Energy Capacity Research Articles

Renewable energy policy performance and technological innovation in Africa: A Bayesian estimation

This paper examines the effect of renewable energy policy performance on innovation activity in the renewable energy sector in a sample of thirty-three African countries during the period 2010–2021. The policy performance we use covers carbon pricing, incentives for grid-connected and distributed renewable energy generation, fiscal incentives for renewable energy, legal framework for renewable energy, off-take risk, network connection and pricing, and policy design attributes. Using patent data and renewable policy performance to fit a Bayesian negative binomial, our results generally show that renewable energy policy in the region supports technological innovation in the sector. Policy initiatives focused on market-based incentives (auctions and tariffs), renewable portfolio standards, risk mitigation, network connection and pricing are largely responsible for a strong and statistically significant relationship between renewable energy policy and innovation activity. We also find evidence that intellectual property rights, renewable energy capacity, electricity prices, affordability of renewable energy, and openness to trade proxies are important drivers of innovation activity in the renewable energy sector. Our analysis finds no evidence that research and development is a significant determinant of renewable energy innovation in African countries. Our results serve to inform policymakers on the areas in which specific policy actions are most effective at promoting innovation in the renewable energy sector.

Theoretical Investigation of a Novel Two-Dimensional Non-MXene Mo3C2 as a Prospective Anode Material for Li- and Na-Ion Batteries.

A new two-dimensional (2D) non-MXene transition metal carbide, Mo3C2, was found using the USPEX code. Comprehensive first-principles calculations show that the Mo3C2 monolayer exhibits thermal, dynamic, and mechanical stability, which can ensure excellent durability in practical applications. The optimized structures of Lix@(3×3)-Mo3C2 (x = 1-36) and Nax@(3×3)-Mo3C2 (x = 1-32) were identified as prospective anode materials. The metallic Mo3C2 sheet exhibits low diffusion barriers of 0.190 eV for Li and 0.118 eV for Na and low average open circuit voltages of 0.31-0.55 V for Li and 0.18-0.48 V for Na. When adsorbing two layers of adatoms, the theoretical energy capacities are 344 and 306 mA h g-1 for Li and Na, respectively, which are comparable to that of commercial graphite. Moreover, the Mo3C2 substrate can maintain structural integrity during the lithiation or sodiation process at high temperature. Considering these features, our proposed Mo3C2 slab is a potential candidate as an anode material for future Li- and Na-ion batteries.

A dispatch model coordinated power and heating system in electricity market considering resource aggregation and decomposition

Abstract With the high proportion of installed capacity of renewable energy, the stability and robustness of the new power system need to be improved. The integration of the power system and heating system is an orientation to promote the ability of wind power accommodation. This thesis first introduces the integrated model considering power and heating systems. However, the integrated model requires the topology in the heat network and the parameters of heat devices, which is difficult to access and complicated to solve. Under this situation, the heat devices are aggregated into an equivalent generation unit in the power network. A coordinated dispatched model based on resource aggregation and decomposition is then proposed. In simulation, the economy, flexibility, and security of a given formulation are investigated through marginal price and units’ behavior.

Energy efficiency, economic growth, and natural resource rent: A trilemma analysis of environmental sustainability in Africa

Climate change, exacerbated by a global economic model reliant on carbon-intensive industrialization and unchecked growth, disproportionately affects vulnerable regions such as Africa. Therefore, transitioning to an ecologically sustainable development paradigm is imperative for developing countries facing climate disruptions. The current study analyzes the trilemma effect of energy efficiency, economic growth, and total natural resource rent on environmental quality in Africa from 2010 to 2018 using SMB-DEA and PMG ARDL methods. The results are as follows: first, SMB-DEA analysis found traditional and renewable energy efficiency at 89 % and 58 %, respectively, indicating infrastructure and policy deficiencies in optimizing renewables. Second, economic expansion poses significant environmental costs; energy efficiency has an insignificant ameliorating effect on efficiency; and counterintuitively, natural resource rents become less environmentally harmful over time, though remain detrimental in the short term. Third, country-specific analyses presented heterogeneous outcomes, reflecting the complexity of global climate solutions. Fourth, transforming inefficient energy-growth-emission systems onto sustainable trajectories requires 262 % CO2 emission cuts and 46.7 % increased renewables capacity to reach efficiency frontiers. Fifth, Bidirectional causal relationships exist between income, energy efficiency, emissions, and resource rents, mutually influencing one another. These findings support suggestions for upscaling green energy capacity and improving green energy efficiency.

