Norway

This paper proposes a technical and cost analysis model to assess the change in costs of a zeroemission high-speed ferry when retrofitting from diesel to green hydrogen. Both compressed gas and liquid hydrogen are examined. Different scenarios explore energy demand energy losses fuel consumption and cost-effectiveness. The methodology explores how variation in the ferry's total weight and equipment efficiency across scenarios impact results. Applied to an existing diesel high-speed ferry on one of Norway's longest routes the study under certain assumptions identifies compressed hydrogen gas as the current most economical option despite its higher energy consumption. Although the energy consumption of the compressed hydrogen ferry is slightly more than the liquid hydrogen counterpart its operating expenses are considerably lower and comparable to the existing diesel ferry on the route. However constructing large hydrogen liquefaction plants could reduce liquid hydrogen's cost and make it competitive with both diesel and compressed hydrogen gas. Moreover liquid hydrogen allows the use of a superconducting motor to enhance efficiency. Operating the ferry with liquid hydrogen and a superconducting motor besides its technical advantages offers promising economic viability in the future comparable to diesel and compressed hydrogen gas options. Reducing the ferry's speed and optimizing equipment improves fuel efficiency and economic viability. This research provides valuable insights into sustainable zero-emission high-speed ferries powered by green hydrogen.

Autonomous underwater vehicles (AUVs) are programmable robotic vehicles that can drift drive or glide through the ocean without real-time control by human operators. AUVs that also can follow a planned trajectory with a chosen depth profile are used for geophysical surveys subsea pipeline inspection marine archaeology and more. Most AUVs are followed by a mother ship that adds significantly to the cost of an AUV mission. One pathway to reduce this need is to develop long-endurance AUVs by improving navigation autonomy and energy storage. Long-endurance AUVs can open up for more challenging mission types than what is possible today. Fuel cell systems are a key technology for increasing the endurance of AUVs beyond the capability of batteries. However several challenges exist for underwater operation of fuel cell systems. These are related to storage or generation of hydrogen and oxygen buoyancy and trim and the demanding environment of the ambient seawater. Protecting the fuel cell inside a sealed container brings along more challenges related to condensation cooling and accumulation of inert gases or reactants. This paper elaborates on these technical challenges and describes the solutions that the Norwegian Defence Research Establishment (FFI) has chosen in its development of a fuel cell system for long-endurance AUVs. The reported solutions enabled a 24 h demonstration of FFI's fuel cell system under water. The remaining work towards a prototype sea trial is outlined.

Climate policy will inevitably lead to the stranding of fossil energy assets such as production and transport assets for coal oil and natural gas. Resourcerich developing countries are particularly aected as they have a higher risk of asset stranding due to strong fossil dependencies and wider societal consequences beyond revenue disruption. However there is only little academic and political awareness of the challenge to manage the asset stranding in these countries as research on transition risk like asset stranding is still in its infancy. We provide a research framework to identify wider societal consequences of fossil asset stranding. We apply it to a case study of Nigeria. Analyzing dierent policy measures we argue that compensation payments come with implementation challenges. Instead of one policy alone to address asset stranding a problem-oriented mix of policies is needed. Renewable hydrogen and just energy transition partnerships can be a contribution to economic development and SDGs. However they can only unfold their potential if fair benefit sharing and an improvement to the typical institutional problems in resource-rich countries such as the lack of rule of law are achieved. We conclude with presenting a future research agenda for the global community and acade

The underground hydrogen storage (UHS) capacities of shut down oil and gas (O&G) fields along the Norwegian continental shelf (NCS) are evaluated based on the publicly available geological and hydrocarbon production data. Thermodynamic equilibrium and geochemical models are used to describe contamination of hydrogen loss of hydrogen and changes in the mineralogy. The contamination spectrum of black oil fields and retrograde gas fields are remarkably similar. Geochemical models suggest limited reactive mineral phases and meter-scale hydrogen diffusion into the caprock. However geochemical reactions between residual oil reservoir brine host rock and hydrogen are not yet studied in detail. For 23 shut down O&G fields a theoretical maximum UHS capacity of ca. 642 TWh is estimated. We conclude with Frigg Nordost Frigg and Odin as the best-suited shut down fields for UHS having a maximum UHS capacity of ca. 414 TWh. The estimates require verification by site-specific dynamic reservoir models.

