using a discounted cash-flow analysis. The results show that the combination of all these elements in the mathematical formulation renders optimal solutions with the gradual infrastructure investments over time required for the transition towards a sustainable hydrogen economy.

Hydrogen has been identified as a fuel of choice for providing clean energy for transport and other applications across the world and the development of materials to store hydrogen efficiently and safely is crucial to this endeavour. Hydrogen has the largest scattering interaction with neutrons of all the elements in the periodic table making neutron scattering ideal for studying hydrogen storage materials. Simultaneous characterisation of the structure and dynamics of these materials during hydrogen uptake is straightforward using neutron scattering techniques. These studies will help us to understand the fundamental properties of hydrogen storage in realistic conditions and hence design new hydrogen storage materials.

Green hydrogen is considered a highly promising vector for deep decarbonisation of energy systems and is forecast to represent 20% of global energy use by 2050. In order to secure access to this resource Japan Germany and South Korea have announced plans to import hydrogen; other major energy consumers are sure to follow. Ammonia a promising hydrogen derivative may enable this energy transport by densifying hydrogen at relatively low cost using well-understood technologies. This review seeks to describe a global green ammonia import/export market: it identifies benefits and limitations of ammonia relative to other hydrogen carriers the costs of ammonia production and transport and the constraints on both supply and demand. We find that green ammonia as an energy vector is likely to be critical to future energy systems but that gaps remain in the literature. In particular rigorous analysis of production and transport costs are rarely paired preventing realistic assessments of the delivered cost of energy or the selection of optimum import/export partners to minimise the delivered cost of ammonia. Filling these gaps in the literature is a prerequisite to the development of robust hydrogen and ammonia strategies and to enable the formation of global import and export markets of green fuel

Demands for space and water heating constitute a significant proportion of the total energy demands in Great Britain and are predominantly satisfied through natural gas which makes the heat sector a large emitter of carbon dioxide. Renewable hydrogen which can be injected into the gas grid or used directly in processes for generating heat and/or electricity is being considered as a low-carbon alternative energy carrier to natural gas because of its suitability for large-scale long- and short-term storage and low transportation losses all of which help to overcome the intermittency and seasonal variations in renewables. This requires new infrastructures for production storage transport and utilisation of renewable hydrogen – a hydrogen value chain – the design of which involves many interdependent decisions such as: where to locate wind turbines; where to locate electrolysers close to wind generation or close to demands; whether to transport energy as electricity or hydrogen and how; where to locate storage facilities; etc. This paper presents the Value Web Model a novel and comprehensive spatio-temporal mixed-integer linear programming model that can simultaneously optimise the design planning and operation of integrated energy value chains accounting for short-term dynamics inter-seasonal storage and investments out to 2050. It was coupled with GIS modelling to identify candidate sites for wind generation and used to optimise a number of scenarios for the production of hydrogen from onshore and offshore wind turbines in order to satisfy heat demands. The results show that over a wide range of scenarios the optimal pathway to heat is roughly 20% hydrogen and 80% electricity. Hydrogen storage both in underground caverns and pressurised tanks is a key enabling technology.

Hydrogen-microvoid interactions were studied via unit cell analyses with different hydrogen concentrations. The absolute failure strain decreases with hydrogen concentration but the failure loci were found to follow the same trend dependent only on stress triaxiality in other words the effects of geometric constraint and hydrogen on failure are decoupled. Guided by the decoupling principle a hydrogen informed Gurson model is proposed. This model is the first practical hydrogen embrittlement simulation tool based on the hydrogen enhanced localized plasticity (HELP) mechanism. It introduces only one additional hydrogen related parameter into the Gurson model and is able to capture hydrogen enhanced internal necking failure of microvoids with accuracy; its parameter calibration procedure is straightforward and cost efficient for engineering purpose