Clean Energy Production Research Articles

Techno-economic assessment of concentrated solar power generation in Saudi Arabia

Saudi Arabia plans to shift a large portion of its domestic energy production away from fossil fuel towards solar energy by 2030. Yet, the solar energy pool is mainly targeting photovoltaic technology. This study analyzes the potential of cleaner energy production from solar energy using concentrated solar power technology. First, different locations for concentrated solar power technology deployment are assessed based on potential development opportunities, solar resources, and infrastructure. Second, the paper assesses the performance and financial feasibility of four concentrated solar power technologies using the capacity factor, levelized cost of energy, and energy yield. The analysis indicates that all the considered locations are suitable for concentrated solar power technologies with a preference for the NEOM city located in the northern region of Saudi Arabia. The simulation results revealed that solar tower technology produces the highest energy yield of 2738 kWh/kW. The levelized cost of energy for the four technologies varies between 14.54 – 22.67 ¢/kWh, with linear Fresnel demonstrating the lowest and parabolic trough exhibiting the highest levelized cost of energy.

Maximizing the cost effectiveness of electric power generation through the integration of distributed generators: wind, hydro and solar power

BackgroundThe transition towards renewable energy sources has become an imperative step to mitigate climate change, reduce carbon emissions and improve energy security and economic prosperity in a sustainable manner. Maximizing the cost effectiveness of electric power generation is crucial to making renewable energy sources viable and attractive options for clean energy production. The strategic allocation of wind, hydro and solar power systems is essential to achieving this goal. This paper attempts to demonstrate how the cost effectiveness of electrical power system could be maximized through the integration of wind, solar and hydropower systems and comparison at different penetration levels of 0, 25, 50, 75 and 100% on cost effectiveness of electric power generation. The different generator technologies were designed based on their electrical output attributions.ResultsThe cost of electric generation for the integration of each generator at the various buses were calculated at different penetration level for fair comparison. The results indicate that the minimum money loss for the integration of solar power was $743.90 at bus 4 and at 50% penetration level, the minimum money loss for the integration of wind power was $999.00 at bus 4 and at 25% penetration level while the minimum amount loss for the integration of hydropower was $546.50 at bus 4 and at 75% penetration level.ConclusionsThe magnitude to which the integration of the different generator affects the cost effectiveness of power production hinges on the type of generator, the penetration level and the location of the generator in the grid.

Combustion of raw Camelina sativa oil in CI engine equipped with common rail system

During the world energy transformation, using some vegetable oils as fuel enables the production of clean and inexpensive energy with the application of the well-known technology of the CI engine. The common rail (CR) fuel system gives many opportunities related to creating an air–fuel mixture and its efficient combustion. Can the system dedicated to diesel oil be used to inject vegetable oil and control its combustion effectively? This paper presents some results of the application of the injection strategy for raw Camelina sativa (CS) oil fueling. The test was conducted on the AVL single-cylinder CI engine equipped with a CR system for engine speed n = 1500 rpm and different excess air coefficients (1.1 < λ < 2.1). The engine parameters and performance obtained for raw CS oil were compared with the results obtained for diesel oil fueling for the same and slightly modified injection strategy. The experiment demonstrated how much the combustion process and its effects differ for these two fuels. In addition, several aspects related to the cultivation and use of Camelina sativa oil as a renewable energy source are presented.

How do Fintech and green bonds ensure clean energy production in China? Dynamics of green investment risk.

This study inquiry examines the vital role that Fintech and green bonds play in ensuring that China generates clean energy in a comprehensive manner, taking into consideration the mechanisms of green investment risk. This paper provides exciting new insights on the link between financial technology (Fintech), green bonds, and China's clean energy economy by using a reliable approach and doing an in-depth data analysis. The findings provide a significant contribution to our understanding of how Fintech may help enable financing for renewable energy projects by using digital platforms, mobile payment technologies, and blockchain technology to boost investor confidence and accessibility to funds for clean energy projects. This aspect of green bonds is emphasized since the study highlights the importance of sustainable energy generation. The need of proactive regulatory frameworks that are able to adjust to the shifting Fintech and green bond markets while supporting good policies, motivating factors, and efficient risk management procedures is emphasized in the research. The study contributes to the enlightenment of academic discourse, focuses efforts at policymaking, and gives knowledge that is helpful to people who are working to promote a greener and more sustainable future.

