Publications

Among the several typologies of storage technologies mainly on different physical principles (mechanical electrical and chemical) hydrogen produced by power to gas (P2G) from renewable energy sources complies with chemical storage principle and is based on the conversion of electrical energy into chemical energy by means of the electrolysis of water which does not produce any toxic or climate-relevant emission. This paper aims to pinpoint the potential uses of renewable hydrogen storage systems in Europe analysing current and potential locations regulatory framework governments’ outlooks economic issues and available renewable energy amounts. The expert opinion survey already used in many research articles on different topics including energy has been selected as an effective method to produce realistic results. The obtained results highlight strategies and actions to optimize the storage of hydrogen produced by renewables to face varying electricity demand and generation-driven fluctuations reducing the negative effects of the increasing share of renewables in the energy mix of European Countries.

Power-to-gas is a promising option for storing interment renewables nuclear baseload power and distributed energy and it is a novel concept for the transition to increased renewable content of current fuels with an ultimate goal of transition to a sustainable low-carbon future energy system that interconnects power transportation sectors and thermal energy demand all together. The aim of this paper is to introduce different Power-to-gas “pathways” including Power to Hydrogen Power to Natural Gas End-users Power to Renewable Content in Petroleum Fuel Power to Power Seasonal Energy Storage to Electricity Power to Zero Emission Transportation Power to Seasonal Storage for Transportation Power to Micro grid Power to Renewable Natural Gas (RNG) to Pipeline (“Methanation”) and Power to Renewable Natural Gas (RNG) to Seasonal Storage. In order to compare the different pathways the review of key technologies of Power-to-gas systems are studied and the qualitative efficiency and benefits of each pathway is investigated from the technical points of view. Moreover different Power-to-gas pathways are discussed as an energy policy option that can be implemented to transition towards a lower carbon economy for Ontario’s energy systems

Hydrogen is widely produced and used for our day-to-day needs. It has also the potential to be used as fuel for industry or can be used as an energy carrier for stationary power. Hydrogen can be produced by different processes like from fossil fuels (Steam methane reforming coal gasification cracking of natural gas); renewable resources (electrolysis wind etc.); nuclear energy (thermochemical water splitting). In this paper few processes have been discussed briefly. Cracking of methane has been given special emphasis in this review for production of hydrogen. There are mainly two types of cracking non-catalytic and catalytic. Catalytic cracking of methane is governed mainly by finding a suitable catalyst; its generation deactivation activation and filament formation for the adsorption of carbon particles (deposited on metal surface); study of metallic support which helps in finding active sites of the catalyst for the reaction to proceed easily. Non-catalytic cracking of methane is mainly based on thermal cracking. Moreover several thermal cracking processes with their reactor configurations have been discussed.

The way to decarbonization will be characterized by the huge production of hydrogen through sustainable routes. Thus the basic production way is water electrolysis sustained by renewable energy sources allowing for obtaining “green hydrogen”. The present paper reviews the main available technologies for the water electrolysis finalized to the hydrogen production. We describe the fundamental of water electrolysis and the problems related to purification and/or desalinization of water before electrolysis. As a matter of fact we describe the energy efficiency issues with particular attention to the potential application in the steel industry. The fundamental aspects related to the choice of high-temperature or low-temperature technologies are analyzed.

