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Utilizing renewable energy (RE) sources can provide a realistic answer to the problem of many nations' energy needs. This paper reviews the current status of using RE to produce electricity in the Kingdom of Saudi Arabia (KSA). The primary aim of the review is to identify and analyze the solar- and wind-energy utilization, problems, and future trends in KSA while taking into account all relevant aspects, associated development hurdles, and suggested solutions. All involved parties will receive useful results and conclusions from a thorough examination and analysis of the pertinent literature that can assist them in understanding the potential of solar and wind energy, considering all the linked issues. [ABSTRACT FROM AUTHOR]

Renewable energy sources are being expanded globally in response to global warming. Solar power generation is closely related to solar radiation and typically experiences significant fluctuations in solar radiation hours during periods of high solar radiation, leading to substantial inaccuracies in power generation predictions. In this paper, we suggest a solar power generation prediction method aimed at minimizing prediction errors during solar time. The proposed method comprises two stages. The first stage is the construction of the Solar Base Model by extracting characteristics from input variables. In the second stage, the prediction error period is detected using the Solar Change Point, which measures the difference between the predicted output from the Solar Base Model and the actual power generation. Subsequently, the probability of a weather forecast state change within the error occurrence period is calculated, and this information is used to update the power generation forecast value. The performance evaluation was restricted to July and August. The average improvement rate in predicted power generation was 24.5%. Using the proposed model, updates to weather forecast status information were implemented, leading to enhanced accuracy in predicting solar power generation. [ABSTRACT FROM AUTHOR]

Summary: This paper is concerned with innovative approaches to renewable energy sources computation methodologies, which provide more refined results than the classical alternatives. Such refinements provide additional improvements especially for replacement of fossil energy usages that emit greenhouse gas (GHG) into the atmosphere leading to climate change impact. Current knowledge gap among each renewable energy source calculation is rather missing fundamentals of plausible, rational, and logical explanations for the interpretation of results. In the literature, there are rather complicated and mechanically applicable methodologies, which require input and output measurement data match with missing physical explanations. The view taken in this review paper is to concentrate on quite plausible, logical, rational, and effectively applicable innovative energy calculation methodologies with simplistic fundamentals. For this purpose, a set of renewable energy methodological approaches is revisited with their innovative structures concerning solar, wind, hydro, current, and geothermal energy resources. With the increase in the renewable energy utilizations to combat the undesirable impacts of global warming and climate change, there is a need for better models that will include physical environmental conditions and data properties in the probabilistic, statistical, stochastic, logical, and rational senses leading to refined and more reliable estimations with application examples in the text. Finally, new research directions are also recommended for more refined innovative energy system calculations. [ABSTRACT FROM AUTHOR]

Algeria, like any other country, has drawn up its roadmap for the use and promotion of renewable energy sources. Motivated by its commitment to the international community in the fight against global warming and its possession of one of the largest solar fields in the world, a series of laws and institutions have consolidated this ambitious schedule. As known, both the climate and the geological area of Algeria take place among the foremost favoured countries in the field of solar energy. The present paper aims at proposing a simple model of photovoltaic module. The authors used Matlab/Simulink software to predict the current-voltage and power-voltage characteristics according to the influence of several factors, such as solar irradiance, cell temperature and series resistance, on the efficiency of photovoltaic module. The proposed experimental investigation can easily predict the curves (current-voltage and power-voltage) of a PV module, where both of simulation and practical results are identical. A single-crystal-line photovoltaic module was introduced close to Badji-Mokhtar Annaba University, Annaba (Algeria) to show the impact of climatic conditions in this coastal region and partial shading on characteristics. [ABSTRACT FROM AUTHOR]

Summary: Photocatalytic conversion of CO2 into value‐added hydrocarbon fuels and/or useful chemical products, using solar energy, has been the focus of active research, owing to its tremendous potential to provide a green fuel (eg, methanol) and simultaneously mitigate global warming by reducing CO2 levels in the atmosphere. CO2 photocatalytic reduction yields various hydrocarbon products. In this paper, we focus on methanol as it is an easily transportable energy‐dense fuel with multifarious applications in the automobile, industrial, and petrochemical sector. The photocatalytic conversion rate of CO2 to methanol depends on 3 factors: the photocatalyst used, photoreactor design, and experimental parameters (or variables). The last factor—experimental parameters—forms the basis of this review paper. These parameters include the reaction temperature, CO2 pressure, solvent used, intensity, wavelength, and duration of the incident light, concentration of organic impurities adsorbed on catalytic surface, addition of hole scavengers, type of reductant used, catalyst loading method, catalyst concentration, and the dissolved oxygen concentration. There have been numerous published works aiming to improve the methanol formation rate by optimizing these experimental parameters. In this paper, we consolidate and review these parameters, and investigate how optimizing them can enhance the photocatalytic conversion rate of CO2 into methanol, thus ushering in the era of a green methanol‐based economy. [ABSTRACT FROM AUTHOR]

