Excess Energy Research Articles

Thermodynamic modeling and analysis of a Carnot battery system integrating calcium looping thermochemical energy storage with coal-fired power plant

Long-term energy storage and carbon capture technologies are pivotal in managing renewable energy surpluses and achieving carbon neutrality. This paper proposes a Carnot battery system integrating calcium-looping thermochemical energy storage with a coal-fired power plant. The system utilizes excess electricity from the grid for energy input, facilitating long-term energy storage, achieving carbon capture, and reducing coal consumption in the power plant. An optimization framework is developed, incorporating component thermodynamic models and optimization algorithms, to maximize the coal savings in plants and energy efficiencies of the Carnot battery system. During the energy release process, the carbonator partially replaces the reheat load of the boiler, necessitating retrofitting of the boiler’s heating surface to ensure normal operation. The base system demonstrates a CO2 capture capacity of 3.23 MJ/kg and a reduction in coal consumption by 7.07 %. The round-trip efficiency and comprehensive efficiency of the base system are 36.93 % and 37.91 %, respectively. The relatively low energy efficiency is primarily due to the deactivation of circulating adsorbents and the limited efficiency of the subcritical coal-fired power plant. By incorporating an additional recarbonation step to mitigate adsorbent deactivation, the system’s comprehensive efficiency is improved to 42.20 %. Further improvements in system efficiency can be achieved by using modified adsorbents with high cycling stability instead of natural limestone and by coupling the system with more efficient ultra-supercritical units instead of the investigated subcritical units. This study offers valuable insights into the development of long-term energy storage solutions and multifunctional Carnot battery technology.

Concept and Modeling of Participation Opportunity for Large-Scale Renewable Energy Plants

Citizen participation in the energy transition is desirable for many reasons: it increases acceptance of renewable energies, fulfils the wish to make one's own contribution to the energy transition and generates relevant parts of the necessary capital for the transformation of the energy system. This paper presents a scalable participation concept for the German legal framework which allows citizens to invest in and partially consume electricity from large-scale renewable energy plants at the time of generation. The developed concept provides a method for direct financial involvement via a direct contract with local electricity suppliers and virtual self-consumption by matching demand with PV generation – without the need for property ownership or new subsidies. Different consumer types and participants shares of a large-scale PV plant are modelled and simulated for the years 2019-2021. The financial advantage of citizen participation depends on the type of energy generation plant, yearly (solar) yield, on the remuneration for the surplus energy quantity, on the electricity procurement costs, on the customer's energy consumption, on the amount, and time flexibility and others. This paper shows that all analysed consumer types have the potential to profit from the model every year, although simulations are dependent on variable annual factors and assume the energy supplier's short-term procurement. The approach’s scalability and organizational simplicity could expedite the development of local participatory projects and contribute significantly to Germany's energy transition.

Consumer Theory-Based Primary Frequency Regulation in Multi-Microgrid Systems within a P2P Energy Management Framework

This paper presents a novel primary frequency regulation strategy for multi-microgrid (MMG) systems, utilizing consumer theory within a peer-to-peer (P2P) energy management framework. By coordinating photovoltaic (PV) systems and energy storage systems (ESS), the proposed method ensures a rapid and effective response to frequency deviations. Unlike conventional approaches, this strategy minimizes the curtailment of renewable energy sources by prioritizing the use of ESS, allowing excess energy to charge the ESS for later use during under-frequency events. This not only enhances energy efficiency but also maximizes renewable energy utilization. Simulations demonstrate that the proposed scheme achieves lower frequency deviations and faster stabilization compared to traditional droop and virtual inertia methods. These results highlight the potential benefits of integrating consumer theory-based models into primary frequency regulation, significantly enhancing system stability and efficiency in power systems with high levels of renewable energy penetration.

Development of the prototype for the SPARC hard X-ray monitor.

