Applications & Pathways
Are We Building Back Better? Evidence from 2020 and Pathways for Inclusive Green Recovery Spending
Mar 2021
Publication
COVID-19 has led to a global crisis threatening the lives and livelihoods of the most vulnerable by increasing poverty exacerbating inequalities and damaging long-term economic growth prospects. The report Are We Building Back Better? Evidence from 2020 and Pathways for Inclusive Green Recovery Spending provides an analysis of over 3500 fiscal policies announced by leading economies in 2020 and calls for governments to invest more sustainably and tackle inequalities as they stimulate growth in the wake of the devastation wrought by the pandemic.
Extremely Halophilic Biohydrogen Producing Microbial Communities from High-Salinity Soil and Salt Evaporation Pond
Jun 2021
Publication
Extreme halophiles offer the advantage to save on the costs of sterilization and water for biohydrogen production from lignocellulosic waste after the pretreatment process with their ability to withstand extreme salt concentrations. This study identifies the dominant hydrogen-producing genera and species among the acclimatized extremely halotolerant microbial communities taken from two salt-damaged soil locations in Khon Kaen and one location from the salt evaporation pond in Samut Sakhon Thailand. The microbial communities’ V3–V4 regions of 16srRNA were analyzed using high-throughput amplicon sequencing. A total of 345 operational taxonomic units were obtained and the high-throughput sequencing confirmed that Firmicutes was the dominant phyla of the three communities. Halanaerobium fermentans and Halanaerobacter lacunarum were the dominant hydrogen-producing species of the communities. Spatial proximity was not found to be a determining factor for similarities between these extremely halophilic microbial communities. Through the study of the microbial communities strategies can be developed to increase biohydrogen molar yield.
Innovating Transport Across Australia: Inquiry into Automated Mass Transit
Mar 2019
Publication
Automated and electric mass transit will play a significant role in the connectivity of our cities and regions. But automated mass transit must be placed within the wider context of the optimum transport needs of those cities and regions— transport networks based on shared and multi-modal mobility. Realising the full potential of these networks will require sustained policy development and investment.<br/>This report examines current and future developments in the use of automation and new energy sources in land-based mass transit including rail and road mass transit point-to-point transport using automated vehicles and the role and responsibilities of the Commonwealth in the development of these technologies. It will analyse the opportunities and challenges presented by automation and new energy sources and the role the Australian Government has to play in managing this transport revolution.
Development and Operation Modes of Hydrogen Fuel Cell Generation System for Remote Consumers’ Power Supply
Aug 2021
Publication
At the present stage of electric power industry development special attention is being paid to the development and research of new efficient energy sources. The use of hydrogen fuel cells is promising for remote autonomous power supply systems. The authors of the paper have developed the structure and determined the optimal composition of a hybrid generation system based on hydrogen fuel cells and battery storage and have conducted studies of its operating modes and for remote consumers’ power supply efficiency. A simulation of the electromagnetic processes was carried out to check the operability of the proposed hybrid generation system structure. The simulation results confirmed the operability of the structure under consideration the calculation of its parameters reliability and the high quality of the output voltage. The electricity cost of a hybrid generation system was estimated according to the LCOE (levelized cost of energy) indicator its value being 1.17 USD/kWh. The factors influencing the electricity cost of a hydrogen generation system have been determined and ways for reducing its cost identified.
Integration Design and Operation Strategy of Multi-Energy Hybrid System Including Renewable Energies, Batteries and Hydrogen
Oct 2020
Publication
In some areas the problem of wind and solar power curtailment is prominent. Hydrogen energy has the advantage of high storage density and a long storage time. Multi-energy hybrid systems including renewable energies batteries and hydrogen are designed to solve this problem. In order to reduce the power loss of the converter an AC-DC hybrid bus is proposed. A multi-energy experiment platform is established including a wind turbine photovoltaic panels a battery an electrolyzer a hydrogen storage tank a fuel cell and a load. The working characteristics of each subsystem are tested and analyzed. The multi-energy operation strategy is based on state monitoring and designed to enhance hydrogen utilization energy efficiency and reliability of the system. The hydrogen production is guaranteed preferentially and the load is reliably supplied. The system states are monitored such as the state of charge (SOC) and the hydrogen storage level. The rated and ramp powers of the battery and fuel cell and the pressure limit of the hydrogen storage tank are set as safety constraints. Eight different operation scenarios comprehensively evaluate the system’s performance and via physical experiments the proposed operation strategy of the multi-energy system is verified as effective and stable.
Review of the Hydrogen Permeability of the Liner Material of Type IV On-Board Hydrogen Storage Tank
Aug 2021
Publication
The hydrogen storage tank is a key parameter of the hydrogen storage system in hydrogen fuel cell vehicles (HFCVs) as its safety determines the commercialization of HFCVs. Compared with other types the type IV hydrogen storage tank which consists of a polymer liner has the advantages of low cost lightweight and low storage energy consumption but meanwhile higher hydrogen permeability. A detailed review of the existing research on hydrogen permeability of the liner material of type IV hydrogen storage tanks can improve the understanding of the hydrogen permeation mechanism and provide references for following-up researchers and research on the safety of HFCVs. The process of hydrogen permeation and test methods are firstly discussed in detail. This paper then analyzes the factors that affect the process of hydrogen permeation and the barrier mechanism of the liner material and summarizes the prediction models of gas permeation. In addition to the above analysis and comments future research on the permeability of the liner material of the type IV hydrogen storage tank is prospected.
The Dawn of Hydrogen - Fuel of the Future
Aug 2021
Publication
This is a time of enormous change for the gas industry as the UK and the world at large attempts to meet the challenges of decarbonisation in the face of climate change. Hydrogen is expected to play a vital role in achieving the government’s commitment of eliminating the UK’s contribution to climate change by 2050 with the industry creating up to 8000 jobs by 2030 and potentially unlocking up to 100000 jobs by the middle of the century. But despite the UK government’s huge ambitions hydrogen is just one piece of the puzzle and it will be necessary to seek solutions that bring the whole energy system together – including not just heat for buildings but hard-to decarbonise areas such as manufacturing road transport aviation and shipping. Here we bring you just a taste of some of the amazing work taking place across the energy sector to understand this fuel more clearly to comprehend its strengths and limitations and to integrate it into our current energy infrastructure. We hope you enjoy this special publication.
The Potential Role of Ammonia as Marine Fuel—Based on Energy Systems Modeling and Multi-Criteria Decision Analysis
Apr 2020
Publication
To reduce the climate impact of shipping the introduction of alternative fuels is required. There is a range of different marine fuel options but ammonia a potential zero carbon fuel has recently received a lot of attention. The purpose of this paper is to assess the prospects for ammonia as a future fuel for the shipping sector in relation to other marine fuels. The assessment is based on a synthesis of knowledge in combination with: (i) energy systems modeling including the cost-effectiveness of ammonia as marine fuel in relation to other fuels for reaching global climate targets; and (ii) a multi-criteria decision analysis (MCDA) approach ranking marine fuel options while considering estimated fuel performance and the importance of criteria based on maritime stakeholder preferences. In the long-term and to reach global GHG reduction the energy systems modeled indicate that the use of hydrogen represents a more cost-effective marine fuel option than ammonia. However in the MCDA covering more aspects we find that ammonia may be almost as interesting for shipping related stakeholders as hydrogen and various biomass-based fuels. Ammonia may to some extent be an interesting future marine fuel option but many issues remain to be solved before large-scale introduction.
