Publications

The Hydrogen Economy concept is being proposed as a means of reducing and eventually decarbonising the world’s energy use. It looks to hydrogen as being a replacement for methane (natural gas) and generally as a way of removing all fossil fuels from the energy supply. The concept however has at least four flaws as follows: (1) hydrogen has significantly different properties to methane; (2) hydrogen has properties that create significant hazards; (3) hydrogen has a very small initiation (activation) energy; and (4) liquid hydrogen cannot readily replace liquefied natural gas (LNG). Hydrogen’s hazards will prevent it from being accepted in a societal sense. To the question ‘Can the Hydrogen Economy concept be the solution to the future energy crisis?’ the answer is ‘no’. Hydrogen has and will have a role in world energy but that role will be limited to industry. For the future we need an advanced electric economy.

ITM Power is a leading electrolyser manufacturer and is a globally recognised expert in hydrogen technologies. In this episode Graham Cooley Chief Executive Officer at ITM Power and John Williams Head of Hydrogen Expertise Cluster at AFRY Management Consulting join us to discuss ITM’s recent announcements. This includes raising £250 million to scale up its electrolyser manufacturing capacity to 5GW per annum by 2024 and forming a partnership with Linde to halve electrolyser manufacturing costs within five years. The episode also explores the UK hydrogen strategy how blue hydrogen compares with green hydrogen the role of electrolysers in hydrogen production and providing flexibility to power grids.

The podcast can be found on their website.

The number of demonstration projects with fuel cell buses has been increasing worldwide. The goal of this paper is to analyse prospects and barriers for fuel cell buses focusing on their economic- technical- and environmental performance. Our results show that the prices of fuel cell buses although decreasing over time are still about 40% higher than those of diesel buses. With the looming ban of diesel vehicles and current limitations of battery electric vehicles fuel cell buses could become a viable alternative in the mid-to long-term. With the requirements for a better integration of renewable energy sources in the transport system interest in hydrogen is rising. Hydrogen produced from renewables used in fuel cell buses has the potential to save about 93% of CO2 emissions in comparison to diesel buses. Yet from environmental point-of-view it has to be ensured that hydrogen is produced from renewables. Currently the major barrier for a faster penetration of fuel cell buses are their high purchase prices which could be significantly reduced with the increasing number of buses through technological learning. The final conclusion is that a tougher transport policy framework is needed which fully reflects the environmental impact of different buses used.

The maritime transport and the port-logistic industry are key drivers of economic growth although they represent major contributors to climate change. In particular maritime port facilities are typically located near cities or residential areas thus having a significant direct environmental impact in terms of air and water quality as well as noise. The majority of the pollutant emissions in ports comes from cargo ships and from all the related ports activities carried out by road vehicles. Therefore a progressive reduction of the use of fossil fuels as a primary energy source for these vehicles and the promotion of cleaner powertrain alternatives is in order. The present study deals with the design of a new propulsion system for a heavy-duty vehicle for port applications. Specifically this work aims at laying the foundations for the development of a benchmark industrial cargo–handling hydrogen-fueled vehicle to be used in real port operations. To this purpose an on-field measurement campaign has been conducted to analyze the duty cycle of a commercial Diesel-engine yard truck currently used for terminal ports operations. The vehicle dynamics has been numerically modeled and validated against the acquired data and the energy and power requirements for a plug-in fuel cell/battery hybrid powertrain replacing the Diesel powertrain on the same vehicle have been evaluated. Finally a preliminary design of the new powertrain and a rule-based energy management strategy have been proposed and the electric energy and hydrogen consumptions required to achieve the target driving range for roll-on and roll-off operations have been estimated. The results are promising showing that the hybrid electric vehicle is capable of achieving excellent energy performances by means of an efficient use of the fuel cell. An overall amount of roughly 12 kg of hydrogen is estimated to be required to accomplish the most demanding port operation and meet the target of 6 h of continuous operation. Also the vehicle powertrain ensures an adequate all-electric range which is between approximately 1 and 2 h depending on the specific port operation. Potentially the hydrogen-fueled yard truck is expected to lead to several benefits such as local zero emissions powertrain noise elimination reduction of the vehicle maintenance costs improving of the energy management and increasing of operational efficiency.

