Australia
Modeling of Thermal Performance of a Commercial Alkaline Electrolyzer Supplied with Various Electrical Currents
Nov 2021
Publication
Hydrogen produced by solar and other clean energy sources is an essential alternative to fossil fuels. In this study a commercial alkaline electrolyzer with different cell numbers and electrode areas are simulated for different pressure temperature thermal resistance and electrical current. This alkaline electrolyzer is considered unsteady in simulations and different parameters such as temperature are obtained in terms of time. The obtained results are compared with similar results in the literature and good agreement is observed. Various characteristics of this alkaline electrolyzer as thermoneutral voltage faraday efficiency and cell voltage are calculated and displayed. The outlet heat rate and generated heat rate are obtained as well. The pressure and the temperature in the simulations are between 1 and 100 bar and between 300 and 360 Kelvin respectively. The results show that the equilibrium temperature is reached 2-3 hours after the time when the Alkaline electrolyzer starts to work.
Blending Ammonia into Hydrogen to Enhance Safety through Reduced Burning Velocity
Sep 2019
Publication
Laminar burning velocities (SL) of hydrogen/ammonia mixtures in air at atmospheric pressure were studied experimentally and numerically. The blending of hydrogen with ammonia two fuels that have been proposed as promising carriers for renewable energy causes the laminar flame speed of the mixture SL to decrease significantly. However details of this have not previously available. Systematic measurements were therefore performed for a series of hydrogen/ammonia mixtures with wide ranges of mole fractions of blended ammonia (XNH3) and equivalence ratio using a heat flux method based on heat flux of a flat flame transferred to the burner surface. It was found that the mixture of XNH3 = 40% has a value of SL close to that of methane which is the dominant component of natural gas. Using three chemical kinetic mechanisms available in the literature i.e. the well-known GRI-Mech 3.0 mechanism and two mechanisms recently released SL were also modelled for the cases studied. However the discrepancies between the experimental and numerical results can exceed 50% with the GRI-Mech 3.0 mechanism. Discrepancies were also found between the numerical results obtained with different mechanisms. These results can contribute to an increase in both the safety and efficiency of the coutilization of these two types of emerging renewable fuel and to guiding the development of better kinetic models.
Hydrogen for Renewable Energy Export: Broadening the Concept of Hydrogen Safety
Sep 2019
Publication
Recently we have seen hydrogen (re)emerge as an important component of widespread decarbonisation of energy sectors. From an Australian perspective this brings with it an opportunity to store transport and export renewable energy—either as liquefied hydrogen or in a carrier such as ammonia. The growth of the hydrogen industry to now include the power and transport sectors as well as the notion of hydrogen export has broadened the range of safety considerations required and seen them extend into the realm of the consumer for the first time.<br/>Hydrogen as well as ammonia and other carriers such as methanol are existing industrial chemicals which have established protocols for their handling and use in the chemicals sector. As their use in energy and transport increases especially in the context of widespread domestic use their handling and use by inexperienced people in less-controlled environments expands shifting the risk profiles and management systems required. There is also the potential for novel hydrogen carriers such as methylcyclohexane/toluene to reach commercial viability at industrial scale.<br/>This paper will discuss some of these emerging applications of hydrogen and its carriers and discuss some of the technological innovations under development that may accompany a new energy industry— with some consideration given to their potential risks and the required safety considerations. In addition we will also provide an overview of global activity in this area and how new standards and regulations would need to be developed for the adaption of these technologies in an Australian context.
An Analysis of Emerging Renewable Hydrogen Policy through an Energy Democracy Lens: The Case of Australia
Mar 2024
Publication
As part of reducing carbon emissions governments across the world are working on measures to transition sectors of the economy away from fossil fuels. The socio-technical regimes being constructed around the energy transition can encourage energy centralisation and constrain actor engagement without proper policy and planning. The energy transition is liable to have significant impacts across all of society but less attention has been given to the role of democratic participation and decision-making in the energy system during this time. Using the energy democracy framework developed by Kacper Szulecki we employ content analysis to investigate how Australia’s renewable hydrogen strategies at the Commonwealth and state levels engage with the broader objective of democratising energy systems. Based on our findings we recommend ways to support a renewable hydrogen regime in Australia in line with the principles of energy democracy such as community engagement built-in participation popular sovereignty community-level agency and civic ownership. This study provides a perspective on the energy transition that is often overlooked and a reminder to policymakers that the topology of an energy transition can take many forms.