As part of the LTS Futures HyTechnical project IGEM requested that DNV GL undertake an assessment of the possible impact of hydrogen transmission on BPDs to support the development of supplements to the existing suite of natural gas standards to accommodate the possible future use of hydrogen. The current state of knowledge of the behaviour of large scale high pressure hydrogen releases is limited in comparison with the considerable body of data from research and operational experience of natural gas but is adequate to undertake an impact assessment to take account of the different gas outflow and fire characteristics of 100% hydrogen vs. natural gas.<br/>Calculations of the BPDs for 100% hydrogen pipeline fires on an equivalent basis to those in IGEM/TD/1 for natural gas have been performed with a degree of confidence in the results and demonstrated that the equivalent BPDs for 100% hydrogen are approximately 10% smaller than for natural gas. The results are presented graphically in this report.<br/>However hydrogen introduces the potential for substantially higher overpressures than natural gas due to the higher flame speed and wider flammable limits if delayed ignition is a credible event. The overpressure estimates presented in this report are intended to be scoping calculations to put the likely overpressures into context. The results suggest that significant overpressures are possible at the BPDs but there is a lack of evidence to support the estimation of the overpressures following delayed ignition of a large turbulent hydrogen release in the open (in contrast to explosions in confined or congested regions) and there is a high degree of uncertainty in the predictions presented here. It is therefore recommended that large scale pipeline rupture experiments are performed similar to those undertaken previously for hydrogen natural gas and natural gas/hydrogen mixtures but with ignition engineered to take place after a short delay in order to measure the overpressures and provide the means to validate or refine the predictions made.<br/>The analysis has highlighted limitations in the original method of calculating BPDs in IGEM/TD/1 which reflects the techniques available at the time approximately 40 years ago. Since then understanding of the hazards from pipeline failures and the ability to model the consequences and predict the associated risks to people in the surrounding area have advanced very considerably facilitated by software tools and documented in standards such as IGEM/TD/2. These methods allow the highly transient nature of a high pressure gas pipeline rupture release to be modelled more accurately and for the thermal effects of fires on people and buildings to be calculated taking account of the time-varying thermal dose.<br/>For these reasons a simple comparison of the possible overpressure effects of delayed ignition of a 100% hydrogen release at the BPDs can be misleading and implies that the overpressure hazards could be more severe than those for fires which may not be the case. Example calculations have been performed for a representative pipeline case which indicate that using current methods the predicted thermal hazard distances for 100% hydrogen pipeline fires (house burning and escape for people) are substantially greater than those estimated for overpressures following delayed ignition for similar levels of vulnerability. This report addresses buried pipelines only – the potential for more severe explosion overpressure effects for hydrogen releases may be more significant for Above Ground Installations (AGIs) especially where congestion or confinement may be present. It is recommended that similar studies are conducted to quantify the effect of hydrogen conversion on the consequences and risks associated with hydrogen releases at AGIs.<br/>Finally it is stressed that the analysis in this report does not consider the relative risks for 100% hydrogen and the equivalent natural gas pipelines. There remain uncertainties in the failure frequencies for steel pipelines transporting hydrogen and particularly the probability of immediate and delayed ignition. The likelihood of delayed ignition of a large turbulent high pressure hydrogen gas pipeline rupture release may be very low due to the wider flammability limits and lower minimum ignition energy for hydrogen compared with natural gas. Additional research is currently ongoing or planned to address the gaps in knowledge for 100% hydrogen which should allow more robust comparisons of the relative risks to be made in the future.

Electrifying transportation is a promising approach to alleviate climate change issues arising from increased emissions. This study examines a system for the production of hydrogen using renewable energy sources as well as its use in buses. The electricity requirements for the production of hydrogen through the electrolysis of water are covered by renewable energy sources. Fuel cells are being used to utilize hydrogen to power the bus. Exergy analysis for the system is carried out. Based on a steady-state model of the processes exergy efficiencies are calculated for all subsystems. The subsystems with the highest proportion of irreversibility are identified and compared. It is shown that PV panel has exergetic efficiency of 12.74% wind turbine of 45% electrolysis of 67% and fuel cells of 40%.

Shipping is one of the largest greenhouse gas (GHG) emitting sectors of the global economy responsible for around 1 Gt of CO₂eq every year. If shipping were a country it would be the 6th biggest GHG emitter. EU related shipping is responsible for about 1/5 of global ship GHG emissions emitting on average 200 Mt/year. This report assesses potential technology pathways for decarbonising EU related shipping through a shift to zero carbon technologies and the impact such a move could have on renewable electricity demand in Europe. It also identifies key policy and sustainability issues that should be considered when analysing and supporting different technology options to decarbonise the maritime sector. The basis of the study is outbound journeys under the geographical scope of the EU ship MRV Regulation.



We have not tried to quantify the emissions reductions that specific regulatory measures to be introduced at the IMO or EU level might contribute towards decarbonisation by 2050 because there are too many uncertainties. We have taken a more limited first approach and investigated how zero carbon propulsion pathways that currently seem feasible to decarbonise shipping would likely affect the future EU renewable energy supply needs.



It is now generally accepted that ship design efficiency requirements while potentially having an important impact on future emissions growth will fall well short of what is needed. Further operational efficiency measures such as capping operational speed will be important to immediately peak energy consumption and emissions but will be insufficient to decarbonise the sector or reduce its growing energy needs. In this context this study assumes that with all the likely immediate measures adopted energy demand for EU related shipping will still grow by 50% by 2050 over 2010 levels. This is within the range of the 20 -1 20% global BAU maritime energy demand growth estimate.



The decarbonisation of shipping will require changes in on -board energy storage and use and the necessary accompanying bunkering infrastructure. This study identifies the technology options for zero emission propulsion that based on current know-how are likely to be adopted. It is not exhaustive nor prescriptive because the ultimate pathways will likely depend on both the requirements of the shipping industry in terms of cost efficiency and safety and on the future renewable electricity sources that the shipping sect or will need to compete for.



