Prospects for hydrogen as a transport fuel

Early forecasts for hydrogen's role in transport usually proved over-optimistic, with several seeing hydrogen as an important transport fuel by year 2010 or even much earlier. Over the past century, vehicular passenger transport has experienced hypergrowth in terms of task, energy use and greenhouse gas emissions. For a variety of reasons, future decades may well see a significantly reduced global passenger transport task, as well as a widespread phasing-out of internal combustion engine vehicles, especially in cities. In contrast, the global freight transport task is unlikely to decline much, and could even grow, so that freight transport will dominate total transport energy use. Even if the world does finally respond seriously to climate change, likely policies will not favour hydrogen for private passenger vehicles for many decades. Nevertheless, hydrogen has clear superiority over electric vehicles for heavy freight transport. Given this advantage, it may be desirable to promote hydrogen for freight well before large amounts of renewable hydrogen are available from surplus intermittent renewable energy electricity.     

Overview of safety practices in sustainable hydrogen economy – An Australian perspective

Hydrogen is a potential future solution addressing global warming, climate change, and energy security challenges. It efficiently allows for storing excess renewable energy and generating heat and electricity without increasing greenhouse gas emissions. It can create a practical pathway to replace fossil fuel vehicles and move toward a net-zero transport sector. Various hydrogen strategies and industry roadmaps have been developed to identify key goals, set targets for progress, and develop strategic plans to remove barriers. As identified through these documents, the development of consistent national and international codes and standards and the creation of clear procedures and regulations are essential for the safe implementation and adaptation of hydrogen systems, leading to the successful process of hydrogen sector. This paper provides a comprehensive and critical review of the different aspects of hydrogen safety to advance hydrogen regulations, codes, and standards. While it summarises the key international hydrogen frameworks, the main focus of the paper is on Australian plans, progress, and working groups for hydrogen deployment that will help future green energy society.     

How to achieve a 100% RES electricity supply for Portugal?

Portugal is a country with an energy system highly dependent on oil and gas imports. Imports of oil and gas accounted for 85% of the country’s requirements in 2005 and 86% in 2006. Meanwhile, the share of renewable energy sources (RES) in the total primary energy consumption was only 14% in 2006. When focusing only on electricity production, the situation is somewhat better. The share of RES in gross electricity production varies between 20% and 35% and is dependent on the hydropower production in wet and dry years. This paper presents, on a national scale, Portugal’s energy system planning and technical solutions for achieving 100% RES electricity production. Planning was based on hourly energy balance and use of H₂RES software. The H₂RES model provides the ability to integrate various types of storages into energy systems in order to increase penetration of the intermittent renewable energy sources or to achieve a 100% renewable island, region or country. The paper also represents a stepping-stone for studies offering wider possibilities in matching and satisfying electricity supply in Portugal with potential renewable energy sources. Special attention has been given to intermittent sources such as wind, solar and ocean waves that can be coupled to appropriate energy storage systems charged with surplus amounts of produced electricity. The storage systems also decrease installed power requirements for generating units. Consequently, these storages will assist in avoiding unnecessary rejection of renewable potential and reaching a sufficient security of energy supply.     

Energy prosumerism using photovoltaic power plant and hydrogen combustion engine: Energy and thermo-ecological assessment

Renewable Energy Sources (RES) represent an attractive way to save natural resources and improve the overall impact of power systems on the environment. A continuous increase of share of RES in national energy mixes is observed, and due to the energy policy of the European Union and many other countries, further increase is expected. A disadvantage of RES is their random, weather-dependent availability, which requires energy storage. A promising method of integrating RES with the energy system is the use of hydrogen as an energy carrier (e.g. coupling RES with electrolyzers in order to directly use the renewable electricity for production of hydrogen). In the present work, a simulation of cooperation of a photovoltaic power plant with a gas piston engine fueled by hydrogen was performed, with and without the presence of energy storage. The aim of the analysis is twofold. First, the “compensation losses” due to forced part-load operation of the engine coupled with RES are evaluated and compared with “storage losses” resulting from the thermodynamic imperfectness of the storage; this allows to calculate the minimum round-trip efficiency of storage required for positive energy effect. The “compensation losses” have been determined to be of the order of magnitude of 2%, and the minimum round-trip efficiency of storage to be at the level of 85%. Second, a thermo-ecological analysis was carried out to determine the impact of the source of hydrogen on the overall ecological effectiveness of the system. Contrary to the commonly used measure of “energy efficiency” describing a local balance boundary, thermo-ecological cost (TEC) evaluates the consumption of non-renewable exergy within a global balance boundary. The analysis confirmed that comparing various hydrogen production methods (especially renewable and non-renewable) in terms of local energy efficiency is inadequate, because it does not tell much about their sustainability. For a hydrogen energy system basing on the water electrolysis – hydrogen transport/storage – combustion in a gas piston engine pathway to be considered sustainable, the input electricity to the electrolysis process should be characterized by TEC lower than ∼0.15 J1/J, a value which even some renewable energy sources fail to achieve.     

