scholarly journals Combining Re-Analyzed Climate Data and Landcover Products to Assess the Temporal Complementarity of Wind and Solar Resources in Iraq

2021 ◽  
Vol 14 (1) ◽  
pp. 388
Author(s):  
Mourtadha Sarhan Sachit ◽  
Helmi Zulhaidi Mohd Shafri ◽  
Ahmad Fikri Abdullah ◽  
Azmin Shakrine Mohd Rafie
Keyword(s):  
Renewable Energy ◽  
Storage Systems ◽  
Pearson Correlation ◽  
Renewable Resource ◽  
Decision Makers ◽  
Geographical Information ◽  
Climate Data ◽  
A Value ◽  
The Stability ◽  
First Time

Considering the spatial–temporal variation of renewable energy (RE) resources, assessment of their complementarity is of great significance for decision-makers to increase the stability of power output and reduce the need for storage systems. In this regard, the current paper presents a roadmap to assess the temporal complementarity patterns between wind and solar resources for the first time in Iraq. A new approach based on re-analyzed climate data, Landcover products, and geographical information system (GIS) is proposed. As such, renewable resource datasets are collected for 759 locations with a daily timescale over five years. Landcover classes are translated into wind shear coefficients (WSCs) to model wind velocity at turbine hub height. Then, the Pearson correlation coefficient (PCC) is applied to calculate the complementarity indices for each month of the year. Results of this investigation reveal that there are significant synergy patterns spanning more than six months in the southwestern regions and some eastern parts of Iraq. The highest complementarity is observed in March and December with a value of −0.70 and −0.63, respectively. Despite this promising potential, no typical temporal complementarity has been discovered that would completely eliminate the fluctuations of clean power generation. However, the synergistic properties yielded by this work could mitigate the reliance on storage systems, particularly as they cover important regions of the country. The proposed approach and tools can help improve the planning of renewable energy systems.

scholarly journals Regional Coordination and Security of Water–Energy–Food Symbiosis in Northeastern China

2021 ◽  
Vol 13 (3) ◽  
pp. 1326
Author(s):  
Hongfang Li ◽  
Huixiao Wang ◽  
Yaxue Yang ◽  
Ruxin Zhao
Keyword(s):  
External Environment ◽  
Northeastern China ◽  
Decision Makers ◽  
Human Survival ◽  
A Value ◽  
Natural Factors ◽  
Regional Coordination ◽  
Micro Level ◽  
The Stability ◽  
Coordination Degree

The interactions of water, energy, and food, which are essential resources for human survival, livelihoods, production, and development, constitute a water–energy–food (WEF) nexus. Applying symbiosis theory, the economic, social, and natural factors were considered at the same time in the WEF system, and we conducted a micro-level investigation focusing on the stability, coordination, and sustainability of the symbiotic units (water, energy, and food), and external environment of the WEF system in 36 prefecture-level cities across three northeastern provinces of China. Finally, we analyzed the synergistic safety and coupling coordination degree of the WEF system by the combination of stability, coordination, and sustainability, attending to the coordination relationship and influences of the external environment. The results indicated that the synergistic safety of the WEF system in three northeastern provinces need to equally pay attention to the stability, coordination, and sustainability of the WEF system, since their weights were 0.32, 0.36 and 0.32, respectively. During 2010–2016, the synergistic safety indexes of the WEF system ranged between 0.40 and 0.60, which was a state of boundary safety. In the current study, the coupling coordination degree of the WEF system fluctuated around a value of 0.6, maintaining a primary coordination level; while in the future of 2021–2026, it will decline to 0.57–0.60, dropping to a weak coordinated level. The conclusion could provide effective information for decision-makers to take suitable measures for the security development of a WEF system.

Comparison of PV potential models for africa and their potential cost implications.

