Excess Energy Research Articles

Investigating the potential for realizing life cycle net-zero energy buildings in Europe using multi-objective optimization

In pursuit of the long-term target of achieving climate neutrality by 2050, it is crucial to strive for buildings with net-zero energy balance from a life cycle perspective. This study employs multi-objective optimization, specifically the non-dominated sorting genetic algorithm II, to explore the feasibility of achieving a life cycle net-zero energy balance for a building case in diverse European climate conditions: including Gothenburg’s humid continental climate (characterized by warm to hot summers and cold, snowy winters), Frankfurt’s oceanic climate (featuring short, cool summers and long, relatively mild winters), and Madrid’s Mediterranean climate (marked by wet, mild winters and dry, hot summers). The study examines this feasibility across three building lifespan durations: the standard 50 years, commonly applied in life cycle analyses, as well as extended lifespans of 100 and 150 years. This examination is vital due to the impact of longer building lifespans, resulting in increased operational energy demand and higher embodied energy due to the more frequent replacements of building components and systems. The findings demonstrate the feasibility of realizing a life cycle net-zero energy building across diverse European climatic conditions and lifespan durations through the identification of optimal passive, active, and renewable measures. The results emphasize the essential role of renewable measures, such as photovoltaic (PV) panels, in effectively offsetting any surplus energy use throughout the building's life cycle, ultimately enabling the achievement of a life cycle net-zero energy building. It was observed that a minimum of 276 m2 (≈ 63.5 kWp), 246 m2 (≈ 56.5 kWp), and 131 m2 (≈ 30.1 kWp) of PV panels would be required to realize a life cycle net-zero energy building in Gothenburg, Frankfurt, and Madrid, respectively. Across all locations and lifespan durations, these PV panels were integrated with optimal active measures, which included geothermal heat pumps for heating, internal air conditioning units for cooling, and mechanical ventilation systems with heat recovery potential. However, the results also indicate that relying solely on active and renewable measures, without incorporating appropriate passive approaches, is insufficient to fully realize life cycle net-zero energy buildings.

Hot phonon effect in mid-infrared HgTe/CdHgTe quantum wells evaluated by quasi-steady-state photoluminescence

Room-temperature photoluminescence (PL) spectra of intensely pumped HgTe/CdHgTe quantum well (QW) heterostructures emitting at around 5 μm wavelength have been investigated. Based on the model description of the PL spectra using a free-electron recombination band approach, effective electronic temperatures were determined depending on the excitation density. Within the quasi-steady-state approximation, we establish the balance between pump-induced heating of the electron gas in the QWs and phonon-mediated dissipation of this excess energy and deduce hot-phonon lifetime of ∼0.47 ps. Maximum operating temperatures for optically pumped HgTe/CdHgTe QW laser heterostructures emitting at around 5 μm are estimated depending on the excitation wavelength, and lasing at Peltier temperatures appears feasible for the pump wavelength of about 3 μm. Thus, the entire 3∼5 μm atmospheric transparency window can be potentially covered by thermoelectrically cooled HgCdTe-based laser sources.

Kombucha enables to inhibit digestive enzymes activity and adipocyte differentiation of OP9 cells.

Obesity is a global challenging epidemic caused by surplus adipose accumulation or energy intake, and available medications are quite limited. Studies focused on identifying potent anti-adipogenic pharmaceuticals and functional foods have gained great interests. This study evaluated the obesity prevention potential of oolong tea kombucha (OTK) and yellow tea kombucha (YTK) by in vitro experiments. The results showed that the total polyphenol content in OTK and YTK increased by 50.00% and 47.49% after fermentation, and the antioxidative capacity of kombucha was enhanced by 7.57% and 7.83% as well. After fermentation, the inhibitory activity of OTK and YTK on α-amylase and lipase was increased by 53.15% and 64.43%, and 45.24% and 39.74%, respectively. The anti-adipogenic effects evaluated by using mouse OP9 cell model indicated that both OTK and YTK could downregulate the expression levels of FABP4, PPARγ, C/EBPα, and SERBP-1C which are involved with adipocyte differentiation. Taken together, kombucha showed great potential in regulating glucose and lipid metabolism by inhibiting digestive enzymes and adipocyte differentiation, which could be a functional beverage in aiding obesity prevention or treatments. However, further animal or clinical experiments are needed to verify its potential in obesity intervention. PRACTICAL APPLICATION: This study showed that kombucha showed great potential in preventing obesity, which provided an alternative functional beverage for obesity intervening or prevention.

