Public Electricity Grid Research Articles

منازل تولد الطاقة المتجددة كحل مستدام لتلبية احتياجات الطاقة المنزلية في ليبيا

This study provides an overview of surplus energy-generating homes for integration with the public electricity grid and its potential for spatial development in Libya. With a special focus on the idea of a surplus energy-generating home, in addition to the study, the basic components of a solar home system are solar panels and the conversion of building glass panels into solar power generators. The performance of housing and its occupants, especially the sustainable development aspects. Then, research and present the most important proposals for the installation of home photovoltaic roofs that generate surplus energy as a guaranteed way to meet the home's energy needs, achieve economic and environmental gains for its occupants, and contribute to sustainable development. Keywords: Solar system, grid integration, sustainable development, home photovoltaic roofs, Smart homes.

Performance Improvement of an Electric Vehicle Charging Station Using Brain Emotional Learning-Based Intelligent Control

Electric vehicle (EV) charging facilities are essential to their development and deployment. These days, autonomous microgrids that use renewable energy resources to energize charging stations for electric vehicles alleviate pressure on the public electricity grid. Nevertheless, controlling and managing such charging stations’ energy is difficult due to the nonlinearity and irregular character of renewable energy sources. The current research recommends using a Brain Emotional Learning Intelligent Control (BELBIC) controller to enhance an autonomous EV charging station’s performance and power management. The charging station uses a battery to store energy and is primarily powered by photovoltaic (PV) solar energy. The principles of BELBIC are dependent on emotional cues and sensory inputs, and they are based on an emotion processing system in the brain. Noise and parameter variations do not affect this kind of controller. In this study, the performance of a conventional proportional–integral (PI) controller and the suggested BELBIC controller is evaluated for variations in solar insolation. The various parts of an EV charging station are simulated and modelled by the MATLAB/Simulink framework. The findings show that, in comparison to the conventional PI controller, the suggested BELBIC controller greatly enhances the transient responsiveness of the EV charging station’s performance. The EV keeps charging while the storage battery perfectly saves and keeps steady variations in PV power, even in the face of any PV insolation disturbances. The suggested system’s simulation results are provided and scrutinized to confirm the concept’s suitability. The findings validate the robustness of the suggested BELBIC control versus parameter variations.

Analysis for the Implementation of Distributed Renewable Energy Generation Systems for Areas of High Vulnerability Due to Hillside Movements: Case Study of Marianza-Cuenca, Ecuador

This research presents a renewable energy system that takes advantage of the energy potential available in the territory. This study emerges as a relevant option to provide solutions to geological risk areas where there are buildings that, due to emergency situations at certain times of the year during deep winter, are a target of danger and where its inhabitants would find it difficult to abandon their properties. The record of mass movements covering the city of Cuenca-Ecuador and part of the province has shown that the main triggering factor of this type of movement comprises the geological characteristics of tertiary formations characterized by lithological components that become unstable in the presence of water and due to their slopes being pronounced. Hybrid systems are effective solutions in distributed electricity generation, especially when it comes to helping people and their buildings in times of great need and the required electricity generation is basic. A hybrid photovoltaic, wind and hydrokinetic system has been designed that supplies electrical energy to a specific area on the opposite geographical side that is completely safe. The renewable energy system is connected to the public electricity grid available on site; however, in the event of an emergency the grid is disconnected for safety and only the hybrid system will work with the support of a battery backup system. In this study, the Homer Pro simulation tool was used and its results indicate that renewable systems that include PV, HKT and WT elements are economically viable, with a COE of USD 0.89/kWh.

