Conventional Diesel Generator Research Articles

Integration of very small modular reactors and renewable energy resources in the microgrid

Hybrid microgrids, integrating local energy resources, present a promising but challenging solution, especially in areas with limited or no access to the national grid. Reliable operation of off-grid energy systems necessitates sustainable energy sources, given the intermittent nature of renewables. While fossil fuel diesel generators mitigate risks, they increase carbon emissions. This study assesses the viability of integrating a very small modular renewable energy reactor into a microgrid for replacing conventional diesel generators, substantially curbing greenhouse gas emissions. A comprehensive analysis, including design and economic evaluation, was conducted for an off-grid community microgrid with an annual generation and load of 8.5 GWh and 7.8 GWh, respectively. The proposed microgrid configurations incorporate very small modular reactors, alongside solar, wind, and battery storage systems. MATLAB modeling and simulation across eight cases, accounting for seasonal variations, demonstrate the technical and economic feasibility of case 7. This configuration, integrating modular reactors, photovoltaics, wind turbines, and battery storage, satisfactorily meets load demands. Notably, it boasts a high internal rate of return up to ∼31% and a shorter payback period of around 4 years compared to alternative scenarios.

Multi-objective optimization of Hybrid Energy Systems based on Life Cycle Exergy and Economic criteria

The present study aims to develop a novel optimal design of hybrid energy systems based on exergy and lifecycle concepts using genetic algorithms. The model consists of both stand-alone and on-grid options with scenarios for exchanging energy with the grid. The objectives include cost minimization or benefit maximization primarily, and lifecycle exergy efficiency, i.e., cost as the sustainability index secondarily. This research considers renewable sources such as solar, wind, hydropower, and hydrogen production and storage in addition to conventional diesel generators. The optimization was performed subject to weather conditions and solar radiation profiles, demand, and environmental or economic aspects. Also, the model contains various modules such as water-heating, waste energy utilization, as well as the options of power exchange with the distribution network and injection of hydrogen produced from excess renewable sources into the gas network. The application was demonstrated in a case study, where specific demands and the climate of Tehran were assumed. The case study considers four scenarios, including standalone, completely on-grid, on-grid with a non-backup generator, and on-grid without an energy sale option. The first optimal objective, the levelized unit cost of energy for the standalone system, is $0.22 per kWh. Moreover, the second optimal objective, the lifecycle exergy cost, ranges from 1.93 to 4.13 in different grid-connection states.

Effect of a Storage System in a Microgrid with EDR and Economic Dispatch Considering Renewable and Conventional Energy Sources

Due to the importance that organizations and governments have placed on environmental pollution and the policies that force organizations to comply with environmental standards, the use of renewable energy sources to meet energy requirements becomes important. The problem of the economic dispatch consists of satisfying the energy demand of the clients, establishing the most convenient source of supply at each moment, considering the established objective (minimize the operating cost of the microgrid) and satisfying the established restrictions. This paper addresses the problem of economic dispatch in a microgrid with a mathematical programming approach. The proposal to meet the energy demand considers: (a) interconnection to the main grid, (b) conventional diesel generators, (c) a photovoltaic system, (d) a hydroelectric turbine, (e) a wind system, (f) a battery-based storage system, (g) capacity to exchange energy with the main grid, (h) incentive for reducing electricity demand (EDR) by customers when an environmental contingency occurs and (i) regeneration of pollutants emitted by conventional generators. The proposal is implemented in the Lingo 17 software. The results show that by including a BESS and the EDR program, it is possible to save between 18% and 75% of the costs of the objective function and stop emitting a little more than 195 kg of pollutants into the environment.