A review of concentrated solar power status and challenges in India

Concentrated Solar Power (CSP) technology has emerged as a promising renewable energy solution, offering a sustainable and efficient means of electricity generation and thermal energy storage. India, endowed with abundant solar irradiance, has made significant strides in promoting CSP technology as part of its renewable energy portfolio. With a growing focus on reducing greenhouse gas emissions and enhancing energy security, the Indian government has initiated numerous policies, incentives, and projects to encourage CSP adoption. Parabolic trough collectors, a type of linear concentrating system, are currently in widespread use. Power or solar towers are the most common type of point concentrating CSP technology currently in use. India aims to achieve a renewable energy capacity of 175 GW by 2022, with solar power constituting 100 GW of the overall target. Concentrated solar power technology is slated to grow 87% during 2018–2023, 32% faster than in the previous five-year period 2012–2017 and reach 4.3 GW in 2023. In future, present review paper can be regarded as a valuable resource for researchers, policymakers and industry professionals seeking to comprehend the present condition of concentrated solar power in India. It can aid in the development of strategies to address obstacles and advance sustainable and efficient solar energy solutions.

Expression of Concern: Using phase change material (PCM) to improve the solar energy capacity of glass in solar collectors by enhancing their thermal performance via developed MD approach

Expression of Concern: Using phase change material (PCM) to improve the solar energy capacity of glass in solar collectors by enhancing their thermal performance via developed MD approach

Enhancing lithium titanate anode performance through surface modification with fluorine and nitrogen co-doped carbon nanotubes

In this study, we explore the efficacy of fluorine and nitrogen co-doped carbon nanotubes (F@N-CNT) as a novel surface modifier for lithium titanate (LTO) anodes in lithium-ion batteries (LIBs). The integration of F@N-CNT enhances the electrochemical properties of LTO anodes by improving electrical conductivity and facilitating lithium-ion diffusion., Electrodes modified with F@N-CNT exhibited significant improvements in capacity retention, achieving 71 % capacity retention over 200 cycles at 2 C and delivering energy capacities up to 162.9 mAh g−1 at 0.2 C, with an impressive high-rate performance of 74.8 mAh g−1 at 30 C. This study demonstrates that F@N-CNT effectively forms a conductive network within the LTO matrix, resulting in superior high-rate performance and stability. It presents a comprehensive analysis of the microstructural changes induced by co-doping and elucidates their impact on the electrochemical performance, providing valuable insights into the design of high-performance anodes for future energy storage applications. This approach not only addresses the current limitations of LTO anodes but also introduces a scalable strategy for enhancing the overall functionality of LIBs.

Strategy of geothermal energy development as a renewable energy source in West Java Indonesia

