Parameter study for dimensioning of a PV optimized hydrogen supply plant

Green hydrogen produced from intermittent renewable energy sources is a key component on the way to a carbon neutral planet. In order to achieve the most sustainable, efficient and cost-effective solutions, it is necessary to match the dimensioning of the renewable energy source, the capacity of the hydrogen production and the size of the hydrogen storage to the hydrogen demand of the application.For optimized dimensioning of a PV powered hydrogen production system, fulfilling a specific hydrogen demand, a detailed plant simulation model has been developed. In this study the model was used to conduct a parameter study to optimize a plant that should serve 5 hydrogen fuel cell buses with a daily hydrogen demand of 90 kg overall with photovoltaics (PV) as renewable energy source. Furthermore, the influence of the parameters PV system size, electrolyser capacity and hydrogen storage size on the hydrogen production costs and other key indicators is investigated. The plant primarily uses the PV produced energy but can also use grid energy for production.The results show that the most cost-efficient design primarily depends on the grid electricity price that is available to supplement the PV system if necessary. Higher grid electricity prices make it economically sensible to invest into higher hydrogen production and storage capacity. For a grid electricity price of 200 €/MWh the most cost-efficient design was found to be a plant with a 2000 kWp PV system, an electrolyser with 360 kW capacity and a hydrogen storage of 575 kg.     

The role of renewable fuel supply in the transport sector in a future decarbonized energy system

Battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) have been identified as two electromobility options which can help to achieve GHG emission reduction targets in the transport sector. However, both options will also impact the future energy system characterized by integration of various demand sectors and increasing intermittent power generation. The objective of this paper is to examine the optimal mix of both propulsion systems and to analyze the cost for renewable fuel supply. We propose a generic approach for dimensioning of fast charging and hydrogen refueling stations and optimization of the fuel supply system. The model is applied in a case study for passenger cars on German highways. The results indicate that a parallel build-up of stations for both technologies does not increase the overall costs. Moreover, the technology combination is also an optimal solution from the system perspective due to synergetic use of hydrogen but limited efficiency losses. Hence, BEVs and FCEVs should jointly contribute to the decarbonization of the future energy system.     

Flexible sector coupling with hydrogen: A climate-friendly fuel supply for road transport

The substantial expansion of renewable energy sources is creating the foundation to successfully transform the German energy sector (the so-called ‘Energiewende’). A by-product of this development is the corresponding capacity demand for the transportation, distribution and storage of energy. Hydrogen produced by electrolysis offers a promising solution to these challenges, although the willingness to invest in hydrogen technologies requires the identification of competitive and climate-friendly pathways in the long run. Therefore, this paper employs a pathway analysis to investigate the use of renewable hydrogen in the German passenger car transportation sector in terms of varying market penetration scenarios for fuel cell-electric vehicles (FCEVs). The investigation focuses on how an H₂ infrastructure can be designed on a national scale with various supply chain networks to establish robust pathways and important technologies, which has not yet been done. Therefore, the study includes all related aspects, from hydrogen production to fueling stations, for a given FCEV market penetration scenario, as well as the CO₂ reduction potential that can be achieved for the transport sector. A total of four scenarios are considered, estimating an FCEV market share of 1–75% by the year 2050. This corresponds to an annual production of 0.02–2.88 million tons of hydrogen. The findings show that the most cost-efficient H₂ supply (well-to-tank: 6.7–7.5 €/kg_H2) can be achieved in high demand scenarios (FCEV market shares of 30% and 75%) through a combination of cavern storage and pipeline transport. For low-demand scenarios, however, technology pathways involving LH₂ and LOHC truck transport represent the most cost-efficient options (well-to-tank: 8.2–11.4 €/kg_H2).     

