Peak Load Requirements Research Articles

An extensive qualitative and quantitative multi criteria analysis for a hybrid renewable energy system applied to tribal zone - based primary health centres, and maximizing the societal parameters

Remote electrification enhances the quality of life quality of people in remote areas, with no access to electricity through distributed coverage of electricity. Due to the irregular and unbalanced fuel cost and impracticable expansion of the grid, hybrid integrated renewable energy sources become dependable substitute for remote electrification. The necessity of uninterrupted power dispatch is a prime factor for primary health centres, located in tribal and remote areas. This article proposes an integrated primary analysis like financial, production, quantity and environmental, applied to an optimum sizing of a hybrid standalone renewable energy source, which might be carried out in eight primary health centres, situated in the Gudalur Zone in Nilgiris District, Tamil Nadu, India. Four different criteria were inspected in this study, as standard loading, boost up loading, step down loading and complete renewable loading. In addition, every criterion was assessed with four kinds of PV tracking arrangements. The peak load requirement of power and energy, for eight primary health centres, was around 121.08 kW and 907.96 kWh/day respectively. HOMER Pro Micro-grid Analysis Tool was used, to analyze the different primary parameters of this study. The foremost financial parameters like COE (Cost of Energy) and NPC (Net Present Cost), could range from 0.102 to 0.118 $ per kWh and from 0.4047 to 0.5708 Million $ respectively. Annual energy production of solar PV could vary from 318.5 to 427.65 MWh. The main quantity parameter like percentage of excess electricity was obtained from 13.3 to 21.5% annually. The leading emission parameters like CO2 and CO were reported to range from 1700 to 4502 and from 7.98 to 28.1 kg per year respectively. Generator and fuel parameters, key properties of energy storage and converter, were also analyzed extensively. In addition, sensitivity analysis and social parameters were also discussed in this study. The result of this work gives a conceptual and flexible design of structure, to make possible the continuous power supply to the remote tribal area - based primary health centres, under in all situations.

Design Optimization of a Grid-Tied Hybrid System for a Department at a University with a Dispatch Strategy-Based Assessment

In this research project, the optimal design and design evaluation of a hybrid microgrid based on solar photovoltaics, wind turbines, batteries, and diesel generators were performed. The conventional grid-tied mode was used in addition to dispatch strategy-based control. The study’s test location was the loads in the Electrical, Electronic and Communication Engineering (EECE) department at Pabna University of Science and Technology (PUST), Pabna, Bangladesh. DIgSILENT PowerFactory was employed to determine the power system-based behaviors (electrical power, current, voltage, and frequency) of the proposed hybrid system, while a derivative-free algorithm was used for the expense, optimal size, and emission assessments. While developing the microgrid, load following (LoF) and cycle charging (CyC) control were employed. The microgrid is supposed to have a 23.31 kW peak load requirement. The estimated microgrid’s levelized cost of energy (LE), its net present cost (NC), its operating cost, and its annual harmful gas emissions were estimated in this work. Additionally, since the microgrid is grid-connected, the amount of energy output that might be exported to the grid was also estimated, which will potentially increase during blackouts. The power system responses found in this study ensure that the various microgrid components’ voltage, frequency, current, and power outcomes are steady within the designated range, making the microgrid practical and robust.

