Publications

The first applications of hydrogen in a natural gas grid will be the admixing of low concentrations in an existing distribution grid. For easy quality and process control it is essential to monitor the hydrogen concentration in real time preferably using cost effective monitoring solutions. In this paper we introduce the use of a platinum based hydrogen sensor that can accurately (at 0.1 vol%) and reversibly monitor the concentration of hydrogen in a carrier gas. This carrier gas that can be nitrogen methane or natural gas has no influence on the accuracy of the hydrogen detection. The hydrogen sensor consists of an interdigitated electrode on a chip coated with a platinum nanocomposite layer that interacts with the gas. This chip can be easily added to a gas sensor for natural gas and biogas that was already developed in previous research. Just by the addition of an extra chip we extended the applicability of the natural gas sensor to hydrogen admixing. The feasibility of the sensor was demonstrated in our own (TNO) laboratory and at a field test location of the HyDeploy program at Keele University in the U.K

Solid oxide fuel cells (SOFC) have significant applications and performance and their integration into coupled and cascading energy systems can improve the overall performance of the process. Furthermore due to the constant time performance of the fuel cell the problem of fuel starvation may arise by changing the amount of load which can adversely affect the overall performance of the process. In the present study the excess heat of the SOFC is converted into electrical energy in two stages using different heat generators. The coupled energy system in the present article has a new configuration in which the relationship of its components is different from the systems reported in the literature. Furthermore since the use of an energy storage system can improve the overall reliability the energy produced by the coupled energy cycle is stored by a storage technology for peak consumption times. The introduced system can generate approximately 580 W of electrical power with an efficiency of 80%. The highest and lowest share in power generation is related to fuel cell with 82% and thermoelectric generator with 5%. The rest of the system power (i.e. 13%) is produced by thermionic generator. In addition the system requires 0.025 kg per hour of hydrogen fuel. It was also found that to operate the system for 5 h a day requires a storage system with a size of 3.3 m3 . Moreover two key issues to enhance the storage system performance are: adjusting the initial pressure of the system to values close to the peak (optimal) value and using turbines and/or pumps with higher efficiencies. With the aim of supplying 5 kWh of electrical energy five different scenarios based on the design of various effective parameters have been presented.

Large-scale stationary hydrogen storage is critical if hydrogen is to fulfill its promise as a global energy carrier. While densified storage via compressed gas and liquid hydrogen is currently the dominant approach liquid organic molecules have emerged as a favorable storage medium because of their desirable properties such as low cost and compatibility with existing fuel transport infrastructure. This perspective article analytically investigates hydrogenation systems' technical and economic prospects using liquid organic hydrogen carriers (LOHCs) to store hydrogen at a large scale compared to densified storage technologies and circular hydrogen carriers (mainly ammonia and methanol). Our analysis of major system components indicates that the capital cost for liquid hydrogen storage is more than two times that for the gaseous approach and four times that for the LOHC approach. Ammonia and methanol could be attractive options as hydrogen carriers at a large scale because of their compatibility with existing liquid fuel infrastructure. However their synthesis and decomposition are energy and capital intensive compared to LOHCs. Together with other properties such as safety these factors make LOHCs a possible option for large-scale stationary hydrogen storage. In addition hydrogen transportation via various approaches is briefly discussed. We end our discussions by identifying important directions for future research on LOHCs.

A solid-state storage system is the most practical option for hydrogen because it is more convenient and safer. Metal hydrides especially MgH₂ are the most promising materials that offer high gravimetric capacity and good reversibility. However the practical application of MgH₂ is restricted by slow sorption kinetics and high stability of thermodynamic properties. Hydrogen storage performance of MgH₂ was enhanced by introducing the Mg–Na–Al system that destabilises MgH₂ with NaAlH₄. The Mg–Na–Al system has superior performance compared to that of unary MgH₂ and NaAlH₄. To boost the performance of the Mg–Na–Al system the ball milling method and the addition of a catalyst were introduced. The Mg–Na–Al system resulted in a low onset decomposition temperature superior cyclability and enhanced kinetics performances. The Al12Mg17 and NaMgH₃ that formed in situ during the dehydrogenation process modify the reaction pathway of the Mg–Na–Al system and alter the thermodynamic properties. In this paper the overview of the recent progress in hydrogen storage of the Mg–Na–Al system is detailed. The remaining challenges and future development of Mg–Na–Al system are also discussed. This paper is the first review report on hydrogen storage properties of the Mg–Na–Al system.