Review paper on Green Hydrogen Production, Storage, and Utilization Techniques in Libya

the world is currently facing energy-related challenges due to the cost and pollution of non-renewable energy sources and the increasing power demand from renewable energy sources. Green hydrogen is a promising solution in Libya for converting renewable energy into usable fuel. This paper covers the types of hydrogen, its features, preparation methods, and uses. Green hydrogen production is still limited in the world due to safety requirements because hydrogen has a relatively low ignition temperature and an extensive ignition range and is considered a hazardous element, the lack of infrastructure in Libya, as well as the high cost of production currently. However, the production costs of one megawatt of green hydrogen and fossil fuels are insignificant. This suggests that electricity production from green hydrogen could become an economic competitor to fossil fuels in Libya. This is due to the cost of adding renewable energy to the public electricity grid. Also, the production of gray hydrogen is possible in Libya because of oil through the installation of systems for converting methane gas and capturing carbon dioxide gas.

Boil-off recovery system for natural gas stations: an approach to increase energy efficiency and reduce greenhouse gases

AbstractImproving the efficiency of energy use is of utmost importance in the context of climate change. Indeed, greater efficiency in the end-use of energy will make a significant contribution to lowering primary energy consumption and reducing CO2 and other greenhouse gas emissions. This paper presents an approach that enables a compact liquefied natural gas station to operate without being connected to the public electric grid. It is achieved by using the Boil-off gas generated by the vehicle supply process and feeding it to a generator which, together with a photovoltaic (PV) system, can produce electrical energy. Results from a year of trial operations at the station in Escariz, Portugal, demonstrate that it is possible to recover an average of 8.66 kg of Boil-off gas daily while generating a 345% excess of electrical energy when combined with the PV system, enabling the station to be self-sustainable in terms of electricity. Based on the experimental data and calculation methodology, the project was able to earn an estimated monthly revenue of €176.27 throughout the study period while also preventing the emission of 8549 kg of CO2 equivalent from natural gas combustion in vehicles.

Sustainable photovoltaic based protective environment controlled farming technology as economy boosters for agro-sectors

In view of boosting the agro-economy of low-income group of farmers, a design initiative and its field validation for photovoltaic based protected environment-controlled farming technology (PV_PECFT) is important, especially for farms without access to the public electricity grid. This paper presents for the first time the PV_PECFT concept with adequate automation having three segments: (a) Agro-process automation embedded in a microcontroller with opto-isolated interfaced sensors with the functionality of managing boundary-based value-control. (b) Unique control algorithm for load-based strategic PV array switching and power control for minimized electrical and thermal losses by adapting add on modular hardware (AOMH) concept. It enables maximum power point operation for maximized energy yield from PV arrays inclined in opposite direction at the rooftop of a hut structure. (c) An energy equilibrium state monitoring index (E2SMI) based model is attempted for energy saving during inside climate control via opto-isolated Si-MOSFET based hardware against external non-linear variation of weather conditions. This PV_PECFT concept has been validated for 97 days; considering criteria of crop leaf area index comparison in the field tried experimental prototype and that in an open land field (1.44 to 1.58 times higher) and comes out with a low budget farming, yet high-tech, scalable technology for a targeted size of the farm with special focus on ease of operation and handling in cultivation.

Household access to the public electricity grid in Cameroon: Analysis of connection determinants

This article empirically examines the determinants of household access to the public electricity grid in Cameroon, using data from a survey conducted by NIS (2014) on a sample of 46560 households. The key findings reveal that social class, housing tenure, education level, area of dwelling, and distance to the electric pole all have a substantial (p 0.001) influence on public grid connection. According to multinomial logistic regression estimates, the main significant predictors of individual connection to the public grid are: residing in a villa (43.27%), higher education (34.91%), and home ownership (34.27%). Furthermore, the main significant predictors of connection without a personal subscription or through intermediaries are: residing in a concession area (42.44%), living in the western region (35.13%), and poverty (25.60%). Finally, the male gender (15.55%) and the home's distance from the electric pole of more than 8 m (9.24%) are the primary predictors of direct connections without a meter. Our findings suggest that increasing the household's access to its own housing and increasing educational attainment could raise formal demand for individual grid subscriptions. Increased investment in electricity distribution infrastructure, particularly in outlying areas, would also benefit public authorities.