SUMMARY: Fossil fuel sources are well suited to fulfill the energy needs of human beings. Unfortunately, there are some limitations and disadvantages pertaining to fossil fuels, some of which are drastic. The main issues are: firstly, there is a finite supply of these fuels, eventually this supply will be exhausted; secondly, burning fossil fuels contributes to global warming, leading to disastrous consequences for the environment and the health of humans. Switching to renewable energy sources is the viable solution to the aforementioned issues. Robots bring numerous benefits in a wide variety of applications. Introducing robots to production environments and other applications results in a remarkable improvement in terms of productivity and efficiency. In this paper, the integration between robots and renewable energy sources is discussed. In other words, two main points are investigated: (1) how can renewable energy be a viable source of energy for robots and (2) how can the renewable energy industry benefit from utilizing robots in the execution of renewable energy-related tasks. Some of the recent developments concerning the integration between robots and renewable energy are reviewed. In addition, more opportunities and expected advancements are also discussed. [ABSTRACT FROM AUTHOR]

Several theoretical studies have been reported in recent years which have indicated that large-scale wind farms can have an impact on local and regional meteorology, possibly on climate. Now evidence of it based on field observations has also begun to emerge. The present paper traces the evolution of this knowledge. It discusses the theoretical studies on the possibility of wind turbines effecting climate change, and summarizes the emerging confirmation of those predictions. The concluding part of the paper assesses the implications of these findings in the context of the world׳s past experience on global warming and its present thrust to meet substantial portions of its energy needs with renewables. [ABSTRACT FROM AUTHOR]

In this paper, the energy performance of a direct expansion solar assisted heat pump has been experimentally assessed with R290 as an alternative to R22 to meet the requirements of Kigali agreement. The experiments have been performed at Calicut climatic conditions (latitude of 11.15° N, longitude of 75.49° E) during the winter climates of 2016. The performance parameters such as, compressor power consumption, condenser heating capacity, energy performance ratio, and solar energy input ratio were evaluated for energy performance comparison. The results showed that, R290 has 6.8% higher energy performance ratio when compared to R22, with 11% reduction in compressor power consumption. Moreover, R290 has negligible global warming impact and zero ozone depletion potential when compared to R22. The effect of wind speed, collector area, ambient temperature, and solar insolation on the system performance found to be with an average value of 0.85%, 12%, 2.5%, and 4.5% for the selected refrigerants, respectively. [ABSTRACT FROM AUTHOR]

The issues of fossil-fired energy shortage and global warming have aroused worldwide attention, and the renewable and sustainable energy sources, therefore, are playing an increasingly important role in future energy consumptions. Energy consumptions in buildings account for almost 40% of the primary energy use in the US. A novel research-based Z er o E nergy (ZØE) Lab as a validation testbed combining various kinds of renewable energies has been presented in this paper. The concept, unique features, and the operation performance by experiments have also been shown in detail. The results of the novel ZØE Lab can open up a good angle for the future development of zero energy buildings. After analyzing the operating data of the ZØE Lab, the energy consumption, energy generation, and energy allocation of the devices have been presented. A new HVAC system with higher performance is recommended to be used in the ZØE Lab to achieve an even lower energy consumption than the current use, as a necessary refinement. [ABSTRACT FROM AUTHOR]

Abstract: Due to the depletion of energy resources and global warming, renewable energies such as the solar collector (SC) and photovoltaic generation (PV), are gaining more widespread use in residential areas. In Japan, incentive to install these units for consumers is provided by governmental support with the introduction of feed-in tariffs (FIT) and governmental subsidies. Thus, it is possible to reduce electricity cost in houses using time-of-use (TOU) price and to get benefit from selling power generated by PV. Furthermore, investment costs of PV and battery systems are decreasing year by year; on however, the price of purchased power for consumers is increasing and the selling price by FIT is decreasing annually. Hence, it is important to reveal which year, at what capacity, and which system and appliances are best choices for the consumer. In this paper, an expansion planning model of PV and battery systems for the smart house is presented. The expansion planning period is 20 years and ranges from 2015 to 2035. The proposed method clarifies the optimal installation year, capacity and appliances during the twenty year period considering variable characteristics such as investment cost, selling price and purchasing price which change year by year. [Copyright &y& Elsevier]

Solar energy harvesting using Photovoltaic (PV) systems is one of the most popular sources of renewable energy, however the main drawback of PV systems is their low conversion efficiency. An optimal system operation requires an efficient tracking of the Maximum Power Point (MPP), which represents the maximum energy that can be extracted from the PV panel. This paper presents a novel control approach for the Maximum Power Point Tracking (MPPT) based on the differential flatness property of the Boost converter, which is one of the most used converters in PV systems. The underlying idea of the proposed control approach is to use the classical flatness-based trajectory tracking control where a reference voltage will be defined in terms of the maximum power provided by the PV panel. The effectiveness of the proposed controller is assessed through numerical simulations and experimental tests. The results show that the controller based on differential flatness is capable of converging in less than 0.15 s and, compared with other MPPT techniques, such as Incremental Conductance and Perturb and Observe, it improves the response against sudden changes in load or weather conditions, reducing the ringing in the output of the system. Based on the results, it can be inferred that the new flatness-based controller represents an alternative to improve the MPPT in PV systems, especially when they are subject to sudden load or weather changes. [ABSTRACT FROM AUTHOR]