Hydrogen induced cracking behaviour of O&G nickel alloy 625+ (UNS N07716) was investigated. Deuterium was introduced electrochemically into samples by cathodic polarisation (3.5 wt.% NaCl.D₂O) under different mechanical conditions. Subsequently deuterium distributions were mapped using NanoSIMS. Deuterium was used as an isotopic tracer instead of hydrogen to avoid the detection of hydrogen artefacts. Complimentary image analysis using scanning electron microscopy (SEM) and low voltage energy dispersive X-ray (EDX) allowed the identification of microstructural features corresponding to deuterium enrichments. The results provided experimental evidence of enrichments at dislocation slip bands (DSB) twin boundary and grain boundary features that include σ precipitates.

Magnesium hydride and selected magnesium-based ternary hydride (Mg2FeH6 Mg2NiH4 and Mg2CoH5) syntheses and modification methods as well as the properties of the obtained materials which are modified mostly by mechanical synthesis or milling are reviewed in this work. The roles of selected additives (oxides halides and intermetallics) nanostructurization polymorphic transformations and cyclic stability are described. Despite the many years of investigations related to these hydrides and the significant number of different additives used there are still many unknown factors that affect their hydrogen storage properties reaction yield and stability. The described compounds seem to be extremely interesting from a theoretical point of view. However their practical application still remains debatable.

Gaseous fuels with low life-cycle emissions of greenhouse gases (GHG) play a prominent role in the European Union’s (EU) decarbonization plans. Renewable and low-GHG hydrogen are highlighted in the ambitious goals for a cross-sector hydrogen economy laid out in the European Commission’s Hydrogen Strategy. Renewable hydrogen and biomethane are given strong production incentives in the Commission’s proposed revision to the Renewable Energy Directive (REDII). The EU uses life-cycle analysis (LCA) to determine whether renewable gas pathways meet the GHG reduction thresholds for eligibility in the REDII. This study aims to support European policymakers with a better understanding of the uncertainties regarding gaseous fuels’ roles in meeting climate goals. Life-cycle GHG analysis is complex and differences in methodology as well as data inputs and assumptions can spell the difference between a renewable gas pathway qualifying or not for REDII eligibility at the 50% to 80% GHG reduction level. It is thus important for European policymakers to use robust LCA to ensure that policy only supports gas pathways consistent with a vision of deep decarbonization. For this purpose we conduct sensitivity analysis of the life-cycle GHG emissions of a number of low-GHG gas pathways including biomethane produced from four feedstocks: wastewater sludge manure landfill gas (LFG) and silage maize; and hydrogen produced from eight sources: natural gas combined with carbon capture and storage (CCS) coal with CCS biomass gasification renewable electricity 2030 EU grid electricity wastewater sludge biomethane manure biomethane and LFG biomethane. For each pathway we estimate the life-cycle GHG intensity using a default central case identify key parameters that strongly affect the fuel’s GHG intensity and conduct a sensitivity analysis by changing these key parameters according to the range of possible values collected from the literature. Figure ES1 summarizes the full range of possible GHG intensities for each gaseous pathway we analyzed in this study—biomethane is depicted in the top figure and hydrogen is shown in the bottom. The bars represent the GHG intensity of the central case and vertical error bars indicate the maximum and minimum GHG intensity of each pathway according to our sensitivity analysis. The dotted orange horizontal line illustrates the fossil comparator which is 94 grams of carbon dioxide equivalent per megajoule (gCO2e/MJ) for transport fuels in the REDII. The dotted yellow line represents the GHG intensity of a 65% GHG reduction goal for biomethane used in the transportation sector or 70% GHG reduction for hydrogen. Pathways are situated from left to right in increasing order of GHG intensity of the central case. Comparing the central cases of the four biomethane pathways the waste-based biomethane pathways generally have negative GHG intensity. However considering the uncertainty in these GHG intensities manure biomethane might have more limited carbon reduction potential in the 100-year timeframe if methane leakage from its production process is high. In contrast wastewater sludge biomethane and LFG biomethane even after accounting for uncertainties retain relatively low GHG emissions. On the other hand biomethane produced from silage maize can have much higher emissions; in the central case we find that silage maize biogas only reduces GHG emissions by 30% relative to the fossil comparator—the low carbon reduction potential is due to the significant emissions emerging from direct and indirect land use change involved in growing maize. Taking into account the variation in assumptions silage maize biomethane can be worse for the climate than fossil fuels.