The SPARC tokamak will be equipped with a hard X-ray (HXR) monitor system capable of measuring the bremsstrahlung emission from runaway electrons with photon energies in excess of about 100keV. This diagnostic will detect the formation of runaway electron beams during plasma start-up and inform the plasma control system to terminate the discharge early to protect the machine. In this work, we present a 0D estimate of the HXR emission in SPARC during plasma start-up. Then we discuss the characterization of a prototype of the HXR monitor. The detector mounts a 1 × 1-in.2 LaBr3 inorganic scintillator coupled with a photomultiplier tube and has been tested with γ-ray sources to find its dynamic range. Finally, two possible modes of operation for spectroscopic and current mode measurements on SPARC are proposed.

SLAPE solar panels: a possible solution for the future energy problems of our society

Today, the silicon photovoltaic cell (SPVC) solar panels are being deployed across the globe by all most all the governments to generate renewable carbon neutral electricity to use in place of the one generated at thermal power plants by burning fossil fuels. These SPVC solar panels generate electricity with less than 20% efficiency, and heat energy with more than 30% efficiency. This 10% excess heat energy released into the atmosphere can cause a very severe damage to the environment and ecology as it is million times higher than the one caused by the equivalent CO2 gas in the atmosphere with a concentration of about 421 ppm. To avoid the harmful and danger effects of heat energy released by these SPVC solar panels into the atmosphere, either they have to be stopped using or the heat generated by them has to be trapped to use for the beneficial purposes of the society or any other alternate safe solar panels have to be developed. In this study, for the first time, the SLAPE (Semiconductor and Liquid Assisted Photothermal Effect) solar panels are introduced to generate electricity from sunlight. In these new solar panels, a semiconducting material along with a stable organic solvent is employed to capture the sunlight reaching the earth surface and to convert it into the heat energy. This in situ generated heat energy is then converted into a rotational mechanical energy with the help of an heat engine, and then into electricity with the help of suitable electric generator. To establish the Proof of Concept (poc), in this study, SPV cells as semiconducting material and γ-butyrolactone were employed to fabricate a one square meter area SLAPE solar panel and generated about 17 V AC electricity with the help of a custom manufactured reciprocally moved steam engine (RMSE) and an electric generator. Thus obtained results are presented and discussed along this article.

Binary aqueous solutions of choline salts: determination and modelling of liquid density (298.15 or 313.15 K) and vapour pressure osmometry (313.15 K)

Salts composed of the cholinium cation (such as choline hydroxide and choline chloride) have become one of the main reactants for the synthesis of greener ionic liquids, but, for a proper description of the aqueous solutions of these strong electrolytes by thermodynamic modelling, reliable data on liquid density (ρ) and vapour pressure (p) are needed, which are often unavailable. So, in this work, the liquid density (ρ) of binary aqueous solutions of choline bicarbonate ([Ch][Bic]), choline (2R,3R)-bitartrate ([Ch][Bit]), choline chloride ([Ch]Cl), choline dihydrogen citrate ([Ch][H2Cit]) and choline hydroxide ([Ch]OH) were measured at 298.15 or 313.15 K and 0.1 MPa and correlated using second-degree polynomials with salt molality (m), obtaining determination coefficients (R2) higher than 0.9974. Furthermore, the osmotic coefficients (ϕ) of these binaries were determined using vapour pressure osmometry (VPO), at 313.15 K and 0.1 MPa, being satisfactorily described by the Extended Pitzer Model of Archer, which yielded low values of standard deviation (3.58<σϕ·103<12.86). Then, the mean molal activity coefficients (γ±) and excess Gibbs free energies (GE/RT) were calculated, following the order [Ch][H2Cit] > [Ch][Bit] > [Ch][Bic] > [Ch]OH > [Ch]Cl, which corresponds to the decreasing polarity of the choline salts and agrees with the empirical law of matching water affinities (LMWA).

Persistent Challenges of Micronutrient Deficiencies in Latin America Needs Action.

