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The purpose of this paper is to refer to ecological economics using two meanings of the term “ecological”. In the strict scientific sense, ecological economics refers to an economic system that is consistent with and honors the basic principles of ecology, which, ultimately, are identical with what the authors call the systemic principles of life. In a broader sense ecological economics refers to economic theory and practice that see the economy as operating within, rather than dominating, the spheres of nature, society, and culture.

The authors distill four fundamental principles for ecological economics based on systems theory of life and philosophy of organism. The four principles are; nested systems, self-generating networks, open systems, and cognitive interactions. The authors discuss how these principles can be applied to design an ecological economic system that is life-enhancing on individual, social and ecological levels.

The authors argue that ecological economics should give priority to activities that maximize well-being of human and non-human beings, as well as entire ecosystems, and that its central purpose should be to serve the life processes in social and ecological systems.

In this paper, the authors connect ecological economics to systems theory and come up with principles relevant for developing economic theory and practice within, rather than dominating, the spheres of nature, society, and culture.

This paper aims to determine factors affecting adaptation to climate variability on crop production among farming households in Tyhume Valley.

This study conducted an empirical analysis of the impact of adaptation on crop yield of farming households and estimated the factors affecting adaptation to climate variability on farming households. The analysis used primary data from 205 farming households practicing crop production in Tyhume Valley communities.

Based on binary logit results, factors affecting rural farming households’ adaptation to climate variability are gender, age, heatwave, employment status, strong high wind occasional experience and cell phone. The adaptation measures adopted by the farming households in the study area include irrigation (94.8%), crop rotation (66%), changing crop variety (7.4%) and other methods of adaptation were found to be (1.3%). The other methods of adaptation used included the use of ash to kill (intuku) mole and using dirty water from washing dishes and clothes when irrigating to kill parasites on crops.

This research paper will be an addition to the body of knowledge on adaptation strategies to climate variability in South Africa, especially at the rural farming household level. This study may assist the rural communities in decision-making when dealing with the challenges of climate variability on their crop production, thereby increasing their crop production. The information gathered in this study might assist policymakers in revising the existing policies. This study will also help rural farming households to practice appropriate adaptation strategies.

Until recently, the Gulf Cooperation Council (GCC) region, whose members consist of Saudi Arabia, the United Arab Emirates, Kuwait, Qatar, Oman and Bahrain, has not significantly focused on the green transition. Specifically, wind energy development has made minimal progress relative to that of other regions.

The abundance of cheap fossil fuels in the region has not incentivized renewable energy development, and where this has taken place solar technologies are often preferred.

However, lower technology costs together with lost investment opportunities – also common elsewhere in the world, has increased the pressure on the GCC region from developers. This work qualitatively addresses the challenges and the strategies for the wind development in the area. It focuses on the analysis of different proposed type of investments – driven by a state-supported proposed fund – such as utility-scale investments, industry-specific investments, manufacturing investments and regional accelerators.

The work also suggests that Gulf sovereign wealth funds should act as the lead investors under new schemes, such as joint ventures, for wind development in the GCC, using their wealth to offering their populations with new sources of employment as well as energy that is sustainable.

The purpose of the paper is to predict the aerodynamic performance of a complete scale model H-Darrieus vertical axis wind turbine (VAWT) with end plates at different operating conditions. This paper aims at understanding the flow physics around a model VAWT for three different tip speed ratios corresponding to three different flow regimes.

This study achieves a first three-dimensional hybrid lattice Boltzmann method/very large eddy simulation (LBM-VLES) model for a complete scaled model VAWT with end plates and mast using the solver PowerFLOW. The power curve predicted from the numerical simulations is compared with the experimental data collected at Erlangen University. This study highlights the complexity of the turbulent flow features that are seen at three different operational regimes of the turbine using instantaneous flow structures, mean velocity, pressure iso-contours, blade loading and skin friction plots.

The power curve predicted using the LBM-VLES approach and setup provides a good overall match with the experimental power curve, with the peak and drop after the operational point being captured. Variable turbulent flow structures are seen over the azimuthal revolution that depends on the tip speed ratio (TSR). Significant dynamic stall structures are seen in the upwind phase and at the end of the downwind phase of rotation in the deep stall regime. Strong blade wake interactions and turbulent flow structures are seen inside the rotor at higher TSRs.

The computational cost and time for such high-fidelity simulations using the LBM-VLES remains expensive. Each simulation requires around a week using supercomputing facilities. Further studies need to be performed to improve analytical VAWT models using inputs/calibration from high fidelity simulation databases. As a future work, the impact of turbulent and nonuniform inflow conditions that are more representative of a typical urban environment also needs to be investigated.