Energy Use Efficiency and Carbon Footprint of Greenhouse Hydroponic Cultivation Using Public Grid and PVs as Energy Providers

As the greenhouse cultivation industry considers new ways to reduce energy demand and increase sustainable production, the global energy crisis constitutes a major issue. In this paper, two different energy sources for heating and cooling the root zone area of baby leafy vegetables grown in hydroponic tanks by resistors and chillers, respectively, were compared in order to fully cover power demand. The energy needs in the first case were met by the public electricity grid, while in the second case, the energy needs were covered by a photovoltaic system. The greenhouse was equipped with photovoltaic panels, an inverter, a charge controller and a storage system. The target-value of the root zone temperature was 22 °C. Data on solar radiation, root zone temperature, air temperature and humidity from the indoor and outdoor space of the greenhouse were recorded, and the energy production and carbon footprint for different seasons of the year were evaluated along with the crop yield. The results showed that the energy provided by solar panels was able to cover 58.0%, 83.3% and 9.6% of the energy for heating or cooling the root zone area during the spring, summer and winter periods, respectively. Regarding the carbon footprint of the energy used between the two systems, the system with the PV had a substantially lower value, which was calculated at 1.6 kg CO2-eq kg−1, compared to 49.9 kg CO2-eq kg−1 for the system with PPG for the whole year.

Decentralised multi-grid coupling for energy supply of a hybrid bus depot using mixed-integer linear programming

The present work refers to two current problems in the context of achieving Greenhouse gas (GHG) neutrality: first the curtailment of renewable, volatile power generation units and secondly the high share of the mobility domain in total GHG-emissions. Both problems can be countered by a decentralised, smart energy system that supplies electricity, gas and heat to a hybrid public transport bus fleet and is simultaneously coupled to the public gas grid, public electricity grid and the district heating grid (Multi-Grid-Coupling). The enabling energy conversion unit is a reversible solid oxide cell (rSOC), which is operated in combined heat and power (CHP) mode or in power-to-gas (P2G) mode. P2G is primarily a solution approach for the first-mentioned problem and can thus successively lead to the replacement of fossil energy sources. Furthermore, by integrating industrial waste gases – as a necessary CO2 source for the P2G process – an additional benefit is gained from the CO2 that is emitted anyhow. The hybrid bus fleet constitutes an ecological alternative concept in public transport and therefore addresses the second-mentioned problem. The system, developed under the current state of the art technologies and the current ecological and economic conditions for Europe and Germany, can be operated profitably from the perspective of the system operator. This applies to the economically and ecologically optimised operating schedule of the controllable system elements such as the electrical, thermal and compressed gas storages, rSOC, compressor and the energy exchange with the public grids. To derive the optimal operating schedule of the cross-sectoral system, a mixed-integer linear programming (MILP) model is implemented and simulated under the current legal situation.

An integrated energy management system using double deep Q-learning and energy storage equipment to reduce energy cost in manufacturing under real-time pricing condition: A case study of scale-model factory

Reducing energy costs is an emerging aspect in the research on the economic and environmental dimensions of manufacturing systems. The share of electricity cost accounts for approximately 60 % of the total energy cost of a manufacturing system, whereas the share of oil, coal, and gas accounts for the remaining 40 %. The electricity cost is dependent on the electricity price and usage. In terms of the electricity price, one of the pricing strategies widely used in the USA and Europe is called real-time pricing (RTP), which is characterised by hourly price changes. Compared to other pricing strategies, RTP yields the highest reward and the highest risk. In the RTP strategy, the electricity price is influenced by the supply and demand of the energy market. Hence, the energy cost of manufacturing cannot be determined by the manufacturing companies, implying a high level of risk. However, if manufacturing companies seize the opportunity to perform more manufacturing tasks when the energy price is low, the cost-savings will be significant, implying a high level of reward. In this study, we propose an integrated energy management system (IEMS) to reduce the energy cost of manufacturing systems. The IEMS consists of an energy storage equipment and an intelligent switch mechanism. When the electricity price is high, the manufacturing system is powered by the energy storage equipment. When the electricity price is low, the manufacturing system is powered by the public electricity grid, and the energy storage equipment is charged. The decision-making of these operations is performed by the intelligent switch mechanism based on double deep Q-learning. To validate this framework, a case study is conducted, in which an IEMS is developed to reduce the electricity cost of a scale-model factory. Based on an online test of the IEMS in different manufacturing cycles, it is concluded that the proposed IEMS approach achieves a cost reduction of approximately 57.21 %.