Micronutrient deficiencies affect growth and development and are critical for maintaining health at all ages. Their critical role in exacerbating complications of infections and chronic diseases continues to impact morbidity, mortality, and quality of life for many. Raising awareness and advocating for micronutrient deficiencies in Latin America is urgent to reduce this preventable burden. Globally, an estimated 372 million preschool-aged children and 1.2 billion non-pregnant women of reproductive age suffer deficiency from 1 or more micronutrient. Data is limited and often old, and the true burden of problem in the region remains unclear. There are also limited data on dietary intake and on the double burden of malnutrition. Latin America has been a leader in the design and implementation of innovative and effective actions to reduce excess energy intake and curb the consumption of unhealthy Actions to address deficiency have been implemented in many countries in the region over the years, but current evidence suggests that micronutrient deficiencies have fallen off the public health agenda in Latin America. Effective programming can be developed / appropriately adapted only with knowledge of the current burden. Such data can also help guide and predict future areas of risk and priorities to missing upcoming nutrition issues in the population. Renewed commitment to quantify and monitor micronutrient deficiencies in the region is essential. Abundant evidence and guidance exist to inform effective program selection, design and implementation to address this public health problem.

Integration of Steam Recovered from Molten Salts in a Solar Integrated Combined Cycle

In the current context of the energy transition, Integrated Solar Combined Cycle (ISCC) power plants are an alternative that are able to reduce carbon emissions from combined cycle (CC) power plants. In addition, the coupling to an energy storage system based on molten salts benefits hybridization, allowing the energy surplus to be to stored to cover peaks in energy demand. Because it is a recent technology, the determination of the optimal injection points for the solar-generated steam into the combined cycle is a critical issue. In this work, a thermodynamic model of a hybrid natural gas and solar thermal CC power plant has been developed using Thermoflex to analyze the integration effects in terms of efficiency and power. For all the steam injection candidate positions, the effects of ‘power boosting’ and ‘fuel saving’ operation modes have been simulated, considering operation conditions that are compatible with the useful range of molten salts. The results show that injection of steam at the high-pressure line before the steam turbine increases the cycle’s gross efficiency with respect to the reference case, estimating a reduction of carbon emissions of 6696 kg/h in the ‘fuel saving’ mode and an increase in gross power of 14.4 MW in the ‘power boosting’ mode. Hence, adapting current combined cycles for hybridization with solar power is a viable solution in the transition period towards more sustainable energy sources.

Hormetic Response of Photosystem II Function Induced by Nontoxic Calcium Hydroxide Nanoparticles

In recent years, inorganic nanoparticles, including calcium hydroxide nanoparticles [Ca Ca(OH)2 NPs], have attracted significant interest for their ability to impact plant photosynthesis and boost agricultural productivity. In this study, the effects of 15 and 30 mg L−1 oleylamine-coated calcium hydroxide nanoparticles [Ca(OH)2@OAm NPs] on photosystem II (PSII) photochemistry were investigated on tomato plants at their growth irradiance (GI) (580 μmol photons m−2 s−1) and at high irradiance (HI) (1000 μmol photons m−2 s−1). Ca(OH)2@OAm NPs synthesized via a microwave-assisted method revealed a crystallite size of 25 nm with 34% w/w of oleylamine coater, a hydrodynamic size of 145 nm, and a ζ-potential of 4 mV. Compared with the control plants (sprayed with distilled water), PSII efficiency in tomato plants sprayed with Ca(OH)2@OAm NPs declined as soon as 90 min after the spray, accompanied by a higher excess excitation energy at PSII. Nevertheless, after 72 h, the effective quantum yield of PSII electron transport (ΦPSII) in tomato plants sprayed with Ca(OH)2@OAm NPs enhanced due to both an increase in the fraction of open PSII reaction centers (qp) and to the enhancement in the excitation capture efficiency (Fv’/Fm’) of these centers. However, the decrease at the same time in non-photochemical quenching (NPQ) resulted in an increased generation of reactive oxygen species (ROS). It can be concluded that Ca(OH)2@OAm NPs, by effectively regulating the non-photochemical quenching (NPQ) mechanism, enhanced the electron transport rate (ETR) and decreased the excess excitation energy in tomato leaves. The delay in the enhancement of PSII photochemistry by the calcium hydroxide NPs was less at the GI than at the HI. The enhancement of PSII function by calcium hydroxide NPs is suggested to be triggered by the NPQ mechanism that intensifies ROS generation, which is considered to be beneficial. Calcium hydroxide nanoparticles, in less than 72 h, activated a ROS regulatory network of light energy partitioning signaling that enhanced PSII function. Therefore, synthesized Ca(OH)2@OAm NPs could potentially be used as photosynthetic biostimulants to enhance crop yields, pending further testing on other plant species.

