In this study, optimum insulation thicknesses were determined for the external walls of buildings in different climatic regions of Turkiye. Energy, economic and environmental performance analyses were carried out by applying optimum insulation thickness for extruded polystyrene () and glass wool as insulating material. According to the thermal insulation rules ( 825) in buildings, for Diyarbak & imath;r, Konya and Kars provinces located in second-, third- and fourth-degree day zones, optimum insulation thicknesses and related energy, economic and environmental performance analyses were made. Life cycle assessment () method was used to determine environmental performance. The optimum insulation thicknesses vary between 0.043 and 0.12 m. Compared to XPS, optimum insulation thickness is higher, both payback period and payback period (LCA) are shorter, and both ES and avoided environmental impact () amounts are higher when glass wool is used for the investigated three provinces. The results indicated that ES and amounts are considerably augmented and LCA is reduced when coal is used compared to natural gas for both insulating materials. According to obtained results, it is suggested that coal as the fuel type and glass wool as the insulation material can be utilised for buildings in the studied three provinces.
Environmental taxes push countries away from carbon-intensive energy, while renewable energy pulls them closer to green energy options. This synergy can be important for environmental quality but little is known about their joint impact on ecological footprint. This study explored moderation and mediation effects in analysing the joint impact of environmental taxes and renewable energy consumption on ecological footprint in Africa, focusing on Ghana, Nigeria, and South Africa from 2017 to 2024. It also examined how renewable energy consumption responds to environmental taxes. The Driscoll and Kraay with Fixed Effects and the Panel-Corrected Standard Error estimators were employed for the analyses. While environmental taxes were found to directly reduce renewable energy consumption, environmental taxes and renewable energy consumption worked together to enhance environmental quality by lowering the ecological footprint based on the moderation and mediation analyses. This suggests a complementary role rather than purely stimulative role of taxation in environmental protection policy and demands a coordinated policy design where environmental tax revenue is invested to promote renewable energy consumption and environmental quality.
Conventional solar stills are constrained by low productivity and limited thermodynamic efficiency. This study experimentally investigates a passive parabolic trough-assisted tubular solar still (TSS-PTC) and compares its performance with a conventional tubular solar still () under identical climatic conditions. A passive parabolic trough reflector is integrated to enhance solar concentration without external energy input, achieving an effective concentration ratio of 2.33 and improving solar energy absorption. Experiments conducted over five consecutive days under peak and average solar irradiance of 970 and 641.5 W/m(2) indicate improved thermal behaviour. The TSS-PTC showed increases in basin water and cover temperatures of 3.84 degrees C and 1.9 degrees C, respectively, leading to a 23.10% rise in the evaporative heat transfer coefficient. Consequently, freshwater productivity increased, with a 54% rise in peak hourly yield and an average productivity improvement of 91.3% compared to the conventional system. The maximum thermal efficiency reached 45.2%, while the conventional one still produced 26.1%. In addition, thermal and exergy efficiencies increased by 59.43% and 91.30%, respectively. Overall, daily distillate output from the TSS-PTC was more than twice that of the conventional still, indicating its suitability for efficient, decentralised solar desalination applications.
Solar drying is increasingly being adopted as a sustainable alternative to conventional fuel-based preservation systems. This study investigates the effect of evacuated tube collector (ETC) count and sand particle size on the performance of a solar dryer integrated with sand-based thermal storage. Experiments were carried out using fine-grained sand (FGS), medium-grained sand (MGS), and coarse-grained sand (CGS) across one-, two-, and three-ETC configurations. Performance evaluation was based on drying rate (g/min) and drying efficiency (%). The results show that drying rate improved consistently with an increase in ETC count, peaking at 0.77 g/min with FGS under three ETCs, followed by MGS (0.63 g/min) and CGS (0.58 g/min) in the same configuration. Fine sand exhibited superior thermal conduction, leading to faster moisture removal, while medium and coarse sands demonstrated steadier drying patterns during late hours. Drying efficiency displayed an opposite trend: the FGS-1 ETC setup achieved the highest efficiency of 70.7%, whereas efficiency declined to 33.4% for two ETCs and 15.8% for three ETCs, regardless of sand size. This analysis highlights the trade-off between maximising drying rate and maintaining energy efficiency.