Transition towards a full self-sufficiency through PV systems integration for sub-Saharan Africa: a technical approach for a smart blockchain-based mini-grid

Access to affordable, reliable and clean energy is an important sustainability goal of the United Nations. In areas where the public electricity grid is unreliable or unavailable, photovoltaic systems can be a solution. However, they are cost-intensive, mainly because of the energy storage systems. Mini-grids can be an answer for reducing upfront investment and overall system lifetime costs while increasing electricity availability. The mini-grid technology is mature, nevertheless, there are downsides when it comes to integrating existing solar systems of different manufacturers. The system topology is usually predefined and a central instance controls the mini-grid. Thus, the integration of existing power systems is difficult due to the communication constraints of these systems with the mini-grid controller. Including existing power systems into a decentralized mini-grid, can highly increase cost-efficiency. In a decentralized approach payments for the consumed energy between mini-grid actors are required. Accounting is, however, a complex administrative procedure, if the respective power systems are owned by different individuals and organizations. A transparent blockchain-based temper-proof approach can be a solution to automate metering and billing, allowing automatic payments between independent subsystem owners using smart contracts. In order to further optimize the smart mini-grid, an artificial intelligence learning algorithm for a dynamic electricity price needs to be developed. This smart and decentralized approach for building Mini-Grids is a novelty bringing solar systems one step closer to self-sufficiency. This paper describes how a smart mini-grid solution can be implemented using the Don Bosco Solar & Renewable Energy Center campus mini-grid in Tema, Ghana as a case study.

A practical method to design the solar photovoltaic system applied on residential building in Indonesia

The use of solar PV system in Indonesia has expanded to various field and area. One example is residential buildings in urban areas. This article discusses calculation methods for designing a solar power generation system that is applied to residential buildings, such as homes, offices, or colleges. Electricity generated from the solar home system (SHS) is used to support many kinds of electrical equipments, where the electrical equipments are used by building occupants in their daily life. The calculation method is considered from the potential of solar energy and the reliability of the on-site system to generate electricity. The system is designed in an off-grid topology by exchanging connections with the public electricity grid owned by PLN. Calculation results shows that this SHS has a generation capacity of 1 kWp, 24 V 300 Ah battery storage, and a 200 W inverter. This SHS can reduce electricity usage in this sector by 18.2 kWh in average every month.

Modelling of Consumption Shares for Small Wind Energy Prosumers

This article describes a simulation of energy distribution in an average household where electricity is produced with a small wind generator or purchased from the public electricity grid. Numerical experiments conducted within an average of five minutes were performed using annual production and consumption graphs. Virtual storage devices, a water tank and a battery were used to buffer energy inside the household. The energy required for non-shiftable consumption and hot water consumption were taken directly from the utility grid. Surplus energy remaining from wind generator production after providing for consumption and storage needs were redirected there. A cover factor was used as a measure of the efficiency of energy distribution. One of the aims of the article was to determine by simulations the change of the cover factor in a virtually designed situation where the expected energy output of the wind generator was known in advance over one to three hours. The results found that for the configuration of the proposed nanogrid option, the positive results were readily achieved when the expected wind generator production was known an hour ahead. Then, the cover factor increased from 0.593 to 0.645. The side result of using projected/expected production is an increase in asymmetrical energy exchanges bilaterally between nanogrid and utility grid in favour of grid sales. Another finding was that the cover factor depended on the wind generator’s production intensity but less on the intensity of consumption within the household.It is hoped/expected that future research will address the prediction of output using mathematical methods.