Techno-economic assessment of fuel cell-based power backup system as an alternative to diesel generators in Nepal: A case study for hospital applications

A fuel cell-based combined heat and power (CHP) system holds significant potential to be a viable alternative to conventional diesel generators for providing backup power during disruptions. The system generates power with only water as a byproduct, thus promoting environmental sustainability through reduction in greenhouse gas emissions. This study provides a comprehensive techno-economic assessment for replacement of 488 kW diesel generator that powers a hospital in Nepal during power disruption. The counter power capacity of fuel cell is 500 kW. The scope of hydrogen generation has been considered both on-site and off-site. The economic analysis performed for the on-site hydrogen production resulted in a net present value of USD 42,717 with a corresponding internal rate of return of 8.40 % and a payback period of around 10 years, making it an economically viable option. The uncertainty and sensitivity analysis revealed the electricity tariff rate as the most significant cost factor. For off-site hydrogen production, the proposed system is economically feasible if the hydrogen can be purchased below 3.5 USD/kg.

Renewable Energy Sourcing to Enhance Sustainable Manufacturing by Using Madhab’s EEE Impact Analysis Model

The world's increasing energy demand, coupled with the depletion of finite energy resources, necessitates a shift towards sustainable energy solutions. This research explores the multifaceted benefits of substituting conventional fossil fuel-based energy sources with renewable energy in industrial settings, with a focus on sustainable manufacturing. A case study was conducted at a printing and packaging factory in Bhubaneswar, Odisha, to analyze economic, environmental, health, safety, and efficiency factors associated with various energy options based on the Madhab’s EEE (Environmental, Efficiency, Economic) impact analysis method. The study identified solar power generation as the optimal energy source, boasting the lowest EEE impact index of 1.90. Wind energy ranked second, followed by conventional GRID power and DG (Diesel Generator) power sources, which were found to be less favorable due to their higher EEE impact indices. Feasibility assessments revealed that the factory had ample rooftop and vacant land space for solar power plant installation, making it self-sufficient in power generation. The return on investment (ROI) for the solar power project was calculated to be 5.54 years, making it a viable option from a sustainability perspective. Moreover, the solar system could be integrated with the GRID through a reverse metering system, enabling excess energy to be sold back to the GRID. This research underscores the significance of transitioning to renewable energy sources in industries for environmental sustainability, energy security, and economic benefits. It emphasizes the need for similar studies in diverse industrial settings to identify the most suitable energy sources, considering all relevant factors.

Optimal sizing and techno-enviro-economic evaluation of a hybrid photovoltaic/wind/diesel system with battery and fuel cell storage devices under different climatic conditions in Cameroon

Due to advancements in renewable energy technology and their ability to mitigate the issue of global warming, solar and wind energy sources are becoming increasingly popular for power generation. However, the intermittent nature of these sources means that their availability does not always correlate with load fluctuations. Hence, to solve the unpredictability concerns associated with solar and wind energy sources, they may be integrated with storage technologies and conventional energy sources (diesel generators) in a hybrid energy system (HES) to continuously supply the load demand. This paper performs a techno-economic and environmental assessment of hybrid systems integrating photovoltaic (PV), wind turbine generator (WT), and diesel generator (DSL), considering fuel cell (FC) and battery (BAT) storage devices, to supply three non-domestic loads at different locations in Cameroon, namely, Fotokol, Idabato, Kousseri, and Figuil. The Cuckoo Search Algorithm (CSA) is introduced to optimally size the various components of the proposed systems in order to fulfill the load demands in the most cost-effective manner with excellent reliability. The results show that in the short term period, hybrid systems incorporating battery storage devices are more cost effective than fuel cell storage systems. Indeed, the most optimal system found was PV/WT/BAT/DSL at the city of Idabato, with a COE of 0.151$/kWh, 0.180$/kWh, and 0.220$/kWh for high, medium, and low consumers, with corresponding break-even distances of 0 km, 0.14 km, and 0.44 km, respectively. Traditionally, using diesel generator systems for power generation costs 0.469$/kWh, 0.618$/kWh, and 0.766$/kWh, with CO2 emissions of 13694.3 kg/year, 10351.4 kg/year, and 8978.1 kg/year for high, medium, and low consumers, respectively. However, using the PV/WT/BAT/DSL configuration at Idabato in comparison to the conventional diesel generator reduces CO2 emissions in this locality by 94.32%, 95.22%, and 93.79% for high, medium, and low consumers, respectively. On the other hand, the PV/WT/FC/DSL hybrid system at Idabato presents COE of 1.018$/kWh, 1.655$/kWh, and 2.289$/kWh, with saving CO2 emissions of 91.27%, 91.76%, and 94.63% for high, medium, and low consumers, respectively.

