Production & Supply Chain
Techno-economic Analysis of Hydrogen Production from PV Plants
Jan 2022
Publication
Hydrogen production through electrolysis from renewable sources is expected to play an important role to achieve the reduction targets of carbon dioxide emissions set for the next decades. Electrolysers can use the renewable energy surplus to produce green hydrogen and contribute to making the electrical grid more stable. Hydrogen can be used as medium-long term energy storage converted into other fuels or used as feedstock in industry thus contributing to decarbonise hard-to-abate-sectors. However due to the intermittent and variable nature of solar and wind power the direct coupling of electrolysers with renewables may lead to high production fluctuations and frequent shutdowns. As a consequence accelerated electrolyser degradation and safety issues related to low load operation may arise. In this study simulations of hydrogen production with an electrolyser fed by a PV system are performed in Matlab for a reference year. The effect of PV power fluctuations on the electrolyser operation and production is investigated. The impact of the electrolyser size for a fixed nominal power of the PV plant is also analysed from both energetic and economic points of view.
Hydrogen Energy Planning with Water Considerations: A SWITCH Model Enhancement for Sustainable Deployment
Apr 2024
Publication
This study presents an enhancement to the Switch optimization model for hydrogen energy planning by integrating the capability to consider the construction and operation of hydrogen electrolysis plants and the operation of water distribution systems. This integration was achieved through the addition of two new modules and their effectiveness is demonstrated through their application in a case study for Durham region. The study highlights the significance of incorporating water distribution systems into energy planning demonstrating how optimal locations for hydrogen plants can significantly influence water and power demand as well as alter the total operating costs. The enhanced Switch model showcases its improved capability to assist policymakers and stakeholders in transitioning towards a sustainable energy future.
Green Hydrogen Production at the Gigawatt Scale in Portugal: A Technical and Economic Evaluation
Mar 2024
Publication
The European Union has committed to achieving carbon neutrality by 2050 and green hydrogen has been chosen as a priority vector for reaching that goal. Accordingly Portugal has drafted a National Hydrogen Strategy laying out the various steps for the development of a green hydrogen economy. One element of this strategy is the development of a gigawatt-scale hydrogen production facility powered by dedicated renewable electricity sources. This work presents an analysis of the technical and economic feasibility of a facility consisting of a gigawatt-scale polymer electrolyte membrane electrolyser powered by solar photovoltaic and wind electricity using the energy analysis model EnergyPLAN. Different capacities and modes of operation of the electrolyser are considered including the complementary use of grid electricity as well as different combinations of renewable power resulting in a total of 72 different configurations. An economic analysis is conducted addressing the related annualised capital expenditures maintenance and variable costs to allow for the determination of the levelised cost of hydrogen for the different configurations. This analysis shows the conditions required for maximising annual hydrogen production at the lowest levelised cost of hydrogen. The best options consist of an electrolyser powered by a combination of solar photovoltaic and wind with limited exchanges with the electricity grid and a levelised cost of hydrogen in the range 3.13–3.48 EUR/kg.
An Insight into Carbon Nanomaterial-Based Photocatalytic Water Splitting for Green Hydrogen Production
Dec 2022
Publication
At present the energy shortage and environmental pollution are the burning global issues. For centuries fossil fuels have been used to meet worldwide energy demand. However thousands of tons of greenhouse gases are released into the atmosphere when fossil fuels are burned contributing to global warming. Therefore green energy must replace fossil fuels and hydrogen is a prime choice. Photocatalytic water splitting (PWS) under solar irradiation could address energy and environmental problems. In the past decade solar photocatalysts have been used to manufacture sustainable fuels. Scientists are working to synthesize a reliable affordable and light-efficient photocatalyst. Developing efficient photocatalysts for water redox reactions in suspension is a key to solar energy conversion. Semiconductor nanoparticles can be used as photocatalysts to accelerate redox reactions to generate chemical fuel or electricity. Carbon materials are substantial photocatalysts for total WS under solar irradiation due to their high activity high stability low cost easy production and structural diversity. Carbon-based materials such as graphene graphene oxide graphitic carbon nitride fullerenes carbon nanotubes and carbon quantum dots can be used as semiconductors photosensitizers cocatalysts and support materials. This review comprehensively explains how carbon-based composite materials function as photocatalytic semiconductors for hydrogen production the water-splitting mechanism and the chemistry of redox reactions. Also how heteroatom doping defects and surface functionalities etc. can influence the efficiency of carbon photocatalysts in H2 production. The challenges faced in the PWS process and future prospects are briefly discussed.