Background: Indonesia has vast renewable energy potential, including biofuels, biomass, and bioenergy from tropical biodiversity spread across the country. Hydropower and geothermal energy are the only forms of renewable energy used to generate electricity and are connected to the grid. Geothermal energy may be incorporated into the grid to create hybrid energy systems that will help to reduce the high energy demand while maintaining low energy costs and net present costs. There are now 14 biosphere reserves in Indonesia, divided into 24 units of core zones, six units of buffer zones, and 13 units of transition zones. The West Java Province has a geothermal potential of 6,101 MWe or 21% of Indonesia's total geothermal resources. Currently, the installed capacity of electricity from geothermal energy in West Java is 1075 MWe or 89% of the total national installed capacity of 1196 MWe. Method: This paper reviews West Java Province data collection from official government bureaus, state-owned businesses, and non-governmental organizations (NGO) reports on geothermal energy capacity, electricity installation, and used area of ​​geothermal power plant and will be limited to the years 2010 through 2020. The collected data will then be refined, extrapolated, and analyzed by the connected trend to aid in studying West Java geothermal growth and use SWOT method analysis. Finding: The result of this research is a strategy for optimizing the development of geothermal energy utilization. The strategies that can be developed are infrastructure improvement as an investment facilitation strategy, a strategy to leverage a costly investment and capital investment, underground mining in conservation forest areas to avoid degradation improvement and supervision of related institutions and stakeholders, implementation of environmentally sustainable development, and socializing programs and providing job opportunities for the local community. Conclusion: Indonesia has an enormous potential for renewable energy, especially geothermal, with West Java Province having the largest installed capacity. This study suggests strategies to optimize geothermal energy development, including improving infrastructure, investment facilities, underground mining, improving supervision, and sustainable development. Novelty/Originality of this study: Research on geothermal energy in West Java provides a comprehensive analysis and specific strategies to optimize the development of this energy in the area, including innovative underground mining approaches.

Sizing of Energy Storage Systems in Electric Vehicles based on Battery-Supercapacitor Technology

The purpose of this research is to determine the ideal hybrid energy storage system (HESS) size with the goal to improve the effectiveness and efficiency of combined battery and supercapacitor energy storage in electric vehicles. The research uses Mixed Integer Linear Programming (MILP) to determine the most suitable configurations using simulation data from a modeled electric vehicle. The results show that MILP works at identifying the specific capacity needs of the storage system, which change based on the vehicle's power and energy capacity. The innovation provides a paradigm for the development of sustainable and highly efficient electric vehicles in the future, while also enhancing the functionality of current electric vehicles.

Power Allocation based on ANN for Hybrid Battery and Supercapacitor Storage System in EV

The paper focuses on presented an ArtificialNeural Network (ANN) approach to allocate power for a hybridenergy storage system (HESS) in an Electric Vehicle (EV). TheHESS is comprised of a battery and supercapacitor, and theANN algorithm aims to optimize power allocation between thesetwo energy storage devices. The data for ANN training wasbased on cost optimization-based power allocation fromprevious research. While optimization can often take highcomputational resource and time, it is expected that a welltrained ANN can allocate power for the EV HESS more quickly.In this research, the inputs to the ANN are the required powerderived from the drive cycle, energy and power capacity of thebattery and supercapacitor, and state of charge (SoC) of thebattery and supercapacitor. The trained ANN was trained withvarious inputs not used in the training and it shows satisfactoryperformance.

Rapid screening of creep resistance in additive manufactured Ti-6Al-4V alloy

In this study, rapid screening of creep resistance for additively manufactured (AM) materials is enabled using an accelerated creep test (ACT) called the dynamic negative stepped test (DNST). Additively manufactured components are on the rise in aerospace systems, particularly turbine engine parts. It can be challenging to identify the AM process parameters that correspond to high-temperature strength and creep resistance. Tests are needed that rapidly screen and qualify creep resistance. In DNST, the temperature is held constant, and the specimen is taken through a series of load holds from high to low. The DNST contains two distinct characteristics: (1) the hold duration for each step is “dynamically” controlled to ensure the minimum-creep-strain-rate is achieved at every step, and (2) the “descending” profile maximizes damage accumulation while remaining on the edge of instability. The DNST assesses a material's ability to resist creep damage accumulated across multiple deformation mechanisms. In this study, electron beam melted Ti–6Al–4V, built at six (6) directions: 0°, 30°, 45°, 60°, 90°, and V, is tested using a four-step DNST at 650 °C. Analysis of the minimum-creep-strain-rate (at each step), creep ductility, and rupture were performed. A strain energy density (SED) benchmark metric was established to rapidly screen and classify creep resistance using an “Ashby-like” plot that balanced energy dissipated and energy dissipation rate. The creep resistance was found to be ranked from V, 60, 45, 30, 90, and 0 in descending order. Microstructural and crystallographic characterization revealed grain refinement progressing from the strain-free to the high-strain regions, indicative of dynamic recrystallization (DRX). Further observations revealed that the material's energy capacity increased with the alignment of the grains' long axis and tensile direction.