An integrated framework for techno-enviro-economic assessment in nanogrids

This paper presents an integrated framework designed for capacity planning of grid-connected nanogrid, a small solar and energy storage system that can provide kilowatt-level services to individual buildings. This framework comprehensively evaluates nanogrid cost-effectiveness, sustainability, and reliability, employing a multi-faceted techno-enviro-economic assessment approach. Traditional nanogrid capacity planning often prioritizes peak load requirements, which may lack optimality owing to occasional peak load occurrences. Conversely, optimizing solely for base load requirements might also fall short of effectiveness, compromising reliability and sustainability objectives. The proposed framework employs a three-step, integrated process for nanogrid (NG) capacity planning. Firstly, the Planner module identifies optimal asset sizing considering a two-day look-ahead logic. Then, the Operator module serves as a digital twin for the system, conducting hourly calculations over a short-term horizon. Lastly, the Evaluator module evaluates technical, environmental, and economic metrics for each solution, assessing the effectiveness of asset-sizing decisions. A simulated case study has demonstrated the effectiveness of the proposed framework. The technical assessment revealed that a PV size of 24 kW and a storage capacity of 91 kWh led to the most reliable solution, with a probability of local sufficiency of 95 percent. Furthermore, the environmental assessment showcased a renewable fraction of 94% with a PV size of 26 kW and a storage of 85 kWh. Economically, the analysis identified that a PV size of 12 kW and a storage size of 24 kWh led to the minimum total cost. In contrast, a PV size of 26 kW and a storage size of 85 kWh yielded a total operating savings of $4,801.

Microstructure engineering of fusion zone in resistance spot welding of martensitic stainless steels: The role of Ni interlayer thickness

Martensitic stainless steel (MSS) spot welds show low fracture toughness due to the formation of a brittle microstructure at the joint area. To realize the full advantage of this class of steels in industrial applications, the strategy of altering the microstructure of the weld nugget through introduction of a Ni interlayer was investigated. For this purpose, Ni interlayers with variable thicknesses of 50 to 400 μm were utilized. The microstructural evolutions were thoroughly scrutinized using Scheil-Gulliver solidification modeling and electron backscatter diffraction (EBSD) analysis. Conventional quasi-static mechanical tests, namely, tensile-shear (TS) and cross-tension (CT) were used to correlate microstructure-mechanical properties relationships. In the absence of Ni interlayer, the weld nugget was predominantly composed martensite-M and presumably residual delta ferrite-δ (M+ δ-95%) phases with minor amounts of austenite-γ (5%), failing to meet the minimum peak load requirements under TS and CT loading conditions. By applying Ni interlayers of 50 and 75 μm, a noticeable increase in the fraction of austenite phase (up to 31%) in the weld nugget was detected; nevertheless, a slight to moderate improvement in the mechanical properties was observed since the solidification mode was still primary δ, and M+δ were still the predominant phases in the microstructure. A significant improvement in mechanical properties was achieved in 100 μm Ni interlayer owing to change in the solidification mode from primary δ to γ along with the formation of a mainly austenitic microstructure. However, due to the incomplete mixing of melted base metals and Ni interlayer, a different microstructure consisting of M, δ and γ was also occasionally perceptible in the weld nugget of this sample. The best mechanical properties in terms of strength and ductility occurred with increasing thickness to 200 μm and above, which coincided with the formation of a fully austenitic microstructure in the entire weld nugget.

Modernisation of DC-DC converter topologies for solar energy harvesting applications: A review

Solar photovoltaic (PV) power generation has become increasingly important as a renewable source of energy due to the many benefits it offers. These benefits include the ease with which it can be allocated; the absence of noise; the longer life; the absence of pollution; the shorter amount of time required for installation; the high mobility and portability of its parts; and the capability of its output power to meet peak load requirements. DC-DC converters are typically incorporated into solar energy harvesting systems because they allow for the more efficient exploitation of solar cells. One of the difficulties is in the selection of a suitable converter since this has an effect on the operation of the PV system. This study discusses the modernisation of several different DC-DC converter topologies for solar energy harvesting systems. Some of these topologies are boost, buck-boost, single-ended primary-inductance converter (SEPIC), Cuk, and flyback. The topologies have been compared so that detailed information on the complexity of the hardware, the cost of implementation, the efficiency of the energy transfer elements, the tracking efficiency, and the efficiency of the converters can be provided. This paper will be useful as a handy reference in choosing the best converter topology for solar energy harvesting applications.