A study was carried out on the valorization of different waste plastics (HDPE PP PS and PE) their mixtures and biomass/HDPE mixtures by means of pyrolysis and in line oxidative steam reforming. A thermodynamic equilibrium simulation was used for determining steam reforming data whereas previous experimental results were considered for setting the pyrolysis volatile stream composition. The adequacy of this simulation tool was validated using experimental results obtained in the pyrolysis and in line steam reforming of different plastics. The effect the most relevant process conditions i.e. temperature steam/plastic ratio and equivalence ratio have on H2 production and reaction enthalpy was evaluated. Moreover the most suitable conditions for the oxidative steam reforming of plastics of different nature and their mixtures were determined. The results obtained are evidence of the potential interest of this novel valorization route as H2 productions of up to 25 wt% were obtained operating under autothermal conditions.

This work is part of a project that aims to develop a micromechanics based damage law taking into account hydrogen assisted degradation. A 'vintage' API 5L X56N and a 'modern' API 5L X70M pipeline steel have been selected for this purpose. The paper focuses on an experimental calibration of ductile damage properties of the well known complete Gurson model for the two steels in absence of hydrogen. A basic microstructural characterization is provided showing a banded ferrite-pearlite microstructure for both steels. Charpy impact tests showed splits at the fracture surface for the X70 steel. Double-notched round bar tensile tests are performed aiming to provide the appropriate input for damage model calibration. The double-notched nature of the specimens allows to examine the material state at maximum load in the unfailed notch and the final material state in the failed notch. Different notch radii are used capturing a broad range of positive stress triaxialities. The notches are optically monitored for transverse necking in two perpendicular directions (transverse to rolling and through thickness) to reveal any anisotropy in plastic deformation and/or damage. It is explained how the occurrence of splits at the segregation zone and anisotropy complicate the calibration procedure. Calibration is done for each steel and acceptable results are obtained. However the occurrence of splits did not allow to evaluate the damage model for the highest levels of tested stress triaxiality.

Exemption is requested from the obligation set out in Regulation 8(1) of the Gas Safety (Management) Regulations 1996 (GSMR) to convey only natural gas that is compliant with the Interchangeability requirements of Part I of Schedule 3 of the GSMR within the G3 element of the Keele University gas distribution network (KU-GDN). The KU-GDN is owned and operated by Keele University. The proposed conveyance of non-compliant gas (hereafter called the “HyDeploy Field Trial”) will last for one year of injection and is part of a Network Innovation Competition Project “HyDeploy”. The project aims to demonstrate that natural gas containing hydrogen at a level above that normally permitted by Schedule 3 of the GSMR can be safely and efficiently conveyed and inform decisions on the feasibility and strategy for wider deployment of natural gas containing hydrogen in Great Britain’s (GB’s) gas transmission and gas distribution systems.<br/>Click the supplements tab for the other documents from this report.

A major requirement for the filling of hydrogen tanks is the maximum gas temperature within the vessels during the process. Different filling strategies in terms of pressure and temperature of the gas injected into the cylinder and their effects on key parameters like maximum temperature state of charge and energy cooling demand are investigated. It is shown that pre-cooling of the gas is required but is not necessary for the whole duration of the filling. Relevant energy savings can be achieved with pre-cooling over a fraction of the time. The most convenient filling strategy from the cooling energy point of view is identified: with an almost linear pressure rise and pre-cooling in the second half of the process a 60% reduction of the cooling energy demand is achieved compared to the case of pre-cooling for the whole filling.

Prestressing steel wires are manufactured by cold drawing during which a preferential orientation is achieved in the matter of pearlitic colonies and lamellae. In addition to this general trend special (unconventional) pearlitic pseudocolonies evolve during the heavy-drawing manufacture process affecting the posterior macro- micro- and nano-structural integrity of the material. This paper discusses the important role of such a special microstructural unit (the pearlitic pseudocolony) in the fracture process in air (inert) environment in the presence of crack-like defects as well as in the case of environmentally assisted cracking (stress corrosion cracking by localized anodic dissolution) or hydrogen embrittlement. Results clearly demonstrate the key role of pearlitic pseudocolonies in promoting crack deflection (and thus mixed-mode propagation) after a global mode I cracking especially in the case of fracture in air and stress corrosion cracking.