Open-cathode PEMFC Heat Utilisation to Enhance Hydrogen Supply Rate of Metal Hydride Canisters
Mar 2019
Publication
In this paper the hydrogen supply to an open-cathode PEM fuel cell (FC) by using metal hydride (MH) storage and thermal coupling between these two components are investigated theoretically. One of the challenges in using MH hydrogen storage canisters is their limited hydrogen supply rate as the hydrogen release from MH is an endothermic reaction. Therefore in order to meet the required hydrogen supply rate high amounts of MH should be employed that usually suggests storage of hydrogen to be higher than necessary for the application adding to the size weight and cost of the system. On the other hand the exhaust heat (i.e. that is usually wasted if not utilised for this purpose) from open-cathode FCs is a low-grade heat. However this heat can be transferred to MH canisters through convection to heat them up and increase their hydrogen release rate. A mathematical model is used to simulate the heat transfer between PEMFC exhaust heat and MH storage. This enables the prediction of the required MH for different FC power levels with and without heat supply to the MH storage. A 2.5-kW open-cathode FC is used to measure the exhaust air temperature at different output powers. It was found that in the absence of heat supply from the FC to the MH canisters significantly higher number of MH canisters are required to achieve the required rate of hydrogen supply to the FC for sustained operation (specially at high power outputs). However using the exhaust hot air from the FC to supply heat to the MH storage can reduce the number of the MH canisters required by around 40% to 70% for power output levels ranging from 500 W to 2000 W.
A Review on Underground Hydrogen Storage: Insight into Geological Sites, Influencing Factors and Future Outlook
Dec 2021
Publication
Without remorse fossil fuels have made a huge contribution to global development in all of its forms. However the recent scientific outlooks are currently shifting as more research is targeted towards promoting a carbon-free economy in addition to the use of electric power from renewable sources. While renewable energy sources may be a solution to the anthropogenic greenhouse gas (GHG) emissions from fossil fuel they are yet season-dependent faced with major atmospheric drawbacks which when combined with annually varying but steady energy demand results in renewable energy excesses or deficits. Therefore it is essential to devise a long-term storage medium to balance their intermittent demand and supply. Hydrogen (H2) as an energy vector has been suggested as a viable method of achieving the objectives of meeting the increasing global energy demand. However successful implementation of a full-scale H2 economy requires large-scale H2 storage (as H2 is highly compressible). As such storage of H2 in geological formations has been considered as a potential solution where it can be withdrawn again at the larger stage for utilization. Thus in this review we focus on the potential use of geological formations for large-scale underground hydrogen storage (UHS) where both conventional and non-conventional UHS options were examined in depth. Also insights into some of the probable sites and the related examined criteria for selection were highlighted. The hydrodynamics of UHS influencing factors (including solid fluid and solid–fluid interactions) are summarized exclusively. In addition the economics and reaction perspectives inherent to UHS have been examined. The findings of this study show that UHS like other storage systems is still in its infancy. Further research and development are needed to address the significant hurdles and research gaps found particularly in replaceable influencing parameters. As a result this study is a valuable resource for UHS researchers.