Optimal Sizing of Storage Elements for a Vehicle Based on Fuel Cells, Supercapacitors, and Batteries
Mar 2019
Publication
To achieve a vehicle-efficient energy management system an architecture composed of a PEM fuel cell as the main energy source and a hybrid storage system based on battery banks and supercapacitors is proposed. This paper introduces a methodology for the optimal component sizing aiming at minimizing the total cost achieving a cheaper system that can achieve the requirements of the speed profiles. The chosen vehicle is an urban transport bus which must meet the Buenos Aires Driving Cycle and the Manhattan Driving Cycle. The combination of batteries and supercapacitors allows a better response to the vehicle’s power demand since it combines the high energy density of the batteries with the high power density of the supercapacitors allowing the best absorption of energy coming from braking. In this way we address the rapid changes in power without reducing the global efficiency of the system. Optimum use of storage systems and fuel cell is analyzed through dynamic programming.
Comprehensive Performance Evaluation of Densified Liquid Hydrogen/Liquid Oxygen as Propulsion Fuel
Jan 2022
Publication
Densified liquid hydrogen/liquid oxygen is a promising propulsion fuel in the future. In order to systematically demonstrate the benefits and challenges of densified liquid hydrogen/liquid oxygen a transient thermodynamical model considering the heat leakage temperature rise engine thrust pressurization pressure of the tank and wall thickness of tank is developed in the present paper and the performance of densified liquid hydrogen/liquid oxygen as propulsion fuel is further evaluated in actual application. For liquid hydrogen/liquid oxygen tanks at different structural dimensions the effects of many factors such as temperature rise during propellant ground parking lift of engine thrust mass reduction of the tank structure and extension of spacecraft in‐orbit time are analyzed to demonstrate the comprehensive performance of liquid hydrogen/liquid oxygen after densification. Meanwhile the problem of subcooling combination matching of liquid hydro‐ gen/liquid oxygen is proposed for the first time. Combining the fuel consumption and engine thrust lifting the subcooling combination matching of liquid hydrogen/liquid oxygen at different mixing ratios and constant mixing ratios are discussed respectively. The results show that the relative engine thrust enhances by 6.96% compared with the normal boiling point state in the condition of slush hydrogen with 50% solid content and enough liquid oxygen. The in‐orbit time of spacecraft can extend about 2–6.5 days and 24–95 days for slush hydrogen with 50% solid content and liquid oxygen in the triple point state in different cryogenic tanks respectively. Due to temperature rise during parking the existing adiabatic storage scheme and filling scheme for densification LH2 need to be redesigned and for densification LO2 are suitable. It is found that there is an optimal subcooling matching relation after densification of liquid hydrogen/liquid oxygen as propulsion fuel. In other words the subcooling temperature of liquid hydrogen/liquid oxygen is not the lower the bet‐ ter but the matching relationship between LH2 subcooling degree and LO2 subcooling degree needs to be considered at the same time. It is necessary that the LO2 was cooled to 69.2 K and 54.5 K when the LH2 of 13.9 K and SH2 with 45% was adopted respectively. This research provides theoretical support for the promotion and application of densification cryogenic propellants.
Problems of Hydrogen Doping in the Methane Fermentation Process and of Energetic Use of the Gas Mixture
Jul 2021
Publication
This article discusses the technology for doping hydrogen into the fermenter to increase methane production and the amount of energy in the mixture. Hydrogen doping is anticipated to enable more carbon to be applied to produce methane. Hydrogen is proposed to be produced by using excess electricity from for example off-peak electricity hours at night. The possibilities of using a mixture of hydrogen and biogas for combustion in boilers and internal combustion engines have been determined. It has been proven that the volumetric addition of hydrogen reduces the heat of combustion of the mixture. Problems arising from hydrogen doping during the methane fermentation process have been identified.
Models of Delivery of Sustainable Public Transportation Services in Metropolitan Areas–Comparison of Conventional, Battery Powered and Hydrogen Fuel-Cell Drives
Nov 2021
Publication
The development of public transport systems is related to the implementation of modern and low-carbon vehicles. Over the last several years there has been a clear progress in this field. The number of electric buses has increased and the first solutions in the area of hydrogen fuel cells have been implemented. Unfortunately the implementation of these technologies is connected with significant financial expenditure. The goal of the article is the analysis of effectiveness of financial investment consisting in the purchase of 30 new public transport buses (together with the necessary infrastructure–charging stations). The analysis has been performed using the NPV method for the period of 10 years. Discount rate was determined on 4% as recommended by the European Commission for this type of project. It is based on the case study of the investment project carried out by Metropolis GZM in Poland. The article determines and compares the efficiency ratios for three investment options-purchase of diesel-powered battery-powered and hydrogen fuel-cell electric vehicles. The results of the analysis indicate that the currently high costs of vehicle purchase and charging infrastructure are a significant barrier for the implementation of battery-powered and hydrogen fuel-cell buses. In order to meet the transport policy goals related to the exchange of traditional bus stock to more eco-friendly vehicles it is necessary to involve public funds for the purpose of financing the investment activities.
An Integrated Hydrogen Fuel Cell to Distribution Network System: Challenging and Opportunity for D-STATCOM
Oct 2021
Publication
The electric power industry sector has become increasingly aware of how counterproductive voltage sag affects distribution network systems (DNS). The voltage sag backfires disastrously at the demand load side and affects equipment in DNS. To settle the voltage sag issue this paper achieved its primary purpose to mitigate the voltage sag based on integrating a hydrogen fuel cell (HFC) with the DNS using a distribution static synchronous compensator (D-STATCOM) system. Besides this paper discusses the challenges and opportunities of D-STATCOM in DNS. In this paper using HFC is well-designed modeled and simulated to mitigate the voltage sag in DNS with a positive impact on the environment and an immediate response to the issue of the injection of voltage. Furthermore this modeling and controller are particularly suitable in terms of cost-effectiveness as well as reliability based on the adaptive network fuzzy inference system (ANFIS) fuzzy logic system (FLC) and proportional–integral (P-I). The effectiveness of the MATLAB simulation is confirmed by implementing the system and carrying out a DNS connection obtaining efficiencies over 94.5% at three-phase fault for values of injection voltage in HFC D-STATCOM using a P-I controller. Moreover the HFC D-STATCOM using FLC proved capable of supporting the network by 97.00%. The HFC D-STATCOM based ANFIS proved capable of supporting the network by 98.00% in the DNS.