Global warming’s major cause is the emission of greenhouse-effect gases (GHG) especially carbon dioxide (CO2) whose main source is the combustion of fossil fuels. Fossil fuels serve as the primary energy source in many industries including shipping which is the focus of this study. One of the measures proposed to tackle GHG emissions is the development of green shipping corridors - carbon-free shipping routes that require the transition to alternative fuels which are gaining competitiveness. One of the reasons for that is carbon pricing which taxes CO2 emissions. However the lack of consensus on the most cost-advantageous alternative fuel in the long run results in the delay of the implementation of green shipping corridors. To make it more accessible for stakeholders to conduct an economic analysis of the various options a framework to determine and minimize the costs of transitioning from fossil fuels to any alternative fuel is proposed over the period of one voyage considering the lost opportunity cost the deployment cost of bunkering vessels at the necessary call ports the cost of converting the vessel the car-bon emissions tax cost and the fuel cost. This will allow stakeholders to choose the most economical alternative fuel accelerating the development of green shipping corridor initiatives. To validate the effectiveness of the framework it was applied in a case study involving a shipowner seeking to transition from heavy fuel oil (HFO) to Ammonia Hydrogen Liquefied Natural Gas (LNG) or Methanol. This study faced limitations due to the unknown costs of installing bunkering vessels for Ammonia and Hydrogen. However it evaluates the cost-effectiveness of alternative fuels providing insights into their short-term economic viability. The results showed that Hydrogen is the most costadvantageous fuel until a deployment cost per bunkering vessel of 1990285$ for a sailing speed of 22 knots and 2190171$ for a sailing speed of 18 knots is reached after which LNG becomes the most economical option regardless of variations in the carbon tax. Moreover a sensitivity analysis was conducted to determine the effects of variations in parameters such as carbon tax fuel prices and vessel conversion costs in the total cost of each fuel option. Results highlighted that even though HFO remains the most economical fuel option even when considering a high increase in carbon tax the cost gap between HFO and alternative fuels narrows significantly with the increase in carbon tax. Furthermore the sailing speed impacts the fuels’ competitiveness as the cost difference between HFO and alternative fuels decreases at higher speeds.

Achieving a net-zero energy system in Europe by 2050 will likely require large-scale deployment of hydrogen and seasonal energy storage to manage variability in renewable supply and demand. This study addresses two key objectives: (1) to develop a modeling framework that integrates seasonal storage into a stochastic multihorizon capacity expansion model explicitly capturing tactical uncertainty across timescales; and (2) to assess the impact of seasonal hydrogen storage on long-term investment decisions in European power and hydrogen infrastructure under three hydrogen demand scenarios. To this end the multi-horizon stochastic programming model EMPIRE is extended with tactical stages within each investment period enabling operational decisions to be modeled as a multi-stage stochastic program. This approach captures short-term uncertainty while preserving long-term investment foresight. Results show that seasonal hydrogen storage considerably enhances system flexibility displacing the need for up to 600 TWh/yr of dispatchable generation in Europe after 2040 and sizing down cross-border hydrogen transmission capacities by up to 12%. Storage investments increase by factors of 5–14 which increases the investments in variable renewables and improve utilization particularly solar. Scenarios with seasonal storage also show up to 6% lower total system costs and more balanced infrastructure deployment across regions. These findings underline the importance of modeling temporal uncertainty and seasonal dynamics in long-term energy system planning.

Renewable hydrogen offers compelling climate mitigation prospects with Norway possessing the opportunity to become a main global producer given its unique combination of wind energy potential available infrastructure and political motivation. However comprehensive environmental impact assessments of hydrogen from offshore wind are lacking and hydrogen leakage rates remain uncertain. A life-cycle assessment of hydrogen production from offshore wind farms in Norway is presented where different combinations of turbines (floating or bottomfixed) storage options (tank or salt cavern) and distribution methods (trucks or pipelines) are considered. Climate change impacts are assessed across the supply chain using global warming potential 100 (GWP100) and 20 (GWP20) and include hydrogen leakage contributions. The results range from 1.56 ± 0.14–2.28 ± 0.14 kg CO2-eq/kg H2 for GWP100 and 2.96 ± 0.76 and 3.75 ± 0.76 kg CO2-eq/kg H2 for GWP20 and are on average 55 % and 45 % lower than those of blue hydrogen respectively. At a default rate of 5 % hydrogen leakage contributes 50–63 % of the total impact for GWP20 and 25–37 % for GWP100. If higher-end leakage rates from literature are considered the impacts increase to 3.46 kg CO2-eq/kg H2 for GWP100 which is still lower than that of blue hydrogen. The scenario combining bottom-fixed turbines salt cavern storage and pipeline distribution presents the lowest environmental impacts. However while bottom-fixed turbines generally offer lower impacts floating turbines pose lesser risk to marine biodiversity. Overall infrastructure represents the main driver of environmental impacts. Mitigation in this area will improve potential benefits.