Hydrogen Energy Demand Growth Prediction and Assessment (2021–2050) Using a System Thinking and System Dynamics Approach
Jan 2022
Publication
Adoption of hydrogen energy as an alternative to fossil fuels could be a major step towards decarbonising and fulfilling the needs of the energy sector. Hydrogen can be an ideal alternative for many fields compared with other alternatives. However there are many potential environmental challenges that are not limited to production and distribution systems but they also focus on how hydrogen is used through fuel cells and combustion pathways. The use of hydrogen has received little attention in research and policy which may explain the widely claimed belief that nothing but water is released as a by-product when hydrogen energy is used. We adopt systems thinking and system dynamics approaches to construct a conceptual model for hydrogen energy with a special focus on the pathways of hydrogen use to assess the potential unintended consequences and possible interventions; to highlight the possible growth of hydrogen energy by 2050. The results indicate that the combustion pathway may increase the risk of the adoption of hydrogen as a combustion fuel as it produces NOx which is a key air pollutant that causes environmental deterioration which may limit the application of a combustion pathway if no intervention is made. The results indicate that the potential range of global hydrogen demand is rising ranging from 73 to 158 Mt in 2030 73 to 300 Mt in 2040 and 73 to 568 Mt in 2050 depending on the scenario presented.
Delivering a Safe, Viable Hydrogen Economy in Australia
Sep 2019
Publication
At Woodside Energy Ltd (Woodside) safety is built into everything we do and progressing hydrogen opportunities is no exception. This paper will present information from the macro level of process safety for hydrogen at a plant level through to the consumer experience. Examples of the benefits of an integrated process safety approach will be used from Woodside’s experience pioneering the liquefied natural gas industry in Australia.<br/>This paper will underscore the reasons why Australia needs to adopt robust safety standards for hydrogen as quickly as possible in order to advance the hydrogen economy across all sectors. Focus areas requiring attention during development of standards and potential mechanisms to close will be proposed. Establishing a hydrogen economy in Australia could lower carbon emissions stabilise power grids increase renewable energy penetration and create jobs. Developing Australian standards that are fully aligned with international standards will facilitate Australia taking a leading role in the global hydrogen economy.
Early Community Engagement with Hydrogen in Australia
Sep 2019
Publication
Community support and acceptance is part of the licence to operate for any industry. The hydrogen industry is no different and we will need to have strong support from the broad community to establish a viable hydrogen economy in Australia.<br/>As Woodside progresses our plans for bulk hydrogen export and associated domestic opportunities stakeholder engagement throughout will be critical to success. This talk will share Woodside’s approach to community engagement and local opportunities and how we plan to draw on more than 30 years’ experience operating liquefied natural gas plants in Western Australia’s Pilbara region.<br/>At this early stage of our hydrogen work we are beginning with the end in mind: engaging the customer. We’ve worked with local Australian businesses to help raise public awareness and interest in hydrogen by producing prototype consumer products. We will share experiences from this work that underscore the value of early engagement with all stakeholders: government regulators industrial and community neighbours and end consumers to enable the hydrogen economy vision for Australia. This paper will present information on community engagement and acceptance of hydrogen in Australia.<br/>This information has come from Woodside Energy Ltd by engaging with small businesses government regulators and the community at large. As we establish community acceptance for hydrogen as an energy carrier in Australia Woodside has been working in parallel to have standards and regulations established for hydrogen in Australia. Through our work with Hydrogen Mobility Australia we are advocating the adoption of ISO standards unless there is a specific geographic or health safety and environment reason not to.
HyP SA – Our safety story
Sep 2019
Publication
Australian Gas Infrastructure Group’s (AGIG’s) vision is to be the leading gas infrastructure business in Australia this means delivering for our customers being a good employer and being sustainably cost efficient. Establishing and developing a hydrogen industry is a key pathway for us to achieve our vision.
In South Australia AGIG is pioneering the introduction of hydrogen into its existing gas distribution networks through the Hydrogen Park South Australia (HyP SA) project. With safety our top priority we would like to give an overview of the safety considerations of our site our network methodology and the development of new safety procedures and culture regarding the production handling and reticulation of a 5% hydrogen blend.
We will cover three themes each having a safety story that is specific to the Australian context and to the project’s success:
The Production Plant and Site
Project site safety known hazards and risk mitigation electrical protection safety procedures lighting and security. Hydrogen storage filling and transportation.
The Network
Securing the network for an isolated safe demonstration footprint. Gas network and hydrogen safety considerations why 5%? Emergency procedures and crew training. New safety regulations blended networks. How does hydrogen perform in a blended gas with respect to leaks? How safe is the existing network and what sensors and controls are we using.