The Role of Electrofuels under Uncertainties for the Belgian Energy Transition
Jul 2021
Publication
Wind and solar energies present a time and space disparity that generally leads to a mismatch between the demand and the supply. To harvest their maximum potentials one of the main challenges is the storage and transport of these energies. This challenge can be tackled by electrofuels such as hydrogen methane and methanol. They offer three main advantages: compatibility with existing distribution networks or technologies of conversion economical storage solution for high capacity and ability to couple sectors (i.e. electricity to transport to heat or to industry). However the level of contribution of electric-energy carriers is unknown. To assess their role in the future we used whole-energy system modelling (EnergyScope Typical Days) to study the case of Belgium in 2050. This model is multi-energy and multi-sector. It optimises the design of the overall system to minimise its costs and emissions. Such a model relies on many parameters (e.g. price of natural gas efficiency of heat pump) to represent as closely as possible the future energy system. However these parameters can be highly uncertain especially for long-term planning. Consequently this work uses the polynomial chaos expansion method to integrate a global sensitivity analysis in order to highlight the influence of the parameters on the total cost of the system. The outcome of this analysis points out that compared to the deterministic cost-optimum situation the system cost accounting for uncertainties becomes higher (+17%) and twice more uncertain at carbon neutrality and that electrofuels are a major contribution to the uncertainty (up to 53% in the variation of the costs) due to their importance in the energy system and their high uncertainties their higher price and uncertainty.
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.
Combustion Characteristics of Diesel-hydrogen Dual Fuel Engine at Low Load
May 2013
Publication
In the present study hydrogen utilization as diesel engine fuel at low load operation was investigated. Hydrogen cannot be used directly in a diesel engine due to its auto ignition temperature higher than that of diesel fuel. One alternative method is to use hydrogen in enrichment or induction. To investigate the combustion characteristics of this dual fuel engine a single cylinder diesel research engine was converted to utilize hydrogen as fuel. Hydrogen was introduced to the intake manifold using a mixer before entering the combustion chamber. The engine was run at a constant speed of 2000 rpm and 10 Nm load. Hydrogen was introduced at the flow rate of 21.4 36.2 and 49.6 liter/minute. Specific energy consumption indicated efficiency and cylinder pressure were investigated. At this low load the hydrogen enrichment reduced the cylinder peak pressure and the engine efficiency. The reaction progress variable and combustion rate of reaction were slower as shown by the CFD calculation.
Total Cost of Ownership and Its Potential Consequences for the Development of the Hydrogen Fuel Cell Powered Vehicle Market in Poland
Apr 2021
Publication
Electromobility is a growing technology for land transport constituting an important element of the concept of sustainable economic development. The article presents selected research results concerning one of the segments of this market-vehicles powered by hydrogen fuel cells. The subject of the research was to gain extensive knowledge on the economic factors influencing the future purchasing decisions of the demand side in relation to this category of vehicles. The research was based on a numerical experiment. For this purpose a comparative analysis of purchase prices in relation to the TCO of the vehicle after 3–5 years of use was performed. The research included selected models that are powered by both conventional and alternative fuels. The use of this method will allow to assess the real costs associated with the hydrogen vehicle. The authors emphasize the important role of economic factors in the form of the TCO index for the development of this market. The experimental approach may be helpful in understanding the essence of economic relations that affect the development of the electro-mobility market and the market demand for hydrogen fuel cell-powered vehicles in Poland.
Demand Side Management Based Power-to-Heat and Power-to-Gas Optimization Strategies for PV and Wind Self-Consumption in a Residential Building Cluster
Oct 2021
Publication
The volatility of renewable energy sources (RES) poses a growing problem for operation of electricity grids. In contrary the necessary decarbonisation of sectors such as heat supply and transport requires a rapid expansion of RES. Load management in the context of power-to-heat systems can help to simultaneously couple the electricity and heat sectors and stabilise the electricity grid thus enabling a higher share of RES. In addition power-to-hydrogen offers the possibility of long-term energy storage options. Within this work we present a novel optimization approach for heat pump operation with the aim to counteract the volatility and enable a higher usage of RES. For this purpose a detailed simulation model of buildings and their energy supply systems is created calibrated and validated based on a plus energy settlement. Subsequently the potential of optimized operation is determined with regard to PV and small wind turbine self-consumption. In addition the potential of seasonal hydrogen storage is examined. The results show that on a daily basis a 33% reduction of electricity demand from grid is possible. However the average optimization potential is reduced significantly by prediction inaccuracy. The addition of a hydrogen system for seasonal energy storage basically eliminates the carbon dioxide emissions of the cluster. However this comes at high carbon dioxide prevention costs of 1.76 e kg−1 .
A Review of the Latest Trends in the Use of Green Ammonia as an Energy Carrier in Maritime Industry
Feb 2022
Publication
This review paper examines the key barriers to using green ammonia as an alternative fuel in maritime industry. A literature survey is performed based on research articles and grey literature with the aim of discussing the technoeconomic problems with and benefits of ammonia and the relevant technologies. The limitations of ammonia as a maritime fuel and its supply chain the expected percentage demand by 2030 and 2050 its economic performance compared to other shipping fuels such as hydrogen and the current regulations that may impact ammonia as a maritime fuel are discussed. There are several key barriers to ammonia’s wide adoption: (1) High production costs due to the high capital costs associated with ammonia’s supply chain; (2) availability specifically the limited geographical locations available for ammonia bunkering; (3) the challenge of ramping up current ammonia production; and (4) the development of ammonia-specific regulations addressing issues such as toxicity safety and storage. The general challenges involved with blue ammonia are the large energy penalty and associated operational costs and a lack of technical expertise on its use. Regardless of the origin for ammonia to be truly zero-carbon its whole lifecycle must be considered—a key challenge that will aid in the debate about whether ammonia holds promise as a zero-carbon maritime fuel.
Spatially Resolved Model for Studying Decarbonisation Pathways for Heat Supply and Infrastructure Trade-offs
Jun 2017
Publication
Heat decarbonisation is one of the main challenges of energy system decarbonisation. However existing energy planning models struggle to compare heat decarbonisation approaches because they rarely capture trade-offs between heat supply end-use technologies and network infrastructure at sufficient spatial resolution. A new optimisation model is presented that addresses this by including trade-offs between gas electricity and heat infrastructure together with related supply and end-use technologies with high spatial granularity. The model is applied in case studies for the UK. For the case modelled it is shown that electrification of heat is most cost-effective via district level heat pumps that supply heat networks instead of individual building heat pumps. This is because the cost of reinforcing the electricity grid for installing individual heat pumps does not sufficiently offset heat infrastructure costs. This demonstrates the importance of considering infrastructure trade-offs. When modelling the utilisation of a decarbonised gas the penetration of heat networks and location of district level heat supply technologies was shown to be dependent on linear heat density and on zone topology. This shows the importance of spatial aspects. Scenario-specific linear heat density thresholds for heat network penetration were identified. For the base case penetration of high temperature heat networks was over 50% and 60% by 2050 for linear heat densities over 1500 and 2500 kWh/m. For the case when medium heat temperature networks were additionally available a mix of both networks was observed. Medium temperature heat network penetration was over 20% 30% and 40% for linear heat densities of over 1500 2500 and 3000 kWh/m while high temperature heat network penetration was over 20% and 30% for linear heat densities of under 2000 and 1500 kWh/m respectively.
The Role of Renewable Hydrogen and Inter-seasonal Storage in Decarbonising Heat – Comprehensive Optimisation of Future Renewable Energy Value Chains
Nov 2018
Publication
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.