The holistic green energy transition of non-interconnected islands faces several challenges if all the energy sectors are included i.e. electricity heating/cooling and mobility. On the one hand the penetration of renewable energy systems (RES) is limited due to design restrictions with respect to the peak demand. On the other hand energy-intensive heating and mobility sectors pose significant challenges and may be difficult to electrify. The focus of this study is on implementing a hybrid Wind–PV system on the non-interconnected island of Anafi (Greece) that utilizes surplus renewable energy production for both building heating through heat pumps and hydrogen generation. This comprehensive study aims to achieve a holistic green transition by addressing all three main sectors—electricity heating and transportation. The produced hydrogen is utilized to address the energy needs of the mobility sector (H2 mobility) focusing primarily on public transportation vehicles (buses) and secondarily on private vehicles. The overall RES production was modeled to be 91724 MWh with a RES penetration of 84.68%. More than 40% of the produced electricity from RES was in the form of excess electricity that could be utilized for hydrogen generation. The modeled generated hydrogen was simulated to be more than 40 kg H2/day which could cover all four bus routes of the island and approximately 200 cars for moderate use i.e. traveled distances of less than 25 km/day for each vehicle.

While Afghanistan’s power sector is almost completely dependent on fossil fuels it still cannot meet the rising power demand of this country. Deploying a combination of renewable energy systems with hydrogen production as the excess energy storage mechanism could be a sustainable long-term approach for addressing some of the energy problems of Afghanistan. Since Badakhshan is known to have a higher average wind speed than any other Afghan province in this study a technical economic and carbon footprint assessment was performed to investigate the potential for wind power and hydrogen production in this province. Wind data of four stations in Badakhshan were used for technical assessment for three heights of 10 30 and 40 m using the Weibull probability distribution function. This technical assessment was expanded by estimating the energy pattern factor probability of wind speeds greater than 5 m/s wind power density annual power output and annual hydrogen output. This was followed by an economic assessment which involved computing the Leveled Cost Of Energy (LCOE) the Leveled Cost Of Hydrogen (LCOH) and the payback period and finally an carbon footprint assessment which involved estimating the consequent CO2 reduction in two scenarios. The assessments were performed for 22 turbines manufactured by reputable companies with capacities ranging from 600 kW to 2.3 MW. The results showed that the entire Badakhshan province and especially Qal’eh-ye Panjeh and Fayazabad have excellent potentials in terms of wind energy that can be harvested for wind power and hydrogen production. Also wind power generation in this province will be highly cost-effective as the produced electricity will cost about one-third of the price of electricity supplied by the government. For better evaluation the GIS maps of wind power and hydrogen outputs were prepared using the IDW method. These maps showed that the eastern and northeastern parts of Badakhshan province have higher wind power-hydrogen production potentials. The results of ranking the stations with SWARA-EDAS hybrid MCDM methods showed that Qal’eh-ye Panjeh station was the best location to produce hydrogen from wind energy.

Hydrogen technologies are promising candidates of new energy technologies for electric power load smoothing. However regardless of long-term public investment hydrogen economy has not been realized. In Japan the National Research and Development Institute of New Energy and Industrial Technology Development Organization (NEDO) a public research-funding agency has invested more than 200 billion yen in the technical development of hydrogen-related technologies. However hydrogen technologies such as fuel cell vehicles (FCVs) have not been disseminated yet. Continuous and strategic research and development (R&D) are needed but there is a lack of expertise in this field. In this study the transition of the budgetary allocations by NEDO were analyzed by classifying NEDO projects along the hydrogen supply chain and research stage. We found a different R&D focus in different periods. From 2004 to 2007 empirical research on fuel cells increased with the majority of research focusing on standardization. From 2008 to 2011 investment in basic research of fuel cells increased again the research for verification of fuel cells continued and no allocation for research on hydrogen production was confirmed. Thereafter the investment trend did not change until around 2013 when practical application of household fuel cells (ENE-FARM) started selling in 2009 in terms of hydrogen supply chain. Hydrogen economy requires a different hydrogen supply infrastructure that is an existing infrastructure of city gas for ENE-FARM and a dedicated infrastructure for FCVs (e.g. hydrogen stations). We discussed the possibility that structural inertia could prevent the transition to investing more in hydrogen infrastructure from hydrogen utilization technology. This work has significant implications for designing national research projects to realize hydrogen economy.