ASSiST - A Superconducting Fault Current Limiter in a Public Electric Power Grid

For installation in the public electric power grid of the city of Augsburg, Germany, a resistive superconducting fault current limiter (SFCL) was designed, constructed, tested and operated in the framework of a partially funded project ‘ASSiST’. Right from the beginning, it was agreed to aim for a prolonged operation even after closure of the project. This endeavor has been started due to a fundamental need to limit the prospective fault currents at a feeder point of the grid and in order to create long-term operational experience on a device seamlessly integrated into commercial grid components and switchgear, thus demonstrating a high level of readiness for widespread application. It revealed that the SFCL was of robust design – withstanding all electrical tests including a special two-phase fault and sustaining stable cryogenic conditions even during partial outages of the cooling system – and that the technology is reducing loss by shunt reactors. Furthermore, due to the control equipment on medium voltage level, valuable insights on grid behavior could be gained. The extended operation for 4 years has clearly shown the performance and robustness of SFCL technology in feeder points on MV level and provides a reference point for further commercialization.

Serverless distributed learning for smart grid analytics* *Project supported by the National Natural Science Foundation of China (Grant Nos. 52007173 and U19B2042), Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ20E070002), and Zhejiang Lab’s Talent Fund for Young Professionals (Grant No. 2020KB0AA01).

The digitization, informatization, and intelligentization of physical systems require strong support from big data analysis. However, due to restrictions on data security and privacy and concerns about the cost of big data collection, transmission, and storage, it is difficult to do data aggregation in real-world power systems, which directly retards the effective implementation of smart grid analytics. Federated learning, an advanced distributed learning method proposed by Google, seems a promising solution to the above issues. Nevertheless, it relies on a server node to complete model aggregation and the framework is limited to scenarios where data are independent and identically distributed. Thus, we here propose a serverless distributed learning platform based on blockchain to solve the above two issues. In the proposed platform, the task of machine learning is performed according to smart contracts, and encrypted models are aggregated via a mechanism of knowledge distillation. Through this proposed method, a server node is no longer required and the learning ability is no longer limited to independent and identically distributed scenarios. Experiments on a public electrical grid dataset will verify the effectiveness of the proposed approach.

Evaluation of the cost-effectiveness of grid-connected photovoltaic solar energy in wineries

The objective of this study was to analyze the cost-effectiveness of photovoltaic (PV) solar energy in wineries. The factors analysed were solar radiation, cost of PV installation, prices in the public electricity grid, size of the winery, power of installed panels, influence of the decreased consumption during weekends, and seasonality in the consumption. The study has been based on the European TESLA project, in which 39 energy audits were carried out in wineries in four European countries. A winery of 30,000 hL/year was characterized as a representative winery. The results showed that seasonality was key in the profitability of the system for self-consumption, related to the optimum power to be installed of PV. It was recommended to install, as an optimal PV power, the stable electrical power that is demanded in the daytime period. Optimizing the installed power of PV panels in the representative winery, the percentage of electrical energy consumption covered by photovoltaic energy varied between 16% and 22%. The percentage of the cost of electric energy covered varied between 18% and 24%, with payback values between 18 years (3.1 peak sun hours of solar radiation -PSH) and 10 years (5.6 peak sun hours of solar radiation - PSH). All the factors involved were analyzed.

Modeling and Simulation of a Hybrid System of Solar Panels and Wind Turbines for the Supply of Autonomous Electrical Energy to Organic Architectures

In this research, the modeling, simulation, and analysis of the energy conversion equations that describe the behavior of a hybrid photovoltaic and wind turbine system that supplies electrical energy to an average organic architecture is performed. Organic constructions have a philosophy that seeks to understand and integrate into the site, taking advantage of the natural potentials and their resources of the surrounding areas so that they form part of a unified and correlated composition. The rooms in these buildings are designed similar to a bean, inspired by the uterus of a mother and her child who are comfortable, at rest, and alive. We are left with the task of spreading this research to integrate its energy potential from the surroundings and transform it into autonomous electrical energy. In this article, a numerical model based on the fundamental equations was developed and coded, and the results compared with experimental data with a real airplane-type system located in a remote area of Ecuador. The model is intended to be used as an optimization and design tool for such hybrid systems applied to organic constructions. After an error analysis it was determined that this model predicted quite interesting results compared to the experimental data under various conditions. It is important to indicate that this analysis has been carried out so that in the future, these power generation systems can be exploited and applied more efficiently in areas far from the public electricity grid.