Controlled Autoignition of Hydrogen in a Direct-injection Optical Engine
Mar 2021
Publication
Research into novel internal combustion engines requires consideration of the diversity in future fuels in an attempt to reduce drastically CO2 emissions from vehicles and promote energy sustainability. Hydrogen has been proposed as a possible fuel for future internal combustion engines and can be produced from renewable sources. Hydrogen’s wide flammability range allows higher engine efficiency than conventional fuels with both reduced toxic emissions and no CO2 gases. Most previous work on hydrogen engines has focused on spark-ignition operation. The current paper presents results from an optical study of controlled autoignition (or homogeneous charge compression ignition) of hydrogen in an engine of latest spark-ignition pentroof combustion chamber geometry with direct injection of hydrogen (100 bar). This was achieved by a combination of inlet air preheating in the range 200–400 C and residual gas recirculated internally by negative valve overlap. Hydrogen fuelling was set to various values of equivalence ratio typically in the range / = 0.40–0.63. Crank-angle resolved flame chemiluminescence images were acquired for a series of consecutive cycles at 1000 RPM in order to calculate in-cylinder rates of flame expansion and motion. Planar Laser Induced Fluorescence (LIF) of OH was also applied to record more detailed features of the autoignition pattern. Single and double (i.e. ‘split’ per cycle) hydrogen injection strategies were employed in order to identify the effect of mixture preparation on autoignition’s timing and spatial development. An attempt was also made to review relevant in-cylinder phenomena from the limited literature on hydrogen-fuelled spark-ignition optical engines and make comparisons were appropriate.
Preliminary Design of a Self-Sufficient Electrical Storage System Based on Electrolytic Hydrogen for Power Supply in a Residential Application
Oct 2021
Publication
The use of renewable energy and hydrogen technology is a sustainable solution for the intermittent feature of renewable energies. Hence the aim of the present work is to design a self-sufficient system for a one-family house by coupling a solar photovoltaic array and an anion exchange membrane water electrolyzer (AEMWE). The first step is the selection of the photovoltaic panel by using PV-SYST 7.0 software. Then the hydrogen production system is calculated by coupling the electrolyzer and photovoltaic panel current–potential curves. A fuel cell is selected to use the hydrogen produced when solar energy is not available. Finally the hydrogen storage tank is also estimated to store hydrogen for a design basis of four consecutive cloudy days according to the hydrogen consumption of the fuel cell. The whole system is designed by a simple procedure for a specific location in Ciudad Real (Spain) for January which is known as the coldest month of the year. The simple procedure described in this work could be used elsewhere and demonstrated that the hydrogen production at low scale is a suitable technology to use renewable energy for self-energy supporting in a residential application without any connection to the grid.
Recent Combustion Strategies in Gas Turbines for Propulsion and Power Generation toward a Zero-Emissions Future: Fuels, Burners, and Combustion Techniques
Oct 2021
Publication
The effects of climate change and global warming are arising a new awareness on the impact of our daily life. Power generation for transportation and mobility as well as in industry is the main responsible for the greenhouse gas emissions. Indeed currently 80% of the energy is still produced by combustion of fossil fuels; thus great efforts need to be spent to make combustion greener and safer than in the past. For this reason a review of the most recent gas turbines combustion strategy with a focus on fuels combustion techniques and burners is presented here. A new generation of fuels for gas turbines are currently under investigation by the academic community with a specific concern about production and storage. Among them biofuels represent a trustworthy and valuable solution in the next decades during the transition to zero carbon fuels (e.g. hydrogen and ammonia). Promising combustion techniques explored in the past and then abandoned due to their technological complexity are now receiving renewed attention (e.g. MILD PVC) thanks to their effectiveness in improving the efficiency and reducing emissions of standard gas turbine cycles. Finally many advances are illustrated in terms of new burners developed for both aviation and power generation. This overview points out promising solutions for the next generation combustion and opens the way to a fast transition toward zero emissions power generation.
Boosting Carbon Efficiency of the Biomass to Liquid Process with Hydrogen from Power: The Effect of H2/CO Ratio to the Fischer-Tropsch Reactors on the Production and Power Consumption
Jun 2019
Publication
Carbon efficiency of a biomass to liquid process can be increased from ca. 30 to more than 90% by adding hydrogen generated from renewable power. The main reason is that in order to increase the H2/CO ratio after gasification to the value required for Fischer-Tropsch (FT) synthesis the water gas shift reaction step can be avoided; instead a reversed water gas shift reactor is introduced to convert produced CO2 to CO. Process simulations are done for a 46 t/h FT biofuel production unit. Previous results are confirmed and it is shown how the process can be further improved. The effect of changing the H2/CO ratio to the Fischer-Tropsch synthesis reactors is studied with the use of three different kinetic models. Keeping the CO conversion in the reactors constant at 55% the volume of the reactors decreases with increasing H2/CO ratio because the reaction rates increase with the partial pressure of hydrogen. Concurrently the production of C5+ products and the consumption of hydrogen increases. However the power required per extra produced liter fuel also increases pointing at optimum conditions at a H2/CO feed ratio significantly lower than 2. The trends are the same for all three kinetic models although one of the models is less sensitive to the hydrogen partial pressure. Finally excess renewable energy can be transformed to FT syncrude with an efficiency of 0.8–0.88 on energy basis.
Thermodynamic and Ecological Preselection of Synthetic Fuel Intermediates from Biogas at Farm Sites
Jan 2020
Publication
Background: Synthetic fuels based on renewable hydrogen and CO2 are a currently highly discussed piece of the puzzle to defossilize the transport sector. In this regard CO2 can play a positive role in shaping a sustainable future. Large potentials are available as a product of biogas production however occurring in small scales and in thin spatial distributions. This work aims to evaluate suitable synthetic fuel products to be produced at farm sites.<br/>Methods: A thermodynamic analysis to assess the energetic efficiency of synthesis pathways and a qualitative assessment of product handling issues is carried out.<br/>Results: Regarding the technical and safety-related advantages in storage liquid products are the superior option for fuel production at decentralized sites. Due to the economy of scale multi-stage synthesis processes lose economic performance with rising complexity. A method was shown which covers a principle sketch of all necessary reaction separation steps and all compression and heat exchanger units. The figures showed that methanol and butanol are the most suitable candidates in contrast to OME3-5 for implementation in existing transportation and fuel systems. These results were underpin by a Gibbs energy analysis.<br/>Conclusions: As long as safety regulations are met and the farm can guarantee safe storage and transport farm-site production for all intermediates can be realized technically. Ultimately this work points out that the process must be kept as simple as possible favoring methanol production at farm site and its further processing to more complicated fuels in large units for several fuel pathways.
Varying Load Distribution Impacts on the Operation of a Hydrogen Generator Plant
Oct 2021
Publication
This study advances several methods to evaluate the operation of a hydrogen generator plant. The model developed helps customize plants that contain multiple generators of varying powers using a decision module which determines the most efficient plant load distribution. Evaluation indices to assess individual devices within the plant are proposed and system flexibility maximizes the amount of renewable energy stored. Three case studies examined the variable load distribution of an electrolysis system connected to a 40 MW wind farm for energy storage purposes and incorporated a “night-valley” operational strategy. These methods facilitate the selection of the proper plant configuration and provide estimates for individual device effectiveness within the system.