Assessing green energy growth in Nepal with a hydropower-hydrogen integrated power grid model

The involvement of green hydrogen in energy transformation is getting global attention. This assessment examines the hydrogen production and its utilization potential in one of the hydropower-rich regions, Nepal under various demand growth and technology intervention scenarios by developing a power grid model of 52 nodes and 68 transmission lines operating at an hourly time-step. The model incorporates a grid-connected hydrogen storage system as well as charging stations for electric and hydrogen vehicles. The least-costly pathways for power grid expansion at the nodal and provincial levels are identified through optimization. The results show that 32 GW of installed capacity is required to meet domestic electricity demand and 14 GW more hydropower should be exploited to completely decarbonize the transport sector by 2050. For maintaining 50% shares of hydrogen vehicle in the transport sector and meet government electricity export targets, Nepal requires 5.7 GW, 12 GW and 23 GW of the additional electrolyzer, hydrogen storage tanks and storage-based hydropower capacities respectively. For a given electricity demand, introducing hydrogen systems can reduce the capacity requirements of hydro storage by storing surplus power generated from pondage run-of-the-river and run-of-the-river hydropower during the rainy season and using it in the dry season.     

SUNRISE – A caesura after nuclear has gone: Energy in Germany(and in other potentially de-nuclearizing countries)

The German Bundestag decided June 30, 2011 to shut down by 2022 stepwise the complete national nuclear power plant capacity which at the time of decision generated some 22% of the nation’s electricity demand. This presentation tries to present a technology forecast of three potential compensations 1) energy and exergy efficiency gains, 2) renewable energies, and 3) hydrogen energy, thereby bearing in mind that fossil fuels such as coal, mineral oil and natural gas will by no means be gone after that short 10 year transition time. Consequently, not only the three compensations, but also fossil fuels – now efficient to the technological utmost – have to meet the obligation of reducing anthropogenic environmental and climate changing influences, and, in Germany’s case with 75% of its energy demand covered by imports of great importance, try to decrease the almost life risking high import rate by distributing suppliers all over the world and start introducing global clean renewable energies and trade in renewable hydrogen energy. Whether SUNRISE will evolve into a paragon for all those nations thinking of, planning for, or already taking the first steps towards saying farewell to nuclear is too early to determine. The four components of energy sustainability compensating for nuclear – energy and exergy efficiency gains, clean fossil, solar and hydrogen – pluck up courage, make headway and leave nuclear behind. And, in particular, hydrogen energy is and will increasingly become humankind’s common cause!     

Transient simulation and techno-economic assessment of a near-zero energy building using a hydrogen storage system and different backup fuels

Proposing a cost-effective off-grid Hybrid Renewable Energy System (HRES) with hydrogen energy storage with a minimum CO2 emission is the main objective of the current study. The electricity demand of an office building is considered to be supplied by Photovoltaic Panels and wind turbines. The office building, modeled in Energy Plus and Open studio, has annual electricity consumption of 500 MWh electricity. 48.9% of the required electricity can be generated via renewable resources. Considering a system without energy storage, the remaining amount of electricity is generated from diesel generators. Hence, for reducing CO2 emission and fuel costs, a hydrogen energy storage system (ESS) is integrated into the system. Hydrogen ESS is responsible for supplying 38.6% of the demand electricity, which means that it can increase the energy supplying ability of the system from 48.9% to 87.5%. In addition to analyzing the application of the hydrogen storage system, the effect of four different kinds of fuel is considered as well. effects of Natural gas, Diesel, Propane, and LPG on the system's application are investigated in this study. Results indicate that natural gas emits less amount of CO2 compared to other fuels and also has a fuel cost of 3054 $/year, while hydrogen ESS is available. For the renewable system without ESS, the fuel cost rises to 10,266 $/year. However, liquid gas, Propane, and LPG have better performance in terms of CO2 emission and fuel cost, respectively.     