The Home
Introducing blended gas to existing homes. Appliance safety and failure mode analysis. Community engagement and education on a 5% renewable hydrogen gas blend and use in the home
.
We aim to give a comprehensive overview of delivering a safe demonstration network for the HyP SA project in terms of the three main ecosystems that the hydrogen will be present our learnings so far and the development of the safety methodologies that will be applied in the industry in the future.
In South Australia AGIG is pioneering the introduction of hydrogen into its existing gas distribution networks through the Hydrogen Park South Australia (HyP SA) project. With safety our top priority we would like to give an overview of the safety considerations of our site our network methodology and the development of new safety procedures and culture regarding the production handling and reticulation of a 5% hydrogen blend.
We will cover three themes each having a safety story that is specific to the Australian context and to the project’s success:
The Production Plant and Site
Project site safety known hazards and risk mitigation electrical protection safety procedures lighting and security. Hydrogen storage filling and transportation.
The Network
Securing the network for an isolated safe demonstration footprint. Gas network and hydrogen safety considerations why 5%? Emergency procedures and crew training. New safety regulations blended networks. How does hydrogen perform in a blended gas with respect to leaks? How safe is the existing network and what sensors and controls are we using.
The Home
Introducing blended gas to existing homes. Appliance safety and failure mode analysis. Community engagement and education on a 5% renewable hydrogen gas blend and use in the home
.
We aim to give a comprehensive overview of delivering a safe demonstration network for the HyP SA project in terms of the three main ecosystems that the hydrogen will be present our learnings so far and the development of the safety methodologies that will be applied in the industry in the future.
Sustainable Power Supply Solutions for Off-Grid Base Stations
Sep 2015
Publication
The telecommunication sector plays a significant role in shaping the global economy and the way people share information and knowledge. At present the telecommunication sector is liable for its energy consumption and the amount of emissions it emits in the environment. In the context of off-grid telecommunication applications off-grid base stations (BSs) are commonly used due to their ability to provide radio coverage over a wide geographic area. However in the past the off-grid BSs usually relied on emission-intensive power supply solutions such as diesel generators. In this review paper various types of solutions (including in particular the sustainable solutions) for powering BSs are discussed. The key aspects in designing an ideal power supply solution are reviewed and these mainly include the pre-feasibility study and the thermal management of BSs which comprise heating and cooling of the BS shelter/cabinets and BS electronic equipment and power supply components. The sizing and optimization approaches used to design the BSs’ power supply systems as well as the operational and control strategies adopted to manage the power supply systems are also reviewed in this paper.
Communicating Leakage Risk in the Hydrogen Economy: Lessons Already Learned from Geoenergy Industries
Sep 2019
Publication
Hydrogen may play a crucial part in delivering a net zero emissions future. Currently hydrogen production storage transport and utilisation are being explored to scope opportunities and to reduce barriers to market activation. One such barrier could be negative public response to hydrogen technologies. Previous research around socio-technical risks finds that public acceptance issues are particularly challenging for emerging remote technical sensitive uncertain or unfamiliar technologies - such as hydrogen. Thus while the hydrogen value chain could offer a range of potential environmental economic and social benefits each will have perceived risks that could challenge the introduction and subsequent roll-out of hydrogen. These potential issues must be identified and managed so that the hydrogen sector can develop adapt or respond appropriately. Geological storage of hydrogen could present challenges in terms of perceived safety. Valuable lessons can be learned from international research and practice of CO2 and natural gas storage in geological formations (for carbon capture and storage CCS and for power respectively). Here we explore these learnings. We consider the similarities and differences between these technologies and how these may affect perceived risks. We also reflect on lessons for effective communication and community engagement. We draw on this to present potential risks to the perceived safety of - and public acceptability of – the geological storage of hydrogen. One of the key lessons learned from CCS and natural gas storage is that progress is most effective when risk communication and public acceptability is considered from the early stages of technology development.