Modeling and optimization of a hybrid solar-battery-diesel power system for remote consumers.

Hybrid power systems can be affected by various uncertain parameters such as technical, economic, and environmental factors. These parameters may have both positive and negative impacts on the overall performance of the system. Therefore, in this study, an effective optimization method for modeling and optimization of a hybrid solar-battery-diesel power structure for remote consumers is proposed. The purpose of this method is to find the optimal configuration of the hybrid structure from the technical-economical-environmental point of view to cover the load demand requirements of remote consumers. To verify the performance of the hybrid microgrid, the results of the hybrid system based on the hourly meteorological data and load profile are compared with the results of the conventional diesel generator (DG). The optimization problem is solved using a harmony search optimization algorithm. The results show that the solar/battery/DG system is more suitable than the DG-only system in different uncertainty indexes based on economic and environmental aspects. Also, by the increase of the uncertainty index from 0.5 to 10%, the optimal total cost of the system decreases by 36.5%, while at the same time the unavailability value increases from 0.2259% to 9.9568%. Additionally, when the interest rate value increases from 1 to 7%, the total cost value increases around 17. 4%.

An effective quantum artificial rabbits optimizer for energy management in microgrid considering demand response

Solving the energy management (EM) problem in microgrids with the incorporation of demand response programs helps in achieving technical and economic advantages and enhancing the load curve characteristics. The EM problem, with its large number of constraints, is considered as a nonlinear optimization problem. Artificial rabbits optimization has an exceptional performance, however there is no single algorithm can solve all engineering problem. So, this paper proposes a modified version of artificial rabbits optimization algorithm, called QARO, by quantum mechanics based on Monte Carlo method to determine the optimal scheduling for MG resources effectively. The main objective is minimization of the daily operating cost with the maximization of MG operator (MGO) benefit. The operating cost includes the conventional diesel generator operating cost and the cost of power transactions with the grid. The performance of the proposed algorithm is assessed using different standard benchmark test functions. A ranking order for the test function based on the average value and Tied rank technique, Wilcoxon's rank test based on median value, and Anova Kruskal–Wallis test showed that QARO achieved best results on the most functions and outperforms all other compared technique. The obtained results of the proposed QARO are compared with those obtained by employing well-known and newly-developed algorithms. Moreover, the proposed QARO is used to solve two case studies of day-ahead EM problem in MG, then the obtained results are also compared with other well-known optimization techniques, the results demonstrate the effectiveness of QARO in reducing the operating cost and maximization the MGO benefit.

A Bottom-Up Approach to PV System Design for Rural Locality Electrification: A Case Study in Burkina Faso

This work evaluates the performance of optimal hybrid PV/battery and PV/diesel generator renewable energy systems for a remote village in Burkina Faso. Based on socioeconomic data and the household sample survey, a technoeconomic simulation and optimization model of electrical loading are presented. Ant colony optimization (ACO) and the loss of power supply probability (LPSP) algorithms were used for the search of the optimal hybrid power system. For the selected village location, the results have shown that the hybrid PV/battery system represents the best renewable energy solution due to abundant solar irradiation and carbon emission free compared to the conventional diesel generator (DG) or PV/DG system. To reach the estimated load power demand of 2150 kWh for the studied location, optimized PV/battery configuration sizing required 650 PV modules of 250 W and 715 batteries of 300 Ah. The economical evaluation reveals a cost investment of about 1,293 025.7 USD for a lifetime of 25 years in comparison of that of PV/DG and DG systems, which are 1,088 701.9 USD and 1,682 850.6 USD, respectively. However, environmental and atmospheric pollution is minimized with a saving of more than 17943 tons of CO2. Therefore, the production of electricity from the PV/battery system leads to better competitiveness reliability for a socioeconomic development of studied remote villages.