Excess properties, intermolecular interaction, and CO2 capture performance of diethylene glycol monomethyl ether + ethylenediamine binary mixed solutions

In this work, the density (ρ) and viscosity (η) values of diethylene glycol monomethyl ether (DEGME) (1) + ethylenediamine (EDA) (2) binary mixed solutions were experimentally measured over the temperature span of 298.15–318.15 K and at a constant pressure of 100.5 kPa. To delve into the physicochemical properties of the binary mixed solutions, the excess properties, including excess molar volume, viscosity deviation, and excess molar activation Gibbs free energy, and thermodynamic values, including activation Gibbs free energy, enthalpy change, entropy change, and activation energy, were systemically calculated. Furthermore, the relationship between mole fraction and temperature was modeled using the Jouyban-Acree (J-A) model and a least squares method. Additionally, the three-body McAllister, the four-body McAllister, the Eyring-Margules, and the Heric viscosity models were employed to establish a relationship between viscosity and mole fraction. The relationship between viscosity and temperature was determined utilizing the Arrhenius equation, and the Redlich-Kister (R-K) polynomial was applied to fit the excess molar volume, viscosity deviation, and excess molar activation Gibbs free energy values of the binary mixed solutions. To further validate the intermolecular interactions within the binary mixed solutions, Raman, UV, and 1H NMR spectroscopic analyses, and density-functional theory (DFT) calculations were also conducted. These comprehensive analyses collectively confirmed the presence of significant intermolecular hydrogen bonds (IHBs) between the DEGME and EDA molecules, which are characterized as the –OH⋯NH2– interaction. Ultimately, the CO2 absorption capacity of the binary mixed solutions was examined, revealing that diethylene glycol monomethyl ether (DEGME) (1) + ethylenediamine (EDA) (2) binary mixed solutions owned superior CO2 absorption efficiency, thus offering a promising approach for CO2 capture.

Estimation of some important thermodynamic properties of organic liquid mixtures at various temperatures (3-pentanol, benzyl salicylate, ethyl salicylate and methyl salicylate)

ABSTRACT This study investigates the thermodynamic and transport properties of binary mixtures of 3-pentanol with methyl salicylate, ethyl salicylate, and benzyl salicylate at selected compositions and temperatures from 303.15 K to 313.15 K. The excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of activation of viscous flow were determined from measured values of densities, viscosities, and speeds of sound. The results reveal the strength of hydrogen bonding interactions between the 3-pentanol molecules hydroxyl group and the salicylate derivative molecules’ -OH groups. Furthermore, the Prigogine-Flory-Patterson (PFP) theory is applied to identify the most predominant molecular interaction, and the Jouyban-Acree model results are discussed in terms of mean relative deviation (MRDs) and individual relative deviation (IRD) between calculated and experimental densities, speeds of sound and viscosities as an accuracy criterion

Isobaric vapour-liquid equilibrium studies for binary systems of a green solvent furfuryl alcohol with aniline and substituted anilines at 101.31 kPa

New experimental vapour-liquid equilibrium (VLE) data, which is expected to be useful in industrial processes such as the design of separation processes is reported in the present article. Isobaric VLE data of an eco-sustainable, green solvent furfuryl alcohol (FFA) as a common component has been measured for three binary systems (i) furfuryl alcohol + aniline (AN), (ii) furfuryl alcohol + N-methylaniline (NMA) and (iii) furfuryl alcohol + N-ethylaniline (NEA) in the complete concentration of FFA at a pressure of 101.31 kPa. The Antoine equation has been used to calculate the vapour pressure of pure samples. The reported VLE data is thermodynamically consistent according to the van Ness, Fredenslund and Herington area tests. The experimental observations of the three systems displayed non-ideal nature and negative deviation from Raoult's law. The Wilson and UNIQUAC activity coefficient models have been applied to correlate the experimental data. The information of the boiling point temperature (T), activity coefficients (γi) and variation of excess Gibbs energy (GE) with the concentration of FFA indicated the presence of dipole-dipole interactions and hydrogen bonding between the molecules of FFA and the selected amines.