Modeling of hydrogen production with a stand-alone renewable hybrid power system

Hydrocarbon resources adequately meet today’s energy demands. Due to the environmental impacts, renewable energy sources are high in the agenda. As an energy carrier, hydrogen is considered one of the most promising fuels for its high energy density as compared to hydrocarbon fuels. Therefore, hydrogen has a significant and future use as a sustainable energy system. Conventional methods of hydrogen extraction require heat or electrical energy. The main source of hydrogen is water, but hydrogen extraction from water requires electrical energy. Electricity produced from renewable energy sources has a potential for hydrogen production systems. In this study, an electrolyzer using the electrical energy from the renewable energy system is used to describe a model, which is based on fundamental thermodynamics and empirical electrochemical relationships. In this study, hydrogen production capacity of a stand-alone renewable hybrid power system is evaluated. Results of the proposed model are calculated and compared with experimental data. The MATLAB/Simscape^® model is applied to a stand-alone photovoltaic-wind power system sited in Istanbul, Turkey.     

Role of hydrogen in future North European power system in 2060

The Balmorel model has been used to calculate the economic optimal energy system configuration for the Scandinavian countries and Germany in 2060 assuming a nearly 100% coverage of the energy demands in the power, heat and transport sector with renewable energy sources. Different assumptions about the future success of fuel cell technologies have been investigated as well as different electricity and heat demand assumptions. The variability of wind power production was handled by varying the hydropower production and the production on CHP plants using biomass, by power transmission, by varying the heat production in heat pumps and electric heat boilers, and by varying the production of hydrogen in electrolysis plants in combination with hydrogen storage. Investment in hydrogen storage capacity corresponded to 1.2% of annual wind power production in the scenarios without a hydrogen demand from the transport sector, and approximately 4% in the scenarios with a hydrogen demand from the transport sector. Even the scenarios without a demand for hydrogen from the transport sector saw investments in hydrogen storage due to the need for flexibility provided by the ability to store hydrogen. The storage capacities of the electricity storages provided by plug-in hybrid electric vehicles were too small to make hydrogen storage superfluous.     

Techno-economical evaluation of a hydrogen refuelling station powered by Wind-PV hybrid power system: A case study for İzmir-Çeşme

Hydrogen fuelling station is an infrastructure for the commercialisation of hydrogen energy utilising fuel cells, particularly, in the automotive sector. Hydrogen fuel produced by renewable sources such as the solar and wind energy can be an alternative fuel to depress the use of fuels based on fossil sources in the transport sector for sustainable clean energy strategy in future. By replacing the primary fuel with hydrogen fuel produced using renewable sources in road transport sector, environmental benefits can be achieved. In the present study, techno-economic analysis of hydrogen refuelling station powered by wind-photovoltaics (PV) hybrid power system to be installed in ?zmir-Çe?me, Turkey is performed. This analysis is carried out to a design of hydrogen refuelling station which is refuelling 25 fuel cell electric vehicles on a daily basis using hybrid optimisation model for electric renewable (HOMER) software. In this study, National Aeronautics and Space Administration (NASA) surface meteorology and solar energy database were used. Therefore, the average wind speed during the year was assessed to be 5.72 m/s and the annual average solar irradiation was used to be 5.08 kW h/m²/day for the considered site. According to optimisation results obtained for the proposed configuration, the levelised cost of hydrogen production was found to be US $7.526–7.866/kg in different system configurations. These results show that hydrogen refuelling station powered by renewable energy is economically appropriate for the considered site. It is expected that this study is the pre-feasibility study and obtained results encougare the hydrogen refuelling station to be established in Turkey by inventors or public institutions.     

Exploring the potential of hydrogen in decarbonizing China's light-duty vehicle market

The Chinese government has pledged to achieve overall carbon neutrality by 2060. Currently, the transportation sector contributes to about 10% of total greenhouse gas (GHG) emissions in China. Hence, China has created a well-defined energy vehicle development strategy to reduce GHG emissions from the transportation sector, further expanding into hydrogen vehicle technologies. In this study, the Transportation Energy Analysis Model (TEAM) investigates the potential of hydrogen internal combustion engine vehicles (H₂-ICEVs) and fuel cell vehicles (FCEVs) as a reliable pathway towards the government's aspiration of carbon neutrality in the transportation sector. According to TEAM, by adopting FCEVs and H₂-ICEVs in the vehicle market, hydrogen demand could reach 25% of the total light-duty transportation energy demand in 2050. Consequently, this will lead to an annual reduction of more than 35 million tons GHG compared to only counting on the electrification pathway in the decarbonization task. Besides, FCEVs would take longer to penetrate the light-duty vehicle market compared to H₂-ICEVs, as the current fuel cell technology still requires much improvement to attain a competitive vehicle cost of production.     