The United Kingdom of Great Britain and Northern Ireland (UK) introduced a pioneering Climate Change Act in 2008, together with a subsequent amendment aimed at achieving net-zero greenhouse gas (GHG) emissions (i.e. carbon neutrality) by 2050. That Act also established an independent, statutory body - the Climate Change Committee (CCC) - with the role of advising the UK government on progress towards securing its emissions targets. The CCC recently noted that the UK is not on track to meet its commitments under the UN climate change process of a 68% reduction in GHG emissions by 2030. This contribution firstly describes the phenomenon of 'carbon leakage' and related issues, along with GHG accounting methods, carbon footprints and standards (based around life-cycle thinking). Examples are then outlined of potential UK climate change options. On mitigation, the challenges associated with low-carbon energy technologies and so-called 'circular economy' interventions are recounted. Various adaptation issues are discussed, alongside climate-respecting engineering design and associated challenges. Across the board, climate change standards - such as those approved by the International Standards Organisation and adopted in the UK via the British Standards Institution - play a pivotal role in accelerating climate action through the adoption of sustainable practices.
With rapid technological growth, the demand for renewable energy sources continues to rise. In this study, Kusum oil has been explored as a raw material for biodiesel production, with efforts directed towards improving the process efficiency. Kusum oil was chosen because it is a non-edible resource that is available in several parts of India and contains a high proportion of suitable fatty acids for biodiesel conversion compared to other non-edible oils. The work focuses on understanding how parameters, such as the molar ratio, reaction time, catalyst concentration, and reaction temperature, affect the yield and quality of the biodiesel. Using the Taguchi approach with a three-level design, these parameters were fine-tuned. The highest biodiesel yield achieved was 86.65%, with lowest 0.23% free fatty acid at a molar ratio of 6:1, 1% (weight) catalyst concentration, 90 min reaction time, and 50 degrees C reaction temperature. Analysis showed that the molar ratio, for the two-step transesterification process which led to reduce the free fatty acid content at first and helped the alcohol to react better with the oil, significantly influenced biodiesel yield (38.29% contribution), while catalyst concentration primarily affected free fatty acid content (67.48% impact) as was found in previous studies on algal or safflower oil biodiesel.
This study aimed to evaluate the cascading effect and interdependencies of critical facilities in urban areas following disasters, with a particular focus on power supply systems as an example. The authors collected and analysed historical disaster data, reviewed cases to examine the propagation patterns and spatial failures of critical infrastructure. The authors then used kernel density estimation to examine the geographic hotspots of facilities and utilised big data on power outages. In addition, this study used a semi-quantitative risk matrix to examine the cascading effect risk of critical facilities following disasters in metropolitan areas. This study applies hazard-vulnerability maps of flooding risk under global warming scenarios to assess the cascading effect risk of critical infrastructure in the current and future situations (global warming scenarios 1°C, 2°C, and 4°C). Because of the complexity and strong interdependency of infrastructure systems, a single failure may lead to a cascading effect of disruptions in other services. In high-risk districts, short-term exposure to hazards may increase service function risks, and as exposure time increases, the facilities in the area may become increasingly affected, resulting in severe consequences and system service failures.
This study aims to examine the effect of frequently used energy strategies, such as insulation of external walls and roof, glazing type, shading devices, and indoor air temperature of the building, by using the artificial neural networks (ANN) of the Balikesir University Hospital building. The different energy-efficient strategies were simulated after modelling and calibrating the building by way of DesignBuilder. The five other insulation materials and window types were selected, and the overhang and louvre were applied with different lengths as a shading device. Based on the strategies, ANN produced 6250 data points eligible for building construction mode and hospital building use. As a result, when comparing the model output values, ANN gives the results with a satisfactory accuracy of 99% for the estimation and test data. After analysing ANN results, when the current indoor temperature results are set, the maximum saving rate is 18.66% and 72.48% for the heating and cooling periods, respectively.