Global maritime transportation is responsible for around 3% of total anthropogenic green‐ house gas emissions and significant proportions of SOx NOx and PM emissions. Considering the predicted growth in shipping volumes to 2050 greenhouse gas emissions from ships must be cut by 75–85% per ton‐mile to meet Paris Agreement goals. This study reviews the potential of a range of alternative fuels for decarbonisation in maritime. A systematic literature review and information synthesis method was applied to evaluate fuel characteristics production pathways utilization technologies energy efficiency lifecycle environmental performance economic viability and cur‐ rent applicable policies. Alternative fuels are essential to decarbonisation in international shipping. However findings suggest there is no single route to deliver the required greenhouse gas emissions reductions. Emissions reductions vary widely depending on the production pathways of the fuel. Alternative fuels utilising a carbon‐intensive production pathway will not provide decarbonisation instead shifting emissions elsewhere in the supply chain. Ultimately a system‐wide perspective to creating an effective policy framework is required in order to promote the adoption of alternative propulsion technologies.

Reducing green‐house gases emission from light‐duty vehicles is compulsory in order to slow down the climate change. The application of High Frequency Ignition systems based on the Corona discharge effect has shown the potential to extend the dilution limit of engine operating conditions promoting lower temperatures and faster combustion events thus higher thermal and indicating efficiency. Furthermore predicting the behavior of Corona ignition devices against new sustainable fuel blends including renewable hydrogen and biogas is crucial in order to deal with the short‐intermediate term fleet electric transition. The numerical evaluation of Corona‐induced discharge radius and radical species under those conditions can be helpful in order to capture local effects that could be reached only with complex and expensive optical investigations. Using an ex‐ tended version of the Corona one‐dimensional code previously published by the present authors the simulation of pure methane and different methane–hydrogen blends and biogas–hydrogen blends mixed with air was performed. Each mixture was simulated both for 10% recirculated exhaust gas dilution and for its corresponding dilute upper limit which was estimated by means of chemical kinetics simulations integrated with a custom misfire detection criterion.

This US Hydrogen Road Map was created through the collaboration of executives and technical industry experts in hydrogen across a broad range of applications and sectors who are committed to improving the understanding of hydrogen and how to increase its adoption across many sectors of the economy. For the first time this coalition of industry leaders has convened to develop a targeted holistic approach for expanding the use of hydrogen as an energy carrier. Due to great variation among national and state policies infrastructure needs and community interests each state and region of the US will likely have its own specific policies and road maps for implementing hydrogen infrastructure. The West Coast for example has traditionally had progressive policies on reducing transportation emissions so it is likely that hydrogen will scale sooner for vehicles in this region especially California. Experts also acknowledge the role that hydrogen in combination with renewables can play in supplying microgrid-type power to communities with the highest risk of shut-offs during seasonal weather-related issues such as high temperatures or wildfire-related power interruptions. Some states have emphasized the need to decarbonize the gas grid so blending hydrogen in natural gas networks and using hydrogen as feedstock may advance more quickly in these regions. Other states are interested in hydrogen as a means to address power grid issues enable the deployment of renewables and support competitive nuclear power. The launch of hydrogen technologies in some states or regions will help to scale hydrogen in various applications across the country laying the foundation for energy security grid resiliency economic growth and the reduction of both greenhouse gas (GHG) emissions and air pollutants. This report outlines the benefits and impact of fuel cell technologies and hydrogen as a viable solution to the energy challenges facing the US through 2030 and beyond. As such it can serve as the latest comprehensive industry-driven national road map to accelerate and scale up hydrogen in the economy across North America

Long-term operation of natural gas transit pipelines implies aging hydrogen-induced and stress corrosion cracking and it causes hydrogen embrittlement of steels degradation of mechanical properties associated to a safe serviceability of pipelines and failure risk increase. The implementation of effective diagnostic measures of pipelines steels degradation would allow planning actions in order to reduce a risk of fracture. In this paper a new scientific and methodical approach based on the electrochemical analysis of fracture surface for evaluation of in-service degradation of operated pipeline steels was developed. It was suggested that carbon diffusion to grain boundaries and to defects inside grains intensified by hydrogen under long-term operation led to formation of nanoparticles of carbides which resulted in intergranular cracking of operated pipeline steels under service and their transgranular cracking under impact toughness testing. Therefore fracture surface was enriched by carbon compounds and electrochemical characteristics were sensitive to this. In-service degradation of ferrite-pearlite pipeline steels was accompanied by a sharp shift in open-circuit potential of the fracture surface (brittle fracture) of specimens after impact toughness tests compared with that of polished steel surfaces. A significant difference between potentials of the fracture surface and the polished steel surface (over 60 mV in 0.3% NaCl solution) of specimens made of ferrite-pearlite pipeline steels observed after their long-term operation was evidently due to the increased content of carbon compounds on the fracture surface. Mechanism of ferrite-pearlite pipeline steels embrittlement under operation consisted in carbides enrichment not only grain boundaries but also intragranular defects has been revealed as it is indicated by an increase of carbon content on transgranular fracture surfaces determined electrochemically.