Literature is nascent on the different techno-economic options likely to be available to decarbonise shipping and individual ships 4 but almost completely lacking on the possible impacts of maritime decarbonisation on the broader energy system(s). Understanding these impacts is nevertheless essential because it will influence financial and economic decision making by the EU and member states including those related to investment in future renewable energy supplies and new ship bunkering infrastructure. With this in mind the report aims to provide a preliminary first answer to the following question: Under different zero emission technology pathways how much additional renewable electricity would be needed to cater for the needs of EU related shipping in 2050?



Link to Document Download on Transport & Environment website

The CEP (Clean Energy Partnership) – Berlin is one of the most diversified hydrogen demonstration projects at present. The first hydrogen fuelling station serving 16 cars is fully integrated in an ordinary highly frequented Aral service station centrally located at Messedamm in Berlin. Hydro has supplied and is the owner of the electrolyser with ancillary systems. This unit produces gaseous hydrogen at 12 bar with use of renewable energy presently serving 13 of the cars involved. The CEP project is planned to run for a period of five years and is supported by the German Federal Government and is part of the German sustainability strategy. During the planning and design phase there have been done several safety related assessments and analyses:

• Hydro has carried out a HAZOP (HAZard and OPerability) analysis of the electrolyser and ancillary systems delivered by Hydro Electrolysers.
• Hydro arranged with support from the partners a HAZOP analysis of the interface between the electrolyser and the compressor an interface with two different suppliers on each side.
• A QRA (Quantitative Risk Assessment) of the entire fuelling station has been carried out.
• Hydro has carried out a quantitative explosion risk analysis of the electrolyser container supplied by Hydro Electrolysers.

The aim in the CEP-Berlin project was to follow the guidelines from the European Integrated Hydrogen Project phase 2 (EIHP2) [1] when planning and designing a new hydrogen fuelling station. These guidelines focus on installation and operation of hydrogen refuelling stations and were based upon best practice and knowledge from the industrial partners in EIHP 2. The explosion risk analysis for the CEP-Berlin facility demonstrated that the safety risk was acceptable if certain design modifications were carried out. Both Aral/BP and Hydro accepted the results from the quantitative risk assessments. These companies have also their own standards regarding safety acceptance criteria which have to be complied with. The fuelling station was opened November 12 2004 and was put in normal operation during winter 2005.

The World Energy Transitions Outlook preview outlines a pathway for the world to achieve the Paris Agreement goals and halt the pace of climate change by transforming the global energy landscape. This preview presents options to limit global temperature rise to 1.5°C and bring CO₂ emissions closer to net zero by mid-century offering high-level insights on technology choices investment needs and the socio-economic contexts of achieving a sustainable resilient and inclusive energy future.



Meeting CO₂ reduction targets by 2050 will require a combination of: technology and innovation to advance the energy transition and improve carbon management; supportive and proactive policies; associated job creation and socio-economic improvements; and international co-operation to guarantee energy availability and access.



Among key findings:

• Proven technologies for a net-zero energy system already largely exist today. Renewable power green hydrogen and modern bioenergy will dominate the world of energy of the future.
• A combination of technologies is needed to keep us on a 1.5°C climate pathway. These include increasingly efficient energy production to ensure economic growth; decarbonised power systems that are dominated by renewables; increased use of electricity in buildings industry and transport to support decarbonisation; expanded production and use of green hydrogen synthetic fuels and feedstocks; and targeted use of sustainably sourced biomass.
• In anticipation of the coming energy transition financial markets and investors are already directing capital away from fossil fuels and towards other energy technologies including renewables.
• Energy transition investment will have to increase by 30% over planned investment to a total of USD 131 trillion between now and 2050 corresponding to USD 4.4 trillion on average every year.
• National social and economic policies will play fundamental roles in delivering the energy transition at the speed required to restrict global warming to 1.5°C.

This preview identifies opportunities to support informed policy and decision making to establish a new global energy system. Following this preview and aligned with the UN High-Level Dialogue process the International Renewable Energy Agency (IRENA) will release the full report which will provide a comprehensive vision and accompanying policy measures for the transition.

Power-to-gas technology plays a key role in the success of the energy transformation. This paper addresses issues related to the legal and technical regulations specifying the rules for adding hydrogen to the natural gas network. The main issue reviewed is the effects of the addition of hydrogen to natural gas on the durability of diaphragm gas meters. The possibility of adding hydrogen to the gas network requires confirmation of whether within the expected hydrogen concentrations long-term operation of gas meters will be ensured without compromising their metrological properties and operational safety. Methods for testing the durability of gas meters applied at test benches and sample results of durability tests of gas meters are presented. Based on these results a metrological and statistical analysis was carried out to establish whether the addition of hydrogen affects the durability of gas meters over time. The most important conclusion resulting from the conducted study indicates that for the tested gas meter specimens there was no significant metrological difference between the obtained changes of errors of indications after testing the durability of gas meters with varying hydrogen content (from 0% to 15%).