Designing a gradual transition to a hydrogen economy in Spain

The lack of sustainability of the current Spanish energy system makes it necessary to study the adoption of alternative energy models. One of these is what is known as the hydrogen economy. In this paper, we aim to plan, for the case of Spain, an initial phase for transition to this energy model making use of the potential offered by each Spanish region. Specifically, the target pursued is to satisfy at least 15% of energy demand for transport by 2010 through renewable sources. We plan to attain this target gradually, establishing intermediate stages consisting of supplying 5 and 10% of the energy demand for transport by 2006 and 2008, respectively. The results obtained allow us to determine, for each region, the hydrogen production and consumption, the renewable energy sources used to obtain hydrogen and the transport requirements between regions.     

Commercial potential for renewable hydrogen in California

The market for renewable hydrogen in California is based primarily on the projected need for hydrogen fuel for fuel cell electric vehicles (FCEV) as they are currently coming to the roads in California. The demand is projected to be 70 million kg/year by 2030. This analysis shows that hydrogen demand can be filled through commercial electrolysis using excess renewable energy. This paper is also focused on the revenue potential for the use of electrolysis to provide fuel for FCEVs, and from demand response at the wholesale level, thus enabling greater penetration of renewables. Clean fuel not only reduces pollution and greenhouse gases from the transport sector, but also provides carbon credits as a bonus revenue stream. The analysis addresses both demand and supply in the 2030 and 2050 timeframes.     

H2RES,Energy planning tool for island energy systems – The case of the Island of Mljet

When it comes to the energy planning, computer programs like H₂RES are becoming valuable tools. H₂RES has been designed as support for simulation of different scenarios devised by RenewIsland methodology with specific purpose to increase integration of renewable sources and hydrogen into island energy systems. The model can use wind, solar, hydro, biomass, geothermal as renewable energy sources and fossil fuel blocks and grid connection with mainland as back up. The load in the model can be represented by hourly and deferrable electricity loads of the power system, by hourly heat load, by hydrogen load for transport and by water load depending on water consumption. The H₂RES model also has ability to integrate different storages into island energy system in order to increase the penetration of intermittent renewable energy sources or to achieve a 100% renewable island. Energy storages could vary from hydrogen loop (fuel cell, electrolyser and hydrogen storage) to reversible hydro or batteries for smaller energy systems. The H₂RES model was tested on the power system of the Island of Porto Santo – Madeira, the islands of Corvo, Graciosa, and Terrciera – Azores, Sal Island – Cape Verde, Portugal, the Island of Mljet, Croatia and on the energy system of the Malta. Beside energy planning of the islands, H₂RES model could be successfully applied for simulation of other energy systems like villages in mountain regions or for simulation of different individual energy producers or consumers.     

Increasing renewable energy sources in island energy supply: case study Porto Santo

While the energy supply of most islands depends mainly on expensive oil derivatives’ importation, the others are linked by usually a weak electricity grid connection to the mainland. Due to high energy costs the islands are proving to be excellent test beds for the introduction of new technologies, and some islands are trying to become so-called renewable islands, to satisfy their energy demand mainly or entirely from indigenous and renewable sources, thus increasing the security of supply, and employment opportunities, without necessarily increasing the costs. Islands that have energy sources, such as hydro or geothermal energy, can easily integrate them into the power system, but those with mainly intermittent renewable energy sources are confronted with the necessity of energy storage. The most promising technologies are reversible hydro where geography allows, and storing hydrogen where it does not. The stored hydrogen can later be used for electricity production, and also for transport. This paper describes the H₂RES model for optimisation of integration of hydrogen usage with intermittent renewable energy sources on the example of an isolated island in the Madeira archipelago, Porto Santo. It shows that it is possible to significantly increase the penetration of renewable energy sources, albeit at a relatively high cost, with hydrogen storage technology. The H₂RES model, which includes reversible hydro and batteries as storage technologies, can serve as a valuable tool for island energy planning.     

