Low-carbon Energy System Research Articles

Domesticating energy flexibility. Learning from great britain’s 2022–2023 demand flexibility service

Demand-response is essential for balancing electricity grids with increasing proportions of intermittent renewable sources of generation. Harnessing the potential for demand-response in domestic settings could deliver widespread benefits for electricity systems and householders. This study applies domestication theory to a major national domestic electricity demand-response programme in Great Britain, exploring how participants integrate demand-response sessions into their everyday routines. The study uses empirical data from twenty-five participants who completed diaries reflecting on their experience of taking part in thirteen demand-response sessions scheduled over a five-month period in winter 2022–23. The study identifies and analyses five pathways for domesticating demand-response, making recommendations to support system-actors in boosting and sustaining the adoption of demand-response. The study concludes that designing electricity demand-response programmes, as a staple of secure low-carbon energy systems, will need to take full account of users’ non-financial motivations, previous experiences of demand-response, and access to enabling technology.

Multi-stage planning of clean resources and energy storage assets with hybrid uncertainty modeling for low-carbon resilient distribution systems

Climate change drives the urgent need for low-carbon and resilient energy system transitions. However, current planning methods ignore the inherent conflicts between carbon emission reduction and resilience enhancement, failing to optimally balance asset allocation for both aspects. They also neglect the long-term dynamic and stochastic nature of transitions, exposing systems to hybrid uncertainties. This paper presents a multi-stage dynamic planning method for clean resources and energy storage assets in power distribution networks. First, to facilitate low-carbon and resilient transitions, adaptive, stage-wise planning decisions are optimally determined under various planning strategies to mitigate risks stemming from hybrid uncertainties. Second, to precisely quantify the impact of hybrid uncertainties on decision-making, a systematic hybrid-uncertainty modeling approach is designed to capture short- and long-term uncertainties arising from both exogenous and endogenous factors. Third, to alleviate computational complexity, a decomposition-based stochastic dynamic dual integer programming method with augmented cut generation is introduced, which decomposes the original problem into stage-wise subproblems coordinated through forward and backward steps. Numerical results show that the proposed method generates cost-effective planning schemes, yielding $60 K in savings and reducing carbon emissions by 3853 tons. The method also demonstrates strong scalability, with a 52% reduction in solution time for large-scale planning problems.

Electrolyte-supported solid oxide electrochemical cells for versatile operations

Electrolyte-supported solid oxide electrochemical cells (SOCs) offer advantages in terms of easier fabrication and enhanced mechanical properties, but achieving high performance and multifunctionality remains challenging. In this study, we develop high-performance and versatile electrolyte-supported SOCs using La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) electrolyte materials through microstructural engineering of Sr2Fe1.5Mo0.5O6-δ (SFM)-based fuel electrodes. We evaluate the cells for power generation, hydrogen production, and carbon dioxide reduction, showcasing the diverse potential of various fuel electrode configurations. Among these, the impregnated SFM@LSGM electrode achieves the best overall performance, with a maximum power density of 739 mW cm−2 in fuel-cell mode, a current density of −0.81 A cm−2 at 1.3 V during steam electrolysis, and an unprecedented current density of −1.92 A cm−2 at 1.5 V in CO₂ electrolysis. Furthermore, it exhibits satisfactory stability across all operational modes. These findings provide valuable insights into the design of versatile electrolyte-supported SOCs and open new possibilities for their flexible applications in future low-carbon energy systems.

Digital financial inclusion role to promote renewable energy technology innovation in Chinese Prefectural cities: Moderating role of environmental governance

Renewable energy technology innovation is not only an important technical component of Chinese construction of low-carbon energy systems but also a key way to realize long-term, sustainable development. Digital inclusive finance plays an indispensable role in this process. Using panel data of 275 Chinese cities from 2011 to 2022, a two-step systematic methodology is used to assess the impacts and mechanisms of digital financial inclusion and the moderating role of different environmental governance models on qualitative and quantitative renewable energy innovation. The results indicate that digital inclusive finance has an incentive effect on both qualitative and quantitative renewable energy innovations, with a stronger incentive effect on qualitative behavior. This effect can act on renewable energy technology innovation by reducing financing constraints and incentivizing information disclosure mechanisms. Moreover, different forms of environmental governance have a positive, moderating effect, while the effect of top-down environmental governance is more manifested in quantitative renewable energy innovation. Furthermore, heterogeneity analyses show that the incentive effect of digital financial inclusion is more pronounced in the PV sector and the eastern regions. The findings provide a theoretical basis and practical insights that enable policy-makers to formulate relevant renewable energy technology innovation policies and promote low-carbon energy transition.