Autoignition of Hydrogen/Ammonia Blends at Elevated Pressures and Temperatures
Sep 2019
Publication
Hydrogen stored or transported as ammonia has been proposed as a sustainable carbon-free alternative for fossil-fuels in high-temperature industrial processes including power generation. Although ammonia itself is toxic and exhibits both a low flame speed and calorific value it rapidly decomposes to hydrogen in high temperature environments suggesting the potential use in applications which incorporate fuel preheating. In this work the rate of ammonia-to-hydrogen decomposition is initially simulated at elevated temperatures to indicate the proportion of fuel conversion in conditions similar to gas pipelines gas-turbines or furnaces with exhaust-gas recirculation. Following this different proportions of hydrogen and ammonia are numerically simulated in independent zero-dimensional plug-flow-reactors at pressures ranging from atmospheric to 50 MPa and pre-heating temperatures from 600 K to 1600 K. Deflagration of very-lean-to-fuel-rich mixtures was investigated employing air as the oxidant stream. Analyses of these reactors provide estimates of autoignition thresholds of the hydrogen/ammonia blends which are relevant for the safe implementation and operation of hydrogen/ammonia blends or pure ammonia as a fuel source. Further operational considerations are subsequently identified for using ammonia or hydrogen/ammonia blends as a hydrogen fuel carrier by quantifying residual concentrations of hydrogen and ammonia fuel products as well as other toxic emissions within the hot exhaust products.
Assessing the Viability of the ACT Natural Gas Distribution Network for Reuse as a Hydrogen Distribution Network
Sep 2019
Publication
The Australian Capital Territory (ACT) has legislated and aims to be net zero emissions by 2045. Such ambitious targets have implications for the contribution of hydrogen and its storage in gas distribution networks Therefore we need to understand now the impacts on the gas distribution network of the transition to 100% hydrogen. Assessment of the viability of decarbonising the ACT gas network will be partly based on the cost of reusing the gas network for the safe and reliable distribution of hydrogen. That task requires each element of the natural gas safety management system to be evaluated.
This article describes the construction of a test facility in Canberra Australia used to identify issues raised by 100% hydrogen use in the medium pressure distribution network consisting of nylon and polyethylene (PE) as a means of identifying measures necessary to ensure ongoing validity of the network's regulatory safety case.
Evoenergy (the ACT's gas distribution company) have constructed a Test Facility incorporating an electrolyser a gas supply pressure reduction and mixing skid a replica gas network and a domestic installation with gas appliances. Jointly with Australian National University (ANU) and Canberra Institute of Technology (CIT) the Company has commenced a program of “bench testing” initially with 100% hydrogen to identify gaps in the safety case specifically focusing on the materials work practices and safety systems in the ACT.
The facility is designed to assess:
The paper addresses major safety issues relating to the production/storage distribution and consumer end use of hydrogen injected into existing gas distribution networks. The analysis is guided by the Safety Management System. The Hydrogen Testing Facility described in the paper provide tools for evaluation of hydrogen safety matters in the ACT and Australia-wide.
Testing to date has confirmed that polyethylene and nylon pipe and their respective jointing techniques can contain 100% hydrogen at pressures used for the distribution of natural gas. Testing has also confirmed that current installation work practices on polyethylene and nylon pipe and joints are suitable for hydrogen service. This finding is subject to variation attributable to staff training and skill levels and further testing has been programmed as outlined in this paper.
Testing of gas isolation by clamping and simulated repair on the hydrogen network has established that standard natural gas isolation techniques work with 100% hydrogen at natural gas pressures.
This article describes the construction of a test facility in Canberra Australia used to identify issues raised by 100% hydrogen use in the medium pressure distribution network consisting of nylon and polyethylene (PE) as a means of identifying measures necessary to ensure ongoing validity of the network's regulatory safety case.
Evoenergy (the ACT's gas distribution company) have constructed a Test Facility incorporating an electrolyser a gas supply pressure reduction and mixing skid a replica gas network and a domestic installation with gas appliances. Jointly with Australian National University (ANU) and Canberra Institute of Technology (CIT) the Company has commenced a program of “bench testing” initially with 100% hydrogen to identify gaps in the safety case specifically focusing on the materials work practices and safety systems in the ACT.