Questioning hydrogen

As an energy carrier, hydrogen is to be compared to electricity, the only widespread and viable alternative. When hydrogen is used to transmit renewable electricity, only 51% can reach the end user due to losses in electrolysis, hydrogen compression, and the fuel cell. In contrast, conventional electric storage technologies allow between 75% and 85% of the original electricity to be delivered. Even when hydrogen is extracted from gasified coal (with carbon sequestration) or from water cracked in high-temperature nuclear reactors, more of the primary energy reaches the end user if a conventional electric process is used instead. Hydrogen performs no better in mobile applications, where electric vehicles that are far closer to commercialization exceed fuel cell vehicles in efficiency, cost and performance. New, carbon-neutral energy can prevent twice the quantity of GHG's by displacing fossil electricity than it can by powering fuel cell vehicles. The same is true for new, natural gas energy. New energy resources should be used to displace high-GHG electric generation, not to manufacture hydrogen.     

The economics and the environmental benignity of different colors of hydrogen

Due to the increasing greenhouse gas emissions, as well as due to the rapidly increasing use of renewable energy sources in the electricity generation over the last years, interest in hydrogen is rising again. Hydrogen can be used as a storage for renewable energy balancing the whole energy systems, and contributing to the decarbonization of the energy system, especially of the industry and the transport sector.The major objective of this paper is to discuss various ways of hydrogen production depending on the primary energy sources used. Moreover, the economic and environmental performance of three major hydrogen colors, as well as major barriers for faster deployment in fuel cell vehicles, are analyzed.The major conclusion is that the full environmental benefits of hydrogen use are highly dependent on the hydrogen production methods and primary sources used. Only green hydrogen with electricity from wind, PV and hydro has truly low emissions. All other sources like blue hydrogen with CCUS or electrolysis using the electricity grid have substantially higher emissions, coming close to grey hydrogen production. Another conclusion is that it is important to introduce an international market for hydrogen to lower costs and to produce hydrogen where conditions are best.Finally, the major open question remaining is whether – including all external costs of all energy carriers, hydrogen of any color may become economically competitive in any sector of the energy system. The future success of hydrogen is very dependent on technological development and resulting cost reductions, as well as on future priorities and the corresponding policy framework. The policy framework should support the shift from grey to green hydrogen.     

The first step towards a 100% renewable energy-system for Ireland

In 2007 Ireland supplied 96% of the total energy demand with fossil fuels (7% domestic and 89% imported) and 3% with renewable energy, even though there are enough renewable resources to supply all the energy required. As energy prices increase and the effects of global warming worsen, it is essential that Ireland begins to utilise its renewable resources more effectively. Therefore, this study presents the first step towards a 100% renewable energy-system for Ireland. The energy-system analysis tool used was EnergyPLAN, as it accounts for all sectors of the energy-system that need to be considered when integrating large penetrations of renewable energy: the electricity, heat, and transport sectors. Initially, a reference model of the existing Irish energy-system was constructed, and subsequently three different 100% renewable energy-systems were created with each focusing on a different resource: biomass, hydrogen, and electricity. These energy-systems were compared so that the benefits from each could be used to create an ‘optimum’ scenario called combination. Although the results illustrate a potential 100% renewable energy-system for Ireland, they have been obtained based on numerous assumptions. Therefore, these will need to be improved in the future before a serious roadmap can be defined for Ireland’s renewable energy transition.     