Investigation of a novel multigeneration system driven by an ammonia-methane Brayton cycle with partial production and utilization of ammonia, methane, and hydrogen: Energy and carbon footprint assessments

In this paper, to address gaps in the development of low-carbon energy systems, an innovative concept of an ammonia-methane Brayton cycle is proposed. This system is interconnected with various subsystems, including the Kalina cycle, high-temperature steam electrolysis, thermoelectric generators, and ammonia and methane synthesis reactors. The primary aim of this system was to reduce dependence on external resources by establishing local sources for water and fuel, thus reducing the environmental impact and enhancing energy sustainability. A thermodynamic model of an energy system was developed via EES codes which leads to a thoughtful perception into the interactions of the proposed system parameters. Also, comprehensive investigations involved the examination of different energy system scenarios. Modeling outputs of the proposed multigeneration system discovered excellent thermal efficiency and power production, with figures of 56.5 % and 17 MW, respectively, while the Brayton system showed the results of 23.7 % and 3.8 MW. This study also highlighted the environmental benefits of the multigeneration system by demonstrating a carbon dioxide emission of 0.058 kg/kWh, representing its significant positive impact on environmental sustainability. Also, the produced ammonia and methane within the system was 0.37 % and 9 %, of fuel in combustion chamber, respectively. Also, the rest of demand fuel was provided from the external resources.

Energy Transition Analysis and Climate Action Strategy in the Power Sector: A Case Study of the Java-Bali System

Abstract The transformation of societies over time has led to a marked shift in energy consumption patterns. In the face of rapid industrial growth and a burgeoning population, Indonesia confronts the multifaceted challenge of achieving a balance among energy trilemma: energy security, economic affordability, and environmental sustainability. This study assesses the feasibility of low-carbon energy systems in Indonesia, evaluating current policies and proposing a roadmap for net-zero emissions. Utilizing the Low Emissions Analysis Platform (LEAP) and the Next Energy Modeling System for Optimization (NEMO), the study explores multiple scenarios—namely, Business-as-Usual (BAU), Carbon Capture and Storage Mitigation (CCSM), and New and Renewable Energy Mitigation (NREM). Of these, the NREM scenario, emphasizing the integration of innovative and renewable energy sources, achieves the most substantial reduction in greenhouse gas emissions while maintaining economic viability. This strategy advocates for the comprehensive adoption of new and renewable energy, aiming to approximate zero emissions by 2060. The peak direct cost of production for this scenario is estimated at $270.8 billion. However, each scenario presents its own set of technological, economic, and policy-related challenges, necessitating strategic solutions for a successful transition to sustainable energy systems.

Techno-economic and environmental assessment of green hydrogen and ammonia production from solar and wind energy in the republic of Djibouti: A geospatial modeling approach

This study conducts a thorough economic and technical analysis to assess the viability of green hydrogen and green ammonia production using renewable energy sources in the Republic of Djibouti. We explore the economic competitiveness of utilizing wind and solar power for sustainable energy production through various measures including levelized cost of energy (LCOE), hydrogen (LCOH), and ammonia (LCOA). Our analysis incorporates sensitivity assessments and Monte Carlo simulations to predict financial feasibility and environmental impact, focusing on CO2 emission reductions. A cost mapping of electricity, green hydrogen, and green ammonia from solar and wind resources was created to find Djibouti's most cost-effective production sites. The feasibility of exporting green ammonia to neighboring countries with high fertilizer demand was also evaluated using rail and truck transport scenarios. Key findings demonstrate that Moulouhlé, endowed with robust wind and solar resources, presents a strategic site for deploying renewable energy technologies. Wind energy, with a lower LCOE of 0.066 $/kWh compared to solar's 0.093 $/kWh, emerges as a more cost-effective solution for both hydrogen and ammonia production. Notably, wind-powered hydrogen production costs are 2.25 $/kgH2, significantly lower than solar-powered costs at 4.17 $/kgH2. In terms of green ammonia, wind power achieves production costs of 399.76 $/tonNH3, outperforming solar power which stands at 537.11 $/tonNH3. Additionally, our study evaluates the logistics of exporting green ammonia, determining rail transport as a more economically viable option than trucking. This research not only underscores Djibouti's potential as a leader in green energy exportation but also aligns with global decarbonization efforts, showcasing significant CO2 savings—154.94 Mt annually from wind. This work emphasizes the importance of strategic resource utilization in Djibouti, offering insights critical for stakeholders in making informed decisions about investing in renewable energy infrastructures. The outcomes suggest a promising future for regional energy sustainability and economic resilience, fostering a transition towards low-carbon energy systems.