Improving Carbon Efficiency and Profitability of the Biomass to Liquid Process with Hydrogen from Renewable Power
Aug 2018
Publication
A process where power and biomass are converted to Fischer-Tropsch liquid fuels (PBtL) is compared to a conventional Biomass-to-Liquid (BtL) process concept. Based on detailed process models it is demonstrated that the carbon efficiency of a conventional Biomass to Liquid process can be increased from 38 to more than 90% by adding hydrogen from renewable energy sources. This means that the amount of fuel can be increased by a factor of 2.4 with the same amount of biomass. Electrical power is applied to split water/steam at high temperature over solid oxide electrolysis cells (SOEC). This technology is selected because part of the required energy can be replaced by available heat. The required electrical power for the extra production is estimated to be 11.6 kWh per liter syncrude (C ) 5+ . By operating the SOEC iso-thermally close to 850 °C the electric energy may be reduced to 9.5 kWh per liter which is close to the energy density of jet fuel. A techno-economic analysis is performed where the total investments and operating costs are compared for the BtL and PBtL. With an electrical power price of 0.05 $/kWh and with SOEC investment cost of the 1000 $/kW(el) the levelized cost of producing advanced biofuel with the PBtL concept is 1.7 $/liter which is approximately 30% lower than for the conventional BtL. Converting excess renewable electric power to advanced biofuel in a PBtL plant is a sensible way of storing energy as a fuel with a relatively high energy density.
Challenges and Outlines of Steelmaking toward the Year 2030 and Beyond—Indian Perspective
Oct 2021
Publication
In FY-20 India’s steel production was 109 MT and it is the second-largest steel producer on the planet after China. India’s per capita consumption of steel was around 75 kg which has risen from 59 kg in FY-14. Despite the increase in consumption it is much lower than the average global consumption of 230 kg. The per capita consumption of steel is one of the strongest indicators of economic development across the nation. Thus India has an ambitious plan of increasing steel production to around 250 MT and per capita consumption to around 160 kg by the year 2030. Steel manufacturers in India can be classified based on production routes as (a) oxygen route (BF/BOF route) and (b) electric route (electric arc furnace and induction furnace). One of the major issues for manufacturers of both routes is the availability of raw materials such as iron ore direct reduced iron (DRI) and scrap. To achieve the level of 250 MT steel manufacturers have to focus on improving the current process and product scenario as well as on research and development activities. The challenge to stop global warming has forced the global steel industry to strongly cut its CO2 emissions. In the case of India this target will be extremely difficult by ruling in the production duplication planned by the year 2030. This work focuses on the recent developments of various processes and challenges associated with them. Possibilities and opportunities for improving the current processes such as top gas recycling increasing pulverized coal injection and hydrogenation as well as the implementation of new processes such as HIsarna and other CO2 -lean iron production technologies are discussed. In addition the eventual transition to hydrogen ironmaking and “green” electricity in smelting are considered. By fast-acting improvements in current facilities and brave investments in new carbon-lean technologies the CO2 emissions of the Indian steel industry can peak and turn downward toward carbon-neutral production.
Challenges and Prospects of Renewable Hydrogen-based Strategies for Full Decarbonization of Stationary Power Applications
Oct 2021
Publication
The exponentially growing contribution of renewable energy sources in the electricity mix requires large systems for energy storage to tackle resources intermittency. In this context the technologies for hydrogen production offer a clean and versatile alternative to boost renewables penetration and energy security. Hydrogen production as a strategy for the decarbonization of the energy sources mix has been investigated since the beginning of the 1990s. The stationary sector i.e. all parts of the economy excluding the transportation sector accounts for almost three-quarters of greenhouse gases (GHG) emissions (mass of CO2-eq) in the world associated with power generation. While several publications focus on the hybridization of renewables with traditional energy storage systems or in different pathways of hydrogen use (mainly power-to-gas) this study provides an insightful analysis of the state of art and evolution of renewable hydrogen-based systems (RHS) to power the stationary sector. The analysis started with a thorough review of RHS deployments for power-to-power stationary applications such as in power generation industry residence commercial building and critical infrastructure. Then a detailed evaluation of relevant techno-economic parameters such as levelized cost of energy (LCOE) hydrogen roundtrip efficiency (HRE) loss of power supply probability (LPSP) self-sufficiency ratio (SSR) or renewable fraction (fRES) is provided. Subsequently lab-scale plants and pilot projects together with current market trends and commercial uptake of RHS and fuel cell systems are examined. Finally the future techno-economic barriers and challenges for short and medium-term deployment of RHS are identified and discussed.
A Combined Heat and Green Hydrogen (CHH) Generator Integrated with a Heat Network
Sep 2021
Publication
Combined heat and power (CHP) systems offer high energy efficiencies as they utilise both the electricity generated and any excess heat by co-suppling to local consumers. This work presents the potential of a combined heat and hydrogen (CHH) system a solution where Proton exchange membrane (PEM) electrolysis systems producing hydrogen at 60–70% efficiency also co-supply the excess heat to local heat networks. This work investigates the method of capture and utilisation of the excess heat from electrolysis. The analysed system was able to capture 312 kW of thermal energy per MW of electricity and can deliver it as heated water at either 75 ◦C or 45 ◦C this appropriate for existing district heat networks and lower temperature heat networks respectively. This yields an overall CHH system efficiency of 94.6%. An economic analysis was conducted based on income generated through revenue sales of both hydrogen and heat which resulted in a significant reduction in the Levelized Cost of Hydrogen.
China Progress on Renewable Energy Vehicles: Fuel Cells, Hydrogen and Battery Hybrid Vehicles
Dec 2018
Publication
Clean renewable energy for Chinese cities is a priority in air quality improvement. This paper describes the recent Chinese advances in Polymer Electrolyte Membrane (PEM) hydrogen-fuel-cell-battery vehicles including buses and trucks. Following the 2016 Chinese government plan for new energy vehicles bus production in Foshan has now overtaken that in the EU USA and Japan combined. Hydrogen infrastructure requires much advance to catch up but numbers of filling stations are now increasing rapidly in the large cities. A particular benefit in China is the large number of battery manufacturing companies which fit well into the energy storage plan for hybrid fuel cell buses. The first city to manufacture thousands of PEM-battery hybrid buses is Foshan where the Feichi (Allenbus) company has built a new factory next to a novel fuel cell production line capable of producing 500 MW of fuel cell units per year. Hundreds of these buses are running on local Foshan routes this year while production of city delivery trucks has also been substantial. Results for energy consumption of these vehicles are presented and fitted to the Coulomb theory previously delineated.