A day‐ahead energy management strategy for electric vehicles in parking lots considering multi‐scenario simulations and hydrogen storage system

AbstractThis article investigated the charge and discharge management structure of electric vehicles (EVs) in intelligent parking lots (IPLs). It seems that with the expansion of renewable energy sources (RESs) as clean energy and investigation of the effects of EVs on the operation and planning of future distribution networks around the way EVs exchange energy with each other and the upstream network operator, RESs such as solar and wind sources, along with hydrogen storage are essential. Therefore, a new stochastic multi‐scenario approach for charge/discharge management of EVs parked in IPL was proposed, in which a newly developed model for the IPL with a hydrogen storage system (HSS) consisting of a fuel cell, an electrolyzer, and a hydrogen storage tank was presented. In the proposed model, the constraints of upstream network and power balance constraints, with the operating constraints related to the IPL, including EVs, renewable energy sources, and the hydrogen storage system, were formulated as the most important objectives of the optimization problem. The optimization algorithm, Competitive Swarm Optimizer (CSO), was formulated for implementation, and its results were compared with those of the PSO and GWO algorithms. The CSO must handle a variety of practical, large‐scale optimization problems. Based on the obtained results, the excess energy purchased from the upstream network or renewable sources was used as hydrogen storage for consumption during peak hours. As expected, the technical constraints and financial goals of the system were met, and the proposed system was evaluated on a 33‐bus network. As the expected benefits will be the most beneficial with the presence of renewable sources, the final profit will be reduced by taking into account uncertainty for charge/discharge management in EVs such as the uncertainty of electric load, market price, wind turbine, and photovoltaic cell sources. Nonetheless, the profit obtained from renewable resources is preferable to losses resulting from the uncertainty of the system, and according to expectation, the performance of the system for managing the optimal charging and discharging of EVs in the IPL will be acceptable with the maximum profit for the grid.

Effect of Planting Ground Treatments Using Artificial Rainfall Slope Simulating Degraded Forestland on Drought Stress Susceptibility of Pinus densiflora

Trees in degraded forest areas are generally exposed to water stress due to harsh environmental conditions, threatening their survival. This study simulated the environmental conditions of a degraded forest area by constructing an artificial rainfall slope and observing the physiological responses of Pinus densiflora to control, mulching, and waterbag treatments. P. densiflora exhibited distinct isohydric plant characteristics of reducing net photosynthetic rate and stomatal transpiration rate through regulating stomatal conductance in response to decreased soil moisture, particularly in the control and waterbag treatments. Additionally, the trees increased photochemical quenching, such as Y(NPQ), to dissipate excess energy as heat and minimize damage to the photosynthetic apparatus. However, these adaptive mechanisms have temporal limitations, necessitating appropriate measures. Under extreme drought stress (DS45), mulching treatment showed 4.5 times and 2.2 times higher in PIabs and SFIabs than in the control, and after the recovery period (R30), waterbag and mulching treatment showed similar levels, while PIabs and SFIabs in the control were only 45% and 75% of those in the mulching and waterbag treatments, respectively. Specifically, mulching extended the physiological mechanisms supporting survival by more than a week, making it the most effective method for enhancing the planting ground in degraded forest areas. Although the waterbag treatment was less effective than mulching treatment, it still significantly contributed to forming better growth conditions compared to the control. These findings highlight the potential for mulching and waterbag treatments to enhance forest restoration efforts, suggesting future research and application could lead to more resilient reforested areas capable of withstanding climate change-induced drought conditions.

