Applications & Pathways
Progress in Energy Storage Technologies and Methods for Renewable Energy Systems Application
May 2023
Publication
This paper provides a comprehensive review of the research progress current state-ofthe-art and future research directions of energy storage systems. With the widespread adoption of renewable energy sources such as wind and solar power the discourse around energy storage is primarily focused on three main aspects: battery storage technology electricity-to-gas technology for increasing renewable energy consumption and optimal configuration technology. The paper employs a visualization tool (CiteSpace) to analyze the existing works of literature and conducts an in-depth examination of the energy storage research hotspots in areas such as electrochemical energy storage hydrogen storage and optimal system configuration. It presents a detailed overview of common energy storage models and configuration methods. Based on the reviewed articles the future development of energy storage will be more oriented toward the study of power characteristics and frequency characteristics with more focus on the stability effects brought by transient shocks. This review article compiles and assesses various energy storage technologies for reference and future research.
Effects of Hydrogen Mixture Ratio and Scavenging Air Temperature on Combustion and Emission Characteristics of a 2-stroke Marine Engine
Nov 2022
Publication
A numerical study was conducted to investigate the effects of hydrogen and scavenging air temperature (SAT) on the combustion and emission characteristics of a 2-stroke heavy-duty dual-fuel (DF) marine engine at full load. The engine had a 700 mm bore fuelled with hydrogen–methane (H2-CH4) mixtures. Three-dimensional simulations of the combustion and emission formation inside the engine cylinder with various H2 contents in the H2-CH4 mixture were performed. ANSYS FLUENT simulation software was used to analyse the engine performance in-cylinder pressure temperature and emission characteristics. The CFD models were validated against the measured data recorded from the engine experiments. The results showed that an increase in the in-cylinder peak pressure increased the engine power when the H2 content in the H2-CH4 mixture increased. Notably CO2 and soot emissions decreased (up to more than 65%) when the H2 content in the gaseous mixture increased to 50%. Specific NO emissions in the DF modes were lower than that of the diesel mode when the H2 content in the gaseous mixture was lower than 40%. However they increased compared to the diesel mode when the H2 content continued to increase. This limits the H2 amount that should be used in a gaseous mixture creating NO emissions. The results also showed that the SAT cooling method can further reduce emission problems while enhancing engine power. In particular reducing the SAT to 28 ◦C in the gaseous mixture with 10% H2 ensured that the DF mode emitted the lowest NO emissions compared to the diesel mode. This reduced NO emissions by 37.92% compared to the measured NO emissions of the research engine (a Tier II marine engine). This study successfully analysed the benefits of using an H2-CH4 mixture as the primary fuel and the SAT cooling method in a 2-stroke ME-GI heavy-duty marine engine.
Hydrogen-Fuel Cell Hybrid Powertrain: Conceptual Layouts and Current Applications
Nov 2022
Publication
Transportation is one of the largest sources of CO2 emissions accounting for more than 20% of worldwide emissions. However it is one of the areas where decarbonization presents the greatest hurdles owing to its capillarity and the benefits that are associated with the use of fossil fuels in terms of energy density storage and transportation. In order to accomplish comprehensive decarbonization in the transport sector it will be required to encourage a genuine transition to low-carbon fuels and the widespread deployment of the necessary infrastructures to allow for a large-scale innovation. Renewable hydrogen shows potential for sustainable transportation applications whether in fuel cell electric vehicles (FCEVs) such as automobiles trucks and trains or as a raw material for ship and airplane synthetic fuels. The present paper aims to present how hydrogen-fuel cell hybrid powertrains for road vehicles work in terms of conceptual layouts and operating strategies. A comprehensive overview of real and current applications is presented concerning existing prototypes and commercially available vehicles with a focus on the main key performance indicators such as efficiency mileage and energy consumption.
Integrated Demand Response Design of Integrated Energy System with Mobile Hydrogen Energy Storage in Time-Domain Two-Port Model
Dec 2022
Publication
With the development of energy integration technology demand response (DR) has gradually evolved into integrated demand response (IDR). In this study for the integrated energy system (IES) on the distribution grid side with electricity heat natural gas network and hydrogen energy equipment the analogy relationship between the thermal and mobile hydrogen energy storage networks is proposed. Moreover a unified model that reflects network commonalities across different energy forms is established. Then considering the time delay of the IES in the nontransient network a time-domain two-port model of the IES considering the time delay is established. This model shows the joint effect of time and space on system parameters. Finally this study validates the model in the application of DR. The verification results show that in DR the time-domain two-port model can accurately “cut peaks and fill valleys” for the IES and effectively reduce the operating cost of the IES system.