The facility is designed to assess:
- Materials in use including aged network materials and components
- Construction and installation techniques both greenfield and live gas work
- Purging and filling techniques
- Leak detection both underground and above ground
- Emergency response and make safe techniques
- Issues associated with use of hydrogen in light commercial and domestic appliances.
- Technicians and gas fitters on infrastructure installation and management
- Emergency response services on responding to hydrogen related emergencies in a network environment; and
- Manage public perceptions of hydrogen in a network environment.
The paper addresses major safety issues relating to the production/storage distribution and consumer end use of hydrogen injected into existing gas distribution networks. The analysis is guided by the Safety Management System. The Hydrogen Testing Facility described in the paper provide tools for evaluation of hydrogen safety matters in the ACT and Australia-wide.
Testing to date has confirmed that polyethylene and nylon pipe and their respective jointing techniques can contain 100% hydrogen at pressures used for the distribution of natural gas. Testing has also confirmed that current installation work practices on polyethylene and nylon pipe and joints are suitable for hydrogen service. This finding is subject to variation attributable to staff training and skill levels and further testing has been programmed as outlined in this paper.
Testing of gas isolation by clamping and simulated repair on the hydrogen network has established that standard natural gas isolation techniques work with 100% hydrogen at natural gas pressures.
Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage
Oct 2017
Publication
Hydrogen has a very diverse chemistry and reacts with most other elements to form compounds which have fascinating structures compositions and properties. Complex metal hydrides are a rapidly expanding class of materials approaching multi-functionality in particular within the energy storage field. This review illustrates that complex metal hydrides may store hydrogen in the solid state act as novel battery materials both as electrolytes and electrode materials or store solar heat in a more efficient manner as compared to traditional heat storage materials. Furthermore it is highlighted how complex metal hydrides may act in an integrated setup with a fuel cell. This review focuses on the unique properties of light element complex metal hydrides mainly based on boron nitrogen and aluminum e.g. metal borohydrides and metal alanates. Our hope is that this review can provide new inspiration to solve the great challenge of our time: efficient conversion and large-scale storage of renewable energy.
A Comparative Technoeconomic Analysis of Renewable Hydrogen Production Using Solar Energy
May 2016
Publication
A technoeconomic analysis of photoelectrochemical (PEC) and photovoltaic-electrolytic (PV-E) solar-hydrogen production of 10 000 kg H2 day−1 (3.65 kilotons per year) was performed to assess the economics of each technology and to provide a basis for comparison between these technologies as well as within the broader energy landscape. Two PEC systems differentiated primarily by the extent of solar concentration (unconcentrated and 10× concentrated) and two PV-E systems differentiated by the degree of grid connectivity (unconnected and grid supplemented) were analyzed. In each case a base-case system that used established designs and materials was compared to prospective systems that might be envisioned and developed in the future with the goal of achieving substantially lower overall system costs. With identical overall plant efficiencies of 9.8% the unconcentrated PEC and non-grid connected PV-E system base-case capital expenses for the rated capacity of 3.65 kilotons H2 per year were $205 MM ($293 per m2 of solar collection area (mS−2) $14.7 WH2P−1) and $260 MM ($371 mS−2 $18.8 WH2P−1) respectively. The untaxed plant-gate levelized costs for the hydrogen product (LCH) were $11.4 kg−1 and $12.1 kg−1 for the base-case PEC and PV-E systems respectively. The 10× concentrated PEC base-case system capital cost was $160 MM ($428 mS−2 $11.5 WH2P−1) and for an efficiency of 20% the LCH was $9.2 kg−1. Likewise the grid supplemented base-case PV-E system capital cost was $66 MM ($441 mS−2 $11.5 WH2P−1) and with solar-to-hydrogen and grid electrolysis system efficiencies of 9.8% and 61% respectively the LCH was $6.1 kg−1. As a benchmark a proton-exchange membrane (PEM) based grid-connected