Green Hydrogen Driven by Wind and Solar—An Australian Case Study
Apr 2024
Publication
The energy transition to wind and solar opens up opportunities for green hydrogen as wind and solar generation tend to bring electricity prices down to very low levels. We evaluate whether green hydrogen can integrate well with wind and solar PVs to improve the South Australian electricity grid. Green hydrogen can use membrane electrolysis plants during periods of surplus renewable energy. This hydrogen can then be electrified or used in industry. The green hydrogen system was analysed to understand the financial viability and technical impact of integrating green hydrogen. We also used system engineering techniques to understand the system holistically including the technical social environmental and economic impacts. The results show opportunities for the system to provide seasonal storage grid firming and reliability services. Financially it would need changes to electricity rules to be viable so at present it would not be viable without subsidy.
Process Reconfiguration and Intensification: An Emerging Opportunity Enabling Efficient Carbon Capture and Low-cost Blue Hydrogen Production
Mar 2023
Publication
Low-carbon hydrogen can play a significant role in decarbonizing the world. Hydrogen is currently mainly produced from fossil sources requiring additional CO2 capture to decarbonize which energy intense and costly. In a recent Green Energy & Environment paper Cheng and Di et al. proposed a novel integration process referred to as SECLRHC to generate high-purity H2 by in-situ separation of H2 and CO without using any additional separation unit. Theoretically the proposed process can essentially achieve the separation of C and H in gaseous fuel via a reconfigured reaction process and thus attaining high-purity hydrogen of ∼99% as well as good carbon and hydrogen utilization rates and economic feasibility. It displays an optimistic prospect that industrial decarbonization is not necessarily expensive as long as a suitable CCS measure can be integrated into the industrial manufacturing process.
Optimization of High-Temperature Electrolysis System for Hydrogen Production Considering High-Temperature Degradation
Mar 2023
Publication
Solid oxide electrolysis cells (SOECs) have great application prospects because of their excellent performance but the long-term applications of the stacks are restricted by the structural degradation under the high-temperature conditions. Therefore an SOEC degradation model is developed and embedded in a process model of the high-temperature steam electrolysis (HTSE) system to investigate the influence of the stack degradation at the system level. The sensitivity analysis and optimization were carried out to study the influence factors of the stack degradation and system hydrogen production efficiency and search for the optimal operating conditions to improve the hydrogen production efficiency and mitigate the stack degradation. The analysis results show that the high temperature and large current density can accelerate the stack degradation but improve the hydrogen production efficiency while the high temperature gradually becomes unfavorable in the late stage. The low air-to-fuel feed ratio is beneficial to both the degradation rate and hydrogen production efficiency. The results show that the optimization method can improve the hydrogen production efficiency and inhibit the stack degradation effectively. Moreover part of the hydrogen production efficiency has to be sacrificed in order to obtain a lower stack degradation rate.
Ecological and Economic Evaluation of Hydrogen Production by Different Water Electrolysis Technologies
Jul 2020
Publication
The economic and ecological production of green hydrogen by water electrolysis is one of the major challenges within Carbon2Chem and other power-to-X projects. This paper presents an evaluation of the different water electrolysis technologies with respect to their specific energy demand carbon footprint and the forecast production costs in 2030. From a current perspective alkaline water electrolysis is evaluated as the most favorable technology for the cost-effective production of low-carbon hydrogen with fluctuating renewables.
Corrosion of Structural Components of Proton Exchange Membrane Water Electrolyzer Anodes: A Review
Dec 2022
Publication
Proton exchange membrane (PEM) water electrolysis is one of the low temperature processes for producing green hydrogen when coupled with renewable energy sources. Although this technology has already reached a certain level of maturity and is being implemented at industrial scale its high capital expenditures deriving from the utilization of expensive corrosion-resistant materials limit its economic competitiveness compared to the widespread fossil fuel-based hydrogen production such as steam reforming. In particular the structural elements like bipolar plates (BPP) and porous transports layers (PTL) are essentially made of titanium protected by precious metal layers in order to withstand the harsh oxidizing conditions in the anode compartment. This review provides an analysis of literature on structural element degradation on the oxygen side of PEM water electrolyzers from the early investigations to the recent developments involving novel anti-corrosion coatings that protect more cost-effective BPP and PTL materials like stainless steels.