Economic dispatch in micro-grids with alternative energy sources and batteries

The problem of economic dispatch in a micro-grid interconnected to the conventional electrical system consists of optimizing the operating cost to satisfy the different operating requirements and the demand for electrical power required by the users. In the development of this proposal, there are challenges caused by the random nature of electricity generation systems based on renewable energy sources, for an adequate operation of the micro-grid, which can be solved through systems Energy Storage System (BESS). This paper addresses the problem of optimal economic dispatch in a microgrid that includes an energy storage system based on a battery bank and interconnected to the main grid through a mathematical programming approach, considering the benefits for customers by reducing their demand of electrical power and taking into account the costs of treatment pollutants produced by conventional energy sources. The generation systems used to satisfy the energy demand of the customers within the interconnected micro-grid are: a) conventional diesel generators, b) wind generation systems, c) photovoltaic systems, d) a hydroelectric turbine, and e) a storage system based on electric batteries. The results of the effectiveness of the proposed mathematical model show that the demand for electrical power to the main grid can be reduced and customers obtain economic benefits by integrating the incentive-based demand response program into the energy management problem when environmental contingency events occur. The results show that when there are peaks in energy demand, the operating costs of the micro-grid increase by up to 380%. In the same way, when there are failures in renewable energy sources, storage systems (BESS) and diesel generators work at 100% of their capacities. The proposal is implemented in Lingo 17.0 software and simulation results show the feasibility of the proposal through the optimization of the operation of the micro-grid.

Techno-economic comparison of standalone solar PV and hybrid power systems for remote outdoor telecommunication sites in northern Ghana

Telecommunication services have continued to evolve to meet the ever-changing bandwidth demand requirements. The electricity grid network of Ghana is faced with challenges, including low voltages, a lack of quick fault response teams, and the proximity to specific locations. Using diesel generators to address the shortfall in grid supply is expensive and has implications for greenhouse gas emissions. This study evaluated the technical and economic benefits of using a standalone solar photovoltaic (PV) system, hybrid (Solar PV/diesel), conventional diesel generators (DG), and grid extension to power an off-grid outdoor telecommunication site. Power solutions configurations were simulated using hybrid optimization of multiple electric renewables (HOMER). The study found the optimum design to be a standalone solar PV/battery system with 56.3 kW solar PV array and Sixty (60) pieces of 12 V SAGM batteries of 135 Ah. The optimum design had a net present cost (NPC) of US$ 88,176.00 and a cost of energy (COE) of US$ 0.321/kWh. The COE and the NPC of the optimum system were approximately 50% less than the design with DG only, which could significantly impact service tariff and improve access to digital connectivity. The COE from the solar PV/battery system is not competitive with the grid power supply (COE = US$0.12). However, considering the electric distance limit or breakeven distance of 4.51km for grid extension, the solar PV/battery is preferred. Therefore, the stakeholders in providing power solutions to off-grid locations should consider solar PV technology.

A practical solution for excess energy management in a diesel-backed microgrid with high renewable penetration

One of the limiting factors in adding high levels of rooftop solar photovoltaic (PV) resources to isolated hybrid microgrids is the ability to maintain the minimum operating point of must-run diesel generators. This research investigates a proposed inexpensive and practical solution to mitigate excess energy from renewables (mainly PVs) while maintaining a diesel-backed grid's acceptable minimum down reserve. It includes the innovative use of a resistive dynamic load bank (DLB) during peak PV periods. A control algorithm was developed to monitor the grid's total generation and control the DLB such that conventional diesel generators are not pushed below a setpoint equal to their minimum reliable operating level defined by the local utility. The setpoint is adjustable to allow for changes in grid conditions over time, such as the addition of more renewable resources or grid upgrades. This DLB system, as a practical and low-cost PV excess energy mitigation solution, has been connected to the grid in coordination with the local utility on the island of Molokai in the Hawaiian Islands. The DLB system addition has enabled the utility to significantly increase the allowed customer-sited PV on the power system without sacrificing grid reliability.