Overview of Energy Systems in Africa: A Comprehensive Review

Africa has abundant solar resources but only 2% of its current capacity is generated from renewable sources. Photovoltaics (PV) offer sustainable, decentralized electricity access to meet development needs. This review synthesizes the recent literature on PV in Africa, with a focus on Mozambique. The 10 most cited studies highlight the optimization of technical components, such as storage and bifacial modules, and challenges in integrating large-scale PV. Case studies demonstrated Mozambique’s potential for PV applications in water heating, irrigation, and rural electrification. These benefits include reduced emissions and energy access. However, barriers, such as high costs, lack of infrastructure, and training, exist. While solar cookers are insufficient, thermal systems have unrealized potential. Mozambique’s urban and rural electrification rates are 57% and 13%, respectively, despite its energy resources. Targeted policies, financing, and community engagement are essential for promoting adoption. While PV can sustainably expand electricity access, coordinated efforts must address costs, infrastructure, maintenance, and social factors for successful implementation. Mozambique has immense solar potential, but strategic planning and support are critical to unlocking these benefits. This review provides insights into optimizing PV systems and policy frameworks for a clean and inclusive energy production future in Africa, to synthesize the 10 most cited studies on photovoltaic solar energy in Africa, and to deeply reflect upon the current energy needs in Mozambique, the benefits of employing PV and solar thermal systems, and the challenges of implementing such systems within the Mozambican context.

NiFe2O4/Ni2P Mott-Schottky heterojunction boosts the oxygen evolution reaction in alkaline water/natural seawater

Exploiting non-noble metal electrocatalysts for sluggish anodic oxygen evolution reaction (OER) is an essential propellant to clean hydrogen energy production from water/seawater electrochemical splitting, but still confronts a grand challenge. Recently, the metal/semiconductor interface effect has been used as a feasible implementation to achieve favorable electrocatalytic performance due to the built-in electric field. Herein, we first report the Mott-Schottky heterojunction electrocatalyst composed of metallic Ni2P and p-type semiconducting NiFe2O4, developed via a two-step hydrothermal-phosphorization method. With the strategy, the catalyst charge redistribution is owning to the self-driven electron carriers transfer in the heterointerfaces of NiFe2O4/Ni2P, leading to the formation of a built-in electric field, thereby favoring the reaction kinetics of OER. Experimental findings that NiFe2O4/Ni2P shows excellent wettability, corrosion resistance, and exceptional OER performance with a low overpotential of 230/260 mV to deliver a current density of 10 mA cm−2, and a low Tafel slope of 53.6/70.8 mV dec−1 in basic solution and natural seawater, respectively. Impressively, the NiFe2O4/Ni2P||Pt/C electrolyzer only needs 1.46/1.56 V to output 10 mA cm−2 and superior stability in water/seawater electrolyte for continuous working for 50 h NiFe2O4/Ni2P Mott-Schottky heterojunction is a promising candidate as a highly efficient OER electrocatalyst for realistic alkaline water/seawater electrolysis.

Efficient photocatalytic production of H2O2 and photodegradation of tetracycline by CdS/square tubular g-C3N4 S-scheme heterojunction photocatalyst

Photocatalytic technology is an effective method for clean energy production and wastewater treatment. In this work, a square tubular g-C3N4 (MCN) is first synthesized by the aid of thermal polymerization of melamine in mixed KCl/LiCl molten salt and then loaded with CdS nanoparticles via a solvothermal method to obtain the final composite (MCN@CdS). This complex exhibits dual catalytic characteristics: photocatalytic oxygen reduction to produce hydrogen peroxide and photocatalytic degradation ability of antibiotics. The specific surface area (SSA) of MCN was enhanced by calcination with the help of molten salt, and the introduction of CdS expanded the absorption edge of MCN@CdS. In addition, electrochemical impedance and photocurrent spectroscopy confirmed that separation and migratory efficiency of photoproduced charge carriers could be promoted by the combination of MCN and CdS. As a result, the yield of hydrogen peroxide photocatalyzed by MCN@CdS is up to 0.95 mmol· L−1 in 80 min under visible light, which is 1.2 and 1.9 times larger than that of pure MCN and CdS. More importantly, the removal rate of tetracycline photocatalyzed by MCN@CdS, within 30 min with the participation of O2, achieved up to 99.5 %, 4 times faster than that in O2-free environment.