Experimental Study on Phase Change Energy Storage Flooring for Low-Carbon Energy Systems in Grassland Pastoral

Phase change energy storage technology enhances the integration of renewable resources into low-carbon energy systems for grassland pastoral settlements, further addressing the balance between energy needs and environmental sustainability. This study examines a heating system using an experimental platform in an environmental chamber, where the thermal storage and release processes of phase change energy storage flooring were monitored. The results revealed that phase change energy storage flooring exhibits higher heat transfer efficiency and faster heating rates. Under 40 °C heating conditions, the heating rate of the thermal storage layer increased by 12.5% within 1 h. The flooring also demonstrated superior heat release performance, with the peak heat flux of the thermal storage layer delayed by 15 min. Higher heating temperatures shortened the heating time and extended the heat release duration of the phase change energy storage flooring. Under 45 °C heating conditions, the heat transfer efficiency of the surface temperature of the thermal storage layer increased by 38% within 1 hour and by 24.7% over 4 h. In addition, energy consumption in different tests was analyzed, and thermal conductivity was discussed according to the heat transfer model. Phase change energy storage flooring, when coupled with the abundant solar energy resources available in grassland pastoral areas, presents a viable option for the construction of low-carbon energy systems in grassland pastoral settlements.

Optimal allocation method of oxygen enriched combustion-carbon capture low-carbon integrated energy system considering uncertainty of carbon-source-load

In the context of green grid, it is crucial to enhance the low-carbon transformation of integrated energy systems. To improve the degree of low-carbon in these systems, this paper proposes an optimal allocation method of oxygen enriched combustion-carbon capture low-carbon integrated energy system considering the uncertainty of carbon-source-load. Firstly, this paper provides an analysis of uncertainties of carbon-source-load and uses budget uncertainty sets to model the three uncertain parameters. Secondly, in the integrated energy system, the by-product O2 of hydrogen production by electrocution and the oxygen storage device are used to provide oxygen-enriched combustion conditions for the gas turbine to reduce the CO2 generated in the combustion process. At the same time, the carbon capture device is used to collect CO2, and the oxygen enriched combustion-carbon capture integrated energy system is formed. Finally, an improved multi-populations quantum-behaved particle swarm optimization algorithm is proposed to solve the proposed model. This method considers the uncertainty of carbon emission intensity, which makes the optimal allocation of integrated energy system more inclined to low-carbon rather than economic. In addition, in terms of model structure, this method integrates oxygen enriched combustion-carbon capture into the integrated energy system to form a low-carbon model, which directly improves the low-carbon performance of the system. The simulation results show that the carbon emission of the proposed method is reduced by 38.8 % compared with other methods.

The impact of energy prices in decarbonizing buildings’ energy use in the EU27

The recent surge in end-use energy prices in the EU has intensified the debate on how price signals influence the decarbonization of the building sector, a key contributor to global energy consumption and emissions. This study investigates the role of energy price signals in driving the decarbonization of the EU-27 building sector using the Invert/EE-Lab model to simulate various scenarios up to 2050. The analysis examines the elasticity of energy demand, particularly how different price scenarios impact investment decisions in energy-related technologies. The findings reveal that a 10 % increase in energy prices can lead to a reduction in energy demand by up to 3 %, depending on the scenario. Furthermore, price elasticity varies across different policy and price settings, with stricter regulations resulting in lower elasticity. The results underscore that while stringent regulatory measures can achieve significant energy savings and reduce greenhouse gas emissions, they also limit the responsiveness to price signals, with heat pump shares reaching 47–86 % in high-efficiency scenarios. Conversely, more moderate policy measures increase price elasticity, leading to 15–55 % heat pump shares. This study highlights the importance of better understanding price elasticity in energy modeling to project better the outcomes of policy interventions aimed at achieving a low-carbon energy system.

