Mehmet Zahid Erel

Renewable energy technologies are becoming more and more relevant in a variety of engineering fields as a result of the move toward low-carbon, sustainable energy systems. Although research has historically concentrated on power generation, it now covers a broad range of applications, including precision agriculture, smart grids, energy storage, healthcare devices, and sustainable buildings. However, existing review studies are often limited to single disciplines or specific technologies, lacking a unified cross-disciplinary perspective that captures the interconnected nature of modern renewable energy systems. This gap motivates the need for a comprehensive review that bridges multiple engineering domains. This review provides a comprehensive synthesis of literature on renewable energy applications in electrical and electronics, computer, environmental, biomedical, architectural, and agricultural engineering. In electrical and electronics engineering, the use of renewable energy sources is largely based on the efficient generation of electricity from natural resources such as solar, wind, and ocean energy. Computer engineering contributes through artificial intelligence (AI), Internet of Things (IoT) architectures, digital twins, and cybersecurity solutions, optimizing energy management. Environmental engineering emphasizes life cycle assessment, carbon footprint reduction, and circular economy strategies. In biomedical engineering, energy harvesting and self-powered devices illustrate micro-scale applications of renewable energy. Architectural engineering integrates renewable systems through building-integrated photovoltaics, net-zero energy designs, and smart building management, while agricultural engineering uses solar-powered irrigation, biomass utilization, agrivoltaic systems, and other sustainable practices. To support a low-carbon future with integrated and sustainable engineering solutions, this study not only highlights innovations within individual fields but also showcases how different disciplines can connect and work together. Overall, the review offers a novel cross-disciplinary framework that advances the understanding of renewable energy systems beyond isolated applications and provides direction for future integrative research.

Thermoelectric generators (TEGs) enable compact waste-heat energy harvesting but require high-gain DC–DC conversion due to their low-output voltage for DC microgrid interfacing. This work proposes a novel TEG-supplied two-stage architecture consisting of a perturb-and-observe (P&O)-based MPPT boost converter followed by a modified Z-source converter regulated through an advanced model predictive control (MPC) framework. The modified Z-source topology enables high-voltage gain without extreme duty ratios and mitigates switching losses by eliminating diode reverse-recovery effects via synchronous operation. To enhance dynamic performance, the advanced MPC strategy incorporating an adaptive ripple-based weighting mechanism is applied to the modified Z-source converter and benchmarked against MPC and sliding mode control (SMC). Simulation results under multiple disturbance scenarios, including hot-side and cold-side temperature variations, multi-condition disturbances, coupling-factor variation, and measurement noise, demonstrate that the proposed system maintains stable 400 V regulation at a 100 W output level. In contrast, MPC exhibits switching frequency deviations that increase switching losses during transient operation, while SMC suffers from significant voltage deviations under source variations. The proposed strategy maintains tight voltage regulation with nearly fixed-frequency operation around 50 kHz, providing a new perspective for TEG researchers while supporting sustainable waste-heat energy utilization.

Thermoelectric generators (TEGs) enable compact waste-heat energy harvesting but require high-gain DC–DC conversion due to their low output voltage for microgrid interfacing. This work proposes a novel TEG-supplied two-stage architecture consisting of a perturb and observe (P&O)-based MPPT boost converter followed by a modified Z-source converter regulated through an advanced control strategy. The modified Z-source topology enables high voltage gain without extreme duty ratios and mitigates switching losses by eliminating diode-related reverse-recovery effects via synchronous operation. To enhance dynamic performance, an advanced model predictive control (MPC) approach is adopted and benchmarked against conventional MPC and sliding mode control (SMC). Simulation results under hot-surface temperature variations demonstrate that the proposed system maintains stable 400-V DC bus regulation at a 100-W output level. In contrast, conventional MPC exhibits switching-frequency deviations that increase switching losses during transients, while conventional SMC suffers from significant voltage deviations. After the temperature variation tests, the proposed control strategy is subjected to a ±20% load test, in which it maintains 400-V regulation with nearly fixed-frequency operation, confirming its superior dynamic suitability for TEG-based systems operating at 50 kHz. The proposed innovative design provides a new perspective for TEG researchers while supporting sustainable waste-heat energy utilization.