Solar-hydrogen power supply system and multichannel median signal selector for spacecraft miniaturization

Solar-hydrogen energy systems for spacecraft reliably provide energy for carrying out various kinds of unscheduled work on board and for eliminating emergency situations. Surplus energy is constantly accumulated on board in the form of the chemical energy of cryogenic hydrogen.The solar-hydrogen spacecraft power supply system is based on the principle of partial conversion of excess energy generated on board into gaseous and cryogenic hydrogen.The efficiency of converting sunlight into hydrogen is 14%. Solar-hydrogen energy systems are also called rechargeable hydrogen cells. They consist of solar panels that generate electricity, water tanks and a membrane that separates hydrogen and oxygen. The power supply system implements three modes in its operation. Mode A - the planned amount of electrical energy generated by solar cells is consumed to meet the needs of the spacecraft in the normal mode. Mode B - from the excess electricity in excess of the energy consumption on board, the solar panels generate electricity, with the help of which water is electrolyzed. The resulting hydrogen is stored in special tanks and can be used during the peak period of energy consumption. Mode C - part of the hydrogen can be liquefied by the onboard cryogenerator and it can be used to generate electricity in fuel cells in super-peak power consumption situations: accidents, repairs, experiments that require a lot of energy. The efficiency of converting sunlight into cryogenic hydrogen is 5%.The article considers a new version of the median signal selection element, which provides the possibility of practically unlimited scaling of the number of input signals without loss of performance, as well as the ability to monitor malfunctions or failures in the operation of the selection element itself.The experiments have shown that the implementation of a selection element for 7 inputs takes no more than 432 logical cells on the Altera Cyclone IV EP4CE115F29C7 FPGA, which is much less than the amount occupied by the analogs discussed in the article. In this case, the delay in calculating the median signal does not exceed one FPGA cycle.

Experiment of laparoscopic sleeve gastrectomy in Al-Imamein Al-Kadhimein Medical City

Background: Obesity is a multifactorial metabolic disorder characterized by the accumulation of excess energy in adipose tissue. The risk of this disorder lies in genetic problems, intake problems, psychological disorders, lack of exercise, eating habits, and medical conditions. Weight loss attempts involving dietary changes, behavioral modifications, and exercise have been of limited benefit to most affected individuals. Weight loss operations have obviously evolved in recent years. The most commonly used and best-studied procedure is laparoscopic sleeve gastrectomy (LSG). Aim: The aim of this study was to assess certain points of LSG (benefits and complications for patients with morbid obesity) performed in Al-Imamein Al-Kadhimein Medical City. Patients and Methods: Data were collected in a prospective cohort study in Al-Imamein Al-Kadhimein Medical City between January 2021 and December 2022. LSG was performed for 40 patients for the treatment of obesity and included the following demographic data: body mass index (BMI, weight in kilograms divided by height in square meters (kg/m2)), hip circumference, waist circumference, total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, HbA1c%, and fasting blood sugar, presence of comorbidity (e.g. diabetes and hypertension), and complications following surgery. All patients were followed 3 months and 9 months postoperatively. Results: A total of 40 obese patients underwent bariatric surgery (laparoscopic sleeve gastrectomy), there were 65% female and 35% male, their mean age was 34.30 ± 5.31 years (range:23-45 years), the mean weight of patients was 146.70 ± 21.92 kg (115- 200 kg), the mean BMI was 51.45 ± 5.65 kg/m2 (37.5-63.8 kg/m2). Excess weight loss was 69% after 9 months. The improvement in comorbid diseases was significant. Conclusion: LSG is a useful procedure for the surgical management of morbid obesity. Most people who underwent these operations experienced a reduction in complications of obesity, such as hypertension and diabetes mellitus.

