Variable-step incremental conductance (Inc.Cond.) technique, for photovoltaic (PV) maximum power point tracking, has merits of good tracking accuracy and fast convergence speed. Yet, it lacks simplicity in its implementation due to the mathematical division computations involved in its algorithm structure. Furthermore, the conventional variable step-size, based on the division of the PV module power change by the PV voltage change, encounters steadystate power oscillations and dynamic problems especially under sudden environmental changes. In this study, an enhancement is introduced to Inc.Cond. algorithm in order to entirely eliminate the division calculations involved in its structure. Hence, algorithm implementation complexity is minimised enabling the utilisation of low-cost microcontrollers to cut down system cost. Moreover, the required real processing time is reduced, thus sampling rate can be improved to fasten system response during sudden changes. Regarding the applied step-size, a modified variable-step size, which depends solely on PV power, is proposed. The latter achieves enhanced transient performance with minimal steady-state power oscillations around the MPP even under partial shading. For proposed technique's validation, simulation work is carried out and an experimental set up is implemented in which ARDUINO Uno board, based on low-cost Atmega328 microcontroller, is employed

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In this paper, a DC-link voltage sensorless control technique is proposed for single-phase two-stage grid-coupled photovoltaic (PV) converters. Matching conventional control techniques, the proposed scheme assigns the function of PV maximum power point tracking (MPPT) to the chopper stage. However, in the inverter stage, conventional techniques employ two control loops; outer DC-link voltage and inner grid current control loops. Diversely, the proposed technique employs only current control loop and mitigates the voltage control loop thus eliminating the DC-link high-voltage sensor. Hence, system cost and footprint are reduced and control complexity is minimized. Furthermore, removal of the DC-link voltage loop proportional-integral (PI) controller enhances system stability and improves its dynamic response during sudden environmental changes. System simulation is carried out and an experimental rig is implemented to validate the proposed technique effectiveness. In addition, the proposed technique is compared to the conventional one under varying irradiance conditions at different DC-link voltage levels, illustrating the enhanced capabilities of the proposed technique.

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Summary Egypt is a country with high solar energy potential and the exploitation of such promising energy resource is critical for national sustainable development through efficient energy planning with gradual independence from fossil fuels. Successive incentive polices had been introduced by the Egyptian electricity authority to encourage the deployment of small‐scale residential rooftop photovoltaic (PV) systems. This article studies the techno‐economic feasibility of grid‐connected rooftop PV system in Egypt under the currently applied retail electricity price and the net energy metering policy. The study investigates three types of residential households with different electricity demand levels; low, medium, and high consumptions. The economic evaluation of various sizes of the PV system is carried out based on different economic measures such as net present value, cost of energy, payback period, and electricity bill saving. Hybrid Optimization of Multiple Energy Resources software has been utilized to carry out such economic evaluation. The results identify that the viability of PV installation in residential applications is clearly affected by the energy consumption pattern, the parameters of the incentive policy applied, and the economical indices of the system.

This paper studies the application of renewable energy sources in wastewater treatment plants to achieve self-sustainability of power. The data of wastewater treatment plant in the rural city of Toukh-EGYPT are presented as a case-study. The primary objective is to provide an entirely renewable standalone power system, which satisfies lowest possible emissions with the minimum lifecycle cost. Mass balance principle is applied on the biodegradable components in the wastewater to evaluate the volume of digester gas that is produced from sludge through anaerobic digestion process. Using digester gas as a fuel lead to study combined-heat-and-power technologies, where fuel cell is selected in order to abide by the low emissions constraint. The study assessed the electrical power obtained from fuel cell and the utilization of the exhausted heat energy for additional electrical power production using a micro-turbine. After covering the major part of load demand, the use of other renewable energy sources was studied. The strength of both solar and wind energy was determined by the case-study location. Hybrid optimization model for electric renewable (HOMER) software was used to simulate the hybrid system composed of combined-heat-and-power units, wind turbines and photovoltaic systems. Simulation results gave the best system configuration and optimum size of each component beside the detailed electrical and cost analysis of the model.