The role of public policy in optimizing renewable energy development in the greater southern Appalachian mountains

This research presents a third component of a comprehensive decision support system for energy planning that allows for combining existing electricity generating capabilities with increased use of renewable energy sources. It focuses on energy planning at the regional level, and concentrates specifically on the greater southern Appalachian mountains of the eastern United States: a region that was chosen for analysis not only due to its heavy dependence on coal for electricity, but also because of its potential for increased use of wind and solar power. Previous research used a geographic information system (GIS) model for identifying renewable energy potential to provide input data for a multi-objective linear programming (MOLP) model to determine the optimal constrained mix of renewable energy sources and existing fossil fuel facilities by balancing annual generation costs against the corresponding greenhouse gas emissions. This new component of the system analyzes three potential public policies—renewable portfolio standard, carbon tax, and renewable energy production tax credit—that have been used to foster increased renewable energy usage. These policies require minor modifications to the MOLP model for implementation. The results of these policy cases were then analyzed to determine the impact that these policies have on generation cost and pollution emissions within the region.     

Toward the clean production of hydrogen: Competition among renewable energy sources and nuclear power

This study elucidates the competition among renewable and nuclear energy sources for the production of hydrogen. These involve the use of solar, wind, biological process, tidal, geothermal and nuclear power to generate hydrogen. A comprehensive economic model, the Taiwan General Equilibrium Model-Clean Energy (TAIGEM-CE) model, is used for forecasting. Based on certain assumptions, the analytical results reveal that the most promising means of generating hydrogen is using wind power. Geothermal power is the most sensitive to external investment as a source of power for producing hydrogen. Solar hydrogen also benefits greatly from investment. Production of biohydrogen will be favorable without external investment, and they are less sensitive to investment than other renewable energy sources. Based on the assumptions made in this study, nuclear energy is not as competitive as most renewable energy sources for hydrogen production.     

MATLAB/Simulink simulation of low-pressure PEM electrolyzer stack

Utilizing renewable energy sources for hydrogen production represents a key step forward in achieving a climate-neutral society by 2050. Water electrolysis using a polymer electrolyte membrane (PEM) electrolyzer is one of the most efficient ways of hydrogen production. For the mentioned electrolyzer, a mathematical model is derived whose purpose is to better describe and predict the behavior of the system and its output parameters with a brief overview of the assumptions introduced to simplify the model and their overall error. A simulation is made using MATLAB/Simulink software to calculate and plot the desired output parameters and compare these results with the data obtained from several manufacturers. To make the simulation as flexible as possible, the possibility of changing the functional simulation parameters is introduced. The option allows more diverse results and diagrams, as well as a closer inside into system performance and the detection of potential calculation errors.     

Assessment of the potential for hydrogen production from renewable resources in Argentina

The potential for hydrogen production from three major renewable resources (wind energy, solar energy and biomass) in Argentina is analyzed. This potential for the annual production of wind, solar and biomass hydrogen is represented with maps showing it per unit area in each department. Thus, by using renewable resource databases available in the country, a new Geographic Information System (GIS) of renewable hydrogen is created. In this system, several geographic variables are displayed, in addition to other parameters such as the potential for renewable hydrogen production per department relative to transport fuel consumption of each province or the environmental savings that would imply the production of hydrogen required to add 20% V/V to CNG, with the aim of developing the cleaner alternative CNG + H₂ fuel. In order to take into account areas where energy development would be restricted, land use and environmental exclusions were considered.     

Investment decisions in imperfect power markets with hydrogen storage and large share of intermittent electricity

This paper analyzes the impact of hydrogen as energy storage on production and investment decisions in an electricity market when individual participants behave strategically. We develop a game-theoretic model on investment and generation game à la Cournot under the open-loop information structure. This framework is implemented as a mixed complementarity problem and applied to the German case assuming the phase-out of the German nuclear power plants, rising renewable energy supply and increasing energy demand for electric vehicles. The numerical results of our analysis indicate that utilization of energy storage has a positive effect on energy systems with large amount of intermittent electricity and inelastic demand. We find that additional hydrogen storage capacities improve system reliability, increase overall welfare and decrease GHG emissions. Adding demand for hydrogen as a fuel for FCEVs allows for a synergetic use of the technology and changes the investment incentives for energy storage. Although the power-to-gas technology has a price-smoothing effect the overall generation capacity is higher with energy storage providing additional supply security in markets with a large amount of intermittent energy production.     