Hydrogen is currently enjoying a renewed and widespread momentum in many national and international climate strategies. This review paper is focused on analysing the challenges and opportunities that are related to green and blue hydrogen which are at the basis of different perspectives of a potential hydrogen society. While many governments and private companies are putting significant resources on the development of hydrogen technologies there still remains a high number of unsolved issues including technical challenges economic and geopolitical implications. The hydrogen supply chain includes a large number of steps resulting in additional energy losses and while much focus is put on hydrogen generation costs its transport and storage should not be neglected. A low-carbon hydrogen economy offers promising opportunities not only to fight climate change but also to enhance energy security and develop local industries in many countries. However to face the huge challenges of a transition towards a zero-carbon energy system all available technologies should be allowed to contribute based on measurable indicators which require a strong international consensus based on transparent standards and targets.

Solar-driven electrolysis of water to generate hydrogen is emerging as a viable strategy to decarbonize the global energy economy. However this direction is more expensive than traditional fossil fuel generation of hydrogen and effective pathways to lower this cost need to be identified. Here we report a Monte Carlo approach to explore a wide range of input assumptions to identify key cost drivers targets and localized conditions necessary for competitive stand-alone dedicated PV powered hydrogen electrolysis. We determine the levelized cost of hydrogen (LCOH) considering historical weather data for specific locations to model our PV system and optimize its size compared to the electrolyzer. This analysis and its methods show the potential for green hydrogen production using off-grid PV shows the merits of remote systems in areas of high solar resource and provides cost and performance targets for electrolyzer technologies.

As renewable energy sources are spreading the problems of energy usage transport and storage arise more frequently. In order that the performance of energy producing units from renewable sources which have a relatively low efficiency should not be decreased further and to promote sustainable energy consumption solutions a living lab conception was elaborated in this project. At the pilot site the produced energy (by PV panels gas turbines/engines) is stored in numerous ways including hydrogen production. The following uses of hydrogen are explored: (i) feeding it into the national natural gas network; (ii) selling it at a H-CNG (compressed natural gas) filling station; (iii) using it in fuel cells to produce electricity. This article introduces the overall implementation plan which can serve as a model for the hybrid energy communities to be established in the future.

In this paper a systematic review of academic literature and policy papers since 2008 is undertaken with an aim of identifying the prevalent energy systems models and tools in the UK. A list of all referenced models is presented and the literature is analysed with regards sectoral coverage and technological inclusion as well as mathematical structure of models. The paper compares available models using an appropriate classification schema the introduction of which is aimed at making the model landscape more accessible and perspicuous thereby enhancing the diversity of models within use. The distinct classification presented in this paper comprises three sections which specify the model purpose and structure technological detail and mathematical approach. The schema is not designed to be comprehensive but rather to be a broad classification with pertinent level of information required to differentiate between models. As an example the UK model landscape is considered and 22 models are classified in three tables as per the proposed schema.

The decarboxylation pathway in ethanol steam reforming ultimately favors higher selectivity to hydrogen over the decarbonylation mechanism. The addition of an optimized amount of Cs to Pt/m-ZrO2 catalysts increases the basicity and promotes the decarboxylation route converting ethanol to mainly H2 CO2 and CH4 at low temperature with virtually no decarbonylation being detected. This offers the potential to feed the product stream into a conventional methane steam reformer for the production of hydrogen with higher selectivity. DRIFTS and the temperature-programmed reaction of ethanol steam reforming as well as fixed bed catalyst testing revealed that the addition of just 2.9% Cs was able to stave off decarbonylation almost completely by attenuating the metallic function. This occurs with a decrease in ethanol conversion of just 16% relative to the undoped catalyst. In comparison with our previous work with Na this amount is—on an equivalent atomic basis—just 28% of the amount of Na that is required to achieve the same effect. Thus Cs is a much more efficient promoter than Na in facilitating decarboxylation.

