• Energy Research

Abstract Bioenergy systems are expected to expand over the coming decades due to their potential to address energy security and environmental pollution challenges. Nevertheless, any renewable energy project can only survive if approved environmentally superior to its conventional counterparts. Life cycle assessment (LCA) is an internationally standardized and validated methodology to evaluate and quantify the environmental impacts of bioenergy systems. However, due to its methodological scope, the LCA method measures only the environmental consequences of the target products of energy systems. The LCA approach can neither allocate the environmental impacts at the component level nor measure the environmental impacts of intermediate products. These challenges can be substantially resolved by systematically integrating the LCA approach with the thermodynamically-rooted exergy, offering a powerful environmental sustainability assessment tool known as “exergoenvironmental analysis“. Due to the unique methodological and conceptual characteristics of exergoenvironmental analysis in revealing the possibilities and trends for improvement, it has recently received increasing attention to mitigate the environmental impacts of bioenergy systems. Therefore, this review is aimed to thoroughly summarize and critically discuss the evaluation of sustainability aspects of bioenergy systems based on exergoenvironmental analysis. The pros and cons of using exergoenvironmental analysis in bioenergy research are also outlined to identify possible future directions for the field. Overall, exergoenvironmental analysis can offer more detailed information on the environmental consequences of each flow and component of bioenergy production plants, thereby diagnosing the breakthrough points for additional environmental improvements.

Using hybrid renewable energy technology is an efficient method for greenhouse gas mitigation caused by fossil fuel combustion. However, these renewable microgrids are not free from environmental damages, especially during the lifetime of hybrid renewable energy systems (HRES). The main objective of this study is to assess the environmental impacts of three optimized HRES for the Sea Water Reverse Osmosis Desalination (SWROD) plant. An objective optimization was developed using the division algorithm, and the environmental impacts of the optimized HRES were investigated by the life cycle assessment approach. The results showed that producing 1 m3 freshwater by an optimal size SWROD integrated with wind turbine/battery is responsible for 3.56E - 07 disability-adjusted life year (DALY). It is significantly less than 1 m3 freshwater production by an optimal size SWROD integrated with solar PV/battery (5.88E - 07 DALY) and solar PV/wind turbine/battery (5.13E - 07 DALY) energy systems. Moreover, 1 m3 freshwater by a SWROD integrated with proposed microgrids in this study led to a damage of 0.089 to 0.193 potentially disappeared fraction of species (PDF)*m2*yr to ecosystem quality. It also results in an emission of 0.143 to 0.339 kg CO2 eq per 1 m3 freshwater. Furthermore, resources for 1 m3 freshwater production by a SWROD are calculated at 2.77 to 4.806 MJ primary. Freshwater production by an optimal size SWROD integrated with solar wind/battery compared with solar PV/battery and solar PV/wind turbine/battery had less damage to ecosystem quality, climate, and resources. The results showed reductions of 91.23% in human health, 73.51% in an ecosystem quality, 92.43% in climate change, and 90.08% in resources for producing 1 m3 of freshwater using SWROD integrated with wind turbine/battery bank compared to fossil-based desalination. Finally, the result showed that solving the optimization problem using the division algorithm compared to other algorithms leads to less environmental damage in freshwater production.

Sustainable socio-economic development largely depends on the sustainability of the energy supply from economic, environmental, and public health perspectives. Fossil fuel combustion only meets the first element of this equation and is hence rendered unsustainable. Biofuels are advantageous from a public health perspective, but their environmental and economic sustainability might be questioned considering the conflicts surrounding their feedstocks, including land use change and fuel vs. food conflict. Therefore, it is imperative to put more effort into addressing the downsides of biofuel production using advanced technologies, such as nanotechnology. In light of that, this review strives to scrutinize the latest developments in the application of nanotechnology in producing biodiesel, a promising alternative to fossil diesel with proven environmental and health benefits. The main focus is placed on nanotechnology applications in the feedstock production stage. First, the latest findings concerning the application of nanomaterials as nanofertilizers and nanopesticides to improve the performance of oil crops are presented and critically discussed. Then, the most promising results reported recently on applying nanotechnology to boost biomass and oil production by microalgae and facilitating microalgae harvesting are reviewed and mechanistically explained. Finally, the promises held by nanomaterials to enhance animal fat production in livestock, poultry, and aquaculture systems are elaborated. Despite the favorable features of using nanotechnology in biodiesel feedstock production, the presence of nanoparticles in living systems is also associated with important health and environmental challenges, which are critically covered and discussed in this work.