Multi-Objective Optimization-Based Health-Conscious Predictive Energy Management Strategy for Fuel Cell Hybrid Electric Vehicles
Feb 2022
Publication
The Energy Management Strategy (EMS) in Fuel Cell Hybrid Electric Vehicles (FCHEVs) is the key part to enhance optimal power distribution. Indeed the most recent works are focusing on optimizing hydrogen consumption without taking into consideration the degradation of embedded energy sources. In order to overcome this lack of knowledge this paper describes a new health-conscious EMS algorithm based on Model Predictive Control (MPC) which aims to minimize the battery degradation to extend its lifetime. In this proposed algorithm the health-conscious EMS is normalized in order to address its multi-objective optimization. Then weighting factors are assigned in the objective function to minimize the selected criteria. Compared to most EMSs based on optimization techniques this proposed approach does not require any information about the speed profile which allows it to be used for real-time control of FCHEV. The achieved simulation results show that the proposed approach reduces the economic cost up to 50% for some speed profile keeping the battery pack in a safe range and significantly reducing energy sources degradation. The proposed health-conscious EMS has been validated experimentally and its online operation ability clearly highlighted on a PEMFC delivery postal vehicle.
Global Green Hydrogen-based Steel Opportunities Surrounding High Quality Renewable Energy and Iron Ore Deposits
May 2023
Publication
The steel sector currently accounts for 7% of global energy-related CO2 emissions and requires deep reform to disconnect from fossil fuels. Here we investigate the market competitiveness of one of the widely considered decarbonisation routes for primary steel production: green hydrogen-based direct reduction of iron ore followed by electric arc furnace steelmaking. Through analysing over 300 locations by combined use of optimisation and machine learning we show that competitive renewables-based steel production is located nearby the tropic of Capricorn and Cancer characterised by superior solar with supplementary onshore wind in addition to high-quality iron ore and low steelworker wages. If coking coal prices remain high fossil-free steel could attain competitiveness in favourable locations from 2030 further improving towards 2050. Large-scale implementation requires attention to the abundance of suitable iron ore and other resources such as land and water technical challenges associated with direct reduction and future supply chain configuration.
Synergistic Value in Vertically Integrated Power-to-Gas Energy Systems
Oct 2019
Publication
In vertically integrated energy systems integration frequently entails operational gains that must be traded off against the requisite cost of capacity investments. In the context of the model analyzed in this study the operational gains are subject to inherent volatility in both the price and the output of the intermediate product transferred within the vertically integrated structure. Our model framework provides necessary and sufficient conditions for the value (NPV) of an integrated system to exceed the sum of two optimized subsystems on their own. We then calibrate the model in Germany and Texas for systems that combine wind energy with Power-to-Gas (PtG) facilities that produce hydrogen. Depending on the prices for hydrogen in different market segments we find that a synergistic investment value emerges in some settings. In the context of Texas for instance neither electricity generation from wind power nor hydrogen production from PtG is profitable on its own in the current market environment. Yet provided both subsystems are sized optimally in relative terms the attendant operational gains from vertical integration more than compensate for the stand-alone losses of the two subsystems.
Alternative Vehicular Fuels for Environmental Decarbonization: A Critical Review of Challenges in Using Electricity, Hydrogen, and Biofuels as a Sustainable Vehicular Fuel
Jan 2023
Publication
Using vehicles powered by alternative fuels such as electricity hydrogen and biofuels have been envisioned as the ideal way to curb noxious vehicular emissions. However the availability of resources for the sustainable use of these alternative fuels the possible risks and their fate at the end of their life are frequently questioned necessitating a detailed assessment of factors influencing the use of all three alternative fuels for vehicular use. Though the vehicles powered by batteries and fuel cells are “locally” zero-emission vehicles (ZEVs) they have resource scarcity infrastructure limitations and are relatively expensive thus restricting their market penetration and consumer acceptance. Biofuels though can be used in the existing vehicles procuring the required amounts of feedstock and mitigating food-versus-fuel issues is still a challenge. Overcoming these challenges is a crucial and critical step for the sustained use of these alternative fuels as primary vehicular fuels. To accomplish this all these challenges need to be categorized and a comparative analysis among them is necessary to address them. This work can therefore serve as a ready reference for researchers and policy makers to take appropriate and informed decisions for long-term action to achieve the goals of the Paris agreement to reduce global temperature.