An analysis of hydrogen production from renewable electricity sources

Three aspects of producing hydrogen via renewable electricity sources are analyzed to determine the potential for solar and wind hydrogen production pathways: a renewable hydrogen resource assessment, a cost analysis of hydrogen production via electrolysis, and the annual energy requirements of producing hydrogen for refueling. The results indicate that ample resources exist to produce transportation fuel from wind and solar power. However, hydrogen prices are highly dependent on electricity prices. For renewables to produce hydrogen at $2 kg⁻¹, using electrolyzers available in 2004, electricity prices would have to be less than $0.01 kWh⁻¹. Additionally, energy requirements for hydrogen refueling stations are in excess of 20 GWh/year. It may be challenging for dedicated renewable systems at the filling station to meet such requirements. Therefore, while plentiful resources exist to provide clean electricity for the production of hydrogen for transportation fuel, challenges remain to identify optimum economic and technical configurations to provide renewable energy to distributed hydrogen refueling stations.     

Renewislands—Renewable energy solutions for islands

Increase of the global energy demand and environmental problems relating to fossil energy utilization request the new energy sources to replace the traditional fossil fuels. With respect to energy production, most of the islands in European Union and in the other parts of the world, depend on importation, mainly from oil and its related products. The global development of renewable energy technologies can assure sustainable supply of power for islands. To overcome the limitation of the sources of renewable energy, hydrogen is utilized as a storage medium integrated with intermittent renewable energy sources such as wind and solar. This paper introduces the programme of “Renewislands—Renewable Energy Solutions for Islands”, the work tasks, details of the design of the activities to develop solutions integrating intermittent renewable energy supply (RES), fuel cell (FC) and hydrogen infrastructure to promote RES and innovative decentralized power systems penetration in islands; main results achieved in each work packages are presented; in addition, the development of intermittent renewable energy penetration in specific European Islands are reviewed briefly.     

Potential of renewable hydrogen production for energy supply in Hong Kong

Hong Kong is highly vulnerable to energy and economic security due to the heavy dependence on imported fossil fuels. The combustion of fossil fuels also causes serious environmental pollution. Therefore, it is important to explore the opportunities for clean renewable energy for long-term energy supply. Hong Kong has the potential to develop clean renewable hydrogen energy to improve the environmental performance. This paper reviews the recent development of hydrogen production technologies, followed by an overview of the renewable energy sources and a discussion about potential applications for renewable hydrogen production in Hong Kong. The results show that although renewable energy resources cannot entirely satisfy the energy demand in Hong Kong, solar energy, wind power, and biomass are available renewable sources for significant hydrogen production. A system consisting of wind turbines and photovoltaic (PV) panels coupled with electrolyzers is a promising design to produce hydrogen. Biomass, especially organic waste, offers an economical, environmental-friendly way for renewable hydrogen production. The achievable hydrogen energy output would be as much as 40% of the total energy consumption in transportation.     

Energy system aspects of hydrogen as an alternative fuel in transport

Considering the enormous ecological and economic importance of the transport sector the introduction of alternative fuels—together with drastic energy efficiency gains—will be a key to sustainable mobility, nationally as well as globally. However, the future role of alternative fuels cannot be examined from the isolated perspective of the transport sector. Interactions with the energy system as a whole have to be taken into account. This holds both for the issue of availability of energy sources as well as for allocation effects, resulting from the shift of renewable energy from the stationary sector to mobile applications. With emphasis on hydrogen as a transport fuel for private passenger cars, this paper discusses the energy systems impacts of various scenarios introducing hydrogen fueled vehicles in Germany. It identifies clear restrictions to an enhanced growth of clean hydrogen production from renewable energy sources (RES). Furthermore, it points at systems interdependencies that call for a priority use of RES electricity in stationary applications. Whereas hydrogen can play an increasing role in transport after 2030 the most important challenge is to exploit short–mid-term potentials of boosting car efficiency.