Everything About Hydrogen Podcast: Improving PEM Efficiency
Jan 2023
Publication
On this episode of EAH we sat down with Alejandro Oyarce Barnett Chief Technology Officer and Co-Founder at Hystar. Hystar is a technology-focused company specializing in PEM electrolysers for hydrogen production using renewable energy. The company got its start as a spin-off from SINTEF one of Europe’s largest independent research organizations and has raised private funding so the company can focus on production of its high-efficiency PEM units and keep pace with demand for hydrogen generation capacity. Hystar announced on January 11 2023 that the company has closed a Series B funding round of USD 26mn to rapidly scale-up to full commercial operations with an automated GW-capacity production line by 2025. Alejandro joined us to discuss in more detail the origins of Hystar its technology and the mission at the core of the company.
The podcast can be found on their website.
The podcast can be found on their website.
Influence of Renewable Energy Power Fluctuations on Water Electrolysis for Green Hydrogen Production
Nov 2022
Publication
The development of renewable energy technologies is essential to achieve carbon neutrality. Hydrogen can be stably stored and transported in large quantities to maximize power utilization. Detailed understanding of the characteristics and operating methods of water electrolysis technologies in which naturally intermittent fluctuating power is used directly is required for green hydrogen production because fluctuating power-driven water electrolysis processes significantly differ from industrial water electrolysis processes driven by steady grid power. Thus it is necessary to overcome several issues related to the direct use of fluctuating power. This article reviews the characteristics of fluctuating power and its generation as well as the current status and issues related to the operation conditions water electrolyzer configuration system requirements stack/catalyst durability and degradation mechanisms under the direct use of fluctuating power sources. It also provides an accelerated degradation test protocol method for fair catalyst performance comparison and share of effective design directions. Finally it discusses potential challenges and recommendations for further improvements in water electrolyzer components and systems suitable for practical use suggesting that a breakthrough could be realized toward the achievement of a sustainable hydrogen-based society.
Everything About Hydrogen Podcast: Easter Eggs
Feb 2023
Publication
On today’s episode of Everything About Hydrogen we speak with Raffi Garabedian CEO and Co-Founder of Electric Hydrogen (EH2) a deep decarbonization company pioneering new technology for low cost high efficiency fossil free hydrogen systems. By using electrolyzers many times larger than the industry standard EH2 aims to help eliminate more than 30% of global GHG emissions from difficult to electrify sectors like steel ammonia and freight.
We are excited to learn more from Raffi about the EH2 technology lessons learned by scaling First Solar and what we might expect to see next.
The podcast can be found on their website.
We are excited to learn more from Raffi about the EH2 technology lessons learned by scaling First Solar and what we might expect to see next.
The podcast can be found on their website.
Energy Assessment of an Integrated Hydrogen Production System
Dec 2022
Publication
Hydrogen is believed to be the future energy carrier that will reduce environmental pollution and solve the current energy crisis especially when produced from a renewable energy source. Solar energy is a renewable source that has been commonly utilized in the production process of hydrogen for years because it is inexhaustible clean and free. Generally hydrogen is produced by means of a water splitting process mainly electrolysis which requires energy input provided by harvesting solar energy. The proposed model integrates the solar harvesting system into a conventional Rankine cycle producing electrical and thermal power used in domestic applications and hydrogen by high temperature electrolysis (HTE) using a solid oxide steam electrolyzer (SOSE). The model is divided into three subsystems: the solar collector(s) the steam cycle and an electrolysis subsystem where the performance of each subsystem and their effect on the overall efficiency is evaluated thermodynamically using first and second laws. A parametric study investigating the hydrogen production rate upon varying system operating conditions (e.g. solar flux and area of solar collector) is conducted on both parabolic troughs and heliostat fields as potential solar energy harvesters. Results have shown that heliostat-based systems were able to attain optimum performance with an overall thermal efficiency of 27% and a hydrogen production rate of 0.411 kg/s whereas parabolic trough-based systems attained an overall thermal efficiency of 25.35% and produced 0.332 kg/s of hydrogen.
Earth-Abundant Electrocatalysts in Proton Exchange Membrane Electrolyzers
Dec 2018
Publication
In order to adopt water electrolyzers as a main hydrogen production system it is critical to develop inexpensive and earth-abundant catalysts. Currently both half-reactions in water splitting depend heavily on noble metal catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. The efforts within this field for the discovery of efficient and stable earth-abundant catalysts (EACs) have increased exponentially the last few years. The development of EACs for the oxygen evolution reaction (OER) in acidic media is particularly important as the only stable and efficient catalysts until now are noble-metal oxides such as IrOx and RuOx. On the hydrogen evolution reaction (HER) side there is significant progress on EACs under acidic conditions but there are very few reports of these EACs employed in full PEM WE cells. These two main issues are reviewed and we conclude with prospects for innovation in EACs for the OER in acidic environments as well as with a critical assessment of the few full PEM WE cells assembled with EACs.
