Publications

Wind and solar energy are often expected to fall victim to their own success: the higher their share in electricity generation the more their revenue in electricity markets (their “market value”) declines. While market values may converge to zero in conventional power systems this study argues that “green” hydrogen production can effectively and permanently halt the decline by adding flexible electricity demand in low-price hours. To support this argument this article further develops the merit order model and uses price duration curves to include flexible hydrogen electrolysis and to derive an analytical formula for the minimum market value of renewables in the long-term market equilibrium. This hydrogen-induced minimum market value is quantified for a wide range of parameters using Monte Carlo simulations and complemented with results from a more detailed numerical electricity market model. It is shown that—due to flexible hydrogen production alone—market values across Europe will likely stabilize above €19 ± 9 MWh− 1 for solar energy and above €27 ± 8 MWh− 1 for wind energy in 2050 (annual mean estimate ± standard deviation). This is in the range of the projected levelized cost of renewables and other types of flexible electricity demand may further increase renewable market values. Market-based renewables may hence be within reach.

On this week’s episode the team discuss the appeal of modular reforming of biogas and natural gas with Mo Vargas from Bayotech. The company use a proprietary modular reformer technology to help provide low cost decentralise hydrogen production units for onsite demand at various scales using biogas waste gases and natural gas with carbon capture. With large scale steam methane reforming accounting for 95% of hydrogen production in major markets like the US and Europe today the team dive into the good the bad and the unusual considerations behind the growing international demand for modular methane reforming technologies and how Bayotech see the transition from a CO2 intensive process today to a net zero emission future. All this and more on the show!

The podcast can be found on their website

Bearing in mind the multiple effects of hydrogen in steels the specific mechanism of hydrogen embrittlement (HE) is active depending on the experimental conditions and numerous factors which can be grouped as environmental mechanical and material influences. A large number of contemporary studies and models about hydrogen environment assisted cracking and HE in steels are presented in the form of critical review in this paper. This critical review represent the necessary background for the development of a multiscale structural integrity model based on correlation between simultaneously active HE micro-mechanisms: the hydrogen-enhanced localized plasticity (HELP) and the hydrogen-enhanced decohesion (HEDE) - (HELP+HEDE) and macro-mechanical response of material unevenly enriched with hydrogen during service of boiler tubes in thermal fossil fuel power plant. Several different experimental methods and techniques were used to determine the boiler tube failure mechanism and afterwards also the viable HE mechanisms in the investigated ferritic-pearlitic low carbon steel grade 20 - St.20 (equivalent to AISI 1020). That represent a background for the development of a structural integrity model based on the correlation of material macro-mechanical properties to scanning electron microscopy fractography analysis of fracture surfaces of Charpy specimens in the presence of confirmed and simultaneously active HE micro-mechanisms (HELP+HEDE) in steel. The aim of this paper is to show how to implement what we have learned from theoretical HE models into the field to provide industry with valuable data and practical structural integrity model.

The graphene oxide @nickel phosphate (GO:NPO) nanocomposites (NCs) are prepared by using a one-pot in-situ solar energy assisted method by varying GO:NPO ratio i.e. 0.00 0.25 0.50 0.75 1.00 1.25 1.50 and 2.00 without adding any surfactant or a structure-directing reagent. As produced GO:NPO nanosheets exhibited an improved photocatalytic activity due to the spatial seperation of charge carriers through interface where photoinduced electrons transferred from NiPO4 to the GO sheets without charge-recombination. Out of the series the system 1.00 GO:NPO NC show the optimum hydrogen production activity (15.37 μmol H2 h−1) towards water splitting under the visible light irradiation. The electronic environment of the nanocomposite GO-NiO6/NiO4-PO4 elucidated in the light of advance experimental analyses and theoretical DFT spin density calculations. Structural advanmcement of composites are well correlated with their hydrogen production activity.