Thermal Performance Study on a Sensible Cool Thermal Energy Storage System for Building Air-Conditioning Applications

In most developed and developing nations, nearly 40% of the energy generated is utilized in the building sector, in which nearly 50% of the energy is consumed by building cooling/heating systems. However, the energy requirement for building cooling/heating varies continuously with respect to time. Hence, in hot countries, if the cooling system is integrated with a storage system, the cooling system need not be designed for the peak load requirement. Further, this kind of storage system is very useful and economically beneficial in the scenario of dynamic electricity tariff, being introduced in many countries in the emerging renewable energy scenario to solve the grid stability issues. Further, it is very useful to promote microgrid with distributed renewable power generation. Considering the above, the major objective of the present research is to demonstrate the integration of the air-conditioning system with a sensible heat storage unit for residential applications. An experimental setup is constructed, and experiments were conducted to evaluate the heat exchange behavior during the charging and discharging process by varying the inlet temperature and the mass flow rate of the heat exchange fluid through the circuit. It is observed that the set temperature of the cool storage tank is to be maintained above +5°C to achieve better efficiency during the charging process. During the discharging process, the room could be maintained at the required comfort condition for a duration of 285 min with 29 cycles of operations between the set point temperature limits of 25°C to 28°C. When the inlet brine temperature of the cooling unit reached 20°C, in the next cycle, bringing down the room temperature again to 25°C could not be achieved. The results shown in this work are beneficial for efficiently operating the cooling system and useful in promoting renewable energy in the near future in the building sector. Also, the low-temperature sensible heat storage system is capable of maintaining the storage temperature at approximately +4°C, instead of -4°C normally employed in the case of latent heat-based storage system that allows higher performance in the sensible heat storage system.

Redesigning capacity market to include flexibility via ramp constraints in high-renewable penetrated system

Capacity markets can co-exist alongside the energy and ancillary markets to ensure the medium-term and long-term supply adequacy by remunerating the generation resources for their availability. With the substantially increasing deployment of renewable generation, the system needs more flexibility to quickly mitigate the variability and uncertainty caused by the renewable generation. However, the present capacity market model does not differentiate the flexibility of generating units, so it might not give appropriate pricing signals to more flexible units that are usually more expensive. This is particularly important considering the increasing penetration levels of renewable generation on the electric grid, which increases the need for flexible units. This paper proposes a novel capacity market model considering flexibility requirement (FR) under the high penetration levels of renewable generation. Therefore, the proposed model can give the market-clearing price (MCP) for not only peak load generation capacity but also flexibility requirement. Thus, flexible units will tend to receive more economic incentives than non-flexible units. In the case studies, the profitability of different generation resources under the proposed capacity market model is analyzed and compared to the present capacity market model. The results show that the proposed method can maintain system reliability with regard to both peak load and flexibility requirement efficiently.

Inverter Control Performance Study on Solar PV Systems and Its Effect on Power Quality

Power generation faces a major challenge in meeting peak load requirements. Energy suppliers are highly dependent on fossil fuels due to the limited resources of non-renewable energy production. Therefore, researchers and scientists are looking for distributed generators (DGs) to provide additional power during peak periods of the energy curve. Solar energy gives them an extra twist to meet the load demand during this time. As a result, the grid-based solar photovoltaic (PV) system is attracting particular attention from researchers and industry in order to reduce the burden of fossil fuel power generation. Single-stage and two-stage photovoltaic systems are suitable for grid connection with or without battery holder. This article provides a comprehensive overview of a grid connected solar system. The entire architecture of the on-grid photovoltaic system includes the construction of a photovoltaic generator, MPPT methods and DC-DC converters.