The Use of Hydrogen to Separate and Recycle Neodymium–iron–boron-type Magnets from Electronic Waste
May 2015
Publication
The rare earth metals have been identified by the European Union and the United States as being at greatest supply risk of all the materials for clean energy technologies. Of particular concern are neodymium and dysprosium both of which are employed in neodymium–iron–boron based magnets. Recycling of magnets based on these materials and contained within obsolete electronic equipment could provide an additional and secure supply. In the present work hydrogen has been employed as a processing agent to decrepitate sintered neodymium–iron–boron based magnets contained within hard disk drives into a demagnetised hydrogenated powder. This powder was then extracted mechanically from the devices with an extraction efficiency of 90 ± 5% and processed further using a combination of sieves and ball bearings to produce a powder containing <330 parts per million of nickel contamination. It is then possible for the extracted powder to be re-processed in a number of ways namely directly by blending and re-sintering to form fully dense magnets by Hydrogenation Disproportionation Desorption Recombination processing to produce an anisotropic coercive powder suitable for bonded magnets by re-melting; or by chemical extraction of the rare earth elements from the alloy. For example it was shown that by the re-sintering route it was possible to recover >90% of the magnetic properties of the starting material with significantly less energy than that employed in primary magnet production. The particular route used will depend upon the magnetic properties required the level of contamination of the extracted material and the compositional variation of the feedstock. The various possibilities have been summarised in a flow diagram.
Development of a Turnkey Hydrogen Fuelling Station
Jul 2010
Publication
The transition to hydrogen as a fuel source presents several challenges. One of the major hurdles is the cost-effective production of hydrogen in small quantities (less than 1MMscf/month). In the early demonstration phase hydrogen can be provided by bulk distribution of liquid or compressed gas from central production plants; however the next phase to fostering the hydrogen economy will likely include onsite generation and extensive pipeline networks to help effect a pervasive infrastructure. Providing inexpensive hydrogen at a fleet operator’s garage or local fuelling station is a key enabling technology for direct hydrogen Fuel Cell Vehicles (FCVs). The objective of this project was to develop a comprehensive turnkey stand-alone commercial hydrogen fuelling station for FCVs with state-of-the-art technology that is cost-competitive with current hydrocarbon fuels. Such a station would promote the advent of the hydrogen fuel economy for buses fleet vehicles and ultimately personal vehicles. Air Products partnering with the U.S. Department of Energy (DOE) The Pennsylvania State University Harvest Energy Technology and QuestAir developed a turnkey hydrogen fuelling station on the Penn State campus. Air Products aimed at designing a station that would have 65% overall station efficiency 82% PSA (pressure swing adsorption) efficiency and the capability of producing hydrogen at $3.00/kg (gge) H2 at mass production rates. Air Products designed a fuelling station at Penn State from the ground up. This project was implemented in three phases. The first phase evaluated the various technologies available in hydrogen generation compression storage and gas dispensing. In the second phase Air Products designed the components chosen from the technologies examined. Finally phase three entailed a several-month period of data collection full-scale operation maintenance of the station and optimization of system reliability and performance. Based on field data analysis it was determined by a proprietary hydrogen-analysis model that hydrogen produced from the station at a rate of 1500 kg/day and when produced at 1000 stations per year would be able to deliver hydrogen at a price of $3.03/kg (gge) H2. The station’s efficiency was measured to be 65.1% and the PSA was tested and ran at an efficiency of 82.1% thus meeting the project targets. From the study it was determined that more research was needed in the area of hydrogen fuelling. The overall cost of the hydrogen energy station when combined with the required plot size for scaled-up hydrogen demands demonstrated that a station using steam methane reforming technology as a means to produce on–site hydrogen would have limited utility in the marketplace. Alternative hydrogen supplies such as liquid or pipeline delivery to a refuelling station need to be included in the exploration of alternative energy site layouts. These avenues need to be explored before a definitive refuelling station configuration and commercialization pathway can be determined.
Hybrid Electric Powertrain with Fuel Cells for a Series Vehicle
May 2018
Publication
Recent environmental and climate change issues make it imperative to persistently approach research into the development of technologies designed to ensure the sustainability of global mobility. At the European Union level the transport sector is responsible for approximately 28% of greenhouse gas emissions and 84% of them are associated with road transport. One of the most effective ways to enhance the de-carbonization process of the transport sector is through the promotion of electric propulsion which involves overcoming barriers related to reduced driving autonomy and the long time required to recharge the batteries. This paper develops and implements a method meant to increase the autonomy and reduce the battery charging time of an electric car to comparable levels of an internal combustion engine vehicle. By doing so the cost of such vehicles is the only remaining significant barrier in the way of a mass spread of electric propulsion. The chosen method is to hybridize the electric powertrain by using an additional source of fuel; hydrogen gas stored in pressurized cylinders is converted in situ into electrical energy by means of a proton exchange membrane fuel cell. The power generated on board can then be used under the command of a dedicated management system for battery charging leading to an increase in the vehicle’s autonomy. Modeling and simulation results served to easily adjust the size of the fuel cell hybrid electric powertrain. After optimization an actual fuel cell was built and implemented on a vehicle that used the body of a Jeep Wrangler from which the thermal engine associated subassemblies and gearbox were removed. Once completed the vehicle was tested in traffic conditions and its functional performance was established.
The Path to Net Zero and Progress on Reducing Emissions in Wales
Dec 2020
Publication
These two joint reports required under the Environment (Wales) Act 2016 provide ministers with advice on Wales’ climate targets between now and 2050 and assess progress on reducing emissions to date. Our advice to the Welsh Government is set out in two parts:
Advice Report: The path to a Net Zero Wales provides recommendations on the actions that are needed in Wales including the legislation of a Net Zero target and package of policies to deliver it.
Progress Report: Reducing emissions in Wales looks back at the progress made in Wales since the 2016 Environment (Wales) Act was passed and assesses whether Wales is on track to meet its currently legislated emissions reductions targets.
This work is based on an extensive programme of analysis consultation and consideration by the Committee and its staff building on the evidence published last year for our Net Zero report. It is compatible with our advice on the UK’s Sixth Carbon Budget. In support of the advice in this report we have also published:
Advice Report: The path to a Net Zero Wales provides recommendations on the actions that are needed in Wales including the legislation of a Net Zero target and package of policies to deliver it.
Progress Report: Reducing emissions in Wales looks back at the progress made in Wales since the 2016 Environment (Wales) Act was passed and assesses whether Wales is on track to meet its currently legislated emissions reductions targets.
This work is based on an extensive programme of analysis consultation and consideration by the Committee and its staff building on the evidence published last year for our Net Zero report. It is compatible with our advice on the UK’s Sixth Carbon Budget. In support of the advice in this report we have also published:
- All the charts and data behind the report as well as a separate dataset for the scenarios which sets out more details and data on the pathways than can be included in this report.
- A public Call for Evidence several new research projects three expert advisory groups and deep dives into the roles of local authorities and businesses.
Hydrogen Energy Systems: A Critical Review of Technologies, Applications, Trends and Challenges
May 2021
Publication
The global energy transition towards a carbon neutral society requires a profound transformation of electricity generation and consumption as well as of electric power systems. Hydrogen has an important potential to accelerate the process of scaling up clean and renewable energy however its integration in power systems remains little studied. This paper reviews the current progress and outlook of hydrogen technologies and their application in power systems for hydrogen production re-electrification and storage. The characteristics of electrolysers and fuel cells are demonstrated with experimental data and the deployments of hydrogen for energy storage power-to-gas co- and tri-generation and transportation are investigated using examples from worldwide projects. The current techno-economic status of these technologies and applications is presented in which cost efficiency and durability are identified as the main critical aspects. This is also confirmed by the results of a statistical analysis of the literature. Finally conclusions show that continuous efforts on performance improvements scale ramp-up technical prospects and political support are required to enable a cost-competitive hydrogen economy.