This study investigates the significant impact of occupant behaviour on reducing air conditioning energy consumption in institutional buildings, using Salah Boubnider University Constantine 3 in Algeria as a case study. Employing integrated methodologies that combine numerical simulations and empirical data analysis, the research demonstrates that a simple behavioural adjustment raising air conditioning setpoints to 26 degrees C can reduce energy consumption by up to 46% equivalent to a drop from 115,894 kWh (baseline) to 62 076 kWh. In contrast, structural improvements, such as implementing double glazing and enhanced insulation, achieve only slightly lower savings of 43%, but at a substantially higher cost and longer implementation period. These findings underscore occupant behaviour as a pivotal factor in achieving immediate, accessible, and cost-effective energy savings. The study recommends prioritising behavioural interventions through targeted awareness campaigns, educational initiatives, and policy enforcement, which collectively offer considerable potential for reducing energy consumption and associated carbon dioxide emissions in institutional settings.
Large numbers of wind farms have been built onshore and many more are planned for offshore areas in tropical cyclone regions. A review of past wind turbine failures in tropical cyclones reveals six general types of design weaknesses. Several key studies show that extreme winds in tropical cyclones, especially in Saffir–Simpson hurricane classes 3 through 5 (major tropical cyclones), are poorly understood. In response to evolving tropical cyclone wind turbine design standards, known design weaknesses in tropical cyclones (and more frequent and intense winds due to climate change) promising wind turbine design innovations may significantly reduce the risk of wind turbine failures and financial losses associated with tropical cyclones. This study identifies three key priorities: (1) adoption of site-specific (Class S) assessments to account for localised cyclone dynamics, (2) implementation of a 100-year return period design standard for structural resilience, and (3) integration of innovative blade force survivability technologies, such as adaptive pitch control and composite reinforcement. Leveraging innovative solutions will play a pivotal role in securing the viability of wind farms in tropical cyclone-prone regions.
Aligned with the United Nations Sustainable Development Goals (SDGs) numbers SDG 7, SDG 9, SDG 11, SDG 12 and SDG13, this study proposes a model of autonomous hydrogen refuelling stations installed on 20 Saudi cities powered by renewable resources. The station is supplied with photovoltaic (PV) panels and wind turbines involving an electrolyser and hydrogen tank for producing and storing hydrogen. Three scenarios are simulated proposing the optimised model by combining the (PV-wind-battery) components. The modelling process demonstrates an extremely competitive levelised cost of energy (LCOE) and levelised cost of hydrogen (LCOH), especially for the third scenario solely based on PV power with an LCOH varying within $12-15.9/kg and LCOE in the range of $0.332-0.414/kWh, for all 20 sites. Furthermore, encouraging lower values of net present cost (NPC) and LCOE are obtained for the futuristic NEOM city for Scenario 3 with NPC = $830 494 and LCOE = $0.332/kWh. On the other hand, replacing conventional gasoline vehicles with hydrogen fuel cell vehicles can significantly reduce CO2 emissions, with cost per kilometre for the hydrogen fuel cell car in ranges of $0.0362/km-$0.0370/km, $0.0306/km-$0.0931/km and $0.0191/km to $0.0241/km, according to Scenario 1, 2 and 3, respectively.