Artificial Intelligence/Machine Learning in Energy Management Systems, Control, and Optimization of Hydrogen Fuel Cell Vehicles
Mar 2023
Publication
Environmental emissions global warming and energy-related concerns have accelerated the advancements in conventional vehicles that primarily use internal combustion engines. Among the existing technologies hydrogen fuel cell electric vehicles and fuel cell hybrid electric vehicles may have minimal contributions to greenhouse gas emissions and thus are the prime choices for environmental concerns. However energy management in fuel cell electric vehicles and fuel cell hybrid electric vehicles is a major challenge. Appropriate control strategies should be used for effective energy management in these vehicles. On the other hand there has been significant progress in artificial intelligence machine learning and designing data-driven intelligent controllers. These techniques have found much attention within the community and state-of-the-art energy management technologies have been developed based on them. This manuscript reviews the application of machine learning and intelligent controllers for prediction control energy management and vehicle to everything (V2X) in hydrogen fuel cell vehicles. The effectiveness of data-driven control and optimization systems are investigated to evolve classify and compare and future trends and directions for sustainability are discussed.
Reduction in Greenhouse Gas and Other Emissions from Ship Engines: Current Trends and Future Options
Nov 2022
Publication
The impact of ship emission reductions can be maximised by considering climate health and environmental effects simultaneously and using solutions fitting into existing marine engines and infrastructure. Several options available enable selecting optimum solutions for different ships routes and regions. Carbon-neutral fuels including low-carbon and carbon-negative fuels from biogenic or non-biogenic origin (biomass waste renewable hydrogen) could resemble current marine fuels (diesel-type methane and methanol). The carbon-neutrality of fuels depends on their Well-to-Wake (WtW) emissions of greenhouse gases (GHG) including carbon dioxide (CO2) methane (CH4) and nitrous oxide emissions (N2O). Additionally non-gaseous black carbon (BC) emissions have high global warming potential (GWP). Exhaust emissions which are harmful to health or the environment need to be equally removed using emission control achieved by fuel engine or exhaust aftertreatment technologies. Harmful emission species include nitrogen oxides (NOx) sulphur oxides (SOx) ammonia (NH3) formaldehyde particle mass (PM) and number emissions (PN). Particles may carry polyaromatic hydrocarbons (PAHs) and heavy metals which cause serious adverse health issues. Carbon-neutral fuels are typically sulphur-free enabling negligible SOx emissions and efficient exhaust aftertreatment technologies such as particle filtration. The combinations of carbon-neutral drop-in fuels and efficient emission control technologies would enable (near-)zero-emission shipping and these could be adaptable in the short- to mid-term. Substantial savings in external costs on society caused by ship emissions give arguments for regulations policies and investments needed to support this development.
Multi-layer Coordinated Optimization of Integrated Energy System with Electric Vehicles Based on Feedback Correction
Sep 2022
Publication
The integrated energy system with electric vehicles can realize multi-energy coordination and complementarity and effectively promote the realization of low-carbon environmental protection goals. However the temporary change of vehicle travel plan will have an adverse impact on the system. Therefore a multi-layer coordinated optimization strategy of electric-thermal-hydrogen integrated energy system including vehicle to grid (V2G) load feedback correction is proposed. The strategy is based on the coordination of threelevel optimization. The electric vehicle charging and discharging management layer comprehensively considers the variance of load curve and the dissatisfaction of vehicle owners and the charging and discharging plan is obtained through multi-objective improved sparrow search algorithm which is transferred to the model predictive control rolling optimization layer. In the rolling optimization process according to the actual situation selectively enter the V2G load feedback correction layer to update V2G load so as to eliminate the impact of temporary changes in electric vehicle travel plans. Simulation results show that the total operating cost with feedback correction is 4.19% lower than that without feedback correction and tracking situation of tie-line planned value is improved which verifies the proposed strategy.