Optimization of microgrid operations using renewable energy sources

Microgrids, comprising localized energy systems capable of operating independently or in conjunction with the main grid, are increasingly being recognized as vital components of modern energy infrastructure. The integration of renewable energy sources (RES) into microgrids offers significant potential for enhancing operational efficiency, sustainability, and resilience. This paper presents an overview of recent advancements and methodologies for optimizing microgrid operations utilizing renewable energy sources. The optimization of microgrid operations involves the strategic coordination and management of diverse energy resources, including solar photovoltaic (PV) systems, wind turbines, and energy storage systems (ESS). Key objectives include minimizing operational costs, reducing greenhouse gas emissions, ensuring reliable power supply, and maintaining system stability. Advanced optimization techniques, such as model predictive control (MPC), mixed-integer linear programming (MILP), and heuristic algorithms, play a crucial role in achieving these objectives by enabling the dynamic adjustment of energy generation and distribution in response to real-time conditions. A critical aspect of microgrid optimization is the accurate forecasting of renewable energy generation and load demand. Machine learning (ML) and artificial intelligence (AI) algorithms have been effectively employed to enhance prediction accuracy, thereby improving decision-making processes. Furthermore, the integration of ESS, such as batteries and flywheels, helps to address the intermittency of RES, providing a buffer that can store excess energy during periods of high generation and release it during peak demand. The implementation of demand response (DR) strategies within microgrids further contributes to optimization efforts. By incentivizing consumers to adjust their energy usage patterns in response to price signals or grid needs, DR programs help to balance supply and demand, reduce peak loads, and enhance overall grid reliability. Case studies and field implementations demonstrate the practical benefits of optimized microgrid operations. For instance, microgrids incorporating high shares of RES have been shown to achieve significant cost savings, improved energy security, and reduced environmental impacts. These successes underline the importance of ongoing research and development in optimization techniques and the need for supportive policy frameworks to facilitate the broader adoption of microgrids. In conclusion, optimizing microgrid operations using renewable energy sources presents a promising pathway toward a more sustainable and resilient energy future. Continued advancements in optimization algorithms, predictive analytics, and integrated system design are essential for unlocking the full potential of microgrids, ensuring they can effectively meet the evolving energy demands and environmental challenges of the 21st century. Keywords: Optimization, Microgrid, Operations, Renewable Energy, Energy Sources.

Molecular events accompanying aggregation-induced energy quenching in fucoxanthin-chlorophyll proteins

In high light, the antenna system in oxygenic photosynthetic organisms switches to a photoprotective mode, dissipating excess energy in a process called non-photochemical quenching (NPQ). Diatoms exhibit very efficient NPQ, accompanied by a xanthophyll cycle in which diadinoxanthin is de-epoxidized into diatoxanthin. Diatoms accumulate pigments from this cycle in high light, and exhibit faster and more pronounced NPQ. The mechanisms underlying NPQ in diatoms remain unclear, but it can be mimicked by aggregation of their isolated light-harvesting complexes, FCP (fucoxanthin chlorophyll-a/c protein). We assess this model system by resonance Raman measurements of two peripheral FCPs, trimeric FCPa and nonameric FCPb, isolated from high- and low-light-adapted cells (LL,HL). Quenching is associated with a reorganisation of these proteins, affecting the conformation of their bound carotenoids, and in a manner which is highly dependent on the protein considered. FCPa from LL diatoms exhibits significant changes in diadinoxanthin structure, together with a smaller conformational change of at least one fucoxanthin. For these LL-FCPa, quenching is associated with consecutive events, displaying distinct spectral signatures, and its amplitude correlates with the planarity of the diadinoxanthin structure. HL-FCPa aggregation is associated with a change in planarity of a 515-nm-absorbing fucoxanthin, and, to a lesser extent, of diadinoxanthin. Finally, in FCPb, a blue-absorbing fucoxanthin is primarily affected. FCPs thus possess a plastic structure, undergoing several conformational changes upon aggregation, dependent upon their precise composition and structure. NPQ in diatoms may therefore arise from a combination of structural changes, dependent on the environment the cells are adapted to.