This study aims to assess the potential risks of setting up a hydrogen infrastructure in the Netherlands. An integrated risk assessment framework capable of analyzing projects identifying risks and comparing projects is used to identify and analyze the main risks in the upcoming Dutch hydrogen infrastructure project. A time multiplier is added to the framework to develop parameters. The impact of the different risk categories provided by the integrated framework is calculated using the discounted cash flow (DCF) model. Despite resource risks having the highest impact scope risks are shown to be the most prominent in the hydrogen infrastructure project. To present the DCF model results a risk assessment matrix is constructed. Compared to the conventional Risk Assessment Matrix (RAM) used to present project risks this matrix presents additional information in terms of the internal rate of return and risk specifics.

In this study we consider fuel cell-powered electric trucks (FCETs) as an alternative to conventional medium- and heavy-duty vehicles. FCETs use a battery combined with onboard hydrogen storage for energy storage. The additional battery provides regenerative braking and better fuel economy but it will also increase the initial cost of the vehicle. Heavier reliance on stored hydrogen might be cheaper initially but operational costs will be higher because hydrogen is more expensive than electricity. Achieving the right tradeoff between these power and energy choices is necessary to reduce the ownership cost of the vehicle. This paper develops an optimum component sizing algorithm for FCETs. The truck vehicle model was developed in Autonomie a platform for modelling vehicle energy consumption and performance. The algorithm optimizes component sizes to minimize overall ownership cost while ensuring that the FCET matches or exceeds the performance and cargo capacity of a conventional vehicle. Class 4 delivery truck and class 8 linehaul trucks are shown as examples. We estimate the ownership cost for various hydrogen costs powertrain components ownership periods and annual vehicle miles travelled.

Massive consumption of fossil fuel leads to shortage problems as well as various global environmental issues. Due to the global climatic problem in the world techniques to supply energy demand change from conventional methods that use fossil fuel as the energy source to clean and renewable sources such as solar and wind. However these renewable energy sources are not permanent. Energy storage methods can ensure to supply the energy demand in need if the energy is stored when the renewable source is available. Hydrogen is considered a promising alternative feedstock owing to has unique properties such as clean energy high energy density absence of toxic materials and carbon-free nature. Hydrogen is used main fuel source in fuel cells and hydrogen can be produced with various methods such as wind or electrolysis of water systems that supply electricity from renewable sources. However the safe effective and economical storage of hydrogen is still a challenge that limits the spread of the usage of hydrogen energy. High pressed hydrogen gas and cryogenic hydrogen liquid are two applied storage pathways although they do not meet the above-mentioned requirement. To overcome these drawbacks materials-based hydrogen storage materials have been mostly investigated research field recently. The aim of the study is that exhibiting various material-based hydrogen storage systems and development of these techniques worldwide. Additionally past and current status of the technology are explained and future perspective is discussed.

Although electricity supply is still dominated by fossil fuels it is expected that renewable sources will have a much larger contribution in the future due to the need to mitigate climate change. Therefore this paper presents a new framework for developing Future Electricity Scenarios (FuturES) with high penetration of renewables. A multi-period linear programming model has been created for power-system expansion planning. This has been coupled with an economic dispatch model PowerGAMA to evaluate the technical and economic feasibility of the developed scenarios while matching supply and demand. Application of FuturES is demonstrated through the case of Chile which has ambitious plans to supply electricity using only renewable sources. Four cost-optimal scenarios have been developed for the year 2050 using FuturES: two Business as usual (BAU) and two Renewable electricity (RE) scenarios. The BAU scenarios are unconstrained in terms of the technology type and can include all 11 options considered. The RE scenarios aim to have only renewables in the mix including storage. The results show that both BAU scenarios have a levelised cost of electricity (LCOE) lower than or equal to today’s costs ($72.7–77.3 vs $77.6/MWh) and include 81–90% of renewables. The RE scenarios are slightly more expensive than today’s costs ($81–87/MWh). The cumulative investment for the BAU scenarios is $123-$145 bn compared to $147-$157 bn for the RE. The annual investment across the scenarios is estimated at $4.0 ± 0.4 bn. Both RE scenarios show sufficient flexibility in matching supply and demand despite solar photovoltaics and wind power contributing around half of the total supply. Therefore the FuturES framework is a powerful tool for aiding the design of cost-efficient power systems with high penetration of renewables.