Assessing the impact of energy R&D on green growth in OECD countries: a CS-ARDL analysis

AbstractSince the introduction of the OECD innovation and green growth strategies in 2007 and 2011, respectively, the OECD countries have been actively engaged in supporting green energy R&D to accelerate the development of clean energy technologies. Specifically, the OECD recognizes that both renewable energy R&D and energy efficiency R&D are key components of a low-carbon and sustainable energy system. This study aims to assess the impact of disaggregated energy R&D on green growth in 21 high-income OECD countries, from 1990 to 2021. Two key green growth indicators, namely energy productivity and CO2 productivity, are used as response variables. The long-run CS-ARDL model results show that renewable energy R&D and fossil fuel R&D have a positive and significant impact on energy productivity in all model specifications, with renewable energy R&D exhibiting a relatively stronger impact compared to fossil fuel R&D. The long-run effects of the disaggregated energy R&D variables on CO2 productivity align with the results of the energy productivity model. Based on the study's findings, policymakers should consider reallocating the energy R&D budget towards renewable energy R&D, fostering international collaboration between OECD countries in renewable energy R&D, and implementing technology-specific policies to encourage investment in renewable energy technologies.

Optimal Hybrid Renewable Energy System to Accelerate a Sustainable Energy Transition in Johor, Malaysia

As the world’s second-largest palm oil producer, Malaysia heavily depends on its extensive oil palm cultivation, which accounts for nearly 90% of the country’s lignocellulosic biomass waste. Approximately 20–22 tonnes of empty fruit bunches (EFBs) can be derived from an initial yield of 100 tonnes of fresh fruit bunches (FFBs) from oil palm trees. The average annual amount of EFBs produced in Johor is 3233 tonnes per day. Recognising that urban areas contribute significantly to anthropogenic greenhouse gas emissions, and to support Malaysia’s transition from fossil fuel-based energy to a low-carbon energy system, this research employed HOMER Pro software 3.18.3 to develop an optimal hybrid renewable energy system integrating solar and biomass (EFB) energy sources in Johor, Malaysia. The most cost-effective system (solar–biomass) consists of 4075 kW solar photovoltaics, a 2100 kW biomass gasifier, 9363 battery units and 1939 kW converters. This configuration results in a total net present cost (NPC) of USD 44,596,990 and a levelised cost of energy (LCOE) of USD 0.2364/kWh. This system satisfies the residential load demand via 6,020,427 kWh (64.7%) of solar-based and 3,286,257 kWh (35.3%) of biomass-based electricity production, with an annual surplus of 2,613,329 kWh (28.1%). The minimal percentages of unmet electric load and capacity shortage, both <0.1%, indicate that all systems can meet the power demand. In conclusion, this research provides valuable insights into the economic viability and technical feasibility of powering the Kulai district with a solar–biomass system.

Uncharted depths: Navigating the energy security potential of deep-sea mining

In the context of a global shift towards low-carbon energy systems, this paper provides an in-depth analysis of deep-sea mining's (DSM) potential role in enhancing global energy security. Addressing the growing demand for critical minerals essential for clean energy technologies, electric vehicles (EVs), and energy storage systems, the paper examines how DSM can diversify the global mineral supply and reduce reliance on geopolitically sensitive sources. It explores DSM's capacity to recalibrate energy prices, influence the competitive landscape of clean energy technologies, and shift geopolitical dynamics. The paper delves into the multi-faceted impacts of DSM on energy security, including geopolitical shifts, supply chain diversification, and environmental trade-offs. By providing a holistic view that links mineral supply security to sustainable energy transitions, this study extends beyond prior research focused mainly on the technical and environmental aspects of DSM. The findings illustrate DSM's intersection with international politics, its effect on energy pricing strategies, and the balance between resource exploitation and environmental stewardship. Strategic policy recommendations are offered to optimize DSM's benefits while minimizing its ecological impacts, aligning the emerging DSM industry with global sustainability goals. In addition to identifying challenges, the paper proposes actionable solutions, contributing a unique perspective to the discourse on DSM and energy security.