Potentials and prospects of solid biowaste resources for biofuel production in Ethiopia: a systematic review of the evidence

AbstractBiowaste is becoming a significant category in the global energy mix to mitigate the negative impacts of burning fossil fuels. The aim of this review paper was to investigate the potential, conversion mechanisms, benefits, and policy gaps related to the utilization of solid biowaste resources as renewable, clean, and affordable energy sources. Thus, a systematic review approach was employed to undertake a comprehensive analysis of the studies that dealt with solid biowaste resources for energy recovery. This review paper was conducted from November 2022 to June 2023. The relevant literature was searched using databases from scholarly journal publishers, online search engines, and websites. A total of 82 studies were determined to be eligible from 659 records. Ethiopia has a huge potential for biowaste resources, with an annual generation potential of 18,446.4 MJ per year. The multifaceted advantages associated with biowaste-to-energy conversion such as clean energy production, waste management, forest conservation, greenhouse gas emission reduction, and maintaining soil fertility using the digestate left after anaerobic digestion were mentioned. This review highlights various conversion technologies for converting solid biowastes into valuable forms of energy, such as thermochemical, biochemical, and physico-mechanical techniques. It also investigated the value-added products of the Solid Biowastes-to-Energy (SBWtoE) process, including bio-oil, syngas, bioethanol, biodiesel, biomethane, bio-briquettes, and pellets, with applications ranging from transportation to power generation. Furthermore, this review addresses the multifaceted challenges associated with implementing a circular economy, emphasizing the need to overcome policy, technological, financial, and institutional barriers. These efforts are crucial for harnessing the growing biowaste resources in Ethiopia, ultimately promoting sustainable and cost-effective energy production while advancing the nation's environmental objectives.

Daily global solar radiation time series prediction using variational mode decomposition combined with multi-functional recurrent fuzzy neural network and quantile regression forests algorithm

Global solar radiation (GSR) prediction capability with a reliable model and high accuracy is crucial for comprehending hydrological and meteorological systems. It is vital for the production of renewable and clean energy. This research aims to evaluate the performance of combined variational mode decomposition (VMD) with a multi-functional recurrent fuzzy neural network (MFRFNN) and quantile regression forests (QRF) models for GSR prediction in daily scales. The hybrid VMD-MFRFNN and QRF models were compared with standalone MFRFNN, random forest (RF), extreme gradient boosting (XGB), and M5 tree (M5T) models across the Lund and Växjö meteorological stations in Sweden. The meteorological data from 2008 to 2017 were used to train the models, while the prediction accuracy was verified by using the data from 2018 to 2021 under five different input combinations. The various meteorological-based scenarios (including the input are air temperatures (Tmin, Tmax, T), wind speed (WS), relative humidity (RH), sunshine duration (SSH), and maximum possible sunshine duration (N)) were considered as input of predictor models. The current study resulted that the M5T model exhibited higher accuracy than RF and XGB models, while the QRF model showed equivalent performance with the M5T model at both study sites. The MFRFNN model outperformed QRF and M5T models across all input combinations at both study sites. The hybrid VMD-MFRFNN model showed the best performance when fewer input variables (Tmin, Tmax, T, WS at Lund station and Tmin, Tmax, T, WS, SSH, RH at Växjö station) were used for GSR prediction. We conclude that the MFRFNN model best predicts average daily GSR when combining all meteorological variables (Tmin, Tmax, T, WS, SSH, RH, N).