Adaptability Evaluation of Power Grid Planning Scheme for Novel Power System Considering Multiple Decision Psychology

With a substantial fraction of renewable energy integrated into the electrical grid, the new power system urgently requires grid planning scheme displaying adaptability to different energy types and their volatility. Considering the indeterminacy of renewable energy generation output and the different attitudes of decision-makers towards its risk, this paper proposes an adaptability assessment methodology for power grid planning schemes considering multiple decision psychology. First, an evaluation indicator framework is established based on the adaptive requirements of the grid planning for novel power system, and the weights of indicators are calculated based on an improved AHP-CRITIC combination weighting method. Second, improved cumulative prospect theory (ICPT) is adopted to improve to the calculation method of the distance between the evaluation program and the positive and negative ideal programs in the GRA and TOPSIS, which effectively characterize the different decision-making psychologies, and a combination evaluation model is constructed based on a cooperative game (CG), namely, an adaptability evaluation model of grid planning schemes for novel power systems based on GRA-TOPSIS integrating CG and ICPT. Finally, the proposed model serves to evaluate grid planning schemes of three regions in China’s 14th Five-Year Plan. The evaluation results show that the adaptability of the schemes varies under different decision-making psychologies, and under the risk-aggressive and loss-sensitive decision-making psychologies, grid planning scheme of Region 1 with the greatest accommodation capacity of renewable energy is preferable.

Multi-Stage Coordinated Planning for Transmission and Energy Storage Considering Large-Scale Renewable Energy Integration

Due to the large-scale integration of renewable energy and the rapid growth of peak load demand, it is necessary to comprehensively consider the construction of various resources to increase the acceptance capacity of renewable energy and meet power balance conditions. However, traditional grid planning methods can only plan transmission lines, often resulting in low utilization rates of newly constructed lines. Additionally, static planning methods can only address single-target scenarios and cannot cope with dynamic growth in load and renewable energy. To address these issues, this paper proposes a multi-stage collaborative planning method for transmission networks and energy storage. This method considers the non-line substitution effect of energy storage resources and their characterization methods. It establishes the coupling relationship between resources across different planning stages to achieve coordinated multi-stage planning for transmission networks and energy storage. Based on the IEEE-24 node system and a case study in a northern province of China, the results show that the proposed method reduces investment costs by approximately 30% compared to static planning methods and by about 7.79% compared to conventional grid planning methods. Furthermore, this method can accommodate more renewable energy.

Interpenetrated Structures for Enhancing Ion Diffusion Kinetics in Electrochemical Energy Storage Devices

HighlightsA new and compact device configuration was created with two interpenetrated, individually addressable electrodes, allowing precise control over the geometric features and interactions between the electrodes.The interpenetrated electrode design improves ion diffusion kinetics in electrochemical energy storage devices by shortening the ion diffusion length and reducing ion concentration inhomogeneity.The device with interpenetrated electrodes outperformed the traditional separate electrode configuration, enhancing both volumetric energy density and capacity retention rate.