The renewable energy targets of the Maghreb countries: Impact on electricity supply and conventional power markets

Morocco, Algeria and Tunisia, the three countries of the North African Maghreb region, are showing increased efforts to integrate renewable electricity into their power markets. Like many other countries, they have pronounced renewable energy targets, defining future shares of “green” electricity in their national generation mixes. The individual national targets are relatively varied, reflecting the different availability of renewable resources in each country, but also the different political ambitions for renewable electricity in the Maghreb states. Open questions remain regarding the targets’ economic impact on the power markets. Our article addresses this issue by applying a linear electricity market optimization model to the North African countries. Assuming a competitive, regional electricity market in the Maghreb, the model minimizes dispatch and investment costs and simulates the impact of the renewable energy targets on the conventional generation system until 2025. Special emphasis is put on investment decisions and overall system costs.     

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.     

Technical and economic analysis of electricity generation from forest, fossil, and wood-waste fuels in a Finnish heating plant

The Finnish energy industry is subject to policy decisions regarding renewable energy production and energy efficiency. Conventional electricity generation has environmental side-effects that may cause global warming. Renewable fuels are superior because they offer near-zero net emissions.In this study, I investigated a heating mill’s ability to generate electricity from forest fuels in southern Finland on a 1-year strategic decision-making horizon. I solved the electricity generation problem using optimization of the energy products and fuel mixtures based on energy efficiency and forest technology. The decision environment was complicated by the sequence-dependent procurement chains for forest fuels. The optimal product and fuel mixtures were selected by minimizing procurement costs, maximizing production revenues, and minimizing energy losses.The combinatorial complexity of the problem required the use of adaptive techniques to solve a multiple-objective linear programming system with industrial relevance. I discuss the properties of the decision-support system and methodology and illustrate pricing of electricity generation based on real industrial data. The electricity-generation, -purchase, and -sales decisions are made based on a comprehensive technical and economic analysis that accounts for procurement of local forest fuels in a holistic supply chain model.     

Management of variable electricity loads in wind – Hydrogen systems: The case of a Spanish wind farm

The main obstacles of most renewable energies are their variability and availability; thus, we propose the ‘hydrogen option’ as a means of energy management, and we study its feasibility in a specific wind farm. The installation will be capable to store electrochemically the surplus energy and return the electricity to the grid during the peak hours. The solution was to connect the system, so that we store the energy as hydrogen when the wind generation exceeds a threshold; this is done by an electrolyzer set, with the appropriate nominal power, where, besides the electrical conversion devices, we have designed a control programme for tuning the voltage and current densities to the optimal operation of the cells. To utilize the hydrogen downstream the storage subsystem, we have selected a fuel-cell and the output is finally converted to the grid requirements.     

Economic viability and production capacity of wind generated renewable hydrogen

Generally, wind to power conversion is calculated by assuming the quality of wind as measured with a Weibull probability distribution at wind speed during power generation. We build on this method by modifying the Weibull distributions to reflect the actual range of wind speeds and wind energy density. This was combined with log law that modifies wind speed based on the height from the ground, to derive the wind power potential at windy sites. The study also provides the Levelized cost of renewable energy and hydrogen conversion capacity at the proposed sites. We have also electrolyzed the wind-generated electricity to measure the production capacity of renewable hydrogen. We found that all the sites considered are commercially viable for hydrogen production from wind-generated electricity. Wind generated electricity cost varies from $0.0844 to $0.0864 kW h, and the supply cost of renewable hydrogen is $5.30 to $ 5.80/kg-H₂. Based on the findings, we propose a policy on renewable hydrogen fueled vehicles so that the consumption of fossil fuels could be reduced. This paper shall serve as a complete feasibility study on renewable hydrogen production and utilization.     

Canada’s constitutional separation of (wind) power

This paper investigates the impact that a federal government structure has on strategic selection of renewable energy policy instruments. The context for this study centers on wind power development in Canada. Canada is a nation that is blessed by all the attributes necessary to catalyze global leadership in installed wind power capacity. Unfortunately, the constitutional separation of powers that underpins Canada’s federal system impedes the creation of a national wind power development strategy because Canada’s provinces have constitutional authority over electricity governance. The insights gleaned from the case study are used to develop a conceptual framework for understanding the impact that federal structure has on policy instrument selection and efficacy under areas of federal, regional and concurrent policy jurisdiction. Finally, this framework is re-applied to identify specific approaches the Canadian federal government could take to resolve what currently amounts to be a fragmented, ineffective approach to wind power development planning.     