2021 ◽  
Author(s):  
Arnold Wasike ◽  
Catherina Cader
Keyword(s):  
Renewable Energy ◽  
Pearson Correlation ◽  
Surface Radiation ◽  
Geographical Information ◽  
Potential Cost ◽  
Energy Agency ◽  
Data Set ◽  
Potential Models ◽  
Photo Voltaic ◽  
Cost Implications

<p>We currently have more than 7500 planned mini grids, most of them in Africa. These will soon connect more than 27 million people and cost about 12 billion dollars <sup>[1]</sup>. Africa is in a good position for Photo voltaic (PV) mini grid optimization, receiving more than 1800 KWh/m<sup>2</sup> Global Horizontal Irradiation (GHI) every year <sup>[2]</sup>, for most parts of the continent. However, the lack of a coordinated renewable energy monitoring and distribution network works against optimization of PV potential models <sup>[3]</sup>. This study shows the accuracy of existing photo voltaic potential estimators like renewables ninja <sup>[3]</sup>, the National Renewable Energy Laboratory (NREL), International Renewable Energy Agency (IRENA), and the global solar atlas <sup>[2]</sup>, by comparing the modeled values with long term measurements from ground solar stations. This is done for more than 20 stations distributed over Africa. Our results show best correlations <sup>[4]</sup> of up to 65.3% from version 2 of the Surface Radiation Data Set from Heliosat (SARAH) derived from the Photovoltaic Geographical Information System (PVGIS). However, we also have correlations as low as 16.2% for models commonly used in off grid simulations. The sensitivities of the modeled cost of a mini grid to the variation in PV potential were tested <sup>[5][6]</sup> using the statistical range in sourced PV potential from the different estimators, giving us cost variation of more than 2.8% that may arise from the different sources.</p><p><strong>References</strong></p><p>1. World Bank, ESMAP - Mini grids for half a billion people</p><p>2. https://globalsolaratlas.info/map</p><p>3. doi: 10.1016/j.energy.2016.08.060</p><p>4. Wikipedia contributors. (2021, January 7). Pearson correlation coefficient. In Wikipedia, The Free Encyclopedia. Retrieved 09:00, January 20, 2021, from https://en.wikipedia.org/w/index.php?title=Pearson_correlation_coefficient&oldid=998963119</p><p>5. Cader. 2018</p><p>5. Hoffmann. 2019</p><p>7. https://doi.org/10.2136/vzj2018.03.0062</p>

Thermodynamic Analysis and Performance Enhancement of Air and CO2 Based Compressed Gas Storage Systems

2019 ◽  
Author(s):  
Abhishek Dahiya ◽  
Jishnu Bhattacharya ◽  
Nitin D. Banker
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Large Scale ◽  
Performance Enhancement ◽  
Storage Systems ◽  
Research Work ◽  
Renewable Resource ◽  
Performance Comparison ◽  
Renewable Energy Resources ◽  
Compressed Gas

Abstract Due to the depletion of fossil fuels and their adverse effects on the environment, there is a need of hour to shift towards the renewable energy resources. However, the most promising renewable resources such as wind power and solar power are intermittent in nature. Thus, a sustainable shift requires economical and efficient energy storage systems. Use of batteries is the widely accepted storage systems for such resources and significant research work has been carried out in last few decades to improve the cycle life of batteries but they are still unsuitable for large scale systems and disposal of discarded batteries is also a major environmental concern. In view of this, researchers found compressed gas energy storage (CGES) system as one of the potential alternatives to store renewable energy at large spatial and temporal scales. The current study provides a comparison between air and carbon dioxide (CO2) based CGES systems from a thermodynamic standpoint. In an effort of improving efficiency of system, it is proposed to supply additional heat via renewable resource to CO2 based system before the expansion of gas in the turbine. The performance comparison of six different systems has been carried out using first and second law efficiencies.

scholarly journals Empirical Analysis and Geomechanical Modelling of an Underground Water Reservoir for Hydroelectric Power Plants

2020 ◽  
Vol 10 (17) ◽  
pp. 5853
Author(s):  
Javier Menéndez ◽  
Falko Schmidt ◽  
Heinz Konietzky ◽  
Antonio Bernardo Sánchez ◽  
Jorge Loredo
Keyword(s):  
Renewable Energy ◽  
Rock Mass ◽  
Energy Storage ◽  
Support System ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Water Reservoir ◽  
Energy Sources ◽  
Pumped Storage ◽  
The Stability