Body-centered cubic (BCC) alloys are considered as promising materials for hydrogen storage with high theoretical storage capacity (H/M ratio of 2). Nonetheless they often suffer from sluggish kinetics of hydrogen absorption and high hydrogen desorption temperature. Carbon materials are efficient hydrogenation catalysts however their influence on the hydrogen storage properties of BCC alloy has not been comprehensively studied. Therefore in this paper composites obtained by milling of carbon catalysts (carbon nanotubes mesoporous carbon carbon nanofibers diamond powder graphite fullerene) and BCC alloy (Ti1.5V0.5) were extensively studied in the non-hydrogenated and hydrogenated state. The structure and microstructure of the obtained materials were studied by scanning and transmission electron microscopes X-ray diffraction (XRD) and Raman spectroscopy. XRD and Raman measurements showed that BCC alloy and carbon structures were in most cases intact after the composite synthesis. The hydrogenation/dehydrogenation studies showed that all of the used carbon catalysts significantly improve the hydrogenation kinetics reduce the activation energy of the dehydrogenation process and decrease the dehydrogenation temperature (by nearly 100 K). The superior kinetic properties were measured for the composite with 5 wt % of fullerene that absorbs 3.3 wt % of hydrogen within 1 min at room temperature.

‘A System For All Seasons’ analyses Britain’s electricity generation and consumption trends concluding that the country’s wind and solar farms will have enough spare electricity generated in spring and summer when demand is lower to produce green hydrogen to the equivalent capacity of 25 Hinkley Point C nuclear power plants.

The hydrogen stored would provide the same amount of energy needed for every person in the UK to charge a Tesla Model S electric vehicle more than 21 times in the autumn and winter months when energy demand is highest creating a clean energy buffer that avoids having to manage limited energy supplies on the international markets.

Crucially the research finds that the UK has enough capacity to store the hydrogen in a combination of salt caverns and disused oil and gas fields in the North Sea as well other locations to meet this demand.

The research also finds that using renewable hydrogen will help reduce the total number of wind farms needed in 2050 by more than 75% because it will ensure electricity generated by Britain’s wind farms is used as efficiently as possible by avoiding surplus electricity going to waste.

‘A System For All Seasons’ finds that:

• Britain’s wind and solar farms could generate between 60-80GW of renewable hydrogen - the equivalent capacity of 25 Hinkley Point C nuclear power plants - from spare renewable electricity generated in the spring and summer months between May and October each year.
• Running the energy system this way will reduce the need for the total electricity generating capacity of UK wind farms from 500-600GW by 2050 down to 140-190GW – a reduction of up to 76%.
• It would mean Great Britain would be using spare renewable electricity that would otherwise go to waste to produce green hydrogen. Under the alternative scenario additional wind farms would need to be built to accommodate for autumn and wind energy demand peaks but be left unused during other times of the year.
• With 140-190GW of wind generation capacity 115 to 140TWh of green hydrogen would be stored – enough energy for every person in the UK to charge a Tesla Model S more than 21 times.
• The potential storage volume from Britain’s salt fields ranges from >1TWh up to 30TWh. For disused oil and gas fields the potential storage volume for individual sites ranges from ~1TWh up to 330TWh.

The unique layered morphology of van der Waals (vdW) heterostructures give rise to a blended set of electrochemical properties from the 2D sheet components. Herein an overview of their potential in energy storage systems in place of precious metals is conducted. The most recent progress on vdW electrocatalysis covering the last three years of research is evaluated with an emphasis on their catalytic activity towards the oxygen reduction reaction (ORR) oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). This analysis is conducted in pair with the most active Pt-based commercial catalyst currently utilized in energy systems that rely on the above-listed electrochemistry (metal–air battery fuel cells and water electrolyzers). Based on current progress in HER catalysis that employs vdW materials several recommendations can be stated. First stacking of the two types vdW materials with one being graphene or its doped derivatives results in significantly improved HER activity. The second important recommendation is to take advantage of an electronic coupling when stacking 2D materials with the metallic surface. This significantly reduces the face-to-face contact resistance and thus improves the electron transfer from the metallic surface to the vdW catalytic plane. A dual advantage can be achieved from combining the vdW heterostructure with metals containing an excess of d electrons (e.g. gold). Despite these recent and promising discoveries more studies are needed to solve the complexity of the mechanism of HER reaction in particular with respect to the electron coupling effects (metal/vdW combinations). In addition more affordable synthetic pathways allowing for a well-controlled confined HER catalysis are emerging areas.