An Improved Fuzzy PID Control Method Considering Hydrogen Fuel Cell Voltage-Output Characteristics for a Hydrogen Vehicle Power System
Sep 2021
Publication
The hydrogen fuel cell (HFC) vehicle is an important clean energy vehicle which has prospects for development. The behavior of the hydrogen fuel cell (HFC) vehicle power system and in particular the proton-exchange membrane fuel cell has been extensively studied as of recent. The development of the dynamic system modeling technology is of paramount importance for HFC vehicle studies; however it is hampered by the separation of the electrochemical properties and dynamic properties. In addition the established model matching the follow-up control method lacks applicability. In attempts to counter these obstructions we proposed an improved fuzzy (Proportional Integral Derivative) PID control method considering HFC voltage-output characteristics. By developing both the electrochemical and dynamic model for HFC vehicle we can realize the coordinated control of HFC and power cell. The simulation results are in good agreement with the experimental results in the two models. The proposed control algorithm has a good control effect in all stages of HFC vehicle operation.
Review of IGEM/SR/25 for Use with Hydrogen
Jan 2021
Publication
This report presents the findings of the initial gap analysis and technical review of IGEM/SR/25 undertaken as a collaborative effort between HSE and DNV GL. The review is intended to help understand the steps which would be involved in updating the standard to include data appropriate for installations using H2 or an H2/NG blend. Furthermore the report highlights where additional research and updated data applicable to H2 installations is needed to enable development of an H2-specific supplement to the standard.<br/>A review of alternative approaches for area classification is presented. This review is aimed at determining whether existing standards or guidance provide methodologies which could be used as an alternative to IGEM/SR/25 for area classification of systems using either H2 or H2/NG blends. The review covers IGEM/SR/25 IGE/SR/23 EI15 BCGA guidance BS EN 60079:10:1 (including Quadvent) NFPA 497 API RP 505 and EIGA Doc. 121/14. Some of these are general like the British Standard BS EN 60079-10-1:2015 while others are industry specific like IGEM/SR/25 and EI15.<br/>Consideration is given to the methodology that each area classification approach presents for establishing the zone and zone size with particular focus on how factors such as ventilation and gas buoyancy are accounted for in the methods. The findings of the review indicate that none of the alternative approaches evaluated in the study provide an approach that is suitable for the gas industry for the area classification of gas network installations involving H2 or an H2/NG blend.
Energy Management Strategies for a Zero-emission Hybrid Domestic Ferry
Oct 2021
Publication
The paper presents three approaches for the sizing and control of a maritime hybrid power-plant equipped with proton exchange membrane fuel cells and batteries. The study focuses on three different power-plant configurations including the energy management strategy and the power-plant component sizing. The components sizing is performed following the definition of the energy management strategy using the sequential optimization approach. These configurations are tested using a dynamic model developed in Simulink. The simulations are carried out to validate the technical feasibility of each configuration for maritime use. Each energy management strategy is developed to allow for the optimization of a chosen set of parameters such as hydrogen consumption and fuel cell degradation. It is observed that in the hybrid power-plant optimization there are always trade-offs and the optimization should be carried out by prioritizing primary factors the ship owner considers most important for day-to-day operations.
Linking the Power and Transport Sectors—Part 2: Modelling a Sector Coupling Scenario for Germany
Jul 2017
Publication
“Linking the power and transport sectors—Part 1” describes the general principle of “sector coupling” (SC) develops a working definition intended of the concept to be of utility to the international scientific community contains a literature review that provides an overview of relevant scientific papers on this topic and conducts a rudimentary analysis of the linking of the power and transport sectors on a worldwide EU and German level. The aim of this follow-on paper is to outline an approach to the modelling of SC. Therefore a study of Germany as a case study was conducted. This study assumes a high share of renewable energy sources (RES) contributing to the grid and significant proportion of fuel cell vehicles (FCVs) in the year 2050 along with a dedicated hydrogen pipeline grid to meet hydrogen demand. To construct a model of this nature the model environment “METIS” (models for energy transformation and integration systems) we developed will be described in more detail in this paper. Within this framework a detailed model of the power and transport sector in Germany will be presented in this paper and the rationale behind its assumptions described. Furthermore an intensive result analysis for the power surplus utilization of electrolysis hydrogen pipeline and economic considerations has been conducted to show the potential outcomes of modelling SC. It is hoped that this will serve as a basis for researchers to apply this framework in future to models and analysis with an international focus.
Cost-optimal Reliable Power Generation in a Deep Decarbonisation Future
Jul 2019
Publication
Considering the targets of the Paris agreement rapid decarbonisation of the power system is needed. In order to study cost-optimal and reliable zero and negative carbon power systems a power system model of Western Europe for 2050 is developed. Realistic future technology costs demand levels and generator flexibility constraints are considered. The optimised portfolios are tested for both favourable and unfavourable future weather conditions using results from a global climate model accounting for the potential impacts of climate change on Europe’s weather. The cost optimal mix for zero or negative carbon power systems consists of firm low-carbon capacity intermittent renewable energy sources and flexibility capacity. In most scenarios the amount of low-carbon firm capacity is around 75% of peak load providing roughly 65% of the electricity demand. Furthermore it is found that with a high penetration of intermittent renewable energy sources a high dependence on cross border transmission batteries and a shift to new types of ancillary services is required to maintain a reliable power system. Despite relatively small changes in the total generation from intermittent renewable energy sources between favourable and unfavourable weather years of 6% emissions differ up to 70 MtCO2 yr−1 and variable systems costs up to 25%. In a highly interconnected power system with significant flexible capacity in the portfolio and minimal curtailment of intermittent renewables the potential role of green hydrogen as a means of electricity storage appears to be limited.
Economic Optima for Buffers in Direct Reduction Steelmaking Under Increasing Shares of Renewable Hydrogen
Oct 2021
Publication
While current climate targets demand substantial reductions in greenhouse gas (GHG) emissions the potentials to further reduce carbon dioxide emissions in traditional primary steel-making are limited. One possible solution that is receiving increasing attention is the direct reduction (DR) technology operated either with renewable hydrogen (H2) from electrolysis or with conventional natural gas (NG). DR technology makes it possible to decouple steel and hydrogen production by temporarily using overcapacities to produce and store intermediary products during periods of low renewable electricity prices or by switching between H2 and NG. This paper aims to explore the impact of this decoupling on overall costs and the corresponding dimensioning of production and storage capacities. An optimization model is developed to determine the least-cost operation based on perfect-foresight. This model can determine the minimum costs for optimal production and storage capacities under various assumptions considering fluctuating H2 and NG prices and increasing H2 shares. The model is applied to a case study for Germany and covers the current situation the medium term until 2030 and the long term until 2050. Under the assumptions made the role of using direct reduced iron (DRI) storage as a buffer seems less relevant. DRI mainly serves as long-term storage for several weeks similar to usual balancing storage capacities. Storing H2 on the contrary is used for short-term fluctuations and could balance H2 demand in the hourly range until 2050. From an economic perspective DRI production using NG tends to be cheaper than using H2 in the short term and potential savings from the flexible operation with storages are small at first. However in the long term until 2050 NG and H2 could achieve similar total costs if buffers are used. Otherwise temporarily occurring electricity price spikes imply substantial increases in total costs if high shares of H2 need to be achieved.