This article presents the modeling and optimization control of a hybrid water pumping system utilizing a brushless DC motor. The system incorporates battery storage and a solar photovoltaic array to achieve efficient water pumping. The solar array serves as the primary power source, supplying energy to the water pump for full-volume water surrender. During unfavorable weather conditions or when the photovoltaic array is unable to meet the power demands of the water pump, the battery discharges only at night or during inadequate solar conditions. Additionally, the photovoltaic array can charge the battery on its own when water distribution is not necessary, negating the need for external power sources. A bi-directional charge control mechanism is employed to facilitate automatic switching between the operating modes of the battery, utilizing a buck-boost DC–DC converter. The study incorporates a control system with loops for battery control and DC voltage control within the bidirectional converter. The water cycle algorithm adjusts four control parameters by minimizing an objective function based on tracking errors. The water cycle optimization is compared to other methods based on overshoot and settling time values to evaluate its performance, showcasing its effectiveness in analyzing the results.

This study investigates the use of division algorithms to optimize the size of a desalination system integrated with a microgrid based on a wind turbine plant and the battery storage to supply freshwater based on cost, reliability, and energy losses. Cumulative exergy demand is used to identify and minimize the energy losses in the optimized system. Division algorithms are used to overcome the drawback of low convergence speed encountered by the well-known method genetic algorithm. The findings indicated that there is a positive relationship between cost, cumulative exergy, and reliability. More specifically, when the loss of power supply probability is 10%, compared to when it is 0%, the total cumulative exergy demand and total life cycle cost are reduced by 34.76% when the battery is full and 45.44% when the battery is empty and there is a 44.43% decrease in total life cycle cost, respectively. However, the more reliable system, the less exergy is lost during the production of 1 m3 freshwater by desalination integrated into wind turbine plant.

Today, with the progress of technology, the world is facing an increasing growth in power consumption. Since the fuel of most power plants is supplied from fossil fuels, it has caused an increase in global fossil fuel consumption and environmental degradation. ّFurthermore, the volatility of fossil fuel prices and unstable energy security have prompted international organizations and governments to apply policies to restrict fossil fuel use and examine alternatives to fossil fuels. Since biofuels come from renewable sources and are clean fuels, they can be an appropriate alternative to fossil fuels and play a more expansive role in supplying energy for transportation industries, power plants, and heat production systems. Although there is some research about the drawbacks of using fossil fuels and the commendation of using biofuels in various industries such as transportation, the literature lacks a comprehensive study on the evaluation and analysis of the potential of using biofuels instead of conventional fuels in power generation systems. The primary purpose of this study is to evaluate the impact of utilizing biofuels instead of fossil fuels in microgrids to achieve carbon neutrality objectives. Furthermore, this paper reviews previous research studies that have operated biofuels in three categories: solid, liquid, and gas, to generate electricity and analyzes the potential of different biofuels to produce heat and electricity for microgrid power systems. In addition to outlining the present knowledge gaps in this area, this study explores the prospects and threats associated with expanding the use of biofuels in the power production industry and the development of sustainable microgrids. This study indicated that if the technical and economic problems of employing biofuels are overcome, these clean fuels have a great potential to obtain the maximum share of the global power generation market and move toward Net Zero Emissions by 2050 Scenario (NZE) goals.