Societal penetration of hydrogen into the future energy system: Impacts of policy,technology and carbon targets

Decarbonization of the energy system is a key goal of the Paris Agreements, in order to limit temperature rises to under 2° Celsius. Hydrogen has the potential to play a key role through its versatile production methods, end uses and as a storage medium for renewable energy, engendering the future low-carbon energy system. This research uses a global model cognizant of energy policy, technology learning curves and international carbon reduction targets to optimize the future energy system in terms of cost and carbon emissions to the year 2050. Exploring combinations of four exploratory scenarios incorporating hydrogen city gas blend levels, nuclear restrictions, regional emission reduction obligations and carbon capture and storage deployment timelines, it was identified that hydrogen has the potential to supply approximately two percent of global energy needs by 2050. Irrespective of the quantity of hydrogen produced, the transport sector and passenger fuel cell vehicles are consistently a preferential end use for future hydrogen across regions and modeled scenarios. In addition to the potential contribution of hydrogen, a shift toward renewable energy and a significant role for carbon capture and storage is identified to underpin carbon target achievement by 2050.     

Large-scale compressed hydrogen storage as part of renewable electricity storage systems

Storing energy in the form of hydrogen is a promising green alternative. Thus, there is a high interest to analyze the status quo of the different storage options. This paper focuses on the large-scale compressed hydrogen storage options with respect to three categories: storage vessels, geological storage, and other underground storage alternatives. In this study, we investigated a wide variety of compressed hydrogen storage technologies, discussing in fair detail their theory of operation, potential, and challenges. The analysis confirms that a techno-economic chain analysis is required to evaluate the viability of one storage option over another for a case by case. Some of the discussed technologies are immature; however, this does not rule out these technologies; rather, it portrays the research opportunities in the field and the foreseen potential of these technologies. Furthermore, we see that hydrogen would have a significant role in balancing intermittent renewable electricity production.     

Renewable energy policy in Turkey with the new legal regulations

Since the energy crises in the 1970’s, public and private decision makers are considering how to achieve a sustainable transition from fossil fuel based energy to sustainable and clean energies - namely renewable energies. Combined with the improvement of energy efficiency and the rational use of energy, renewable energy can provide everything fossil fuels currently offer in terms of heating and cooling, electricity generation and transportation. Renewable energy technologies posses many long term benefits including energy security, job creation, business opportunities, sustainable development and prevention of global warming.Turkey’s population is growing at an annual rate of 1.04%. If Turkey uses only traditional energy sources, it simply will not have enough energy capacity for its population. Renewable energy sources have the potential to make a large contribution to Turkey’s sustainable and independent energy future.Turkey aims to utilize its energy potential, including from renewable sources in a cost-effective manner. Turkey targets the share of renewable resources in electricity generation to be at least 30% by 2023 has in its 2009 Electricity Market and Security of Supply Strategy. Positive achievements have been obtained in renewable energy development and manufacturing in Turkey over the past decade. The renewable energy related legislation has been intensified. To meet its 30% target, the current promotion mechanism for renewable sources of electricity relies on feed-in tariffs for different renewable energy sources. Large hydropower is already competitive to conventional fossil-based electricity, so feed-in tariffs in the new RE Law are set to facilitate expanding the deployment of other, less mature renewable energy technologies.     

Risk analysis for the infrastructure of a hydrogen economy

Increasing scarcity of fossil fuels makes the deployment of hydrogen in combination with renewable energy sources, nuclear energy or the utilization of electricity from full time operation of existing power stations an interesting alternative. A pre-requisite is, however, that the safety of the required infrastructure is investigated and that its design is made such that the associated risk is at least not higher than that of existing supplies. Therefore, a risk analysis considering its most important objects such as storage tanks, filling stations, vehicles as well as heating and electricity supplies for residential buildings was carried out. The latter are considered as representative of the entire infrastructure. The study is based on fault and event tree analyses, wherever required, and consequence calculations using the PHAST code. The procedure for evaluating the risk and corresponding results are presented taking one of the objects as an example.