New Combustion Modelling Approach for Methane-Hydrogen Fueled Engines Using Machine Learning and Engine Virtualization
Oct 2021
Publication
The achievement of a carbon-free emissions economy is one of the main goals to reduce climate change and its negative effects. Scientists and technological improvements have followed this trend improving efficiency and reducing carbon and other compounds that foment climate change. Since the main contributor of these emissions is transportation detaching this sector from fossil fuels is a necessary step towards an environmentally friendly future. Therefore an evaluation of alternative fuels will be needed to find a suitable replacement for traditional fossil-based fuels. In this scenario hydrogen appears as a possible solution. However the existence of the drawbacks associated with the application of H2 -ICE redirects the solution to dual-fuel strategies which consist of mixing different fuels to reduce negative aspects of their separate use while enhancing the benefits. In this work a new combustion modelling approach based on machine learning (ML) modeling is proposed for predicting the burning rate of different mixtures of methane (CH4 ) and hydrogen (H2). Laminar flame speed calculations have been performed to train the ML model finding a faster way to obtain good results in comparison with actual models applied to SI engines in the virtual engine model framework.
Assessment and Recommendations for a Fossil Free Future for Track Work Machinery
Oct 2021
Publication
Current railway track work machinery is mainly operated with diesel fuel. As a result track maintenance of Austrian Federal Railways (OeBB) amounts to nearly 9000 t CO2 equivalent per year according to calculations from Graz University of Technology. OeBB’s total length of railway lines only accounts for 0.56% of the world’s length of lines. This indicates huge potential for mitigating greenhouse gas emissions considering the need for track maintenance worldwide. Environmental concerns have led to the introduction of alternative drives in the transport sector. Until now R&D (Research & Development) of alternative propulsion technologies for track work machinery has been widely neglected. This paper examines the possibility of achieving zero direct emissions during maintenance and construction work in railways by switching to alternative drives. The goal is to analyze alternative propulsion solutions arising from the transport sector and to assess their applicability to track work machinery. Research results together with a calculation tool show that available battery technology is recommendable for energy demands lower than 300 kWh per construction shift. Hydrogen fuel cell technology is an alternative for energy demands higher than 800 kWh. For machinery with energy requirements in between enhancements in battery technology are necessary and desirable for the coming years.
Experimental Investigation of the Effect of Hydrogen Addition on Combustion Performance and Emissions Characteristics of a Spark Ignition High Speed Gasoline Engine
Sep 2014
Publication
Considering energy crises and pollution problems today much work has been done for alternative fuels for fossil fuels and lowering the toxic components in the combustion products. Expert studies proved that hydrogen one of the prominent alternative energy source which has many excellent combustion properties that can be used for improving combustion and emissions performance of gasoline-fuelled spark ignition (SI) engines. This article experimentally investigated the performance and emission characteristics of a high speed single cylinder SI engine operating with different hydrogen gasoline blends. For this purpose the conventional carburetted high speed SI engine was modified into an electronically controllable engine with help of electronic control unit (ECU) which dedicatedly used to control the injection timings and injection durations of gasoline. Various hydrogen enrichment levels were selected to investigate the effect of hydrogen addition on engine brake mean effective pressure (Bmep) brake thermal efficiency volumetric efficiency and emission characteristics. The test results demonstrated that combustion performances fuel consumption and brake mean effective pressure were eased with hydrogen enrichment. The experimental results also showed that the brake thermal efficiency was higher than that for the pure gasoline operation. Moreover HC and CO emissions were all reduced after hydrogen enrichment.
A Comparison of Steam Reforming Concepts in Solid Oxide Fuel Cell Systems
Mar 2020
Publication
Various concepts have been proposed to use hydrocarbon fuels in solid oxide fuel cell (SOFC) systems. A combination of either allothermal or adiabatic pre-reforming and water recirculation (WR) or anode off-gas recirculation (AOGR) is commonly used to convert the fuel into a hydrogen rich mixture before it is electrochemically oxidised in the SOFC. However it is unclear how these reforming concepts affect the electrochemistry and temperature gradients in the SOFC stack. In this study four reforming concepts based on either allothermal or adiabatic pre-reforming and either WR or AOGR are modelled on both stack and system level. The electrochemistry and temperature gradients in the stack are simulated with a one-dimensional SOFC model and the results are used to calculate the corresponding system efficiencies. The highest system efficiencies are obtained with allothermal pre-reforming and WR. Adiabatic pre-reforming and AOGR result in a higher degree of internal reforming which reduces the cell voltage compared to allothermal pre-reforming and WR. Although this lowers the stack efficiency higher degrees of internal reforming reduce the power consumption by the cathode air blower as well leading to higher system efficiencies in some cases. This illustrates that both stack and system operation need to be considered to design an efficient SOFC system and predict potentially deteriorating temperature gradients in the stack.
A Review of Hydrogen as a Fuel in Internal Combustion Engines
Sep 2021
Publication
The demand for fossil fuels is increasing because of globalization and rising energy demands. As a result many nations are exploring alternative energy sources and hydrogen is an efficient and practical alternative fuel. In the transportation industry the development of hydrogen-powered cars aims to maximize fuel efficiency and significantly reduce exhaust gas emission and concentration. The impact of using hydrogen as a supplementary fuel for spark ignition (SI) and compression ignition (CI) engines on engine performance and gas emissions was investigated in this study. By adding hydrogen as a fuel in internal combustion engines the torque power and brake thermal efficiency of the engines decrease while their brake-specific fuel consumption increase. This study suggests that using hydrogen will reduce the emissions of CO UHC CO2 and soot; however NOx emission is expected to increase. Due to the reduction of environmental pollutants for most engines and the related environmental benefits hydrogen fuel is a clean and sustainable energy source and its use should be expanded.
A Comparison between Fuel Cells and Other Alternatives for Marine Electric Power Generation
Mar 2016
Publication
The world is facing a challenge in meeting its needs for energy. Global energy consumption in the last half-century has increased very rapidly and is expected to continue to grow over the next 50 years. However it is expected to see significant differences between the last 50 years and the next. This paper aims at introducing a good solution to replace or work with conventional marine power plants. This includes the use of fuel cell power plant operated with hydrogen produced through water electrolysis or hydrogen produced from natural gas gasoline or diesel fuels through steam reforming processes to mitigate air pollution from ships.
Heat in Buildings Strategy: Achieving Net Zero Emissions in Scotland's Buildings
Oct 2021
Publication
Sets out our vision for the future of heat in buildings and the actions we are taking in the buildings sector to deliver our climate change commitments maximise economic opportunities and ensure a just transition including helping address fuel poverty.
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