This study explores an optimised adsorption refrigeration system by integrating mass and heat recovery using CaCl2 impregnated activated carbon as the adsorbent. Experiments assessed the effects of recovery mechanisms and temperature conditions on system performance, particularly specific cooling power (SCP) and coefficient of performance (COP). Tests were conducted with a heating power of 3.6 kW and an evaporator temperature of -20 degrees C. Without recovery, the system achieved an SCP of 514.3 W/kg. Introducing mass recovery increased SCP to 797.5 W/kg (a 28.7% gain), while the combined mass and heat recovery approach elevated SCP to 1026.2 W/kg (70.8% improvement). COP values improved accordingly, indicating enhanced energy efficiency. Further analysis showed that increasing cooling water temperatures (14-26 degrees C) reduced SCP from 340 to 280.5 W/kg and COP from 0.14 to 0.10. Heating power variations (1.64-1.96 kW) also influenced performance, confirming the system's sensitivity to thermal conditions. The optimised system reached a maximum SCP of 0.45 kW/kg and a COP of 0.62, demonstrating the effectiveness of recovery strategies for low-grade thermal energy applications.
The widespread use of R410A is under mounting pressure to gradually phase out due to its high global warming potential (GWP). The Kigali amendment to the Montreal Protocol mandates developed nations to eliminate R410A from air conditioning systems by the late 2020s, necessitating the adoption of alternatives by the mid-2020s. One such alternative, R466A, has emerged as a promising refrigerant mixture with thermodynamic properties that could make it a suitable replacement for R410A. R466A boasts a remarkable 65% reduction in GWP compared to R410A and is classified as non-flammable (Class A1). Previous evaluations in air-cooled chillers and residential split-system heat pumps showed performance mostly in line with expectations, with slight variations in capacity and efficiency compared to R410A. Additional experiments conducted in residential heat pumps and transport refrigeration units further supported R466A's viability as an alternative. Capacities varied by 5% decrease to 2% increase, while efficiencies ranged from 3% decrease to 4% increase compared to R410A. These findings underscore R466A's suitability for various HVAC&R applications, offering both reduced GWP and non-flammability, facilitating its integration into existing equipment designs or as a substitute for R410A in practical use cases.
The maturation of renewable energy technologies has brought them to a point of 'socket parity', enabling direct competition with traditional energy generation. However, this milestone introduces a critical challenge named price cannibalisation, where excess renewable supply leads to price erosion in energy markets. This research introduces an innovative pricing model that accounts for marginal costs and system price erosion, integrating lognormal and Poisson distributions. The model leverages metrics such as market tightness and capacity utilisation to address complexities of renewables integration. Key innovation is incorporation of zero marginal cost production uncertainties, with important implications for pricing dynamics. Specifically, the model integrates expected production, weighted by Weibull distribution, to capture full spectrum of wind speeds while solar irradiation is weighted by gamma distribution. This novel approach transforms the typically stochastic nature of renewables into a deterministic framework, focusing on average effects of wind and solar rather than modelling full variability. Our findings validate the hypothesis that price cannibalisation influenced more by utilisation than by the level of penetration or tightness. These results present a breakthrough in energy pricing, offering valuable insights for simulation, market design, and energy policy.
A hybrid method integrating the Weather Research and Forecasting (WRF) model and computational fluid dynamics (CFD) was developed to evaluate wind resources in Liaoning Province, China. The WRF model first simulated annual mean wind speeds at a 3 km x 3 km resolution, providing boundary conditions for the CFD model. Using the Reynolds-averaged Navier-Stokes equations with the realisable k-epsilon turbulence model, CFD refined the results to 1 km x 1 km accuracy, accounting for complex terrain effects. Wind-power density was calculated via conversion formulas, enabling analysis of wind energy reserves and technical exploitable potential. At 70 m height, Liaoning's land area exhibits a technical exploitable capacity of 593 346 MW, with high-wind zones concentrated along the Circum-Bohai-Sea shoreline, northwestern mountainous regions, Changbai Mountain's main ridge, and central plains. The study validates the WRF-CFD coupling approach, demonstrating its efficacy in downscaling coarse WRF outputs to high-resolution grids through CFD terrain correction. This method provides spatially refined wind resource data, critical for optimising wind farm siting and supporting regional energy planning. Key advantages include enhanced accuracy in complex topography and scalable grid resolution, offering actionable insights for sustainable wind energy development.
