Techno-Economic Performance Analysis of GridInterfaced Microgrid for Different Facilities

Power systems have been undergoing radical changes in recent years, and their planning and operation will be surely undertaken according to the Smart Grid (SG) vision in the near future. The SG initiatives aim at introducing new technologies and services in power systems, to make the electrical networks more reliable, efficient, secure and environmentally-friendly. In particular, it is expected that communication technologies, computational intelligence and distributed energy sources will be widely used for the whole power system in an integrated fashion. In particular, nowadays, unprecedented challenges like as stringent regulations, environmental concerns, growing demand for high quality, reliable electricity and rising customer expectations are forcing utilities to rethink about electricity generation and delivery from the bottom up. Moreover, the availability of low cost computing and telecommunications technologies, new generation options, and scalable, modular automation systems push utilities to be dynamic, innovative and ambitious enough to take advantage of them. Driven by the dynamics of the new energy environment, leading utilities, technology vendors and government organizations have created a vision of the next generation of energy delivery systems: the Smart Grid. Operational changes of the grid, caused by restructuring of the electric utility industry and electricity storage technology advancements, have created an opportunity for storage systems to provide unique services to the evolving grid. Especially Battery Energy Storage Systems (BESSs), thanks to the large number and variety of services they can provide, are powerful tools for the solution of some challenges that future grids will face. This consideration makes BESSs critical components of the future grids. The BESS can be applied for different services into the different levels of power system chain to satisfy technical challenges and provide financial benefits. In the context of the application of BESSs in SGs, there are two main problems that need to be addressed in a way that exploits the BESS potential, that are linked to their operation and sizing. This thesis focuses on both these aspects, proposing new strategies that allow optimizing the BESS adoption. When dealing with BESSs, sizing and operation are strictly linked. The correct sizing of a BESS, in fact, needs to take into account its operation which in turn will be effected with the aim of optimizing the whole system where it is included. In the first part of this research study, advanced optimal operating strategies were proposed for BESSs by considering both the distribution system operator perspective and the end user. Thus, the proposed operating strategies were performed with the aim of (i) leveling the active power requested by the loads connected to a distribution system (distribution system operator service), (ii) reducing the electricity costs sustained by an end-use costumer that provides demand response (DR) (end user service) and (iii) scheduling a microgrid (µG) with DR resources such as Plug-in Electric Vehicles (PEVs) and Data Centers (DCs) (both the two section service). The proposed strategies also satisfied technical constraints of BESSs and other components of the µG. The second part of the thesis presented the optimal sizing of BESSs aimed at maximizing the benefits related to their use. In the thesis, the sizing, which is performed by considering the end user point of view with reference to both the industrial and residential customers, is effected by adopting both deterministic and probabilistic approaches. With reference to the deterministic approach, a simple and quick closed form procedure for the sizing of BESSs in residential and industrial applications was proposed. In case of probabilistic approach, the case of a BESS installed in an industrial facility was considered and the sizing was performed based on the decision theory. Technical improvements and economic benefits of optimal operation and optimal sizing of BESSs in SG are demonstrated by the obtained results which are reported in the numerical applications. More specifically, it was clearly determined that BESSs can offer technical supports into the distribution operator section of the grid in terms of load management and security challenges. Moreover optimal integration of BESSs into the grid was also appealing for end users thanks to valuable amounts of electricity bill cost reduction. Regarding the original contribution of the thesis, the following considerations can be done. With reference to the load leveling service, an innovative two-step procedure (day-ahead scheduling and very short time predictive control) was proposed which optimally controls a BESS connected to a distribution substation in order to perform load leveling. In case of DR, a proper control of the BESS was proposed in order to perform DR under different price schemes, such as Real Time Pricing (RTP) and Time of Use (TOU) without modifying the daily work cycle of the industrial loads. The control procedure allows achieving contemporaneously two important goals that are the reduction of the bill costs and the prolonging the battery's lifetime so further reducing the costs sustained by the customer. With reference to the scheduling of microgrids, the original contribution of the thesis is focused on the proposal of optimization strategies aimed at managing and coordinating, simultaneously, batteries on board of vehicles or equipping data centers' Uninterruptable Power Supply (UPS) and Distributed Generation (DG) units. Also comparisons among different single-objective based strategies are made in order to highlight the most convenient. With reference to the sizing based on deterministic approach, unlike the other relating literature, the innovative contribution is that the closed form procedure takes into account both the technical constraints of the battery and contractual agreements between the customer and the utility. Moreover, in the economical analysis performed for the sizing, which is applied with reference to both residential and small industrial customers and is based on actual TOU tariffs, a wide sensitivity analysis to consider different perspectives in terms of life span and future costs was performed. Some aspects that affect the profitability of the battery, such as technological limitations (e.g. the battery and converter efficiency), economic barriers (e.g. capital cost and the rate of change of the cost) and variation of the load profile along the years were deeply analyzed. In case of sizing based on probabilistic approach, the original contributions of the thesis are mainly referred to the proposal of a new method that uses a decision theory-based process to obtain the best sizing alternative considering the various uncertainties affecting the sizing procedure. The thesis is organized in three chapters which are dealing with integration of BESSs in SGs. The first chapter reports basic concepts and characteristics of BESSs, fundamental components and features of SGs and different services that BESSs can provide. The optimal operation strategies of BESS are considered in second chapter which includes their problem formulation, solving procedures and results. The third chapter deals with the optimal sizing problem of BESSs for which the problem formulation, solving procedures and results are reported. Finally, the conclusions are presented in the last part of thesis.