The current Brazilian energy model: 2016 to 2020

Power production growth in Brazil is a reality. Therefore, it is necessary carrying out analyses about energy sources to achieve sustainable and feasible development. A country with huge hydroelectric potential has the production of clean energy in comparison to other energy sources as positive feature. Observing the power generation sector’s origin, and comparing and understanding its dynamics, are duties of both the State and the community. The aim of the review in the present article is to objectively understand the Brazilian energetic potential and its several sources. Accordingly, a bibliographic review was conducted to better understand the Brazilian energetic scenario. Brazil accounts for the biggest biodiversity on the planet, as well as for having great climatic variety, such as equatorial, tropical and altitude tropical, sub-tropical, semiarid and Atlantic tropical climate. Brazilian power supply is in the hands of big power plants, like hydroelectric, thermo-electric, wind and solar plants. Hydroelectric plants correspond to approximately 59% of the country’s total installed capacity; moreover, it is often presented as clean and renewable energy source. Yet, although there is much to be developed when it comes to the sustainability of the hydroelectric source, it remains as the most feasible and cleanest Brazilian energy channel.

Technological design for the environmental transition of the city. Opportunities for innovation

In the contemporary context of the polycrisis, ways and criteria for sustainable urban transformation are discussed that shift the needle of ecological transition from building to city, towards energy self-sufficiency and social self-determination. Alternative forms of management, containment and production of clean and accessible energy from renewable sources are explored that have feedback in terms of process, design and social innovation. The paper aims to highlight the active and adaptive dimensions of technological design in its ability to support and promote behaviour favouring sustainable environmental transition.

Numerical modeling of a mooring line system for an offshore floating wind turbine in Vietnamese sea conditions using nonlinear materials

The offshore renewable energy industry has been developing farms of floating offshore wind turbines in water depths up to 100 m. In Vietnam, floating offshore wind turbines have been developed to increase the production of clean and sustainable energy. The mooring system, which is used to keep the turbine stable and ensure the safety and economic efficiency of wind power production, is an important part of a floating offshore wind turbine. Appropriate selection of the mooring type and mooring line material can reduce the risks arising from the motion of wind turbines. Different types of mooring line material have been simulated and compared in order to determine the optimal type with the minimum motion risk for a floating wind turbine. This study focused on numerical modeling of semi-taut mooring systems using nonlinear materials for a semi-submersible wind turbine. Several modeling approaches common to current practice were applied. Hydrodynamic analysis was performed to investigate the motion of the response amplitude operators of the floating wind turbine. Dynamic analysis of mooring systems was performed using a time domain to obtain the tension responses of mooring lines under the ultimate limit states and fatigue limit states in Vietnamese sea conditions. The results showed that the use of nonlinear materials (polyester and/or nylon) for mooring systems can minimize the movement of the turbine and save costs. The use of synthetic fibers can reduce the maximum tension in mooring lines and the length of mooring lines. However, synthetic fiber ropes showed highly nonlinear load elongation properties, which were difficult to simulate using numerical software. The comparison of the characteristics of polyester and nylon mooring lines showed that the maximum and mean tensions of the nylon line were less than those of the polyester line. In addition, the un-stretched length of the polyester line was greater than that of the nylon line under the same mean tension load. Therefore, nylon material is recommended for the mooring lines of a floating offshore wind turbine.

Photosynthetic Efficiency of Microalgae and Cyanobacteria on Reduced Graphene Oxide (RGO) Anode Surface for Utilization in Bio-Photovoltaics (BPV)

Bio-photovoltaics (BPV) is sustainable energy production technology that utilize photosynthetic organisms and convert it into electricity. This Study has been carried out to study the photosynthetic efficiency of three microalgae on a Reduced Graphene Oxide (RGO) anode surface. RGO, with its exceptional electrical conductivity and large surface area, presents an attractive platform for enhancing the performance of BPV systems. The work aims to investigate the combined effect of microalgae and RGO anodes for use in BPV technology. RGO was synthesized and characterized on which Chlorella vulgaris, Gloeocapsa and Synechocystis were allowed to grow. A model BPV system was assembled, incorporating the microalgae and cyanobacteria as photoactive agents and RGO as the anode surface. The system was subjected to different experimental condition and photosynthetic efficiency, current generation, and power output were collected and analysed. Results demonstrated a significant improvement in the photosynthetic activity of microalgae when cultured on the RGO anode surface. Chlorella Shows maximum Efficiency in terms of growth and current generation. Statistical analysis confirmed the reliability and significance of these findings. Our finding bridges a crucial knowledge gap in the field of BPV, highlighting the potential of microalgae-RGO systems for cleaner energy production.