Techno-economic feasibility assessment model for integrating hybrid renewable energy systems into power systems of existing ships: A case study of a patrol boat

The shipping industry has set out to reduce CO2 emissions by 50% by 2050 compared to 2008, as op. cit. in the note by the International Maritime Organisation to the UNFCCC Talanoa Dialogue. In order to achieve this target, ship owners and operators are to consider replacing the conventional diesel generators and gas turbines with renewable energy and other cleaner power producing systems. In this paper, a techno-economic feasibility evaluation model for integrating hybrid renewable energy systems (HRES) into the power architecture of existing ships for greener and sustainable shipping is presented. For HRES to qualify as technically and economically feasible, a decision is made based on a ‘techno-economic measure’ which is estimated by combining space availability, load served and economic performance. The proposed model is applied to a patrol boat sailing along the Eastern Coast of Ghana with three different proposed HRES. The results from the applied case shows that the most technical and economically feasible HRES for the patrol boat that meets the key performance indicators and offers low GHG emission is a hybrid solar PV, wind turbine and diesel generator system. The results further shows that the proposed model is capable of assisting ship owners to integrate affordable and cleaner energy into the power architecture of ships.

A Brief Overview of Energy Efficiency Resources in Emerging Wireless Communication Systems

It is crucial to design new communication technologies to surmount the setbacks in RF communication systems. A suitable energy-efficiency scheme helps evade needless energy consumption in wireless communication. Appropriate choice of the most suitable energy-efficiency scheme aids in selecting the most energy-efficient equipment to minimize the expense of energy towards decreasing individual network element energy consumption without affecting their unique features. This review presents the energy efficiency challenges in wireless communication by employing different technologies. The emergence of visible light communication (VLC) provides an energy-efficient wireless communication system despite the various challenges inherent in its adoption that limit its physical realization. This work seeks to harness the potential of the transmission capabilities of VLC while providing an insight into novel practical implementation techniques. The work also addresses the energy consumption problem of low-active components and idle period of active components of base stations by using sleep modes for their systematic turning off and on. The high cost of power supply and the environmental emission of gases from base stations are also addressed by integrating a renewable energy resource into the conventional standalone diesel generators. Overall, the work provides an overview of information necessary for foundational research in energy-efficient resources applied to emerging wireless communication systems.

Variable Speed Diesel Generators: Performance and Characteristic Comparison

Diesel generators (DGs) are set to work as a backup during power outages or support the load in remote areas not connected to the national grid. These DGs are working at a constant speed to produce reliable AC power, while electrical energy demand fluctuates according to instantaneous needs. High electric loads occur only for a few hours a day in remote areas, resulting in oversizing DGs. During a low load operation, DGs face poor fuel efficiency and condensation of fuel residues on the walls of engine cylinders that increase friction and premature wear. One solution to increase combustion efficiency at low electric loads is to reduce diesel engine (DE) speed to its ideal regime according to the mechanical torque required by the electrical generator. Therefore, Variable Speed Diesel Generators (VSDGs) allow the operation of the diesel engine at an optimal speed according to the electrical load but require additional electrical equipment and control to maintain the power output to electrical standards. Variable speed technology has shown a significant reduction of up to 40% fuel consumption, resulting in low GHG emissions and operating costs compared to a conventional diesel generator. This technology also eliminates engine idle time during a low load regime to have a longer engine lifetime. The main objective of this survey paper is to present the state of the art of the VSDG technologies and compare their performance in terms of fuel savings, increased engine lifetime, and reduced greenhouse gases (GHG) emissions. Various concepts and the latest VSDG technologies have been evaluated in this paper based on their performance appraisal and degree of innovation.