A holistic techno-economic feasibility analysis of residential renewable energy systems: An insight into Turkish case

Accelerated development of eco-friendly technologies, such as renewable energy (RE), smart grids, and electric transportation will shape the future of electric power generation and supply. The power consumption characteristics of modern power systems are designed to be more flexible and easily controllable, which will also affect the sizing of power generation system. This paper presents a methodology for the joint capacity optimization of a typical residential standalone microgrid (MG) employing RE sources, i.e., solar photovoltaic (PV), wind turbines (WTs), diesel generators (DGs), and battery energy storage system (BESS). The MG supplies a residential community load comprising of typical residential load plus electric vehicles (EVs) charging load. The realistic mathematical models of PV, WT, diesel generation system, BESS, and EV load are formulated to improve the capacity optimization methodology, which involves various realistic constraints associated with the RE sources, diesel generation system, BESS, and EV load. The labyrinthine optimization problem is formulated and solved innovatively to 1) minimize the cost; 2) reduce greenhouse gases (GHG) emissions; and 3) curtail dump energy. All three objectives have special significance in designing a standalone MG, for example, cost is related to the economics, GHG emissions deal with global warming, and dump energy is related to the stability and economics of the system. The optimization problem is solved for different possible combinations of PV, WT, DG, and BESS to determine the best possible combination to serve the load effectively and economically. In addition, the impact of load shifting on the sizes of distributed generators and BESS in terms of per-unit cost and GHG emissions is analyzed using the concept of controllable loads. This study could be assumed as a powerful roadmap for decision makers, analysts, and policy makers.

This paper presents the control algorithm for Battery Energy Storage System (BESS) connected in Micro-Grid (MG), operating in grid-connected and islanded-mode. The MG consists of configurable units such as BESS, PV, diesel generator and load. The BESS is connected with Voltage Source Converter (VSC) for active and reactive power sharing in grid-connected mode. Two control scheme algorithms are presented. Firstly, inner current control loop and secondly outer active/reactive power (PQ) control loop is presented. Also the charging and discharging control of BESS is designed to maintain the SOC. In islanded-mode, Power-frequency (P-f) control of BESS is proposed to maintain the frequency of MG and supply power to the load. P-f control provides reference power for PQ control. BESS provide primary frequency control to MG; however, the low power capacity of BESS demands for a backup. Diesel generator provides a backup frequency control in islanded-mode, supply active/ reactive power to loads and charge the BESS. The control is designed in dq reference frame. The simulation results show the effectiveness of control system.