Evaluation of indoor environment and energy performance of dwellings in heritage buildings. The case of hot summers in historic cities in Mediterranean Europe

The potential benefits for making the historic buildings of heritage cities non-polluting and energy efficient have only recently stirred the interest of researchers and policy makers in facing the necessary challenges. In southern Europe, most of these buildings are residential and are mainly listed at low grades of protection, allowing for significant transformation.This article quantitatively evaluates the indoor environment and energy performance of the residential heritage building stock under the severe summer conditions characteristic of the Mediterranean climate zone. The historic centre of Seville (Andalusia, Spain) is used as a case study. Three dwellings located in representative listed buildings within its conservation area were monitored and analysed taking occupant behaviour into account. The findings show that many dwellings may lack thermal comfort conditions, which cannot always be guaranteed by passive strategies alone. In addition, these buildings are more polluting than recently constructed ones because they depend entirely for their energy supply on the public electricity grid. Interestingly, in most cases reducing the mechanical cooling demand would not require intrusive physical interventions, but would largely rely on suitable window shading and nightly natural ventilation when outdoor conditions allow.

Residential Energy Supply Concept with Integration of Renewable Energies and Energy Storage

AbstractRenewable energies are gaining importance in urban management and in the planning of new residential and mixed‐use areas. Attention is also paid to self‐sufficiency, as the public electrical grid is strained through the integration of renewables. Here, an energy supply concept for an urban residential area in the planning phase is discussed to meet both economic and ecologic criteria. Based on the demand, different technical options are analyzed. The integration of renewables is coupled with energy storage to increase the self‐sufficiency of the residential area. The economic feasibility of the energy supply concept depends on the requirements to be met as well as the regulatory framework. With the currently available technology and the regulatory framework in place, self‐sufficiency and economic feasibility are opposing targets.

A novel paradigm for a sustainable mobility based on electric vehicles, photovoltaic panels and electric energy storage systems: Case studies for Naples and Salerno (Italy)

The paper presents an in-depth analysis of a novel scheme for the sustainable mobility, based on electric vehicles, photovoltaic energy and electric energy storage systems. The work aims to analyse such innovative system, putting in evidence its advantages in comparison to a conventional one, based on the grid-to-vehicle technology. The study also provides interesting guidelines for potential users and system designers. Two case studies are presented: i) the taxi fleet of the city centre of Naples and ii) the cargo vans of the city of Salerno; both towns are in Southern Italy. For each case, the hourly power consumption of the vehicles was evaluated, as a function of the daily trip length. An accurate procedure was implemented to select the sites suitable for the installation of the charging stations, including a photovoltaic field and an electric storage system. A comparison was also performed between two different electric storage technologies: lead-acid and lithium-ion battery. The case studies were analysed by means of a detailed dynamic simulation model, developed in TRNSYS. A sensitivity analysis was also performed, to evaluate how different values of the most important design and operating parameters affect the system overall performance. It was found that the results are mostly affected by solar field area, capacity of the energy storage system and investment cost. The comparison between the two selected storage technologies did not exhibit significant differences. For both the cases investigated, it was found that, during the summer, solar energy covers an important amount of the total energy demand. On the contrary, in winter the amount of energy provided by the public electric grid was high. From an economic point of view, assuming a lithium-ion battery capital cost equal to 90 €/kWh, acceptable pay-back periods (about 6 years) were obtained, for both the applications considered.