The LBM methodology is shown to be a reliable approach for VAWT power prediction. Dynamic stall and blade wake interactions reduce the aerodynamic performance of a VAWT. An ideal operation close to the peak of the power curve should be favored based on the local wind resource, as this point exhibits a smoother variation of forces improving operational performance. The 3D flow features also exhibit a significant wake asymmetry that could impact the optimal layout of VAWT clusters to increase their power density. The present work also highlights the importance of 3D simulations of the complete model including the support structures such as end plates and mast.

Accurate predictions of power performance for Darrieus VAWTs could help in better siting of wind turbines thus improving return of investment and reducing levelized cost of energy. It could promote the development of onsite electricity generation, especially for industrial sites/urban areas and renew interest for VAWT wind farms.

A first high-fidelity simulation of a complete VAWT with end plates and supporting structures has been performed using the LBM approach and compared with experimental data. The 3D flow physics has been analyzed at different operating regimes of the turbine. These physical insights and prediction capabilities of this approach could be useful for commercial VAWT manufacturers.

Despite South Africa’s ailing electrical grid, substantial renewable energy (RE) integration is planned for the country. As grid-integrated RE affects all grids differently, this study aims to develop an adaptable grid code-guided renewable power plant (RPP) control real-time simulation testbed, tailored to South African grid code requirements to study grid-integrated RE’s behaviour concerning South Africa’s unique conditions.

The testbed is designed using MATLAB’s Simulink and live script environments, to create an adaptable model where grid, RPP and RPP guiding grid codes are tailorable. This model is integrated with OPAL-RT’s RT-LAB and brought to real-time simulation using OPAL-RT’s OP4510 simulator. Voltage, frequency and short-circuit event case studies are performed through which the testbed’s abilities and performance are assessed.

Case study results show the following. The testbed accurately represents grid code voltage and frequency requirements. RPP point of connection (POC) conditions are consistently recognized and tracked, according to which the testbed then operates simulated RPPs, validating its design. Short-circuit event simulations show the simulated wind farm supports POC conditions relative to short-circuit intensity by curtailing active power in favour of reactive power, in line with local grid code requirements.

To the best of the authors’ knowledge, this is the first design of an adaptable grid code-guided RPP control testbed, tailored to South African grid code requirements in line with which RPP behavioural and grid integration studies can be performed.

Agricultural workers represent an important part of the population exposed to high heat-related health and productivity risks. This study aims to estimate the heat-related productivity loss (PL) for moderate work activities in sun and shady areas and evaluating the economic cost locally in an Italian farm and generally in the whole province of Florence. Benefits deriving by working in the shade or work-time shifting were provided. Comparisons between PL estimated in Mediterranean (Florence, Italy) and subtropical (Guangzhou, China) areas were also carried out.

Meteorological data were collected during summers 2017–2018 through a station installed in a farm in the province of Florence and by two World Meteorological Organization (WMO)‐certified meteorological stations located at the Florence and Guangzhou airports. These data were used to calculate the wet-bulb globe temperature and to estimate the hourly PL and the economic cost during the typical working time (from 8 a.m. to 5 p.m.) and by advancing of 1 h and 2 h the working time. Significant differences were calculated through nonparametric tests.

The hourly PL and the related economic cost significantly decreased (p < 0.05) by working in the shade and by work-time shifting. Higher PL values were observed in Guangzhou than in Florence. The decrease of PL observed by work-time shifting was greater in Florence than in Guangzhou.

Useful information to plan suitable heat-related prevention strategies to counteract the effects of heat in the workplace are provided. These findings are essential to quantify the beneficial effects due to the implementation of specific heat-related adaptation measures to counter the impending effects of climate change.

A flexible model which is based on a Triangular intuitionistic flexibility ranking and aggregating (TIFRA) operator is proposed for failure detection and reliability management in a Wind Turbine system. The model which is employed when there are limited research data and valid source of information, uses expert-based knowledge/opinion for failure detection and reliability management. The results from the study concludes that, the most important area affected by failure with respect to the failure criteria used, includes; oil level sensor tilt sensors for tower installation and accelerometers for tower sway (A₂), Pressure sensor for blade monitoring (A₃), and the Pitch actuator (A₄). The main advantage of the proposed method is that it provides advanced information about faults that identifies the intensity of the system behavior also; the method provides a more complete view of the reliability management and root cause of failure in the Wind Turbine (WT) system using the flexibility parameter in the model.