The European Union policy of encouraging renewable energy sources and a sustainable and safe low-carbon economy requires flexible energy storage systems (FESSs), such as pumped-storage hydropower (PSH) systems. Energy storage systems are the key to facilitate a high penetration of the renewable energy sources in the electrical grids. Disused mining structures in closed underground coal mines in NW Spain have been selected as a case study to analyze the construction of underground pumped-storage hydropower (UPSH) plants. Mine water, depth and subsurface space in closured coal mines may be used for the construction of FESSs with reduced environmental impacts. This paper analyzes the stability of a network of tunnels used as a lower water reservoir at 450 m depth in sandstone and shale formations. Empirical methods based on rock mass classification systems are employed to preliminarily design the support systems and to determinate the rock mass properties. In addition, 3D numerical modelling has been conducted in order to verify the stability of the underground excavations. The deformations and thickness of the excavation damage zones (EDZs) around the excavations have been evaluated in the simulations without considering a support system and considering systematic grouted rock bolts and a layer of reinforced shotcrete as support system. The results obtained show that the excavation of the network of tunnels is technically feasible with the support system that has been designed.

Ethnopharmacological Survey of Medicinal Plants Used in Traditional Treatment of Kidney Diseases in Fez–Meknes Region, Morocco

2019 ◽  
Vol 18 (2) ◽  
pp. 99-114
Author(s):  
M. Chebaibi ◽  
D. Bousta ◽  
I. Iken ◽  
H. Hoummani ◽  
A. Ech-Choayeby ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Medicinal Plants ◽  
Kidney Diseases ◽  
Rank Order ◽  
Pearson Correlation ◽  
Use Value ◽  
Traditional Treatment ◽  
Toxic Plants ◽  
A Value ◽  
Chi Squared

The purpose of this study was to inventory and collect information on plants and mixtures commonly used by herbalists to treat kidney disease in the Fez–Meknes region. We also aimed to compare the results obtained with the results of the other studies and exploit the correlations between different factors. An ethnopharmacological survey was conducted from 289 local herbalists in eight different areas of Fez–Meknes region. Ethnomedicinal uses and ethnobotanical indices were analyzed using quantitative tools, i.e., the total number of citation (TNC), use value (UV), family use value (FUV), fidelity level (FL), and rank order priority (ROP). Statistical analyses such as Pearson correlation and chi-squared test were performed to delineate any correlation. Two hundred and eighty-nine herbalists were questioned. Sixty-nine plant species belonging to 38 families were cited by herbalists for traditional treatment of kidney disease. The highest value of UV was obtained for Herniaria glabra L. (UV = 0.79), and Caryophyllaceae was the family frequently cited (FUV = 0.795). Ammodaucus leucotrichus Coss. & Dur. had the highest value of FL with a value of 100%, and the highest value of ROP was recorded for Herniaria glabra L. (ROP = 91%). Sociodemographic characteristics had a significant impact on the knowledge of toxic plants. Our study has revealed a cultural heritage linked to herbalism and a great wealth of medicinal plants, whose valorization and protection are necessary. Several studies are needed to sensitize herbalists and population on the danger of toxic plants, to extract chemical compounds from the main plants used, and to evaluate their toxicity.

Modeling an Energy Storage System Based on a Hybrid Renewable Energy System in Stand-alone Applications

2017 ◽  
Vol 68 (11) ◽  
pp. 2641-2645
Author(s):  
Alexandru Ciocan ◽  
Ovidiu Mihai Balan ◽  
Mihaela Ramona Buga ◽  
Tudor Prisecaru ◽  
Mohand Tazerout
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Energy Storage System ◽  
Compressed Air ◽  
Energy Sources ◽  
Energy Storage Systems ◽  
Hybrid Renewable Energy System

The current paper presents an energy storage system that stores the excessive energy, provided by a hybrid system of renewable energy sources, in the form of compressed air and thermal heat. Using energy storage systems together with renewable energy sources represents a major challenge that could ensure the transition to a viable economic future and a decarbonized economy. Thermodynamic calculations are conducted to investigate the performance of such systems by using Matlab simulation tools. The results indicate the values of primary and global efficiencies for various operating scenarios for the energy storage systems which use compressed air as medium storage, and shows that these could be very effective systems, proving the possibility to supply to the final user three types of energy: electricity, heat and cold function of his needs.

scholarly journals Economic Analysis of the Investments in Battery Energy Storage Systems: Review and Current Perspectives