On the atomistic origin of internal length scale in strain-gradient plasticity models: The case of grain boundary structures and energies

The mechanical behavior of polycrystalline materials is controlled by microstructural size effects such as grain size or precipitate size. Various models of strain gradient plasticity have been proposed to capture such size effects, many of which have incorporated geometrically-necessary dislocation (GND) densities to introduce characteristic internal lengths. Recent developments have focused on models that incorporate a GND density into the internal energy functional. In such models, one needs to physically justify the functional form chosen and quantify the inherent internal length parameter. Our present study aims at probing relevant forms and internal length values in the case of grain boundary (GB) atomistic structures and core energies. We use an atomistic-to-continuum crossover approach that predicts an atomistic structure dependent GB energy by molecular static simulations, which is then recovered at the continuum-level by using a strain gradient, atomistically informed, field dislocation mechanics fast Fourier transform model. This allows (i) delineating the atomistic structure of GBs using an equivalent Nye GND density, and (ii) capturing the associated continuous elastic fields in the GB core area. We probe (i) a generalized non-quadratic GND density dependent energy functional to account for the core energy of defects, and (ii) elucidate the contributions of core versus elastic energy to the overall GB excess energy. We investigate and discuss the possible relevant choices for the energy functional form, as well as the physical origin of the inherent internal length parameter and its dependence to the types of grain boundaries, atomistic structures, and spatial resolution.

Advancing solar thermal utilization by optimization of phase change material thermal storage systems: A hybrid approach of artificial neural network (ANN)/Genetic algorithm (GA)

Solar energy is critical to the global shift towards sustainable and low-carbon energy solutions. Unlike fossil fuels, solar energy produces no emissions during operation, making it a key driver of environmentally friendly power generation. However, the intermittency of solar power remains a challenge, necessitating efficient energy storage systems to ensure a steady supply. Thermal energy storage systems utilizing phase change materials (PCMs) offer a solution by storing excess solar energy and releasing it when needed. This study focuses on enhancing the charging capacity of the PCM within a novel triplex tube heat exchanger (TTHE). The design incorporates bionic-shaped fins to compensate for thermal conductivity within the PCM. Three artificial neural network (ANN) models were employed to estimate the melting duration for the PCM to attain liquid fractions of 0.5, 0.8, and 1. The expansion angle (θ), initial length (D), and length of fin branches (Z) were systematically varied to investigate their influence on heat absorption. The ANN models exhibited high accuracy, with R2 values of 0.998 for the liquid fraction of 0.5, 0.998 for the liquid fraction of 0.8, and 0.996 for the liquid fraction of 1, demonstrating their precise predictive capability. The results revealed that θ significantly reduced melting time, while Z consistently shortened the duration and eventually became the dominant factor. However, an excessive increase in these geometric parameters led to a counterproductive rise in the total melting time. Through optimization using a genetic algorithm, three optimal designs (design 1 (D1), design 2 (D2), and design 3 (D3)) were proposed. Compared to the fin-less TTHE, these designs reduced the full melting time by 71.58 %, 73.41 %, and 73.54 %, respectively. Faster melting improves the system's ability to store and release thermal energy more quickly, enabling more efficient utilization of solar power within the limited period of sunlight availability (usually 4–6 h a day). These findings underscore the potential of ANN-based approaches in optimizing the efficiency of solar energy storage systems.

Aqueous Supercapacitor with Wide-Temperature Operability and over 100,000 Cycles Enabled by Water-in-Salt Electrolyte.

Supercapacitors are crucial in renewable energy integration, satellite power systems, and rapid power delivery applications for mitigating voltage fluctuations and storing excess energy. Aqueous electrolytes offer a promising solution for low-cost and safe supercapacitors. However, they still face limitations in cycle life and wide-temperature range performance. Here, we present a symmetric supercapacitor utilizing activated carbon electrodes and a "water-in-salt" electrolyte (WiSE) based on lithium perchlorate. The WiSE electrolyte exhibits an expanded electrochemical stability window, endowing the aqueous supercapacitor with remarkable stability and long cycle life of over 100,000 cycles at 500 mA g-1 with more than 91 % capacity retention. Moreover, the supercapacitor demonstrates good rate capability and wide temperature operability ranging from -20 to 80 °C. The use of high concentrations of salt in the aqueous electrolyte contributes not only to the enhancement of supercapacitor performance and cycle life but also to the temperature stability range, enabling all-season operability.