The development of clean hydrogen and photovoltaic (PV) systems is lagging behind the goals set in the Net Zero Emissions scenario of the International Energy Agency. For this reason efficient hydrogen production systems powered from renewable energy need to be deployed faster. This work presents an optimization procedure for a stand-alone fully PVpowered alkaline electrolysis system. The approach is based on the Particle Swarm Optimization algorithm to obtain the best configuration of the PV plant that powers the electrolyzer and its compressor. The best configuration is determined with one of three indicators: cost efficiency or wasted energy. The PV plant needs to be oversized 2.63 times with respect to the electrolyzer to obtain minimum cost while for high efficiency this number increases by 2%. Additionally the configuration that minimizes cost wasted energy or maximizes efficiency does not correspond to the configuration that maximizes the annual PV yield. Optimizing for cost results also leads to the best operation of the electrolyzer at partial loads than optimizing for efficiency or wasted energy.

The intermittent production of the renewable energy imposes the necessity to temporarily store it. Large amounts of exceeding electricity can be stored in geological strata in the form of hydrogen. The conversion of hydrogen to electricity and vice versa can be performed in electrolyzers and fuel elements by chemical methods. The nowadays technical solution accepted by the European industry consists of injecting small concentrations of hydrogen in the existing storages of natural gas. The progressive development of this technology will finally lead to the creation of underground storages of pure hydrogen. Due to the low viscosity and low density of hydrogen it is expected that the problem of an unstable displacement including viscous fingering and gravity overriding will be more pronounced. Additionally the injection of hydrogen in geological strata could encounter chemical reactivity induced by various species of microorganisms that consume hydrogen for their metabolism. One of the products of such reactions is methane produced from Sabatier reaction between H2 and CO2. Other hydrogenotrophic reactions could be caused by acetogenic archaea sulfate-reducing bacteria and iron-reducing bacteria. In the present paper a mathematical model is presented which is capable to reflect the coupled hydrodynamic and bio-chemical processes in UHS. The model has been numerically implemented by using the open source code DuMuX developed by the University of Stuttgart. The obtained bio-chemical version of DuMuX was used to model the evolution of a hypothetical underground storage of hydrogen. We have revealed that the behavior of an underground hydrogen storage is different than that of a natural gas storage. Both the hydrodynamic and the bio-chemical effects contribute to the different characteristics.

Autonomous Underwater Vehicles (AUVs) are vehicles that are primarily used to accomplish oceanographic research data collection and auxiliary offshore tasks. At the present time they are usually powered by lithium-ion secondary batteries which have insufficient specific energies. In order for this technology to achieve a mature state increased endurance is required. Fuel cell power systems have been identified as an effective means to achieve this endurance but no implementation in a commercial device has yet been realized. This paper summarizes the current state of development of the technology in this field of research. First the most adequate type of fuel cell for this application is discussed. The prototypes and design concepts of AUVs powered by fuel cells which have been developed in the last few years are described. Possible commercial and experimental fuel cell stack options are analyzed examining solutions adopted in the analogous aerial vehicle applications as well as the underwater ones to see if integration in an AUV is feasible. Current solutions in oxygen and hydrogen storage systems are overviewed and energy density is objectively compared between battery power systems and fuel cell power systems for AUVs. A couple of system configuration solutions are described including the necessary lithium-ion battery hybrid system. Finally some closing remarks on the future of this technology are given.