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2503
Author(s):  
Paulo Rotella Junior ◽  
Luiz Célio Souza Rocha ◽  
Sandra Naomi Morioka ◽  
Ivan Bolis ◽  
Gianfranco Chicco ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Economic Analysis ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Residential Areas ◽  
Energy Storage Systems ◽  
Battery Energy Storage ◽  
Battery Energy Storage Systems ◽  
Battery Energy

Sources such as solar and wind energy are intermittent, and this is seen as a barrier to their wide utilization. The increasing grid integration of intermittent renewable energy sources generation significantly changes the scenario of distribution grid operations. Such operational challenges are minimized by the incorporation of the energy storage system, which plays an important role in improving the stability and the reliability of the grid. This study provides the review of the state-of-the-art in the literature on the economic analysis of battery energy storage systems. The paper makes evident the growing interest of batteries as energy storage systems to improve techno-economic viability of renewable energy systems; provides a comprehensive overview of key methodological possibilities for researchers interested in economic analysis of battery energy storage systems; indicates the need to use adequate economic indicators for investment decisions; and identifies key research topics of the analyzed literature: (i) photovoltaic systems with battery energy storage systems for residential areas, (ii) comparison between energy storage technologies, (iii) power quality improvement. The last key contribution is the proposed research agenda.

scholarly journals Thermally Stimulated Desorption Optical Fiber-Based Interrogation System: An Analysis of Graphene Oxide Layers’ Stability

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 70
Author(s):  
Maria Raposo ◽  
Carlota Xavier ◽  
Catarina Monteiro ◽  
Susana Silva ◽  
Orlando Frazão ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Layer By Layer ◽  
Film Stability ◽  
A Value ◽  
Device Reliability ◽  
Sensor Devices ◽  
Lbl Films ◽  
The Stability

Thin graphene oxide (GO) film layers are being widely used as sensing layers in different types of electrical and optical sensor devices. GO layers are particularly popular because of their tuned interface reflectivity. The stability of GO layers is fundamental for sensor device reliability, particularly in complex aqueous environments such as wastewater. In this work, the stability of GO layers in layer-by-layer (LbL) films of polyethyleneimine (PEI) and GO was investigated. The results led to the following conclusions: PEI/GO films grow linearly with the number of bilayers as long as the adsorption time is kept constant; the adsorption kinetics of a GO layer follow the behavior of the adsorption of polyelectrolytes; and the interaction associated with the growth of these films is of the ionic type since the desorption activation energy has a value of 119 ± 17 kJ/mol. Therefore, it is possible to conclude that PEI/GO films are suitable for application in optical fiber sensor devices; most importantly, an optical fiber-based interrogation setup can easily be adapted to investigate in situ desorption via a thermally stimulated process. In addition, it is possible to draw inferences about film stability in solution in a fast, reliable way when compared with the traditional ones.

scholarly journals Application of Battery Energy Storage Systems for Primary Frequency Control in Power Systems with High Renewable Energy Penetration

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1379
Author(s):  
Md Ruhul Amin ◽  
Michael Negnevitsky ◽  
Evan Franklin ◽  
Kazi Saiful Alam ◽  
Seyed Behzad Naderi
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Storage Systems ◽  
Frequency Control ◽  
Battery Energy Storage ◽  
Battery Energy Storage Systems ◽  
Battery Energy ◽  
Primary Frequency ◽  
Primary Frequency Control

In power systems, high renewable energy penetration generally results in conventional synchronous generators being displaced. Hence, the power system inertia reduces, thus causing a larger frequency deviation when an imbalance between load and generation occurs, and thus potential system instability. The problem associated with this increase in the system’s dynamic response can be addressed by various means, for example, flywheels, supercapacitors, and battery energy storage systems (BESSs). This paper investigates the application of BESSs for primary frequency control in power systems with very high penetration of renewable energy, and consequently, low levels of synchronous generation. By re-creating a major Australian power system separation event and then subsequently simulating the event under low inertia conditions but with BESSs providing frequency support, it has been demonstrated that a droop-controlled BESS can greatly improve frequency response, producing both faster reaction and smaller frequency deviation. Furthermore, it is shown via detailed investigation how factors such as available battery capacity and droop coefficient impact the system frequency response characteristics, providing guidance on how best to mitigate the impact of future synchronous generator retirements. It is intended that this analysis could be beneficial in determining the optimal BESS capacity and droop value to manage the potential frequency stability risks for a future power system with high renewable energy penetrations.

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