Use of Sustainable Fuels in Aviation—A Review
Mar 2022
Publication
As the push for carbon-neutral transport continues the aviation sector is facing increasing pressure to reduce its carbon footprint. Furthermore commercial air traffic is expected to resume the continuous growth experienced until the pandemic highlighting the need for reduced emissions. The use of alternative fuels plays a key role in achieving future emission goals while also lowering the dependency on fossil fuels. The so-called sustainable aviation fuels (SAF) which encompass bio and synthetic fuels are currently the most viable option but hydrogen is also being considered as a long-term solution. The present paper reviews the production methods logistical and technological barriers and potential for future mass implementation of these alternative fuels. In general biofuels currently present higher technological readiness levels than other alternatives. Sustainable mass production faces critical feedstock-related challenges that synthetic fuels together with other solutions can overcome. All conventional fuel replacements though with different scopes will be important in meeting long-term goals. Government support will play an important role in accelerating and facilitating the transition towards sustainable aviation.
Everything About Hydrogen Podcast: Plotting the Course for a Decarbonized Global Maritime Industry
Jan 2023
Publication
On this episode of EAH we sat down with Dr. Bo Cerup-Simonsen Chief Executive Officer of the Maersk Mc-Kinney Møller Center for Zero Carbon Shipping. Bo holds a PHD in Naval Architecture and Mechanical Engineering and spent seven years as a research engineer at MIT.
Bo explains the Center's work and we discuss decarbonization of shipping using hydrogen derived green fuels.
The podcast can be found on their website.
Bo explains the Center's work and we discuss decarbonization of shipping using hydrogen derived green fuels.
The podcast can be found on their website.
Optimal Energy Management for Hydrogen Economy in a Hybrid Electric Vehicle
Feb 2023
Publication
Fuel cell hybrid electric vehicles (FCEVs) are mainly electrified by the fuel cell (FC) system. As a supplementary power source a battery or supercapacitor (SC) is employed (besides the FC) to enhance the power response due to the slow dynamics of the FC. Indeed the performance of the hybrid power system mainly depends on the required power distribution manner among the sources which is managed by the energy management strategy (EMS). This paper considers an FCEV based on the proton exchange membrane FC (PEMFC)/battery/SC. The energy management strategy is designed to ensure optimum power distribution between the sources considering hydrogen consumption. Its main objective is to meet the electric motor’s required power with economic hydrogen consumption and better electrical efficiency. The proposed EMS combines the external energy maximization strategy (EEMS) and the bald eagle search algorithm (BES). Simulation tests for the Extra-Urban Driving Cycle (EUDC) and New European Driving Cycle (NEDC) profiles were performed. The test is supposed to be performed in typical conditions t = 25 ◦C on a flat road without no wind effect. In addition this strategy was compared with the state machine control strategy classic PI and equivalent consumption minimization strategy. In terms of optimization the proposed approach was compared with the original EEMS particle swarm optimization (PSO)-based EEMS and equilibrium optimizer (EO)-based EEMS. The results confirm the ability of the proposed strategy to reduce fuel consumption and enhance system efficiency. This strategy provides 26.36% for NEDC and 11.35% for EUDC fuel-saving and efficiency enhancement by 6.74% for NEDC and 36.19% for EUDC.
Optimal Design and Operation of Dual-Ejector PEMFC Hydrogen Supply and Circulation System
Jul 2022
Publication
A proton exchange membrane fuel cell (PEMFC) system requires an adequate hydrogen supply and circulation to achieve its expected performance and operating life. An ejector-based hydrogen circulation system can reduce the operating and maintenance costs noise and parasitic power consumption by eliminating the recirculation pump. However the ejector’s hydrogen entrainment capability restricted by its geometric parameters and flow control variability can only operate properly within a relatively narrow range of fuel cell output power. This research introduced the optimal design and operation control methods of a dual-ejector hydrogen supply/circulation system to support the full range of PEMFC system operations. The technique was demonstrated on a 70 kW PEMFC stack with an effective hydrogen entrainment ratio covering 8% to 100% of its output power. The optimal geometry design ensured each ejector covered a specific output power range with maximized entrainment capability. Furthermore the optimal control of hydrogen flow and the two ejectors’ opening and closing times minimized the anode gas pressure fluctuation and reduced the potential harm to the PEMFC’s operation life. The optimizations were based on dedicated computational fluid dynamics (CFD) and system dynamics models and simulations. Bench tests of the resulting ejector-based hydrogen supply/circulation system verified the simulation and optimization results.
