This paper aims to investigate the techno-economic feasibility analysis of stand-alone diesel system, stand-alone PV/storage system, PV/diesel hybrid system, PV/diesel/storage hybrid system for the Pratas island in Taiwan. The power supply of outlying islands in Taiwan still use fossil fuel generators. The fuel cost is higher than that of on shore of Taiwan, and it has a great impact on the environment. This problem can be mitigated by hybrid energy systems. Through the investigation to know the existing generator set and Photovoltaic (PV) operating status, load consumption, etc., the study collects the required data for statistical meteorological analysis and economic analysis, and uses Hybrid Optimization Models for Energy Resources (HOMER) to simulate techno-economics of the stated hybrid energy systems. The analysis contains the capital cost, net present cost (NPC), cost of energy (COE) and fuel saving in different capacities for each power supply system with different constraints. From the simulation results, the lowest COE is 0.3569 $/kWh that can be found at the PV/diesel hybrid system configuration scheme with a total PV system capacity of 200 kWp, the renewable fraction (RF) is 15.3% and the excess electricity fraction is 2.6%, which is lower than the generally acceptable 5%. Although the COE of PV/diesel/storage hybrid is higher than that of stand-alone diesel system, the annual total CO2 emissions is reduced by 31.63%, which is of great benefit to environmental protection.

As the cost of the battery energy storage system (BESS) is lower, the penetration rate of battery storage is rising in the behind-the-meter (BTM) market. BESS with time-of-use rates (TOU) for charge and discharge scheduling can be used to reduce electricity costs. This research uses 6,600KW contract capacity for industrial customers as the study case. Through the BESS techno-economic simulation in Hybrid Optimization Models for Energy Resources (HOMER) Grid software, the optimal capacity planning can be obtained from the electricity demand. The results show that the contract capacity can be adjusted to 6,100kW with a project benefit of $68,557, levelized cost of energy (LCOE) of 0.09338 $/kWh, net present cost (NPC) of $−$24,768,508, internal rate of return (IRR) of 3.72%, return of investment (ROI) of 2.16%, and discounted payback of 8.37 years in the 500kW/1065kWh required BESS capacity case. The sensitivity of the electricity price, key components cost, and real interest rate are evaluated and the method will be applied as a reference for planning the BTM BESS of other utility customers.

Achieving universal electricity access is a challenging goal for the governments of developing countries such as Ethiopia. Extending the national grid to the remotely located, scattered, and island populations demands a huge investment. This paper aims to show the techno-economic feasibility of minigrid renewable energy system to electrify Kibran Gabriel island in Ethiopia, through the execution of simulation, optimization and sensitivity analysis using Hybrid Optimization Models for Energy Resources (HOMER Pro) software. The minigrid systems were compared with both diesel generation (DG) and grid extension systems. The hybrid photovoltaic (PV)/DG/battery system is more economically feasible compared with other minigrid systems, and the best cost-effective option is the one including load flow (LF) strategy with 25 kW of PV, 10 kW of DG, 40 kWh of battery, and 5 kW of bi-directional convertor. The optimal PV/DG/Battery system, having levelized cost of energy (COE) of USD 0.175/kWh, net present cost (NPC) of USD 119,139 and renewable fraction (RF) of 86.4%, reduces the pollutant emissions by 33,102 kg/yr compared with the stand-alone DG system. The optimal minigrid sensitivity to the variations in global horizontal irradiance (GHI), diesel price and load consumption were considered in the sensitivity analysis, and the result shows that the system will operate reasonably well.

The Philippines consists of 7100 islands, many of which still use fossil fuel diesel generators as the main source of electricity. This supply can be complemented by the use of renewable energy sources. This study uses a Philippine offshore island to optimize the capacity configuration of a hybrid energy system (HES). A thorough investigation was performed to understand the operating status of existing diesel generator sets, load power consumption, and collect the statistics of meteorological data and economic data. Using the Hybrid Optimization Models for Energy Resources (HOMER) software we simulate and analyze the techno-economics of different power supply systems containing stand-alone diesel systems, photovoltaic (PV)-diesel HES, wind-diesel HES, PV-wind-diesel HES, PV-diesel-storage HES, wind-diesel-storage HES, PV-wind-diesel-storage HES. In addition to the lowest cost of energy (COE), capital cost, fuel saving and occupied area, the study also uses entropy weight and the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method to evaluate the optimal capacity configuration. The proposed method can also be applied to design hybrid renewable energy systems for other off-grid areas.

The electrical distribution system has experienced a number of important changes due to the integration of distributed and renewable energy resources. Optimal integration of distributed generators (DGs) and distribution network reconfiguration (DNR) of the radial network have significant impacts on the power system. The main aim of this study is to optimize the power loss reduction and DG penetration level increment while keeping the voltage profile improvements with in the permissible limit. To do so, a hybrid of analytical approach and particle swarm optimization (PSO) are proposed. The proposed approach was tested on 33-bus and 69-bus distribution networks, and significant improvements in power loss reduction, DG penetration increment, and voltage profile were achieved. Compared with the base case scenario, power loss was reduced by 89.76% and the DG penetration level was increased by 81.59% in the 69-bus test system. Similarly, a power loss reduction of 82.13% and DG penetration level increment of 80.55% was attained for the 33-bus test system. The simulation results obtained are compared with other methods published in the literature.

Islanded microgrids with high renewable energy penetration face critical challenges in maintaining frequency and voltage stability owing to their low system inertia, communication delays, and intermittent generation. This paper proposes a hierarchical control framework that integrates adaptive virtual synchronous generator (VSG) dynamics, a delay-compensated consensus protocol, and battery energy storage system (BESS) optimization. The framework adopts VSGs with dynamically adjustable inertia, combined with adaptive Q–V droop control, to coordinately regulate frequency and voltage while compensating for communication delays using predictive feedback and event-triggered mechanisms. A multi-objective BESS strategy achieves a balance among synthetic inertia support, voltage regulation, and state-of-charge (SoC) limitations. Simulation results for a 500 kW microgrid with 70% renewable energy show that the proposed framework outperforms conventional droop control and fixed-inertia VSGs. The main results include frequency deviation below 0.04 Hz (versus 0.12 Hz for droop control), voltage regulation error within ±1.2% (versus ±4.2% for droop control), and a 50% reduction in communication traffic. In the case of a 150 kW diesel generator loss, PV system slowdown, and load surge, the adaptive VSG reduced the stabilization time by 30% and maintained the SoC of the BESS in the range of 20%–80%. This approach effectively addresses the challenges posed by low inertia, enhances the physical resilience of the grid, and provides a scalable solution for microgrids dominated by renewable energy sources. Future research will focus on hardware-in-the-loop verification and cyber-attack-resilience integration.