Trapping processes of large volumes of natural hydrogen in the subsurface: The emblematic case of the Bourakebougou H2 field in Mali

Most of the ongoing discussions about natural hydrogen (H2) exploration focus on surface hydrogen occurrences and generation processes. However, the trapping process is the most critical issue with regard to both discovering significant accumulations of hydrogen in the subsurface and providing profitable clean energy production for humankind. The extremely high mobility of hydrogen molecules is due to their very small size that confers very diffusive properties, and this results in frequent surface seepages that have recently been recorded worldwide. During this study, we performed a detailed characterization of the caprocks (dolerites) that retain hydrogen in the Bourakebougou natural H2 field. Our investigation on the sealing capacity of these dolerites revealed that their thickness is important in addition to the density and size of their fractures. The role of aquifers has also been highlighted as contributing to the retention of H2 in subsurface. Indeed, hydrogen being poorly soluble in water at low pressure and temperature conditions, it is less likely to diffuse easily to the surface at shallow depth. This study highlights that the exploration of H2 fields should not be based only on the presence of an H2 generation process, but also based on the presence of a very efficient trapping system.

Clean energy production index and CO2 emissions in OECD countries

This study aimed to analyze the relationship between the energy transition index recently developed by Lau et al. (2023) and CO2 emissions in OECD countries. The topic is relevant, as the energy transition is a sustainable path to reduce CO2 emissions in countries. The CS-ARDL approach is used to estimate the short-run and long-run coefficients. Additionally, the Dumitrescu and Hurlin (2012) test is employed to determine the causal relationship between the variables. It was found that a 1 % increase in clean energy production reduces CO2 emissions by 0.33 % and 0.23 % in the short and long run, respectively. Furthermore, a bidirectional causal relationship exists between CO2 emissions and the energy transition indicator. This suggests that policies implemented by OECD countries to reduce carbon emissions will inevitably entail the adoption of cleaner energy sources.

Multi-Walled CNTs/BiVO4 Heterostructures for Solar-Driven Evaporation System and Efficient Photocatalytic Activity against Oxytetracycline.

Developing a sustainable environment requires addressing primitive water scarcity and water contamination. Antibiotics such as oxytetracycline (OTC) may accumulate in the environment and in the human body, increasing the risks to the ecosystem. The treatment of polluted water and the production of potable water can be achieved in a variety of ways, including photodegradation, solar distillation, and filtration. Freshwater supplies can be increased by implementing energy-efficient technologies for the production of clean water. Solar water evaporation combined with photocatalytic degradation and sterilization offers a promising avenue for integration into the clean water and energy production fields. The present study reports the synthesis of a 3D solar steam generator comprised of BiVO4 and carbon nanotubes (CNT) nanocomposite decorated over a cigarette filter as the light-to-heat conversion layer for solar steam generation. The BiVO4@CNT-based 3D solar evaporator over the hydrophilic cellulosic fibers of the cigarette filter endowed excellent evaporation rates (2.36 kg m-2 h-1) under 1 kW m-2 solar irradiation, owing to its superior hydrophilicity and broadband solar absorption (96%) equipped with localized heating at microscale thermal confinement optimized by the minimum thermal conductivity of the overall system. Furthermore, the BiVO4@CNT composite exhibited a heightened photo activity up to 83% of the photodegradation of oxytetracycline (OTC) antibiotic due to the inhibition of charge recombination from the industrial effluents. This approach transforms the water-energy nexus into a synergistic bond that offers opportunities to meet expected demand, rather than being competitive.

