Performance Analysis of a VPV/FC Hybrid System for Generating Electricity in Iraq's Remote Areas

A reliable electrical energy supply is a prerequisite for improving the standard economic and quality of life levels in a country. As is the case in many countries, Iraq is home to a collection of remote villages. Since it is uneconomical to connect these villages to the existing grid, the installation of stand-alone electrical power generators has become common practice. As a result, diesel stand-alone power generators see widespread use in these remote locales, which, whilst fit for their intended purpose, unfortunately suffer from several drawbacks, including instability in regards to everyday oil prices and a number of environmental issues. The implementation of a PV/FC hybrid power system could be one potential alternative to help solve these problems. Therefore, this paper will present PV/FC system control strategies alongside information relating to the performance of such system components, based on a case study that was conducted in Al-Gowair, Iraq. This study is especially important in terms of envisioning the future energy supply needs of Iraq. The HOMER simulation results showed that by using the proposed control strategies and suggested components of a PV/FC system, it was able to produce a satisfactory outcome

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Transesterification of moringa oleifera oil to biodiesel using potassium flouride loaded eggshell as catalyst

In recent years, biodiesel has received great attention in the production of engine fuel. Biodiesel can be produced by esterification reaction, transesterification reaction or both esterification and transesterification reactions of non-edible oil. However, high production cost of biodiesel is a remaining problem. Therefore, a low-cost andreliable feedstocks for biodiesel production such as moringa oleifera as non-edible plant oils could be a potential of alternative fuel. In addition, waste egg shell can be a good candidate as a low-cost catalyst for the reaction. In this study, potassium fluoride (KF) loaded on calcium oxide (CaO) and eggshell were prepared. The catalysts were characterized by X-ray Powder Diffraction (XRD), Fourier Transform In frared (FTIR) spectroscopy, Field Emission Scanning Electron Microscope (FESEM) and nitrogen adsorption-desorption analysis. The biodiesel productions (fatty acid methyl esters, FAME) were carried out in a batch reactor with different parameters such as temperature (50&deg;C-60&deg;C), molar ratio of methanol to oil (4-6), reaction time (1-3 hours) and KF loading (1wt%-25wt%) on eggshell. Maximum FAME yield of 94.2% is observed on KF/eggshell with 5% of catalyst amount, 6:1 molar ratio of methanol to oil, 50&deg;C reaction temperature, 1 hour reaction time and 1% of KF loading is observed to be optimum for better conversions. Therefore, the KF/eggshell catalyst has been proven to be a promising catalyst for biodiesel production which is simple, economical and efficient.</p

The development and performance evaluation of an alternative energy-based hybrid cold storage system

The development of cold storage systems with solar-integrated thermal energy storage (TES) could be an exciting alternative energy solution to fossil fuel-based cold storage. For this novel technology to be commercially applicable, significant scientific research is required. Although few attempts have been made in this area, the limitations of existing studies encourage further investigation to advance the field. This research aims to develop a solar-based hybrid cold storage (SHCS) system and perform the techno-economic analysis (TEA) of the system to address the existing research challenges and enhance the understanding of commercial applications. An SHCS of L 4.88 m × W 2.44 m × H 2.44 m has been developed by integrating 500 kg phase change materials (PCM) of ethylene glycol aquas solution, as latent thermal energy storage (LTES), to store energy and provide backup during off-solar time. Three different modes of the power system, Latent Thermal Energy Storage (LTES)-based, Electrochemical Energy Storage (EES)-based (Battery), and no storage; and three types of construction materials, sandwich polyurethane (PUR) panels, sandwich expanded polystyrene (EPS) panels, and concrete were considered in the TEA of the SHCS. The power mode with LTES showed a nearly 1.5 years shorter payback period and 130 % higher net present value (NPV) than the EES mode. The solidification and melting characteristics of the LTES system are uniform at different levels during charging and discharging, which may enhance the heat transfer rate. The PCM system is remarkable in that it maintains a storage temperature of 3 °C in the fresh food chamber for approximately 13 h without an external source of energy. Regarding the construction material of SHCS, sandwich PUR panels outperformed concrete owing to their lower density (40 kg/m3), improved thermal insulation, and modular nature, though the rate of return of PUR panels is slightly lower (0.26 % and 0.81 %) than its counterparts due to its higher initial cost. Overall, it was found that PUR panel-made SHCS integrated with an LTES system provides better techno-economic performance when energy storage is necessary and could be considered to scale up the system in the future for commercial application