Integrated optimal design of concentrated photovoltaic-thermoelectric generators systems and dynamic configurations for multi-electrolyzers: Enhancing direct-coupling reliability and hydrogen production

Efficient direct coupling of renewable energy sources (RESs) with multi-electrolyzers (multi-ELZs) requires continuous alignment of multi-ELZs’ operating points with the maximum power point (MPP) of RESs under varying environmental conditions. A promising approach to achieve this alignment is to dynamically configure the multi-ELZs by switching their series units for MPP tracking. However, frequent switching events in the series units of multi-ELZs shorten their lifespan, posing a critical challenge to system reliability and efficiency. To address this issue, this paper proposes an integrated optimal design for a hybrid energy system that includes a concentrated photovoltaic (CPV) array and thermoelectric generators (TEGs) with an effective and simplified switching strategy for dynamically configuring the series units of multi-ELZs based on the maximum current values of the CPV and TEG arrays. This design aims to maximize the transmitted power to the multi-ELZs and enhance dynamic tracking of the MPP while minimizing the frequency of switching events in the series units of the multi-ELZs. The TEGs are positioned beneath the CPV to improve system efficiency by recovering waste heat from the CPV array and converting it into electrical energy while simultaneously providing cooling, thereby boosting the performance of the CPV. Additionally, an updated dichotomic rotational symmetry (UDRS) design is introduced for the optimal design of CPV and TEG arrays. This method addresses the uneven distribution of concentrated radiation and associated temperature, ensuring consistent peak power generation and consequently reducing the switching frequency for configuring the multi-ELZs while maintaining MPP alignment under fluctuating conditions. The proposed design is compared against state-of-the-art designs, including series–parallel (SP), total cross-tied (TCT), and rotational symmetry (DRS) systems, based on key performance metrics such as CPV-TEG maximum harvested power, the frequency of switching events for configuring the multi-ELZs, power delivered to multi-ELZs, and the hydrogen production rate. Results indicate that the proposed approach significantly reduces radiation non-uniformity, which boosts the maximum harvested power of the CPV-TEG arrays, minimizes the switching frequency for configuring the multi-ELZs by nearly 50% across twelve operating conditions compared to the SP and TCT. It enhances power delivered to the multi-ELZs system coupled with the CPV array by over 10% to 40% compared to the SP and TCT, improves power delivered to the multi-ELZs system coupled with the TEG array by over 15% to 30% compared to the DRS design, and increases hydrogen production by more than 12.89% and 18.05% compared to the SP and TCT designes. Thus, following the proposed approach represents a significant step toward achieving the United Nations Sustainable Development Goal 7 (SDG 7), which aims to ensure access to clean and affordable energy.