The potential of agricultural and livestock wastes as a source of biogas in Vietnam: Energetic, economic and environmental evaluation

Zeolite-Y-catalyst production from locally sourced Meta-kaolin: Computer-Aided scale-up process design and economic analysis with Monte-Carlo-Simulation

Optimizing the bidding strategy and assessing profitability of over-install renewable plants equipped with battery energy storage systems

There is mounting evidence that the global warming and, consequently, the climate changes are anthropogenic and attributed to fossil fuel consumption. Therefore, it is mandatory to find alternative solutions that can replace current resources. One of those resources is solar energy, and specifically Photovoltaic solar panels. Qatar is a sun-belt country with daily average solar radiation in the range of 5.1 kWh/m2. Namely, in such hot and dry region, solar energy seems to be the most important source of renewable energy. The local government has been aware of this fact and planning to generate 200 MW of electricity in 2020 from solar power. In hot country like Qatar air conditioning systems account for more than 65% energy consumption. This provides the challenge to study the possibility of utilizing renewable energy in air conditioning sector. In the light of the improvements achieving in the performance of photovoltaic systems beside the reduction in its price, the combination between the photovoltaic and air conditioning systems is becoming more practical. Unlike other renewable energy resources, the maximum available solar energy corresponds with the peak cooling demand. This increases the viability of utilizing solar energy in air conditioning applications. The current work demonstrates the technical and economic potential of utilizing solar energy at the working conditions of Qatar. For this aim a most common mosque design in Doha, Qatar, was selected as a case study. Among the different solar module brands available in the market, Solar Leading module brand was considered. Two simulation models including hourly analysis program and system advice model were used in order to carry out the technical and economic analysis. From technical viewpoint, current study resulted in determination of required number of a considered PV module which has been found to be 77 panels. These panels can provide the air conditioning system of the considered mosque with annual electricity demand the A/C system, see Figure 1. The objective of the economic analysis is to determine the costs and the benefits of investment and to quantify with the determination of appropriate financial indicators the economic convenience of PV systems. In particular the economic analysis resulted in determination of different figures of merit including net present value (NPV), internal rate of return (IRR), the payback time (PBT), and levelized cost of electricity (LCOE). The NPV, IRR, PBT, and LCOE were found to be $3700, 3.8%, 22 years, and 0.070 $/KWh, respectively, see Figure 2. The obtained results show that utilization of solar energy for air conditioning purposes has big potential for saving economic and environment at working conditions of Qatar.

Integrated Economic Adoption Model for residential grid-connected photovoltaic systems: An Australian case study

The world has not been able to achieve minimum greenhouse gas emissions in buildings’ energy consumptions because the energy and emissions optimization techniques have not been fully utilized. Thermal comfort is one of the most important issues for both residential and commercial buildings. Out of the 40% of global energy consumed by buildings, a large fraction is used to maintain their thermal comfort. In this study, a comprehensive review of the recent advancements in building energy conservation and efficiency application is presented based on existing high-quality research papers. Additionally, the retrofit of the heating/cooling and hot water system for an entire community in Cyprus is presented. This study aims to analyze the technical and environmental benefits of replacing existing electric heaters for hot water with heat pump water heating systems and the use of heat pump air conditioners for thermal comfort in place of the existing ordinary air conditioners for space heating and cooling. One administrative building, 86 apartments (including residential and commercial) buildings, and a restaurant building is retrofitted, and the feasibility of the project is determined based on three economic indicators, namely; simple payback period (SPP), internal rate of return (IRR), and net present value (NPV). The electrical energy required by the hot water systems and the heating/cooling system is reduced by 263,564 kWh/yr and 144,825 kWh/yr, respectively. Additionally, the retrofit project will reduce Cyprus’ CO2 emission by 121,592.8 kg yearly. The SPP, IRR, and NPV for the project show that the retrofit is economically feasible.

The rising demand for electric vehicles (EVs) presents both an opportunity and a challenge. While EVs offer a low-emission alternative to conventional transport, their charging infrastructure mostly depends upon fossil fuel powered grids, reducing their environmental benefits. This paper addresses the problem by proposing a solar photovoltaic based EV charging station as a sustainable and economically viable solution. A 29.7 kWp grid-connected PV system was designed and simulated for Noida Sector 105 using PVsyst, targeting specifically four wheelers charging demand. The system demonstrated an annual energy generation of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$41,171 \text{kWh}$</tex>, with a performance ratio of 79.5 %, offsetting <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$33.76 \text{tCO}_{2}$</tex> emissions annually. Financially, the project yields strong results: a Net Present Value (NPV) of Rs.77.31 lakh, an Internal Rate of Return (IRR) of 40 %, a payback period of 2.5 years, and a Return on Investment (ROI) of 265 % over a 25 -year lifecycle. The Levelized Cost of Energy (LCOE) was estimated at Rs.8.8 per kWh, competitive with prevailing commercial grid tariffs. Compared to conventional grid-powered EV charging systems, the proposed solar-integrated model not only reduces long term operating costs but also improves environmental performance by reducing the significant amount of GHG emissions. This study proves that solar PV-based EV charging infrastructure is not only feasible but also provides a scalable and replicable model for sustainable urban transport.