electrolysis system was analyzed. Assuming a system efficiency of 61% and a grid electricity cost of $0.07 kWh−1 the LCH was $5.5 kg−1. A sensitivity analysis indicated that relative to the base-case increases in the system efficiency could effect the greatest cost reductions for all systems due to the areal dependencies of many of the components. The balance-of-systems (BoS) costs were the largest factor in differentiating the PEC and PV-E systems. No single or combination of technical advancements based on currently demonstrated technology can provide sufficient cost reductions to allow solar hydrogen to directly compete on a levelized cost basis with hydrogen produced from fossil energy. Specifically a cost of CO2 greater than ∼$800 (ton CO2)−1 was estimated to be necessary for base-case PEC hydrogen to reach price parity with hydrogen derived from steam reforming of methane priced at $12 GJ−1 ($1.39 (kg H2)−1). A comparison with low CO2 and CO2-neutral energy sources indicated that base-case PEC hydrogen is not currently cost-competitive with electrolysis using electricity supplied by nuclear power or from fossil-fuels in conjunction with carbon capture and storage. Solar electricity production and storage using either batteries or PEC hydrogen technologies are currently an order of magnitude greater in cost than electricity prices with no clear advantage to either battery or hydrogen storage as of yet. Significant advances in PEC technology performance and system cost reductions are necessary to enable cost-effective PEC-derived solar hydrogen for use in scalable grid-storage applications as well as for use as a chemical feedstock precursor to CO2-neutral high energy-density transportation fuels. Hence such applications are an opportunity for foundational research to contribute to the development of disruptive approaches to solar fuels generation systems that can offer higher performance at much lower cost than is provided by current embodiments of solar fuels generators. Efforts to directly reduce CO2 photoelectrochemically or electrochemically could potentially produce products with higher value than hydrogen but many as yet unmet challenges include catalytic efficiency and selectivity and CO2 mass transport rates and feedstock cost. Major breakthroughs are required to obtain viable economic costs for solar hydrogen production but the barriers to achieve cost-competitiveness with existing large-scale thermochemical processes for CO2 reduction are even greater.
Towards Climate Resilient Urban Energy Systems: A Review
Jun 2020
Publication
Climate change and increased urban population are two major concerns for society. Moving towards more sustainable energy solutions in the urban context by integrating renewable energy technologies supports decarbonizing the energy sector and climate change mitigation. A successful transition also needs adequate consideration of climate change including extreme events to ensure the reliable performance of energy systems in the long run. This review provides an overview of and insight into the progress achieved in the energy sector to adapt to climate change focusing on the climate resilience of urban energy systems. The state-of-the-art methodology to assess impacts of climate change including extreme events and uncertainties on the design and performance of energy systems is described and discussed. Climate resilience is an emerging concept that is increasingly used to represent the durability and stable performance of energy systems against extreme climate events. However it has not yet been adequately explored and widely used as its definition has not been clearly articulated and assessment is mostly based on qualitative aspects. This study reveals that a major limitation in the state-of-the-art is the inadequacy of climate change adaptation approaches in designing and preparing urban energy systems to satisfactorily address plausible extreme climate events. Furthermore the complexity of the climate and energy models and the mismatch between their temporal and spatial resolutions are the major limitations in linking these models. Therefore few studies have focused on the design and operation of urban energy infrastructure in terms of climate resilience. Considering the occurrence of extreme climate events and increasing demand for implementing climate adaptation strategies the study highlights the importance of improving energy system models to consider future climate variations including extreme events to identify climate resilient energy transition pathways.