Alternative and Innovative Solid Oxide Electrolysis Cell Materials: A Short Review
Jun 2021
Publication
Solid oxide electrolysis cell is the leading technology for production of green hydrogen by high temperature electrolysis. However optimization of existing reference materials constituting the cell and development of innovative materials remain critical for solid oxide electrolysis cell. In particular they are key to reach performance and durability targets compatible with a commercialization for the three main markets identified as follows: large-scale H2 production Power-to-X and Power-to-Power. This short review summarizes the latest progress in research and development of alternative and innovative materials for solid oxide electrolysis cells with a main focus on cathode-supported cell materials. A brief description of the layers constituting the solid oxide electrolysis cell is provided with the associated current state-of-the-art materials. A further emphasis on the most promising alternative and innovative materials for each layer follows based on the major aspects from an industrial perspective to reach a competitive hydrogen production cost for the main targeted markets: performance durability scaling up/manufacturing ability and operational flexibility.
Open-source Project Feasibility Tools for Supporting Development of the Green Ammonia Value Chain
Nov 2022
Publication
Ammonia plays a vital role in feeding the world through fertilizer production as well as having other industrial uses. However current ammonia production processes rely heavily on fossil fuels mostly natural gas to generate hydrogen as a feedstock. There is an urgent need to re-design and decarbonise the production process to reduce greenhouse emissions and avoid dependence on volatile gas markets and a depleting resource base. Renewable energy driven electrolysis to generate hydrogen provides a viable pathway for producing carbon-free or green ammonia. However a key challenge associated with producing green ammonia is managing low cost but highly variable wind and solar renewable energy generation for hydrogen electrolysis while maintaining reliable operation of the less flexible ammonia synthesis unit. To date green ammonia production has only been demonstrated at pilot scale and optimising plant configurations and scaling up production facilities is an urgent task. Existing feasibility studies have demonstrated the ability to model and cost green ammonia production pathways that can overcome the technical and economic challenges. However these existing approaches are context specific demonstrating the ability to model and cost green ammonia production for defined locations with set configurations. In this paper we present a modelling framework that consolidates the array of configurations previously studied into a single framework that can be tailored to the location of interest. Our open-source green ammonia modelling and costing tool dynamically simulates the integration of renewable energy with a wide range of balancing power and storage options to meet the flexible demands of the green ammonia production process at hourly time resolution over a year or more. Unlike existing models the open-source implementation of our tool allows it to be used by a potentially wide range of stakeholders to explore their own projects and help guide the upscaling of green ammonia as a pathway for decarbonisation. Using Gladstone in Australia as a case study a 1 million tonne per annum (MMTPA) green ammonia plant is modelled and costed using price assumptions for major equipment in 2030 provided by the Australian Energy Market Operator (AEMO). Using a hybrid (solar PV and wind) renewable energy source and Battery Energy Storage System as balancing technology we estimate a levelized cost of ammonia (LCOA) between 0.69 and 0.92 USD kgNH3 -1 . While greater than historical ammonia production costs from natural gas falling renewables costs and emission reduction imperatives suggest a major future role for green ammonia.
Modeling of Hydrogen Production System for Photovoltaic Power Generation and Capacity Optimization of Energy Storage System
Sep 2022
Publication
Hydrogen production using solar energy is an important way to obtain hydrogen energy. However the inherent intermittent and random characteristics of solar energy reduce the efficiency of hydrogen production. Therefore it is necessary to add an energy storage system to the photovoltaic power hydrogen production system. This paper establishes a model of a photovoltaic power generation hydrogen system and optimizes the capacity configuration. Firstly the mathematical model is modeled and analyzed and the system is modeled using Matlab/Simulink; secondly the principle of optimal configuration of energy storage capacity is analyzed to determine the optimization strategy we propose the storage capacity configuration algorithm based on the low-pass filtering principle and optimal time constant selection; finally a case study is conducted whose photovoltaic installed capacity of 30 MW verifying the effectiveness of the proposed algorithm analyzing the relationship between energy storage capacity and smoothing effect. The results show that as the cut-off frequency decreases the energy storage capacity increases and the smoothing effect is more obvious. The proposed algorithm can effectively reduce the 1 h maximum power variation of PV power generation. In which the maximum power variation of PV generation 1 h before smoothing is 4.31 MW. We set four different sets of time constants the maximum power variation of PV generation 1 h after smoothing is reduced to 0.751 0.389 0.078 and 0.04 MW respectively.