A multi-objective collaborative planning method for a PV-powered hybrid energy system considering source-load matching

A hybrid system including photovoltaic panels, an air-source heat pump, batteries, and a hot water tank is proposed to satisfy the building’s demands. To discover the optimal energy scheduling scheme, a multi-objective two-stage planning method is developed. In the first stage, considering the seasonal fluctuations of photovoltaic power and the loads, several operation modes are designed. Moreover, the influence of objective functions with and without the energy self-consumption (SCR) and self-sufficiency rate (SSR) on the system configuration is analyzed. The second stage aims to explore the synergetic benefits with demand response, in which the hourly loads are reconstructed accounting for the municipal tariffs. The results show that when accounting for the annual cost (AC) and primary energy (PE), the ideal operation mode is as follows: favor thermal storage during periods of energy surplus and prioritize discharging electricity in winter and heat in summer in cases of insufficient power. When considering the SCR and SSR additionally, storing heat in summer with charging batteries in winter is preferred when excess energy is available. Otherwise, give priority to thermal storage. Furthermore, based on the proposed energy scheduling scheme, the AC, PE, SCR, and SSR are improved by −31.1 %, −19.4 %, +1.5 %, and +11.3 %, respectively.

A hybrid building-integrated solar-powered anaerobic digestion system: Energy, economic, and environmental analysis in Morocco

In this study, we propose a hybrid solar-anaerobic digestion system for a cleaner energy in the building sector. This system offers sustainable treatment of organic waste, utilizing waste generated by residential buildings. We conducted an investigation into the energy, economic, and environmental aspects of integrating a hybrid solar anaerobic digester treating kitchen waste (KW) and blackwater (BW) into Moroccan residential buildings under different climatic conditions. Two building categories were considered: buildings compliant with Moroccan thermal regulations of construction (MTRC), and non-compliant buildings, which represent the majority in Morocco. Results indicate that the proposed hybrid system, utilizing only waste generated by the building, can, on average, satisfy approximately 26 % of the total heating, cooling, and electricity needs of the considered MTRC non-compliant buildings. As for the MTRC compliant buildings, about 30 % of the total energy needs are met. Simulation outcomes also demonstrate that increasing the quantity of organic waste enhances system autonomy, allowing it to meet 100 % of the energy demand of the studied buildings. Excess heat energy generated by the hybrid system was allocated to the buildings' thermal and domestic hot water demands. Furthermore, the study highlights the significant influence of fixed costs and waste quantity on the system's profitability. Environmental benefits were also evident, with the designed hybrid system reducing CO2 emissions by 66 % compared to using grid electricity.

Physico-chemical studies of non-aqueous binary liquid mixtures of N-methyl aniline with amino alcohols at various temperatures

ABSTRACT Densities (ρ), speeds of sound (u) and viscosities (η) for three binary mixtures of N-methyl aniline with amino alcohols (3-amino-propan-1-ol, 2-amino-2-methyl-propan-1-ol and 1-amino propan-2-ol) were measured at temperatures ranging from 303.15 to 313.15 K and at atmospheric pressure across the entire composition range. Excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of activation of viscous flow were calculated using experimental data. Partial molar properties and infinite dilution molar partial properties were also determined for each binary system. The Prigogine-Flory-Patterson theory is used to identify the most important interaction. The results of the Jouyban-Acree model are discussed in terms of the mean relative deviation and individual relative deviation between the calculated and experimental densities, speed of sound, and viscosities as an accuracy criterion. FTIR studies have also been added to confirm the experimental findings of the investigated mixtures.