An Ontological Representation of an Adaptive Access Control Mechanism for Enterprise Cloud

With the increased development of cloud computing, access control is of paramount importance as a security concern. Numerous access control approaches exist in various published works. Among such prevalent approaches, Role Based Access Control (RBAC) model for enterprise cloud is scope of the present study. Nowadays, resource management, along with the primary aspect of security concern, is also addressed by the access control policies through restricting the allocation of the computing resources based on the roles assigned to the users. Keeping in view of the upcoming peak-load requirements or certain constraints, the policies may have ineffective resource allocation which leads to over/under-utilization of the resources over a period of time. So, an adaptive access control mechanism is desired that can vary their policies dynamically for resource allocation depending upon the ongoing requirements, for its efficient utilization. This is presented in the form of an adaptive access control mechanism (AACM) that aims to effectively utilize the computing resources in the enterprise cloud. It will aid in identifying the over- and under-allocation of the computing resources defined as access control policies and redefine these policies so as to ensure efficient and effective usage of the enterprise cloud resources. In this paper, this novel approach to access control mechanism for the enterprise cloud is represented using ontologies developed in Protégé. This is developed by identification of the underlying concepts and their interrelationships through properties, in the enterprise cloud. The presented ontology is for the sake of knowledge representation to represent knowledge and facts.

An Optimal Model to Meet the Hourly Peak Demands of a Specific Region With Solar, Wind, and Grid Supplies

The objective of the work is to make Rameswaram, a region in Tamil Nadu self-sufficient for its energy needs by making use of hybrid energy to the maximum and utilizing fossil-based energy to the minimum. To calculate the wind and solar energy for a particular region, the wind speed and solar irradiance of that region are to be forecasted. Then the peak load requirement for a year of that region is identified and the installation capacities of wind and solar farms are fixed. Storage devices like batteries, are not used in this work. Hence all the power drawn from installed array of solar panels are utilized first to meet the hourly peak demands. If the power drawn from solar panels are insufficient to meet the demand, then the wind turbines are operated. The number of wind turbines to be operated will differ from time to time based on the demand that could not be met with solar power alone. The grid supply is used only in case of any deficiency from solar and wind power to meet the peak demand requirements. A new algorithm is proposed which will help in estimating the number of wind turbines to be operated to meet the hourly peak demands. Later the costs of utilizing energy from grid and renewable energy are estimated separately and the results compared. The entire process is automated for ease of operation using the proposed algorithm. This model can be extended to any region where this type of configuration is proposed.

The effect of climate change on electricity needs – A case study from Mediterranean Europe

This paper assesses additional electricity requirements and the associated costs in the Mediterranean island of Cyprus by the mid-21st century because of projected anthropogenic climate change, following an interdisciplinary approach that combines climate science with economics. An econometric model of electricity demand is used, in conjunction with climate projections from a state-of-the-art Global Circulation Model with a regional focus on the Eastern Mediterranean. Annual electricity demand is projected to rise by about 6% compared to a ‘no climate change’ case. Although these additional power requirements are not very remarkable on an annual basis, total costs up to 2050, which may exceed 730 million Euros at today's prices, imply that the country may need to forgo one or two years of economic growth in order to cope with extra electricity needs due to climate change. This outlook indicates that a reasonable future energy path in regions with Mediterranean climate would involve substantial deployment of solar-powered electricity generation, which can meet peak load requirements while reducing the country's energy dependence. Moreover, this forecast highlights the need for adaptation to climate change through investments in the improvement of the energy performance of the building stock.

Energy system impacts from heat and transport electrification

Electrifying the energy system and powering it by low carbon electricity is one of the key decarbonisation pathways of the energy system. This study examines annual electricity and gas consumption in a high electrification scenario in Great Britain (GB) and the implications for electricity generation and transmission infrastructure using a suite of soft-linked models. High electrification of heating and transport services, which are two major fossil fuel consumers in GB, increases annual electricity consumption and peak electricity load by 35% and 93%, respectively, by 2050 while reducing overall annual energy consumption compared to a reference case. Meeting this high electricity consumption with a supply strategy that is dependent on offshore wind could more than double the supply-side investments required compared to a reference case, if demand-side measures are not available. High electrification would also impact existing gas and oil energy infrastructure by reducing consumption of these fuels. It was found that uncertainties in socio-economic growth can amplify these implications and therefore need serious consideration by analysts and policymakers involved in designing energy transition strategies. A case study and discussion demonstrate that smart-grid aided demand-side management has the potential to minimise electricity peak load and infrastructure requirements from high electrification.