Hydrogen as an environmentally friendly energy carrier has received special attention to solving uncertainty about the presence of renewable energy and its dependence on time and weather conditions. This material can be prepared from different sources and in various ways. In previous studies fossil fuels have been used in hydrogen production but due to several limitations especially the limitation of the access to this material in the not-too-distant future and the great problem of greenhouse gas emissions during hydrogen production methods. New methods based on renewable and green energy sources as energy drivers of hydrogen production have been considered. In these methods water or biomass materials are used as the raw material for hydrogen production. In this article after a brief review of different hydrogen production methods concerning the required raw material these methods are examined and ranked from different aspects of economic social environmental and energy and exergy analysis sustainability. In the following the current position of hydrogen production is discussed. Finally according to the introduced methods their advantages and disadvantages solar electrolysis as a method of hydrogen production on a small scale and hydrogen production by thermochemical method on a large scale are introduced as the preferred methods.

Considering the targets of the Paris agreement rapid decarbonisation of the power system is needed. In order to study cost-optimal and reliable zero and negative carbon power systems a power system model of Western Europe for 2050 is developed. Realistic future technology costs demand levels and generator flexibility constraints are considered. The optimised portfolios are tested for both favourable and unfavourable future weather conditions using results from a global climate model accounting for the potential impacts of climate change on Europe’s weather. The cost optimal mix for zero or negative carbon power systems consists of firm low-carbon capacity intermittent renewable energy sources and flexibility capacity. In most scenarios the amount of low-carbon firm capacity is around 75% of peak load providing roughly 65% of the electricity demand. Furthermore it is found that with a high penetration of intermittent renewable energy sources a high dependence on cross border transmission batteries and a shift to new types of ancillary services is required to maintain a reliable power system. Despite relatively small changes in the total generation from intermittent renewable energy sources between favourable and unfavourable weather years of 6% emissions differ up to 70 MtCO2 yr−1 and variable systems costs up to 25%. In a highly interconnected power system with significant flexible capacity in the portfolio and minimal curtailment of intermittent renewables the potential role of green hydrogen as a means of electricity storage appears to be limited.

Liquid hydrogen is the main fuel of large-scale low-temperature heavy-duty rockets and has become the key direction of energy development in China in recent years. As an important application carrier in the large-scale storage and transportation of liquid hydrogen liquid hydrogen cryogenic storage and transportation containers are the key equipment related to the national defense security of China’s aerospace and energy fields. Due to the low temperature of liquid hydrogen (20 K) special requirements have been put forward for the selection of materials for storage and transportation containers including the adaptability of materials in a liquid hydrogen environment hydrogen embrittlement characteristics mechanical properties and thermophysical properties of liquid hydrogen temperature which can all affect the safe and reliable design of storage and transportation containers. Therefore it is of great practical significance to systematically master the types and properties of cryogenic materials for the development of liquid hydrogen storage and transportation containers. With the wide application of liquid hydrogen in different occasions the requirements for storage and transportation container materials are not the same. In this paper the types and applications of cryogenic materials commonly used in liquid hydrogen storage and transportation containers are reviewed. The effects of low-temperature on the mechanical properties of different materials are introduced. The research progress of cryogenic materials and low-temperature performance data of materials is introduced. The shortcomings in the research and application of cryogenic materials for liquid hydrogen storage and transportation containers are summarized to provide guidance for the future development of container materials. Among them stainless steel is the most widely used cryogenic material for liquid hydrogen storage and transportation vessel but different grades of stainless steel also have different applications which usually need to be comprehensively considered in combination with its low temperature performance corrosion resistance welding performance and other aspects. However with the increasing demand for space liquid hydrogen storage and transportation the research on high specific strength cryogenic materials such as aluminum alloy titanium alloy or composite materials is also developing. Aluminum alloy liquid hydrogen storage and transportation containers are widely used in the space field while composite materials have significant advantages in being lightweight. Hydrogen permeation is the key bottleneck of composite storage and transportation containers. At present there are still many technical problems that have not been solved.