Environmental Sustainability Assessment of Large-scale Hydrogen Production Using Prospective Life Cycle Analysis
Nov 2022
Publication
The need for a rapid transformation to low-carbon economies has rekindled hydrogen as a promising energy carrier. Yet the full range of environmental consequences of large-scale hydrogen production remains unclear. Here prospective life cycle analysis is used to compare different options to produce 500 Mt/yr of hydrogen including scenarios that consider likely changes to future supply chains. The resulting environmental and human health impacts of such production levels are further put into context with the Planetary Boundaries framework known human health burdens the impacts of the world economy and the externality-priced production costs that embody the environmental impact. The results indicate that climate change impacts of projected production levels are 3.3–5.4 times higher than the allocated planetary boundary with only green hydrogen from wind energy staying below the boundary. Human health impacts and other environmental impacts are less severe in comparison but metal depletion and ecotoxicity impacts of green hydrogen deserve further attention. Priced-in environmental damages increase the cost most strongly for blue hydrogen (from ∼2 to ∼5 USD/kg hydrogen) while such true costs drop most strongly for green hydrogen from solar photovoltaic (from ∼7 to ∼3 USD/kg hydrogen) when applying prospective life cycle analysis. This perspective helps to evaluate potentially unintended consequences and contributes to the debate about blue and green hydrogen.
Energy and Economic Costs of Chemical Storage
May 2020
Publication
The necessity of neutralizing the increase of the temperature of the atmosphere by the reduction of greenhouse gas emissions in particular carbon dioxide (CO2) as well as replacing fossil fuels leads to a necessary energy transition that is already happening. This energy transition requires the deployment of renewable energies that will replace gradually the fossil fuels. As the renewable energy share increases energy storage will become key to avoid curtailment or polluting back-up systems. This paper considers a chemical storage process based on the use of electricity to produce hydrogen by electrolysis of water. The obtained hydrogen (H2) can then be stored directly or further converted into methane (CH4 from methanation if CO2 is available e.g. from a carbon capture facility) methanol (CH3OH again if CO2 is available) and/or ammonia (NH3 by an electrochemical process). These different fuels can be stored in liquid or gaseous forms and therefore with different energy densities depending on their physical and chemical nature. This work aims at evaluating the energy and the economic costs of the production storage and transport of these different fuels derived from renewable electricity sources. This applied study on chemical storage underlines the advantages and disadvantages of each fuel in the frame of the energy transition.
Flexible Power and Biomass-To-Methanol Plants With Different Gasification Technologies
Jan 2022
Publication
The competitiveness of biofuels may be increased by integrating biomass gasification plants with electrolysis units which generate hydrogen to be combined with carbon-rich syngas. This option allows increasing the yield of the final product by retaining a higher amount of biogenic carbon and improving the resilience of the energy sector by favoring electric grid services and sector coupling. This article illustrates a techno-economic comparative analysis of three flexible power and biomass to methanol plants based on different gasification technologies: direct gasification indirect gasification and sorptionenhanced gasification. The design and operational criteria of each plant are conceived to operate both without green hydrogen addition (baseline mode) and with hydrogen addition (enhanced mode) following an intermittent use of the electrolysis system which is turned on when the electricity price allows an economically viable hydrogen production. The methanol production plants include a gasification section syngas cleaning conditioning and compression section methanol synthesis and purification and heat recovery steam cycle to be flexibly operated. Due to the high oxygen demand in the gasifier the direct gasification-based plant obtains a great advantage to be operated between a minimum load to satisfy the oxygen demand at high electricity prices and a maximum load to maximize methanol production at low electricity prices. This allows avoiding large oxygen storages with significant benefits for Capex and safety issues. The analysis reports specific fixed-capital investments between 1823 and 2048 €/kW of methanol output in the enhanced operation and LCOFs between 29.7 and 31.7 €/GJLHV. Economic advantages may be derived from a decrease in the electrolysis capital investment especially for the direct gasification-based plants which employ the greatest sized electrolyzer. Methanol breakeven selling prices range between 545 and 582 €/t with the 2019 reference Denmark electricity price curve and between 484 and 535 €/t with an assumed modified electricity price curve of a future energy mix with increased penetration of intermittent renewables.
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