Decarbonization in the Oil and Gas Sector: The Role of Power Purchase Agreements and Renewable Energy Certificates

This study examines the adoption of Power Purchase Agreements (PPAs) and Renewable Energy Certificates (RECs) as strategic tools for decarbonization in the oil and gas sector. Focusing on the 21 largest oil and gas companies across Europe, North America, and South America, the analysis reveals varied adoption rates and strategic emphases between regions. European companies exhibit robust integration of PPAs and RECs to expand renewable energy capacities and reduce emissions, aligning closely with aggressive EU climate policies. In contrast, American companies show a cautious approach, focusing more on emission reduction from existing operations than on renewable expansions. The study’s findings indicate that, while both regions are advancing in their decarbonization efforts, European companies are leading with more defined renewable energy targets and comprehensive low-carbon strategies. This research contributes to understanding how different regulatory environments and market conditions influence corporate strategies towards sustainable energy transitions in traditionally hard-to-abate industries.

Green Hydrogen from Hydroelectric Energy: Assessing the Potential at the Abanico Power Plant in Morona Santiago Province

A key strategy for optimizing the utilization of clean energy sources involves integrating energy vectors to effectively manage surplus power generated from renewable sources. This study specifically delves into the assessment of a hydrogen (H₂) generation project utilizing energy generated by the Hidroabanico power plant. Over a span of 13 years, the average monthly energy production was meticulously scrutinized, with a determination that 20% of this energy would be allocated for H₂ production. The operational framework of the prototype plant, which relies on Proton Exchange Membrane (PEM) electrolyser technology, is comprehensively elucidated. This system boasts an annual energy capacity capable of reaching 62,439 MWh (20% of total production), culminating in the production of 1,123 Tn of H₂. However, it is noteworthy that this quantity remains relatively limited compared to analyses conducted utilizing alternative technologies.

Hybrid wind-solar energy potential modeling using ERA5 and solar irradiation data in google Earth Engine

Renewable energies play a significant role in mitigating the climate change impacts. Wind and solar energy are projected to supply larger amount to the total renewable energy capacity of many nations. Long-term wind and solar data availability and analysis is vital for sustainable renewable energy farming. In this research, we analyze wind speed u- and v-components at 10 m height of the ERA5 daily reanalysis aggregates at a mesh of 31 Km during a long period (2010–2020) over the Red Sea and the Gulf of Suez coasts of Egypt. Google Earth Engine (GEE) code is developed and used for the analysis. The prime objective is to derive estimates on the spatio-temporal variability of speed, direction, and the wind energy estimates in the area. Further, the solar energy potential has been evaluated using reference data of the PVOUT – Photovoltaic power potential (kWh/m2/day) data, at nearly 1 km resolution, which is normalized at the evaluated sites, and then used to rank sites with their solar energy potential. Evaluation of estimates is carried out at selected thirteen sites distributed along the coasts to better understand the hybrid wind-solar energy potential. Frequency analysis is carried out to the wind speed spatial estimates to demarcate highest frequency wind events potential for wind farming. Reference in-situ wind speed observations available at daily and monthly time scales for Hurghada weather station is used for investigating the reanalysis data performance. The Hurghada site had the highest average wind speed (6.7 m s−1), frequency of events (75 %), and mean daily (60.4 kWh) and annual (22.02 MWh) wind energy. The windiest time intervals were the September month, 2017 year, and the summer season. The north had wind energy directions of 130°, while the south had 110°. Trend analysis showed declining trends for northern locations and rising yearly wind speed estimates for Berenice (0.005) and Halayeb (0.002). El-Tor location had the highest solar energy output, with a daily mean of 5.52 kWh/m2 and an annual mean of almost 2015 kWh/m2. The Hurghada, Jemsa, G. Zeit, and El-Tor sites achieved the highest rankings in terms of hybrid wind-solar energy potential. The results can be very valuable for optimal location of hybrid solar-wind energy facilities and provide viable and promising solutions for sustainably meeting Egypt's growing clean energy demands.