SMART ENERGY MANAGEMENT SYSTEM FOR DOMESTIC APPLICATIONS IN PAKISTAN

Modern lifestyle has put natural resources under unprecedented strain. The ever increasing demand for energy asks for not only increase in the production of energy but for ways and means to efficiently manage energy from various sources. Pakistan is experiencing the worst energy crisis in its history that has crippled its economy and impeded its GDP growth. Absence of any potent government effort to resolve the crisis has forced the households to look for alternate sources of energy. The solutions employed by the household range from gas powered generator units to solar and wind power units. Fluctuations in gas supply have necessitated the diversity of power sources. Households employing diverse sources of energy need a system that can efficiently manage the available sources of energy to meet the baseline and peak load requirements by using a cost effective mix of the available sources. This paper proposes a smart energy management system that provides the household with a cost effective mix of energy from the available power sources i.e. solar, wind, gas powered generator and the utility (grid).

183MW 대용량 동기기 구동 LCI 시스템 기동운전 분석 및 시험

Gas turbine systems are applied extensively in energy supplies to cover peak load requirements. The gas turboset must be accelerated by starting device up to 60%∼80% of rated speed to ignite the gas turbine. Recently, the most favorable and economical starting device is the LCI(Load Commutated Inverter). The LCI runs up the gas turboset by feeding the generator as a synchronous motor. In this paper, we discuss in detail the driving principles and features of 183MW gas turbine system. During field application of LCI system, many tests have been conducted and the results were described in this paper. The test results will be considered as the important resources for development in future.

Producing Power Using Stirling Engines by Tapping Heat from the Condenser of Power Plants

Mankind’s lax approach towards energy sources during its past years of incessant growth has led to chopping of fossil fuels and done immense harm to the environment. Today we are faced with a challenge to develop eco friendly systems that ensure sustainable development with minimum harm to our fragile surroundings We propose a system consisting a Stirling engine that, using the temperature difference between the condenser inlets and outlets of a power plant (nuclear or thermal), produces power. This will sooth our problems to some extent. In this paper, we will briefly discuss the working of thermal/nuclear power plants in combination with Stirling engine in order to increase the efficiency of conventional power plant systems up to the order of 80% . Above all our system causes lower emissions when compared to the already existing systems since the engine producing power has zero emission. The main advantage of our proposed system is that there will be increase in power production of the existing plants without any further increase in the energy supply. This small auxiliary system working in synchronization with the main system increases the overall efficiency of the plant by increasing the power output without additional energy being expended and also reduces the load on the power plants during peak load requirements.

The thermodynamic effect of thermal energy storage on compressed air energy storage system

With the increasing penetration of renewable energy into energy market, it is urgent to solve the problem of fluctuations of renewable energy sources (RES). Energy storage technology is regarded as one method to cope with the unstable nature of RES. One of these technologies is compressed air energy storage (CAES), which is a modification of the basic gas turbine technology. Electric power supplied by CAES can meet peak-load requirement of electric utility systems. Because there is heat waste in the existing CAES systems during compression process, fossil fuels are used to improve the expansion work to generate peak power. In order to avoid the use of fuels and keep high efficiency of system, CAES system with thermal energy storage (TES) is designed to capture and reuse the compressed air heat. This paper uses a thermodynamic model of a CAES system with TES to analyze the effect of TES on system efficiency. Besides, this paper evaluates the influence of temperature and pressure on the utilization of heat in TES. Results show that even when power efficiency reaches maximum, there is still a proportion of thermal energy left in TES for other use. Meanwhile, the utilization of heat in TES can be affected by pressure in the air storage chamber. With appropriate selection of pressure limits, the utilization of compressed air heat can be optimized. ► A system model for thermodynamic analysis is established under assumptions. ► Formula derivation of thermodynamic parameters. ► Energy utilization in TES is related to system efficiency directly. ► The impact of temperature and pressure on heat utilization in TES is studied.