Multi-objective coordinated optimization of low-carbon building energy systems based on high renewable energy penetration

In the context of China's targets to achieve a "carbon peak" by 2030 and "carbon neutrality" by 2060, the operation and maintenance of buildings with low-carbon and zero-energy consumption emerge as a critical technology for accomplishing the "dual carbon" goals in the building sector. As a novel energy supply system, low-carbon building energy systems can provide low-carbon, efficient, and economical energy supplies. Accordingly, this paper initially constructs a low-carbon building energy system based on a high penetration of renewable energy sources. Subsequently, considering the benefits of economic efficiency, carbon emissions, and renewable energy utilization, a multi-objective cooperative optimization model for low-carbon building energy systems with high renewable energy penetration is established. Finally, a multi-objective particle swarm optimization algorithm is applied to solve the model, and the system is studied and analyzed using a large domestic park as a case study. The results indicate that the low-carbon building energy system with high renewable energy integration, aiming for economic efficiency, carbon reduction, and increased renewable energy consumption, achieves supply energy costs of $ 19.2/m2 and carbon emissions of 49.1 kg/m2. These values represent reductions of $ 7.4/m2 and 60.9 kg/m2 compared to separate supply systems. Lastly, the study of the low-carbon building energy system provides theoretical references for renewable energy integration and energy transition in the building sector.

Solar Driven Syngas Production Potential in Portugal

The production of synthesis gas, or syngas, from the thermochemical conversion of different carbon-based feedstocks, including biomass, is an important alternative for the conversion of waste from sources such as agroforestry or urban waste into renewable gases or fuels. The use of solar radiation as an energy source for these thermochemical processes can reduce or even eliminate their environmental impacts and increase the energy content of the resulting syngas. Portugal, with its high levels of solar radiation, has significant potential for solarized syngas production through biomass gasification. This paper analyzes the cost competitiveness of solar-driven syngas production in Portugal using different feedstocks and solar radiation levels and compares these costs to conventional gasification costs. The results show that solarized syngas production in Portugal is economically viable and has the potential to contribute to a more sustainable and low-carbon energy system.

Enhancing concentrated photovoltaic power generation efficiency and stability through liquid air energy storage and cooling utilization

Amid escalating climate concerns, particularly global warming, there is a significant shift towards renewable energy sources. Concentrated Photovoltaics (CPV) are at the forefront of this transition due to their high efficiency and clean energy generation capabilities. However, CPV cell stability and reliability are compromised by high operating temperatures, necessitating effective cooling solutions. This study proposes a novel coupled Concentrated Photovoltaic System (CPVS) and Liquid Air Energy Storage (LAES) to enhance CPV power generation efficiency and mitigate the challenges of high cell temperatures and grid integration. The research introduces an innovative process employing the cell liquefaction cycle for LAES, utilizing surplus cooling capacity to maintain CPV cells at optimal temperatures. A comprehensive thermodynamic analysis optimizes the coupled system’s operation and evaluates its economic benefits. The integrated system improves generation efficiency and economic viability of CPVS, resulting in a 24.41 % increase in photovoltaic module efficiency and a 2.03 % increase in overall rated power output. This leads to a 56.59 % increase in annual revenue for a 50 MW CPVS. Importantly, the findings demonstrate that integrating LAES with CPVS not only enhances solar energy utilization and economic benefits but also significantly contributes to the sustainability of clean, low-carbon energy systems, inspiring a greener future.

Exergetic efficiency and CO2 intensity of hydrogen supply chain including underground storage