Integrating microbial activity into underground hydrogen storage models is crucial for simulating longterm reservoir behavior. In this work we present a coupled framework that incorporates bio-geochemical reactions and compositional flow models within the Matlab Reservoir Simulation Toolbox (MRST). Microbial growth and decay are modeled using a double Monod formulation with populations influenced by hydrogen and carbon dioxide availability. First a refined Equation of State (EoS) is employed to accurately capture hydrogen dissolution thereby improving phase behavior and modeling of microbial activity. The model is then discretized using a cell-centered finite-volume method with implicit Euler time discretization. A fully coupled fully implicit strategy is considered. Our implementation builds upon MRST’s compositional module by incorporating the Søreide–Whitson EoS microbial reaction kinetics and specific effects such as bio-clogging and molecular diffusion. Through a series of 1D 2D and 3D simulations we analyze the effects of microbialinduced bio-geochemical transformations on underground hydrogen storage in porous media.These results highlight that accounting for bio-geochemical effects can substantially impact hydrogen loss purity and overall storage performance.

Transitioning to renewable energy is vital to achieving decarbonization at the global level but energy storage is still a major challenge. This review discusses the role of energy storage in the energy transition and the blue economy focusing on technological development challenges and directions. Effective storage is vital for balancing intermittent renewable energy sources like wind solar and marine energy with the power grid. The development of battery technologies hydrogen storage pumped hydro storage and emerging technologies like sodium-ion and metal-air batteries is discussed for their potential for large-scale deployment. Shortages in critical raw materials environmental impact energy loss and costs are some of the challenges to large-scale deployment. The blue economy promises opportunities for offshore energy storage notably through ocean thermal energy conversion (OTEC) and compressed air energy storage (CAES). Moreover the capacity of datadriven optimization and artificial intelligence to enhance storage efficiency is discussed. Policy interventions and economic incentives are necessary to spur the development and deployment of sustainable energy storage technology. Education and workforce training are also important in cultivating future researchers engineers and policymakers with the ability to drive energy innovation. Merging sustainability training with an interdisciplinary approach can potentially establish an efficient workforce that is capable of addressing energy issues. Future work needs to focus on higher energy density efficiency recyclability and cost-effectiveness of the storage technologies without sacrificing their environmental sustainability. The study underlines the need for converging technological economic and educational approaches to enable a sustainable and resilient energy future.

Towards low-carbon buildings with resilient energy performance renewable energy resources and flexible energy assets play key roles in managing the electrical and heat demands. Hydrogen-based systems represent a promising solution through renewable hydrogen production and long-term storage. This paper systematically reviews 35 peer-reviewed studies (1990–2024) on hydrogen integration in buildings focusing on demand-side management (DSM) optimization methods and system performance. The review covers the environmental impacts feasibility and economic viability of integrating different hydrogen systems for supplying energy. Across critical reviews case studies hydrogen supplementary systems achieved CO2 reductions between 12 % and 87 % operational cost decreases of up to 40 % and efficiency gains exceeding 80 %. Payback periods varied widely between 9 and 20 years demonstrating high investment costs. Key gaps include limited field validation economic feasibility and public acceptance of hydrogen homes. One key area for future investigation is optimizing energy flows across production storage and demand particularly in Vehicle-to-Building (V2B) applications. This review paper highlights opportunities especially the potential of hydrogen system in decarbonization of buildings by long-term energy storage barriers and policy needs for implementing hydrogen technologies in grid-connected and remote areas to enhance sustainable and resilient buildings.