The fast development of electric vehicles (EVs) has resulted in several topics of research in this area, such as the development of a charging pricing strategy, charging control, location of the charging station, and the structure within the charging station. This paper proposes the optimal design of the structure of an EV fast-charging station (EVFCS) connected with a renewable energy source and battery energy storage systems (BESS) by using metaheuristic algorithms. The optimal design of this structure aims to find the number and power of chargers. Moreover, the renewable energy source and BESS can reduce the impact on the grid, so these energy sources are considered as ones of the optimally-designed structure of EVFCS in this work. Thus, it is necessary to determine the optimal sizing of the renewable energy source, BESS, and the grid power connected to EVFCS. This optimal structure can improve the profitability of the station. To solve the optimization problem, three metaheuristic algorithms, including particle swarm optimization (PSO), Salp swarm algorithm (SSA), and arithmetic optimization algorithm (AOA), are adopted. These algorithms aim to find the optimal structure which maximizes the profit of the EVFCS determined by its net present value (NPV), and the results obtained from these algorithms were compared. The results demonstrate that all considered algorithms could find the feasible solutions of the optimal design of the EVFCS structure where PSO provided the best NPV, followed by AOA and SSA.

On relationships between ROI and IRR under inflation: A constant real cash-flow case

The most crucial global issue discussed at the Fourth Intergovernmental Review Meeting on the Implementation of the Global Program of Action for the Protection of the Marine Environment from Bali Land Based Activities (IGR-4) in 2018 is the danger of detergent. Up to 45% of Indonesia’s rivers are in the category of being heavily polluted by detergent. Furthermore, Enzymatic Eco Detergent is a new, renewable, and innovative biodegradable product made from vegetable surfactants based on palm oil (MES). It is also enriched with organic enzymes produced by simple biotechnology from processing organic waste, such as fruits and vegetable peels, based on garbage enzyme/eco-enzyme. And it also has excellent potential to be developed on a micro business scale (Start-up). As a new product, conducting a business feasibility analysis is necessary to reduce the risk of failure or loss. Therefore, this study aims to analyze the feasibility of the Eco Detergent factory start-up business with a capacity of 12,000 liters per year based on a financial analysis involving the Payback Period, Net Present Value, Internal Rate of Return, and Return on Investment. The data obtained were analyzed using Microsoft Excel 2013 software. The result showed that the payback period (PP) is three years (2 years and 3 months) faster than the project age of 5 years, hence the Green detergent start-up project, "Enzymatic Eco Detergent," is feasible to be implemented. Meanwhile, the Net Present Value (NPV) criteria have a positive IDR of 1,117,448,350.97. The Internal Rate of Return (IRR) and the Return on Investment (ROI) obtained are 57.57% and 54%, respectively. Conclusively, the investment is considered profitable with a return rate of 10.37%, hence, it is feasible to be implemented.

In this paper, stability of current control of battery energy storage system (BESS) connected with a diesel generator for a stand-alone microgrid are analyzed in four cases. The stand-alone microgrid system consists of 50kW BESS, 50kW diesel generator and controllable loads, where BESS is composed of 115kWh battery bank and 50kW DC-AC inverter. The four cases are 1) BESS with a stiff grid 2) BESS with the diesel generator 3) BESS with passive damping + diesel generator 4) BESS with active damping + diesel generator, and their stabilities are analyzed in the frequency domain and discrete time domain. Demonstration site for the stand-alone microgrid is constructed and comparative analysis for the four cases are verified through simulation and experiments, where experimental results show a good agreement with the analysis.