Hydrogen plays a crucial role in the transition to low-carbon energy systems, especially when integrated into energy storage applications. In this study, the concept of exergy-return on exergy-investment (ERoEI) is applied to investigate the exergetic efficiency (defined as the ratio of useful exergy output to invested exergy input) and CO2 equivalent intensity of the hydrogen supply chain, with a specific focus on the underground hydrogen storage process. Our findings reveal that the overall exergetic efficiency of the electricity-to-hydrogen-to-electricity conversion process can reach up to 25 %. Among the hydrogen production methods, green hydrogen, produced via electrolysis powered by renewable energy, exhibits the lowest CO2 equivalent intensity. Blue hydrogen, produced from natural gas with carbon capture, can significantly reduce the carbon footprint of electricity generation, though this advantage comes at the expense of decreased exergetic efficiency. Analysis further indicates that the exergetic efficiency of underground storage components ranges from 72 % to 92 %. A substantial fraction of the exergy is lost during compression and injection of the stored hydrogen. Nevertheless, the subsurface operations contribute a minimal CO2 emission, between 1.46–4.56 grams of equivalent CO2 per megajoule (gr-CO2eq/MJ) when powered by low-carbon energy sources. Furthermore, it is found that hydrogen loss in the reservoir, along with methane and hydrogen leak during surface operations, notably affects the overall efficiency of the storage process.

Decoupling Economic Growth from Carbon Emissions: A Transition Toward Low-Carbon Energy Systems—A Critical Review

Climate change has become a global nightmare, and the awareness of the causes of carbon emissions has resulted in rigorous studies. These studies linked the increase in global warming with booming economic growth. Since global warming has become more apparent, researchers have explored ways to decouple economic activities from carbon growth. Economic and carbon growth must be decoupled to achieve a low-carbon economy to support the carbon-growth plan or emission-reduction strategy. The world is transitioning toward a carbon-neutral and green ecosystem, so finding ways to decouple carbon emissions from economic activities is an exciting topic to explore. This study reviews current information on the importance of decoupling energy from economic growth innovative techniques that thoroughly examine the challenges and constraints of low-carbon energy systems. In order to examine the detrimental effects of carbon emissions on ecosystems and the ways in which economic expansion contributes to carbon footprints, more than three hundred research papers were gathered using several search engines, including Elsevier and Google Scholar. This review revealed that decarbonization and dematerialization had been achieved without declining global economic growth. It also provides information on energy use and economic activities leading to global carbon emissions and alternative solutions to the global challenge of climate change. The decoupling methods commonly used to determine the impact of energy decarbonization on economic growth are explored. All the results suggest that economic growth is a primary mover of global carbon emission increase and must be separated to achieve a carbon environment.

Low-carbon operation of integrated electricity–gas system with hydrogen injection considering hydrogen mixed gas turbine and laddered carbon trading

Green hydrogen produced by the power-to-gas facilities can be blended into the natural gas system, which is a promising way toward a low-carbon energy system. This paper proposes a laddered carbon trading-based operation model for integrated electricity–gas system with hydrogen injection considering the complex combustion properties of hydrogen mixed gas turbine (HMGT). The power-to-hydrogen, hydrogen methanation, and carbon emission processes are combined with the methane reactor and the flexible carbon capture, utilization and storage facility. Then, a HMGT combustion model based on the system thermodynamics and chemical reaction kinetics is introduced. The piecewise linearization technique is adopted to describe the varying hydrogen production efficiency of electrolysis system. Moreover, an energy balance based quasi-steady-state model to deal with the calorific value problem of the gas mixture is proposed and solved by an advanced sequential cone programming algorithm. Case studies are carried on a 30-bus-20-node system and a 197-bus-171-node practical system in Northwest China to illustrate the effectiveness of the proposed model.

Socioeconomic Factors Driving the Transition to a Low-Carbon Energy System

Citizen participation via different investment schemes may be a promising solution to the financing barriers inhibiting energy transition. In this regard, citizens may be approached as potential investors in renewables, but, to mobilize their capital, strategies need to be developed. Much like other services or products seeking to improve their market position, renewable energy investments by citizens also require dedicated efforts to acquire a strong market position. Using a large sample of Greek citizens, this study investigated whether it is possible to identify distinct and addressable citizen clusters which can enable energy developers and marketers to effectively address the preferences and needs of potential investor segments. The performance of k-means cluster analysis identified four clusters: Indifferent Investors were neither driven by economic or social factors, Enthusiastic Investors were motivated both by economic and social factors, Pro-environmental Investors were driven by the environmental benefits, and Social Investors were motivated by the social aspects of the investment. Moreover, each cluster demonstrated different levels of willingness-to-invest in renewable energy and were knowledge about renewable energy investments. It was concluded that citizens should not be approached as a homogeneous target group by marketing experts and policymakers, while novel strategies should be followed.