Multi-objective multi-verse optimization of renewable energy sources-based micro-grid system: Real case

Hybrid micro-grid systems (HMGS) are small scale power system where the energy sources are installed to supply local customers. These systems may be considered as promising energy solution to meet the increased in energy demand and traditional sources depletion. Cost of electricity, system reliability, and environmental impacts of the system are three design criteria that must be considered in obtaining the accurate parameters of hybrid renewable energy system components. In this paper, hybrid micro-grid renewable energy system includes photovoltaic system, (PV) wind energy system, (WES) battery bank, (BB) and conventional diesel generator (DG) are proposed to meet the energy requirements in remote area, located in Red Sea called city of Bernice, Egypt, at 23° 54′ 31″ N, 35° 28′ 21″ E. Optimization of Cost of Electricity (COE), Renewable Factor (RF), and Loss of Power Supply Probability (LPSP) are main objective of the designing process of the hybrid system considered as the objective functions. Then, Multi-objective multi-verse optimization (MOMVO) algorithm is used with considering two scenarios, the first one is renewable sources and the second is renewable/diesel energy source. All the possible HMGS configurations namely: PV/battery, wind/battery, PV/wind/battery and PV/battery/diesel, wind/battery/diesel, PV/wind/battery/diesel are studied and analyzed. Moreover, one year hourly meteorological weather data for case study are recorded. Reverse osmosis desalination (ROD) is considered in conjunction with the residential load. The proposed power management strategy is used to manage the system operation when supplying the load. A linear fuzzy membership function is used for purpose of decision making. The simulation results show that MOMVO produces appropriate components size and the PV/wind/battery/diesel is the optimum configuration with values of COE = 0.2720$/KWh, LPSP = 0.1397, and RF = 92.37% at w 1 = 0.5, w 2 = 0.3, and w 3 = 0.2. Sensitivity analysis is performed to show the effect of changing system parameters on the objective functions. It is also shown that the techno-economic feasibility of using HMGS for rural electrification systems and enhance energy access.

Improving Hybrid Power Supply System for Telecommunication Service Providers in Nigeria

Abstract: The aim of this research is to use a combination of renewable energy sources and conventional diesel generator to model a cost effective, alternative energy source for telecommunication base stations in Nigeria. Actually, this study uses various theoretical and mathematical modelling tools, such as, Mat lab Simulink and HOMER software. In the same way, the study references several Base Transceiver Stations (BTS) from gsm providers at select geographical locations in Rivers State. The study references BTS infrastructure in locations such as Ogoni, Port Harcourt and Emohua. These locations were selected to reflect different climatic conditions in Rivers state. Against this background, various hybrid combinations comprising at least two sources of renewable energy e.g Wind Turbine generator(WTG) and Solar Photovoltaic (SPV) were modelled. Also, Fuzzy logic optimization algorithm was used in tracking the maximum power in the SPV. A sample Diesel Generator(DG) was studied to analyze which possible combination gives optimum performance and is most cost effective. The total cost for installation and maintenance of the hybrid system was also considered. Consequently, one of the common negative effects of conventional power generation and usage, which is environmental pollution, was also highlighted during the study. In the course of this research, Homer was used to model a hybrid system in which the initial capital Cost (ICC) was N101,517,040 for 96 nos battery, 1 no 10kw WTG, 1 no hydro-turbine, 48 nos converters, labour etc. The replacement cost for component has a depreciation of 30%; while maintenance for diesel is 30% of the ICC. Eventually, the results obtained from the simulations showed that with an increase in supply from renewable energy sources the overall cost spent when compared to using a diesel generator only is cut by 50%, while the pollution effects also dropped. In fact, the cost also reduces if the renewable energy system is designed efficiently to track and harness maximum power. Furthermore, it is also evident that the location of the base station site and the availability of Renewable energy source affects the efficiency and cost of the entire system. Hence, it is recommended that any telecommunication company which intends installing a hybrid power system for its base stations must carry out detailed feasibility studies using input parameters described here; especially, as it relates to siting of base stations in rural off-grid areas. Keywords: Hybrid Power Supply System

