Ireland

Decarbonising economies and improving environment can be enhanced through circular economy energy and environmental systems integrating electricity water and gas utilities. Hydrogen production can facilitate intermittent renewable electricity through reduced curtailment of electricity in periods of over production. Positioning an electrolyser at a wastewater treatment plant with existing sludge digesters offers significant advantages over stand-alone facilities. This paper proposes co-locating electrolysis and biological methanation technologies at a wastewater treatment plant. Electrolysis can produce oxygen for use in pure or enhanced oxygen aeration offering a 40% reduction in emissions and power demand at the treatment facility. The hydrogen may be used in a novel biological methanation system upgrading carbon dioxide (CO2)in biogas from sludge digestion yielding a 54% increase in biomethane production. A 10MW electrolyser operating at 80% capacity would be capable of supplying the oxygen demand for a 426400 population equivalent wastewater treatment plant producing 8500 tDS/a of sludge. Digesting the sludge could generate 1409000 m 3 CH4/a and 776000 m 3 CO2/a. Upgrading the CO2 to methane would consume 22.2% of the electrolyser generated hydrogen and capture 1.534 ktCO2e/a. Hydrogen and methane are viable advanced transport fuels that can be utilised in decarbonising heavy transport. In the proposed circular economy energy and environment system sufficient fuel would be generated annually for 94 compressed biomethane gas (CBG) heavy goods vehicles (HGV) and 296 compressed hydrogen gas fuel cell (CHG) HGVs. Replacement of the equivalent number of diesel HGVs would offset approximately 16.1 ktCO2e/a.

Uncertainty surrounding the total cost of ownership system costs and life cycle environmental impacts means that stakeholders may lack the required information to evaluate the risks of transitioning to low-carbon fuels and powertrains. This paper assesses the life cycle costs and well-to-wheel environmental impacts of using electricity and electrofuels in Heavy Good Vehicles (HGVs) whilst considering input parameter uncertainty. The complex relationship between electricity cost electrolyser capacity factor CO2 capture cost and electricity emissions intensity is assessed within a Monte Carlo based framework to identify scenarios where use of electricity or electrofuels in heavy goods vehicles makes economic and environmental sense. For vehicles with a range of less than 450 km battery electric vehicles achieve the lowest total cost of ownership for an electricity cost less than 100 €/MWh. For vehicles that require a range of up to 900 km hydrogen fuel cell vehicles represent the lowest long-term cost of abatement. Power-to-methane and power-to-liquid scenarios become economically competitive when low-cost electricity is available at high-capacity factors and CO2 capture costs for fuel synthesis are below 100 €/tCO2; these fuels may be more applicable to decarbonise shipping and aviation. Battery electric HGVs reduce greenhouse gas emissions by 50% compared to the diesel baseline with electricity emissions of 350 gCO2e/kWh. Electricity emissions less than 35 gCO2e/kWh are required for the power-to-methane and power-to-liquid scenarios to meet EU emissions savings criteria. High vehicle capital costs and a lack of widespread refuelling infrastructure may hinder initial uptake of low-carbon fuels and powertrains for HGVs.

The rise in intermittent renewable electricity production presents a global requirement for energy storage. Biological hydrogen methanation (BHM) facilitates wind and solar energy through the storage of otherwise curtailed or constrained electricity in the form of the gaseous energy vector biomethane. Biological methanation in the circular economy involves the reaction of hydrogen – produced during electrolysis – with carbon dioxide in biogas to produce methane (4H2 + CO2 = CH4 + 2H2) typically increasing the methane output of the biogas system by 70%. In this paper several BHM systems were researched and a compilation of such systems was synthesized facilitating comparison of key parameters such as methane evolution rate (MER) and retention time. Increased retention times were suggested to be related to less efficient systems with long travel paths for gases through reactors. A significant lack of information on gas-liquid transfer co-efficient was identified

This paper describes the development of a general-purpose geospatial model for assessing the economic viability of hydrogen production from offshore wind power. A key feature of the model is that it uses the offshore project's location characteristics (distance to port water depth distance to gas grid injection point). Learning rates are used to predict the cost of the wind farm's components and electrolyser stack replacement. The notional wind farm used in the paper has a capacity of 510 MW. The model is implemented in a geographic information system which is used to create maps of levelised cost of hydrogen from offshore wind in Irish waters. LCOH values in 2030 spatially vary by over 50% depending on location. The geographically distributed LCOH results are summarised in a multivariate production function which is a simple and rapid tool for generating preliminary LCOH estimates based on simple site input variables.

The current research on green hydrogen can focus from the perspective of production but understanding the demand side is equally important to the initial creation of a hydrogen ecosystem in countries with low industrial activities that can utilise large amounts of hydrogen in the short term. Early movers in these countries must create a demand market in parallel with the green hydrogen plant commissioning. This paper presents research that explores the heavy-duty transport sector as a market-of-interest for early deployment of green hydrogen in Ireland. Conducting a survey-based market research amongst this sector indicate significant interest in hydrogen on the island of Ireland and the barriers the participants presented have been overcome in other jurisdictions. The study develops a model to estimate 1.) the annual hydrogen demand and 2.) the corresponding delivery cost to potential hydrogen consumers either directly or to central hydrogen fuelling hubs.