Modern view of the problem: the influence of obesity as a key component of metabolic syndrome on the development and progression of endometrial cancer

Unlike many other malignancies, the incidence and mortality of endometrial cancer continues to rise. This unfortunate trend is in no small part the result of the worldwide obesity epidemic, which is caused by reduced physical activity, poor diet and chronic stress. Currently, more than 50 % of endometrial cancer cases are associated with obesity, which is recognized as an independent risk factor for the development of this disease. Adipose tissue is not only the main place of storage of excess energy, but also a full-fledged endocrine organ that affects the metabolism, immune response and production of biologically active substances involved in cell growth and differentiation, angiogenesis, apoptosis and carcinogenesis. In this review, we assess the impact of obesity as a key component of metabolic syndrome on the development and progression of endometrial cancer. There are several mechanisms by which obesity enlarges the risk of endometrial cancer, including increased endogenous sex steroid hormones, hyperglycemia, insulin resistance, adipokine secretion, and chronic inflammation. The purpose of this review is to analyze publications, reflecting the already known aspects of the biological effect of obesity, as well as new data from recent years.

Numerical analysis of hydrogen storage in lined rock cavern under high pressure and its implications to hydrogen embrittlement

Underground hydrogen storage could provide buffer capacity to store the excess energy from renewable resources. A lined rock cavern (LRC) is one of the hydrogen geologic storage site options. It offers great flexibility because it does not rely on the existence of salt caverns, aquifer formations or depleted hydrocarbon reservoir fields. However, many important aspects have to be investigated before its full-scale implementation, among them (1) the effect of spatial variation of rock mass properties and (2) hydrogen embrittlement on the steel lining. We present a numerical study on these two aspects by simulating field tests at a pilot LRC project. For the effect of rock heterogeneity, we assign a spatial variation of elastic properties based on the Gaussian covariance model. The results show a good agreement with the field measurements. The spatial correlation length of rock mass elastic properties only has a minor impact on the cavern surface deformation. Regarding hydrogen embrittlement, our simulations predict a significant hydrogen diffusion in the low alloy steel (S355) lining after ∼2 months of operation. The fracture simulations show little fracture propagation even after 10 years of contact with hydrogen gas. However, the product loss may be too high for the low alloy steel (S355). We would recommend the use of stainless steel to inhibit the hydrogen diffusion. We show that advanced numerical models are powerful tools to ensure the safety of hydrogen storage in LRCs.

Control of Grid-Connected and Standalone Microhydraulic Turbine Using a Six-Phase Induction Generator

Microhydraulic turbines offer a promising solution for decentralized energy production, suitable for both grid-connected and standalone applications, due to their compactness and high efficiency. This paper introduces a control approach for such systems employing microhydraulic turbines as distributed generators (DGs), utilizing six-phase induction generators for electricity production. This study emphasizes control strategies for both grid-connected and standalone modes utilizing proportional-integral (PI) controllers. An integrated energy storage system based on Li-Ion battery technology is also implemented to store the excess energy and compensate for production deficits to meet demand. The results obtained using MATLAB/Simulink demonstrate efficient and reliable power management among production sources, the grid and the local load, highlighting the unique contribution of employing a six-phase induction generator with the energy storage system.

A Comparison of the Effects of Continuous Illumination and Day/Night Regimes on PHB Accumulation in Synechocystis Cells.

Poly(3-hydroxybutyrate) (PHB) is a biobased and biodegradable polymer with properties comparable to polypropylene and therefore has the potential to replace conventional plastics. PHB is intracellularly accumulated by prokaryotic organisms. For the cells PHB functions manly as carbon and energy source, but all possible functions of PHB are still not known. Synechocystis (cyanobacteria) accumulates PHB using light as energy and CO2 as carbon source. The main trigger for PHB accumulation in cyanobacteria is nitrogen and phosphorous depletion with simultaneous surplus of carbon and energy. For the above reasons, obtaining knowledge about external factors influencing PHB accumulation is of highest interest. This study compares the effect of continuous light exposure and day/night (16/8 h) cycles on selected physiology parameters of three Synechocystis strains. We show that continuous illumination at moderate light intensities leads to an increased PHB accumulation in Synechocystis salina CCALA 192 (max. 14.2% CDW - cell dry weight) compared to day/night cycles (3.7% CDW). In addition to PHB content, glycogen and cell size increased, while cell density and cell viability decreased. The results offer new approaches for further studies to gain deeper insights into the role of PHB in cyanobacteria to obtain bioplastics in a more sustainable and environmentally friendly way.