The balance issue of the proportion between new energy and traditional thermal power: An important issue under today's low-carbon goal in developing countries

The stability of the new power system depends on the balance between controllable flexible resources and uncontrollable uncertain resources. For many developing countries and regions lacking advanced flexible resources, thermal power is the main force in solving the problem of new energy consumption. Finding the balance between new energy and traditional thermal power is the key for today's low-carbon goal. To solve this problem, this paper calculates the power range and climbing rate range of thermal power based on physical principles and actual data, and characterizes the characteristics of wind power, photovoltaic power, load and net load based on the five proposed volatility indicators. Then, a logically clear method for determining the required number of thermal power units based on the volatility indicators of new energy from the mechanism and principle perspective is proposed. Finally, under the premise of meeting the power balance and flexibility balance of the power system, the reasonable ratios between the installed capacity of new energy and the number of thermal power units are calculated in four seasons. The results indicate that the judgment system can provide guidance for the energy structure of developing regions.

Pressure-dependent band gap engineering with structural, electronic, mechanical, optical, and thermal properties of CsPbBr3: first-principles calculations.

In the renewable industry, pressure-dependent CsPbBr3 perovskite has a lot of potential due to its exceptional properties. Present work revealed the mechanical stability of CsPbBr3 between 0 to 50GPa. The bandgap of unstressed CsPbBr3 is 2.90eV, indicating a direct bandgap. Band gap values decrease by increasing external pressure. CsPbBr3 structure showed a direct band gap from 0 to 35GPa and in-direct from 40 to 50GPa. The unit cell volume and lattice constants are substantially decreased. Mechanical parameters, i.e., Young's modulus, bulk modulus, anisotropy factor, shear modulus, and poison's ratio are obtained. Under ambient conditions, the mechanical properties of CsPbBr3 showed ductile behavior and with induced pressure, their ductility has significantly improved. By applying stresses ranging from 0 to 50GPa, the considerable fluctuation in values of dielectric function (imaginary and real), absorption, reflectivity, loss function, refractive index (imaginary and real), and conductivity (imaginary and real), was also identified. When pressure rises, the optical parameters increase and drag in the direction of high energies. Response functions are used to predict the density of states and the phonon lattice dispersion to study the phonon properties. By using the quasi-harmonic Debye model, the thermal effect on the free energy, entropy, enthalpy, and heat capacity were predicted and compared. These results would be useful for theoretical research and indicate how external pressure significantly affects the physical characteristics of CsPbBr3 perovskites, which may open up new possibilities for use in optoelectronic, photonic, and solar cell applications. The structural, electrical, mechanical, optical, and thermal properties of cesium lead bromide (CsPbBr3) are investigated by applying external pressure from 0 to 50GPa, using generalized gradient approximations (GGA) and Perdew-Burke-Ernzerhof (PBE) with CASTEP code built-in material studio by density functional theory (DFT).

Response of fruit fly (Drosophila pseudoobscura) to diet manipulation of nutrient density

AbstractCaloric intake can greatly affect many aspects of an organism's life. A deficiency of calories can lead to stress resulting in decreased fecundity, insufficient calories to maintain tissues and increased lifespan. Conversely, increasing caloric density increases fecundity and decreases lifespan. Despite decades of work exploring food quality and quantity on physiology in the model species Drosophila melanogaster Meigan 1830 (Diptera: Drosophilidae) and the melanogaster group in general, relatively little work explores the physiological responses to diet manipulation in other Drosophila species, like the obscura species group. Here, we looked at the effects of five different caloric densities (0.5×, 0.75×, 1.0×, 1.5× and 3.0×) on food intake, body weight, body fat, fecundity and longevity in D. pseudoobscura Frolova & Astaurov, 1929 (Diptera: Drosophilidae). Comparing longevity and fecundity across diets, we found that heavy caloric concentration (3.0×) decreases lifespan and that calorie restriction (0.5× and 0.75×) led to significant decreases in fecundity and body weight. However, calorie concentration did not significantly increase D. pseudoobscura body fat. By expanding our understanding of the physiological responses to diet stress to D. pseudoobscura, we establish the framework for comparative work across Drosophila species. With this information, we can then identify which physiological responses to diet manipulation might be most conserved and comparable across species.