Recent Progress in Ammonia Fuel Cells and their Potential Applications
Nov 2020
Publication
Conventional technologies are largely powered by fossil fuel exploitation and have ultimately led to extensive environmental concerns. Hydrogen is an excellent carbon-free energy carrier but its storage and long-distance transportation remain big challenges. Ammonia however is a promising indirect hydrogen storage medium that has well-established storage and transportation links to make it an accessible fuel source. Moreover the notion of ‘green ammonia’ synthesised from renewable energy sources is an emerging topic that may open significant markets and provide a pathway to decarbonise a variety of applications reliant on fossil fuels. Herein a comparative study based on the chosen design working principles advantages and disadvantages of direct ammonia fuel cells is summarised. This work aims to review the most recent advances in ammonia fuel cells and demonstrates how close this technology type is to integration with future applications. At present several challenges such as material selection NOx formation CO2 tolerance limited power densities and long term stability must still be overcome and are also addressed within the contents of this review.
Electric and Hydrogen Buses: Shifting from Conventionally Fuelled Cars in the UK
May 2020
Publication
For the UK to meet their national target of net zero emissions as part of the central Paris Agreement target further emphasis needs to be placed on decarbonizing public transport and moving away from personal transport (conventionally fuelled vehicles (CFVs) and electric vehicles (EVs)). Electric buses (EBs) and hydrogen buses (HBs) have the potential to fulfil requirements if powered from low carbon renewable energy sources.
A comparison of carbon dioxide (CO2) emissions produced from conventionally fuelled buses (CFB) EBs and HBs between 2017 and 2050 under four National Grid electricity scenarios was conducted. In addition emissions per person at different vehicle capacity levels (100% 75% 50% and 25%) were projected for CFBs HBs EBs and personal transport assuming a maximum of 80 passengers per bus and four per personal vehicle.
Results indicated that CFVs produced 30 g CO2km−1 per person compared to 16.3 g CO2 km−1 per person by CFBs by 2050. At 100% capacity under the two-degree scenario CFB emissions were 36 times higher than EBs 9 times higher than HBs and 12 times higher than EVs in 2050. Cumulative emissions under all electricity scenarios remained lower for EBs and HBs.
Policy makers need to focus on encouraging a modal shift from personal transport towards sustainable public transport primarily EBs as the lowest level emitting vehicle type. Simple electrification of personal vehicles will not meet the required targets. Simultaneously CFBs need to be replaced with EBs and HBs if the UK is going to meet emission targets.
A comparison of carbon dioxide (CO2) emissions produced from conventionally fuelled buses (CFB) EBs and HBs between 2017 and 2050 under four National Grid electricity scenarios was conducted. In addition emissions per person at different vehicle capacity levels (100% 75% 50% and 25%) were projected for CFBs HBs EBs and personal transport assuming a maximum of 80 passengers per bus and four per personal vehicle.
Results indicated that CFVs produced 30 g CO2km−1 per person compared to 16.3 g CO2 km−1 per person by CFBs by 2050. At 100% capacity under the two-degree scenario CFB emissions were 36 times higher than EBs 9 times higher than HBs and 12 times higher than EVs in 2050. Cumulative emissions under all electricity scenarios remained lower for EBs and HBs.
Policy makers need to focus on encouraging a modal shift from personal transport towards sustainable public transport primarily EBs as the lowest level emitting vehicle type. Simple electrification of personal vehicles will not meet the required targets. Simultaneously CFBs need to be replaced with EBs and HBs if the UK is going to meet emission targets.
Electrocatalyst Derived from NiCu–MOF Arrays on Graphene Oxide Modified Carbon Cloth for Water Splitting
Apr 2022
Publication
Electrocatalysts are capable of transforming water into hydrogen oxygen and therefore into energy in an environmentally friendly and sustainable manner. However the limitations in the research of high performance catalysts act as an obstructer in the development of using water as green energy. Here we report on a delicate method to prepare novel bimetallic metal organic framework derived electrocatalysts (C–NiCu–BDC–GO–CC) using graphene oxide (GO) modified carbon cloth as a 3D flexible and conductive substrate. The resultant electrocatalyst C–NiCu–BDC– GO–CC exhibited very low electron transfer resistance which benefited from its extremely thin 3D sponge-like morphology. Furthermore it showed excellent oxygen evolution reaction (OER) activity achieving 10 mA/cm2 at a low overpotential of 390 mV in 1 M KOH electrolyte with a remarkable durability of 10 h.
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