The defect-rich porous CoP4/Co4S3 microcubes as robust electrocatalyst for clean H2 energy production via alkaline overall water splitting

Although water electrolysis is one of the most environmentally friendly methods for producing hydrogen (H2) and oxygen, designing robust non-noble electrocatalysts for overall water splitting remains a massive challenge. Modulating the morphology and chemical composition of non-noble-metal bifunctional electrocatalysts is an effective way to enhance catalytic activity in water electrolysis. Herein, a robust electrocatalyst with porous CoP4/Co4S3 microcubes rich in defects was synthesized through the phosphorylation and hydrothermal vulcanization of a Co–Co Prussian blue analog (Co–Co PBA). Given that the as-prepared CoP4/Co4S3 microcubes can provide additional active sites to accelerate electron transfer at the heterointerface, they exhibit enhanced catalytic activities in hydrogen and oxygen evolution reactions in 1.0 M KOH. When used as a bifunctional catalyst in a two-electrode electrolyzer, the micrucubesrequire a cell voltage of 1.67 V to achieve a current density of 10 mA cm−2 in 1.0 M KOH, indicating its potential as an efficient alkaline non-noble electrocatalyst for overall water splitting. This study provides a promising electrocatalyst for clean H2 energy production by modulating its morphology and chemical composition.

Coal Gangue Target Detection Based on Improved YOLOv5s

Coal gangue sorting is a necessary process in coal mine production, and removing gangue is the basis for the coal production of clean energy; it is also an important approach to reduce the cost of washing, improve the grade of finished coal and increase the economic efficiency of coal mining enterprises. For the problem of high similarity and low-degree dynamic recognition of coal and gangue, a coal gangue target detection method based on improved YOLOv5s is proposed. Based on the YOLOv5s network, the decoupled head and SimAM attention mechanism are introduced and the CSP module in the neck part of YOLOv5s is replaced with the VoV-GSCSP structure. The experimental results show that the proposed method improves the mAP value by 6.1% over YOLOv5s in the gangue target detection task, while maintaining a higher detection speed. The coal gangue classification precision reaches 99.7% when tested on 1479 images. Compared with YOLOv5 series, YOLOv7 series, SSD and Faster-RCNN, the proposed method invariably yields higher precision and detection speed to meet the requirements of real-time detection. The experiments prove that the method proposed in this paper can be applied to the coal gangue sorting industry for fast and high-precision identification of coal gangue.

A first-principles study of the electronic structure, surface stability, and band alignment of niobium pentoxide

Currently, there is a growing development to find new materials to achieve clean and sustainable energy production, and one of the key processes in this effort is to replace expensive noble element catalysts with less costly transition metal oxides. Niobium pentoxide (Nb2O5) is a wide-gap semiconductor with good catalytic properties which makes it an essential material in this kind of technological applications, however, there are no theoretical studies on the surface physical properties for the different phases of this compound. In this work, we have performed first-principles calculations to study the bulk electronic properties and the low-index non-polar surfaces of the B and R crystallographic phases of Nb2O5. We have used a semi-local exchange–correlation functional (PBEsol) along with the GoWo approximation to calculate their gap and band alignments with respect to the vacuum. It has been found that these phases are indirect wide-gap semiconductors, the calculated gaps for B (R) are EgPBEsol=2.6eV (2.1 eV) and EgGoWo=4.2eV (3.8 eV). On the other hand, it is established that the most stable surfaces are (010) and (001) for B and R, respectively, and their highest conduction band edges are along the (1̄01) and (100) terminations, both being above the CO2/CH2O2 reduction potential at pH = 7. Our results present clues into utilizing these Nb2O5 phases on technological applications such as photocatalytic uses on water splitting and carbon dioxide reduction.

A Hydro Wheel System in A Non-Natural Pond Using Renewable

One of the most cost-effective ways to generate electricity is through waterwheels. Because of the need for clean energy and sustainable electricity production, hydropower currently plays an important role in meeting energy demand. Although water wheels were studied academically as early as the eighteenth century, they were mostly ignored until the twentieth century. Only in the last two decades has there been a revived interest in their use among scientists. The researcher came up with this topic to discuss its benefits and how it will be beneficial in our daily lives and make our surroundings safe, which needs enough light and helps the school or park premises lighten up the dark areas at night. Having enough illumination inside the premises of in schools and parks, according to numerous sources and data gathering findings, will help folks become comfortable in the location they are staying or visiting. Good illumination can help with mobility, safety, and security.