The National Hydrogen Strategy sets out the strategic vision on the role that hydrogen will play in Ireland’s energy system looking to its long-term role as a key component of a zero-carbon economy and the short-term actions that need to be delivered over the coming years to enable the development of the hydrogen sector in Ireland.<br/>The Strategy is being developed for three primary reasons:<br/>1. Decarbonising our economy providing a solution to hard to decarbonise sectors where electrification is not feasible or cost-effective<br/>2. Enhancing our energy security through the development of an indigenous zero carbon renewable fuel which can act as an alternative to the 77% of our energy system which today relies on fossil fuel imports<br/>3. Developing industrial opportunities through the potential development of export markets for renewable hydrogen and other areas such as Sustainable Aviation Fuels<br/>The Strategy considers the needs of the entire hydrogen value chain including production end-uses transportation and storage safety regulation markets innovation and skills.<br/>It also sets out that Ireland will focus its efforts on the scale up and production of renewable ""green"" hydrogen as it supports both our decarbonisation needs and energy security needs given our vast indigenous renewable resources. Renewable hydrogen is a renewable and zero-carbon fuel that can play a key role in the ""difficult-to-decarbonise"" sectors of our economy where other solutions such as direct electrification are not feasible or cost effective.<br/>In the coming years renewable hydrogen is envisioned to play an important role as a zero-emission source of dispatchable flexible electricity as a long duration store of renewable energy in decarbonising industrial processes and as a transport fuel in sectors such as heavy goods transport maritime and aviation. The Strategy will provide clarity for stakeholders on how we expect the hydrogen economy to develop and scale up over the coming decades across the entire value chain.

This paper presents the results of techno-economic modelling for hydrogen production from a photovoltaic battery electrolyser system (PBES) for injection into a natural gas transmission line. Mellitah in Libya connected to Gela in Italy by the Greenstream subsea gas transmission line is selected as the location for a case study. The PBES includes photovoltaic (PV) arrays battery electrolyser hydrogen compressor and large-scale hydrogen storage to maintain constant hydrogen volume fraction in the pipeline. Two PBES configurations with different large-scale storage methods are evaluated: PBESC with compressed hydrogen stored in buried pipes and PBESL with liquefied hydrogen stored in spherical tanks. Simulated hourly PV electricity generation is used to calculate the specific hourly capacity factor of a hypothetical PV array in Mellitah. This capacity factor is then used with different PV sizes for sizing the PBES. The levelised cost of delivered hydrogen (LCOHD) is used as the key techno-economic parameter to optimise the size of the PBES by equipment sizing. The costs of all equipment except the PV array and batteries are made to be a function of electrolyser size. The equipment sizes are deemed optimal if PBES meets hydrogen demand at the minimum LCOHD. The techno-economic performance of the PBES is evaluated for four scenarios of fixed and constant hydrogen volume fraction targets in the pipeline: 5% 10% 15% and 20%. The PBES can produce up to 106 kilotonnes of hydrogen per year to meet the 20% target at an LCOHD of 3.69 €/kg for compressed hydrogen storage (PBESC) and 2.81 €/kg for liquid hydrogen storage (PBESL). Storing liquid hydrogen at large-scale is significantly cheaper than gaseous hydrogen even with the inclusion of a significantly larger PV array that is required to supply additional electrcitiy for liquefaction.

Using a discrete choice experiment (DCE) a survey of international tourists on the island of Tenerife is conducted to examine preferences for fuel cell vehicle (FCV) rental while on vacation. Survey respondents were generally supportive of FCVs and willing to hire one as part of their trip but for most individuals this is contingent on an adequate fuel station infrastructure. A latent class model was used to identify three distinct groups; one of which potentially represent early adopters e they have a high willingness-to-pay (WTP) for green hydrogen and are more likely to accept a low number of fuel stations but it could be challenging to convince them to use FCVs if they are not run on green hydrogen.

Green hydrogen is a tentative solution for the decarbonisation of hard-to-abate sectors such as steel chemical cement and refinery industries. Green hydrogen is a form of hydrogen gas that is produced using renewable energy sources such as wind or solar power through a process called electrolysis. The green hydrogen supply chain includes several interconnected entities such as renewable energy providers electrolysers distribution facilities and consumers. Although there have been many studies about green hydrogen little attention has been devoted to green hydrogen supply chain risk identification and analysis especially for hard-to-abate sectors in Europe. This research contributes to existing knowledge by identifying and analysing the European region’s green hydrogen supply chain risk factors. Using a Delphi method 7 categories and 43 risk factors are identified based on the green hydrogen supply chain experts’ opinions. The best-worst method is utilised to determine the importance weights of the risk categories and risk factors. High investment of capital for hydrogen production and delivery technology was the highest-ranked risk factor followed by the lack of enough capacity for electrolyser and policy & regulation development. Several mitigation strategies and policy recommendations are proposed for high-importance risk factors. This study provides novelty in the form of an integrated approach resulting in a scientific ranking of the risk factors for the green hydrogen supply chain. The results of this study provide empirical evidence which corroborates with previous studies that European countries should endeavour to create comprehensive and supportive standards and regulations for green hydrogen supply chain implementation.

Unprecedented investments in clean energy technology are required for a net-zero carbon energy system before temperatures breach the Paris Agreement goals. By performing a Monte-Carlo Analysis with the detailed ETSAPTIAM Integrated Assessment Model and by generating 4000 scenarios of the world’s energy system climate and economy we find that the uncertainty surrounding technology costs resource potentials climate sensitivity and the level of decoupling between energy demands and economic growth influence the efficiency of climate policies and accentuate investment risks in clean energy technologies. Contrary to other studies relying on exploring the uncertainty space via model intercomparison we find that the CO2 emissions and CO2 prices vary convexly and nonlinearly with the discount rate and climate sensitivity over time. Accounting for this uncertainty is important for designing climate policies and carbon prices to accelerate the transition. In 70% of the scenarios a 1.5 ◦C temperature overshoot was within this decade calling for immediate policy action. Delaying this action by ten years may result in 2 ◦C mitigation costs being similar to those required to reach the 1.5 ◦C target if started today with an immediate peak in emissions a larger uncertainty in the medium-term horizon and a higher effort for net-zero emissions.