Diffusion Monte Carlo calculation of fully heavy pentaquarks

Using a diffusion Monte Carlo algorithm, we calculated the spectra of all possible S-wave fully heavy pentaquarks within the framework of the quark model. Our aim was to compare the masses of different spin-color configurations corresponding to the same spatial wave function for each quark composition. In particular, we computed the masses of the configuration with the maximum number of undistinguishable quarks and those of all the possible baryon+meson splittings compatible with the total number of b’s and c’s for a given pentaquark. What we found was that, in all cases, compact baryon+meson configurations had lower masses than their more symmetric counterparts. Moreover, those “molecular” associations were unstable (with larger masses) that their infinitely separated noninteracting pieces except in the case of (ccb)(cb¯) and (bbc)(bc¯) pentaquarks. In any case, even for unstable arrangements, the excess masses are so small (∼20–60 MeV) as to make those compact molecular structures serious candidates to be experimentally detected. Published by the American Physical Society 2024

Comparative Analysis of Hydrogen Production and Economic Feasibility: Direct versus Indirect Coupling of Photovoltaic Systems with Electrolyzers

Hydrogen production using photovoltaics (PV) is essential for decarbonizing many sectors of the economy. The integration of PV and hydrogen electrolyzers is actively debated, with focus on direct versus indirect configurations and the option of storage. Direct configuration connects PV directly to the electrolyzer, offering simplicity and reduced installation costs but depends on the weather for efficient power transfer. Indirect configuration adds a power stage, increasing complexity and losses, but enabling maximum power tracking. Adding batteries allows storage of excess PV energy, extending hydrogen production. This study optimizes a PV generator to maximize annual hydrogen production in the direct configuration, then uses the same PV array for indirect configurations with and without batteries for a fair comparison. Results show that the indirect configuration with a battery yields 78% more hydrogen annually than without a battery and 109% more than the direct configuration. The indirect configuration with a battery uses 86.9% of PV energy for hydrogen production, yielding the highest profit at 2.53 € ⋅ W−1 (euros per watt‐peak of PV), compared to the direct and indirect configurations without a battery, which use 41.9% and 44.6% of PV energy and generate 1.49 and 1.83 € ⋅ W−1, respectively.

Nuclear burning in an accretion flow around a stellar-mass black hole embedded within an AGN disc

ABSTRACT A stellar-mass black hole, embedded within the accretion disc of an active galactic nuclei (AGN), has the potential to accrete gas at a rate that can reach approximately ${\sim}10^9$ times the Eddington limit. This study explores the potential for nuclear burning in the rapidly accreting flow towards this black hole and studies how nucleosynthesis affects metal production. Using numerical methods, we have obtained the disc structure while considering nuclear burning and assessed the stability of the disc. In contrast to gas accretion onto the surface of a neutron star or white dwarf, the disc remains stable against the thermal and secular instabilities because advection cooling offsets the nuclear heating effects. The absence of a solid surface for a black hole prevents excessive mass accumulation in the inner disc region. Notably, nuclear fusion predominantly takes place in the inner disc region, resulting in substantial burning of $\rm ^{12}C$ and $\rm ^{3}He$, particularly for black holes around $M = 10\,{\rm M}_\odot$ with accretion rates exceeding approximately ${\sim}10^7$ times the Eddington rate. The ejection of carbon-depleted gas through outflows can lead to an increase in the mass ratio of oxygen or nitrogen to carbon, which may be reflected in observed line ratios such as N v/C iv and O iv/C iv. Consequently, these elevated spectral line ratios could be interpreted as indications of supersolar metallicity in the broad-line region.

Photoisomerization Paths of α,ω-Diphenylpolyenes: Reaction Rate Dependence on Temperature, Excitation Wavelength, and Deuteration.