How to Reduce the Greenhouse Gas Emissions and Air Pollution Caused by Light and Heavy Duty Vehicles with Battery-electric, Fuel Cell-electric and Catenary Trucks
Mar 2021
Publication
The reduction of greenhouse gas emissions is one of the greatest global challenges through 2050. Besides greenhouse gas emissions air pollution such as nitrogen oxide and particulate matter emissions has gained increasing attention in agglomerated areas with transport vehicles being one of the main sources thereof. Alternative fuels that fulfill the greenhouse gas reduction goals also offer the possibility of solving the challenge of rising urban pollution. This work focuses on the electric drive option for heavy and light duty vehicle freight transport. In this study fuel cell-electric vehicles battery-electric vehicles and overhead catenary line trucks were investigated taking a closer look at their potential to reduce greenhouse gas emissions and air pollution and also considering the investment and operating costs of the required infrastructure. This work was conducted using a bottom-up transport model for the federal state of North Rhine-Westphalia in Germany. Two scenarios for reducing these emissions were analyzed at a spatial level. In the first of these selected federal highways with the highest traffic volume were equipped with overhead catenary lines for the operation of diesel-hybrid overhead trucks on them. For the second spatial scenario the representative urban area of the city of Cologne was investigated in terms of air pollution shifting articulated trucks to diesel-hybrid overhead trucks and rigid trucks trailer trucks and light duty vehicles to battery-electric or fuel cell-electric drives. For the economic analysis the building up of a hydrogen infrastructure in the cases of articulated trucks and all heavy duty vehicles were also taken into account. The results showed that diesel-hybrid overhead trucks are only a cost-efficient solution for highways with high traffic volume whereas battery overhead trucks have a high uncertainty in terms of costs and technical feasibility. In general the broad range of costs for battery overhead trucks makes them competitive with fuel cell-electric trucks. Articulated trucks have the highest potential to be operated as overhead trucks. However the results indicated that air pollution is only partially reduced by switching conventional articulated trucks to electric drive models. The overall results show that a comprehensive approach such as fuel cell-electric drives for all trucks would most likely be more beneficial.
Advancements in Hydrogen Production, Storage, Distribution and Refuelling for a Sustainable Transport Sector: Hydrogen Fuel Cell Vehicles
Jul 2023
Publication
Hydrogen is considered as a promising fuel in the 21st century due to zero tailpipe CO2 emissions from hydrogen-powered vehicles. The use of hydrogen as fuel in vehicles can play an important role in decarbonising the transport sector and achieving net-zero emissions targets. However there exist several issues related to hydrogen production efficient hydrogen storage system and transport and refuelling infrastructure where the current research is focussing on. This study critically reviews and analyses the recent technological advancements of hydrogen production storage and distribution technologies along with their cost and associated greenhouse gas emissions. This paper also comprehensively discusses the hydrogen refuelling methods identifies issues associated with fast refuelling and explores the control strategies. Additionally it explains various standard protocols in relation to safe and efficient refuelling analyses economic aspects and presents the recent technological advancements related to refuelling infrastructure. This study suggests that the production cost of hydrogen significantly varies from one technology to others. The current hydrogen production cost from fossil sources using the most established technologies were estimated at about $0.8–$3.5/kg H2 depending on the country of production. The underground storage technology exhibited the lowest storage cost followed by compressed hydrogen and liquid hydrogen storage. The levelised cost of the refuelling station was reported to be about $1.5–$8/kg H2 depending on the station's capacity and country. Using portable refuelling stations were identified as a promising option in many countries for small fleet size low-to-medium duty vehicles. Following the current research progresses this paper in the end identifies knowledge gaps and thereby presents future research directions.