This study addresses global construction challenges by improving the energy efficiency of a semi-buried residential building in Marrakech, Morocco. It combines two approaches, sensitivity analysis and multi-objective optimisation, to determine the optimal combination of retrofit measures that minimise building energy needs and enhance occupants' thermal comfort in various climate types. To emphasise the thermal performance benefits of buried building construction, a preliminary analysis is conducted resulting in significant energy reductions of up to 29.28% for a 69.23% burial depth of above-ground floor. Subsequently, a comprehensive sensitivity analysis is conducted using Python to identify critical design variables associated with building envelope elements influencing global energy requirements. This analysis highlights the significance of effective roof insulation and glazing types. The optimisation procedure is performed through the coupling of TRNSYS and GenOpt. Findings demonstrate that the optimised design schemes yield substantial energy savings, ranging from 66.36% to 75.85% according to the climate type. These results provide tailored solutions for sustainable building design, offering valuable insights to enhance energy efficiency and promote environmental sustainability.
Energy poverty, impacting millions in the UK, exacerbates social and economic inequality by limiting access to affordable and sustainable energy. This issue is intensified by rising energy costs, inefficient housing, and broader systemic injustices. Simultaneously, the UK’s commitment to decarbonisation and net zero by 2050 necessitates significant renewable energy expansion, creating land use conflicts. Brownfield sites – previously developed but now underutilised or contaminated land – offer an innovative solution to both crises by providing space for renewable energy projects, such as solar and wind installations. Despite their potential, challenges exist in redeveloping brownfield sites, including environmental contamination, regulatory complexity, and financial barriers. However, addressing these through targeted policies, incentives, and community-led energy initiatives can enhance energy justice, ensuring fair access to clean energy. Using the PRISMA framework, this paper explores the alignment of brownfield redevelopment with the three core principles of energy justice: distributive, procedural, and recognition justice. Repurposing these underutilised lands enables a more equitable distribution of energy resources, fosters community engagement in decision making, and acknowledges the historical neglect faced by marginalised communities. To materialise these goals, supportive policies and simplified approval processes should be implemented, while community-led energy models should be promoted to boost local involvement and ensure fairness.
Numerous studies have explored the impact of extreme fetch swells from the Southern Hemisphere on the canary coasts, with most focusing on oceanographic and coastal engineering aspects. In this study, the arrival of these swells in the Canary Islands is examined. They are characterised by long periods and low height compared with its wavelength. Their smoother and more predictable nature makes them well suited for certain wave energy converters and hybrid offshore energy systems. To estimate the wave energy, the characteristic wave parameters from buoy records anchored in deep waters south of Tenerife were analysed. In addition, the data collected by this buoy were contrasted to that from the nearest virtual buoy (SIMAR hindcast point). The energy period ratio obtained from the spectral moments over the peak period is 0.87 in the study area. Although their small height reduces individual power output, their long wave periods make them particularly well suited for co-location alongside offshore wind farms. This hybrid approach could maximise energy yield from the same marine space, combining the strengths of both technologies for more efficient and consistent renewable power generation.
Traditional project evaluation models were focusing on individual project impact factors and there is a lack of systematic research on comprehensive project evaluation during the pre-investment period, which include construction assessment and economic evaluation. In light of the complex construction environment and high investment cost of offshore wind power projects, a key metric evaluation system for offshore wind power projects during the pre-investment period was put forward based on the multi-level fuzzy comprehensive evaluation method. Two specific cases in China were evaluated with the assessment model. The results showed that Case 1 in the East China Sea was built in a less favourable environment than Case 2 in the South China Sea, but its electricity price is higher. The system can assist the decision-making procedure by systematic evaluation and comparison of investment opportunities. The system provides technical support for development planning, policy making, and investment management in the offshore renewable energy field.