A Comparative Study of the Optimal Sizing and Management of Off-Grid Solar/Wind/Diesel and Battery Energy Systems for Remote Areas

Electrification in rural areas is relatively costly compared to urban areas. Therefore, the aim of this research is to identify the best combination of hybrid renewable energy systems (HRESs) to satisfy the load demand in a sustainable and cost-efficient way. The techno-economic study of stand-alone hybrid photovoltaic–wind turbine–diesel–battery-converter energy systems based on the hybrid optimization model for electric renewable (HOMER) simulation has been analyzed for various locations in the Tamil Nadu state, India. Various combinations of the systems have been compared and analyzed based on the performance of their technical parameters, costs, the electrical power production of each source, and unmet load. The findings indicated that the off-grid solar–wind–diesel–battery configuration is the most economical for all the sites among other system configurations. Comparing with conventional diesel generators among all the locations, a combination of solar/wind/diesel/battery is the economically best design for Thoothukudi, with the least and most reliable solution in terms of net present cost and cost of energy. Also, the impact of intermittent variables becomes significant, so sensitivity analysis for the various parameters has been carried out. The study finds that the least cost of electricity and the net present cost of electricity for Thoothukudi are achieved at 0.266 $/kWh and 138,197 $, respectively. This is economical compared to a stand-alone diesel system where the obtained COE is $1.88 and the NPC is $977523. In the stand-alone diesel operating mode, 41854 kg of CO2is produced, which is higher than CO2emissions associated with any other renewable energy systems. According to the results, the Kanyakumari location outperforms in terms of producing environmental pollutants with emission of 1,020 kg/y CO2at their best. Moreover, the results of the proposed study imply that the proposed renewable energy system in remote sites could be a more economical measure.

Renewable energy can make small-scale mining in Europe more feasible

As one of the largest energy consumers and greenhouse gas (GHG) emitters, the mining industry is switching to renewable energy to help reduce its energy and environmental impacts. There are already renewable energy systems (RES) in operation at large-scale mines. However, for off-grid small-scale mining operations, conventional diesel generators are still preferred given their mobility and modularity. The aim of this paper is to assess the techno-economic feasibility of RES for switch-on, switch-off mining, an emerging concept for mobile small-scale mining, in Europe. Simulations were performed using the HOMER Pro software to evaluate whether mobile and modular containerised RES available on the market are economically viable compared with diesel generators for potential mine sites across Europe. The results suggests that mobile and modular containerised RES are technically and financially feasible for powering switch-on, switch-off mining at different geographical locations in Europe, with varying system designs depending on the renewable resources available and providing significant reductions in GHG and air pollutant emissions. However, the use of RES in SSM could potentially have both positive and negative environmental and social impacts from a life cycle perspective, which extend beyond the mine site due to a diverse supply chain and deserve further research.

Performance analysis of a novel hybrid power generation system integrated diesel generator with compressed heat energy storage

ABSTRACT The time-dependent energy demand of energy islands may frequently change the operating condition of diesel generator (DG), leading to diesel engine operating under off-design conditions with low efficiency. In order to make the DG operate under efficient conditions and balance the mismatch of energy supply and demand in time, a novel hybrid power generation system integrated DG with compressed heat energy storage (CHEST) using sensible and latent thermal energy storage is proposed in this study. The overall efficiency of the proposed system could be further improved due to the waste heat recovery of exhaust and cooling water. Firstly, a parametric analysis of the CHEST unit is conducted to select optimal parameters and conditions for the CHEST unit. Then a comparative analysis between the traditional DG system and the proposed DG-CHEST coupling system with three operating strategies is carried out. Results indicate that Strategy A, B, and C could save fuel of 45.48 kg (17.74%), 44.22 kg (16.19%), and 38.89 kg (14.23%) a day, corresponding to the overall efficiency of 28.02%, 27.83%, and 26.22%, respectively, while it is only 20.89% for the conventional DG system. The comparative results among the three strategies show that the discharged power index (DPI) and discharged fraction (DF) decrease with the increase of control level of load factor.