This study proposes a more effective utilization of fuel cell (FC) technology by integrating a thermoelectric generator (TEG), which harnesses waste heat to generate electrical energy. While the FC still requires hydrogen, the integration of a TEG enables supplementary power generation from waste heat without any additional fuel input, resulting in a more efficient and compact hybrid system. The Perturb and Observe (P&O) MPPT-based SEPIC converter is highlighted for use in light fuel cell electric vehicle (FCEV) applications due to its inherent buck–boost capability, making it particularly suitable for practical implementations. To achieve maximum efficiency and ensure stable operation of the TEG, the FC is operated at its nominal power of 93.75 W in this system. The integrated TEG system, combined with a high-efficiency boost converter, contributes approximately 5-W to the proposed hybrid energy system, which achieves an overall efficiency of 96.1%. The proposed hybrid energy system holds great potential for providing sustainable energy solutions in transportation applications.

Wireless power transfer (WPT) presents a promising approach for charging electric vehicles (EVs), offering increased convenience, reliability, and safety for EV customers. Recently, the incorporation of multiple coil structures in wireless charging systems has addressed various operational challenges, enhanced power transfer, and provided a scalable solution for EVs. However, cross-coupling issues and space limitation problems arise when multiple coils are introduced to the WPT system. In this paper, a novel integrated compact coupler is proposed, including two naturally decoupled coils on the transmitter side, while both are coupled with the receiver coil to improve the power transfer capability of the system. ANSYS Maxwell is employed to simulate the proposed coupler and evaluate its performance under misalignment operations. The proposed wireless charging system inherently detects misalignment direction based on the variation of output voltage with respect to x-misalignment. As a result, the experimental prototype of the designed wireless WPT system presents a peak efficiency of 97.08% at 1.147-kW output power for an air gap of 120 mm under fully-aligned condition. Additionally, the designed compensation coil can transfer power of 243.76-W under fully-aligned condition and increases reliability in power transfer during misalignment operations.

Inductive wireless charging has emerged as a viable solution for charging electric vehicles (EVs) both in stationary mode and on the go, i.e., dynamic charging. EVs are produced at a commercial level, and their wired charging stations are widely available. However, challenges still restrict the development of wireless charging infrastructure on a commercial scale. One significant challenge is the presence of foreign objects on the magnetic coupler surface. Although several foreign object detection (FOD) methods exist, the implementation of each method is cost-dependent. Among these methods, the parametric detection method is considered the most cost-effective. However, the effective precision of this method is still debatable. In this article, the performance of the magnetic coupler is analyzed under the influence of different materials as foreign objects. The analysis presented in this article is threefold. Firstly, a mathematical model of the magnetic coupler in the presence of a foreign object is developed. Secondly, the effect of different materials is analyzed as a function of coil parameters, including inductance, resistance, and coil losses. Lastly, the magnetic field distribution and magnitude are studied using finite element analysis (FEA). The influence of these materials is ultimately evaluated in terms of output power losses and efficiency. The study concludes that the presence of aluminium as a foreign object is responsible for significant power losses in the wireless power transfer system.

Dynamic wireless charging is making its way to charge electric vehicles (EVs) on the go. It has the potential to reduce both EV battery size and cost. However, the dynamic wireless power transfer (DWPT) system needs to be optimized before it can become widely available in the market. This includes designing compact magnetic couplers that can easily be placed under EVs and can handle both static and dynamic charging. This article recommends a single-sided flux-generating magnetic coupler with optimized performance factors. The proposed coupler has a better coupling coefficient and mutual inductance with considerably lower self-inductance, when compared to the conventional magnetic couplers. When tested for DWPT operation with three symmetric transmitters, the proposed coupler offers low mutual inductance with neighboring transmitters and naturally decouples with the third transmitter, reducing the effort required for decoupling multiple transmitters. The proposed receiver offers only 1.3% pulsating output voltage. Also, the proposed optimization helps to achieve 360° rotational misalignment tolerance with zero null zone present in its output I-V characteristics. To validate the proof of concept, a 1.6kW output power dynamic using LCC-S compensation at 85kHz resonance frequency is designed for 200mm air-gap, with maximum recorded efficiency to be DC-DC ~93%.

Capacitive power transfer (CPT) technology has gained more and more importance in recent years. This paper investigates the effects of temperature and relative humidity on CPT system performance. The conventional four-plate horizontal and vertical co...