The photoisomerization rate kiso of trans-stilbene (tS) and trans-trans-diphenylbutadiene (ttD) is studied in solution and compared to that in jet/gas. Rice-Ramsperger-Kassel-Marcus (RRKM) theory correctly predicts the tS rate in jet, kRRKM = Am exp(-Ein/kTm) with Ein = 1398 cm-1, and Am = 1.8 ps-1 corresponding to frequency νiso = 60 cm-1 of the reactive mode, Tm being the molecular temperature. However, the behavior in solution cannot be explained by the RRKM rate alone. In solution the rate kiso = AS exp(-Eb/kTS) has a similar form, but depends mainly on solvent temperature TS and proceeds much faster, AS = 19 ps-1, Eb = 1520 cm-1 in n-hexane. Moreover, excitation at high excess energy, resulting in molecular temperature Tm = 607 K, affects the rate only slightly, unlike in jet, and contrary to common theoretical models. The experimental results clearly indicate two isomerization paths in solution: via relatively slow intramolecular activation Am ∼ 1 ps-1, and by much faster solvent activation AS = 18 ps-1 due to solute-solvent interactions (collisions). The data in n-alkanes confirm previously established power dependence kiso ∼ ηα on viscosity η, with α = 0.30 for tS, and α = 0.35 for ttD. With Eη being the viscosity barrier, its contribution to Eb can be isolated, giving the intramolecular barrier Ein = (Eb - αEη), slightly lower than in jet/gas, probably due to the dispersive/induction interactions in solution.

Abstract 4140191: ChREBP Drives Brown Adipocyte Differentiation and Lipid Utilization for Excess Energy Expenditure

Introduction: Although several anti-obesity drugs have become recently available, they reduce patients’ appetite, which might worsen cardiovascular disease (CVD) prognosis by malnutrition/cachexia. Brown adipose tissue (BAT) oxidizes glucose and lipids for thermogenesis, a process that requires excess energy expenditure provided by uncoupling protein 1 (UCP1) + cells. Recently, critical roles of BAT in cardio-protection have been discovered. Taken together, boosting BAT activity can be a novel anti-obesity treatment suitable for CVD patients. In this study, we aimed to establish anti-obesity strategy by manipulation of the glucose-sensing lipid-storage transcription factor, ChREBP, with unexpected function of boosting lipid utilization in BAT. Methods and Results: Through mouse/human single-cell/nucleus RNA sequencing analyses, we identified ChREBP as specifically expressed in highly thermogenic UCP1 + brown adipocytes ( Fig.A ). To investigate the role of ChREBP in BAT formation, we generated human brown adipocyte-like model from induced pluripotent stem cells (iPSC-BAT, Fig.B ). The iPSC-BAT exhibited high UCP1 and ChREBP expression, multi-locular lipid droplets, and vigorous oxygen consumption. Knocking down ChREBP strongly blocked iPSC-BAT differentiation ( Fig.C ) and impaired lipid utilization ( Fig.D ). Consistently, in vitro deletion of ChREBP in mouse BAT progenitors impeded differentiation, lipid droplet accumulation, and oxygen consumption ( Fig.E-F ). In vivo, BAT-specific deletion of all ChREBP isoforms reduced lipid accumulation and BAT characteristics. Conversely, using a new mouse model for Cre-mediated ChREBPβ overexpression, we showed that ChREBPβ overexpression in BAT (Chβ BATOX) increased BAT cellularity and activated lipogenic machineries, with paradoxical decreased lipid content, suggesting excessively activated lipid consumption in BAT ( Fig.G ). More importantly, Chβ BATOX maintained UCP1 expression and reduced fat volume ( Fig.H ) even after strongly inhibiting BAT activity. Conclusion: In summary, ChREBP is essential for BAT development and thermogenic capacity by affecting lipid utilization. Our results suggest that ChREBPβ activation may be a novel anti-obesity avenue for CVD patients.

Overexpression of HvVDE gene improved light protection in transgenic tobacco (Nicotiana tabacum).