Sustainable Public Transport Strategies—Decomposition of the Bus Fleet and Its Influence on the Decrease in Greenhouse Gas Emissions
Mar 2022
Publication
The COVID pandemic has caused a major exodus of passengers who chose urban and suburban transport. In many countries especially in the European Union there is a tendency to choose individual means of transport causing damage to the environment and contributing significantly to greenhouse gas emissions. One method to promote urban transport is replacing bus fleets with newer ones thus making public transport more attractive and reducing the emission of harmful exhaust fume components into the atmosphere. The aim of this study was to show a methodology for calculating CO2e for bus fleets. When determining CO2e the principal greenhouse gases such as CO2 CH4 and N2O are usually considered. However CO emissions also have indirect effects on climate through enhanced levels of tropospheric O3 and increased lifetime of CH4; therefore CO2 CH4 N2O and CO emissions were determined for CO2e emission calculations. Two bus fleet variant scenarios were analysed; the first non-investment variant assumed passenger transport using the old fleet without any P&R parking zones. The second scenario was based on the current state which includes the purchase of new low-emission buses and the construction of P&R infrastructure. The calculations were performed using the COPERT emission model with real data from 52 buses running on 13 lines. For the analysed case study of the Rzeszow agglomeration and neighbouring communes implementing the urban and suburban transport modernisation project resulted in a reduction in estimated CO2e emissions of about 450 t. The methodology presented which also considers the impact of CO emissions on the greenhouse effect is a new element of the study that has not been presented in previous works and may serve as a model for other areas in the field of greenhouse gas emission analyses. The future research scope includes investigation of other fuels and powertrain supplies such as hydrogen and hybrid vehicles.
An Integrated Demand Response Dispatch Strategy for Low-carbon Energy Supply Park Considering Electricity-Hydrogen-Carbon Coordination
Apr 2023
Publication
Driven by the goal of ‘carbon peak carbon neutrality’ an integrated demand response strategy for integrated electricity– hydrogen energy systems is proposed for low-carbon energy supply parks considering the multi-level and multi-energy characteristics of campus-based microgrids. Firstly considering the spatial and temporal complementary nature of wind and photovoltaic generation and energy utilization the energy flow framework of the park is built based on the electricity and hydrogen energy carriers. Clean energy is employed as the main energy supply and power heat cooling and gas loads are considered energy consumption. Secondly the operation mechanism of coupled hydrogen storage hydrogen fuel cell and carbon capture equipment is analyzed in the two-stage power-to-gas conversion process. Thirdly considering the operating costs and environmental costs of the park an integrated demand response dispatch model is constructed for the coupled electricity– hydrogen–carbon system while satisfying the system equipment constraints network constraints and energy balance constraints of the park system. Finally Case study in an energy supply park system is implemented. The dispatch results of the integrated demand response with customer participation in the conventional electricity–hydrogen and electricity–hydrogen–carbon modes are compared to verify the effectiveness of the proposed strategy in renewable accommodation environmental protection and economic benefits.
Efficiency and Optimal Load Capacity of E-Fuel-Based Energy Storage Systems
Apr 2023
Publication
This work evaluates the effectiveness of chemical-based solutions for storing large amounts of renewable electricity. Four “Power-to-X-to-Power” pathways are examined comprising hydrogen methane methanol and ammonia as energy carriers. The pathways are assessed using a model scenario where they are produced with electricity from an onshore wind farm stored in suitable facilities and then reconverted to electricity to meet the energy demand of a chemical site. An energy management and storage capacity estimation tool is used to calculate the annual load coverage resulting from each pathway. All four pathways offer a significant increase in load coverage compared to a scenario without storage solution (56.19%). The hydrogen-based pathway has the highest load coverage (71.88%) and round-trip efficiency (36.93%) followed by the ammonia-based (69.62% 31.37%) methanol-based (67.85% 27.00%) and methane-based (67.64% 26.47% respectively) pathways. The substantially larger storage capacity required for gaseous energy carriers to ensure a steady supply to the consumer could be a decisive factor. The hydrogen pathway requires a storage volume up to 10.93 times larger than ammonia and 16.87 times larger than methanol. Notably ammonia and methanol whose load coverages are only 2.26 and 4.03 percentage points lower than that of hydrogen offer the possibility of implementing site-specific storage solutions avoiding potential bottlenecks due to limited pipeline and cavern capacities.
No more items...