The development of a design methodology for dynamic power distribution management on a civil transport all electric aircraft

This paper presents a methodology for more efficient systems power distribution management with the purpose of minimizing the rated power generating capacity and the mass of the electrical power system in an All Electric Aircraft (AEA). The power supply priority levels of all loads requiring management will be discussed and developed. The power request equations and control equations of electrical loads will be established. Furthermore, the electrical system architecture, distributed power distribution system and the dynamic power distribution management system for all-electrical aircraft are presented. By using the method of dynamic power distribution management, all the electrical consumers and sub-systems powered by electricity can be managed effectively. The performance of aircraft can be optimized due to reduced peak load requirement of the electrical system.

Reliability constrained coordination of generation and transmission expansion planning in power systems using mixed integer programming

This paper presents a new approach on expansion planning problem in power systems. The simultaneous expansion of generation and transmission subsystems has been formulated as a mixed integer programming problem to cover different constraints. The method introduces a static planning method which models the least cost deviation from the initial point (pre-expansion condition) in a manner that matches the peak load requirements of the planning horizon (post-expansion condition). The DC power flow model is used to reflect transmission flow constraint in a framework that automatically eliminates disconnected bus problem. Instead of considering just one candidate design for a corridor, different types of designs have been included in the model. This fact makes the model more practical in the transmission expansion planning section. Environmental constraints and fuel supply limitations have been also included for thermal units. Besides, a heuristic algorithm has been proposed to assure the required amount of reliability at hierarchical level II. The algorithm is based on reinforcing the economically optimal plan to upgrade its reliability level to any desired value. The scheme is capable of suggesting an economical level of reliability for a given system by reflecting cost and worth of reinforcements. To numerically evaluate the efficiency of the proposed method, simulation results on the modified Garver6-bus and IEEE 30-bus systems are provided. In spite of huge computation burden at hierarchical level II (HLII) reliability assessment, the results indicate high efficiency of the proposed method.

Numerical Study of a Novel Built-In Energy-Absorbing Component for Adaptive Steering Columns

The steering-wheel—steering-column assemblies fitted in automobiles must have a high energy absorption performance in order to minimize occupant chest injuries in the event of a collision. This paper proposes a novel built-in energy-absorbing (EA) component which causes the impact load transmitted to the occupant to vary in accordance with the crash severity and the occupant mass. A finite element (FE) model of the steering-column system is constructed on the basis of realistic product computer-aided design data, and a series of LS-DYNA simulations are performed to examine the dynamic responses of the steering wheel and steering column in body block impact tests performed using body blocks of different weights. The validity of the FE model is confirmed by comparing the numerical results for the torso force profile over the duration of the impact with the experimental results obtained in two standard body block tests. The validated model is then used to examine the energy absorption performance of the proposed EA device consisting of a hollow cylindrical tube patterned with an array of circular openings. The simulations focus specifically on the effects of the total hole-opening area, the cylinder thickness, and the cylinder material on the torso force profile over the duration of the impact. It is shown that, given an appropriate specification of the design parameters, the proposed EA device satisfies the peak load requirement specified in the FMVSS 203 standard and absorbs 163 J and 235 J of the impact kinetic energy for body block weights of 24 kgf and 34 kgf respectively.

The economics of wind power with energy storage

We develop a nonlinear mathematical optimization program for investigating the economic and environmental implications of wind penetration in electrical grids and evaluating how hydropower storage could be used to offset wind power intermittence. When wind power is added to an electrical grid consisting of thermal and hydropower plants, it increases system variability and results in a need for additional peak-load, gas-fired generators. Our empirical application using load data for Alberta's electrical grid shows that costs of wind-generated electricity vary from $37 per MWh to $68/MWh, and depend primarily on the wind profiles of installed turbines. Costs of reducing CO 2 emissions are estimated to be $41–$56 per t CO 2. When pumped hydro storage is introduced in the system or the capacity of the water reservoirs is enhanced, the hydropower facility could provide most of the peak load requirements obviating the need to build large peak-load gas generators.