Hosta is commonly acknowledged as a popular and preferred plant for landscaping and gardening. The 'sunburn' caused by prolonged exposure to strong sunlight is reducing the ornamental values of Hosta plants. However, there is a scarcity of research focusing on the genetic components linked to light-induced harm in Hosta . Here, the violaxanthin de-epoxidase (VDE) homolog from Hosta ventricosa was isolated and functionally identified through conducting HvVDE -overexpression tobacco (Nicotiana tabacum ) lines. The results showed that HvVDE encodes a putative protein comprising 481 amino acids with a molecular weight of 54.304kDa. The phylogenetic analysis found that HvVDE exhibited close similarity to JcVDE. Besides, the expression patterns of HvVDE found that HvVDE was expressed differently across tissues, withexpression induced by high light intensities. And overexpression of HvVDE led to the restoration of non-photochemical quenching in tobacco, suggesting that HvVDE plays a role in dissipating excess light energy as thermal energy in H. ventricosa . These findings underscore the significance of HvVDE in mitigating photoinhibition and enhancing photoprotection mechanisms in H. ventricosa .

THE POTENTIAL FOR PEER-TO-PEER ELECTRICITY TRADING IN GEORGIA

The global energy transition is fundamentally reshaping electricity markets, moving from centralized systems reliant on fossil fuels to decentralized, renewable energy solutions. Distributed energy resources such as solar panels and storage batteries are empowering consumers to become active participants in the energy market. Peer-to-peer (P2P) electricity trading, enabled by blockchain technology, presents a new model for consumers to trade surplus energy directly with one another, bypassing traditional suppliers. This article explores the potential of P2P electricity trading in Georgia, a country with significant renewable energy resources but limited experience with decentralized energy systems. As Georgia aligns its energy policies with European regulations, the development of a P2P trading market could enhance energy security, empower prosumers, and drive local economic development. Through an analysis of global trends, technological innovations, and the current Georgian energy landscape, this article assesses the opportunities and challenges in implementing P2P trading. By building the necessary infrastructure and fostering public participation, Georgia has the potential to transform its energy market and contribute to a more resilient and sustainable energy future.

An Optimized Strategy for the Integration of Photovoltaic Systems and Electric Vehicles into the Real Distribution Grid

The increasing spread of photovoltaic systems for private households (PVs) and electric vehicles (EVs) in order to reduce carbon emissions significantly impacts operation conditions in existing distribution networks. Variable and unpredictable PVs can stress distribution network operation, mainly manifested in voltage violations during the day. On the other hand, variable loads such as EV chargers which have battery storage in their configuration have the ability of storying a surplus energy and, if it is necessary, support a distribution network with energy, commonly known as vehicle-to-grid concept (V2G), to help voltage stability network enhancement. This paper proposes an optimal power flow (OPF)-based model for EV charging to minimize power exchange between the superior-10 kV grid and the observed distribution feeder. The optimization procedure is realized using the co-simulation approach that connects power flow analysis software and optimization method. Three different scenarios are observed and analysed. The first scenario is referred to as a base case without optimization. The second and third scenarios include optimal EV charging and discharging patterns under different constraints. To test the optimization model, a 90-bus unbalanced distribution feeder modelled based on real-life examples is used. The obtained results suggest that this optimization model does not only significantly reduce the power exchange between an external network and the distribution feeder but also improves voltage stability and demand curve in the distribution feeder.

Processes independent of nonphotochemical quenching protect a high-light-tolerant desert alga from oxidative stress.

Non-photochemical quenching (NPQ) mechanisms are crucial for protecting photosynthesis from photoinhibition in plants, algae, and cyanobacteria, and their modulation is a long-standing goal for improving photosynthesis and crop yields. The current work demonstrates that Chlorella ohadii, a green micro-alga that thrives in the desert under high light intensities that are fatal to many photosynthetic organisms does not perform nor require NPQ to protect photosynthesis under constant high light. Instead of dissipating excess energy, it minimizes its uptake by eliminating the photosynthetic antenna of photosystem II. In addition, it accumulates antioxidants that neutralize harmful reactive oxygen species (ROS) and increases cyclic electron flow around PSI. These NPQ-independent responses proved efficient in preventing ROS accumulation and reducing oxidative damage to proteins in high-light-grown cells.