In this article, a module-based plug-n-play (PnP) dc microgrid (MG) is introduced to help rural electrification. It provides a bottom-up way to form an MG with multilayer expandability and PnP feature. The module-based MG overcomes the drawback of conventional MG that requires central design and implementation which leads to high upfront cost and long lead time. It provides an organic way to form an MG that allows user to scale up the system as their demands grow, and fully utilize the existing resources. The proposed MG module is expandable on different layers that can meet the requirements of customers with different power consumption requirements. Each module, which contains PV generation and energy storage, can work as a stand-alone solar home system. Multiple modules can be connected as a group to scale up the local power supply. Groups can be interconnected through a public bus with gateway converter modules to form a community network, which can supply public usage and enable power exchange in a community range with relatively high distribution efficiency. The control of the proposed MG is in a fully decentralized manner such that central control and communication network can be omitted, which makes the system more user-friendly and highly robust. Detailed design, analysis, and implementation of the proposed PnP MG is provided in this article. Simulation and experimental results have been provided to verify the concept and analytical study.

The development of an efficient, eco-friendly, practical, and selective way to decompose formic acid (FA) into H-2 and CO2 is crucial for the utilization of FA as a chemical hydrogen storage material in hydrogen economy. In this regard, photocatalytic FA dehydrogenation attracts great attention owing to its potential to meet the above-mentioned requirements. Interestingly, there is no example of heterojunction photocatalyst that tunes the hole potential of the semiconductor, resulted in a better photocatalytic activity. We report herein for the first time the design and fabrication of a novel Z-scheme heterojunction photocatalyst for FA dehydrogenation, denoted as g-CN/Ag/Ag3PO4-AgPd comprising graphitic carbon nitride (g-CN) and Ag3PO4 semiconductors, Ag and AgPd alloy nanoparticles (NPs). The designed g-CN/Ag/Ag3PO4-AgPd photocatalysts boosted the FA dehydrogenation by creating more positive hole potential and improving the charge separation efficiency of the two distinct semiconductors. The g-CN/Ag/Ag3PO4-AgPd photocatalysts provided a very high turnover frequency (TOF) of 2107 h(-1) in the FA dehydrogenation under white-LED illumination at 50 degrees C. This TOF is 3.2 times and 44 times greater than those of g-CN/AgPd and g-CN/Pd binary non-Z-scheme heterojunction catalysts, respectively, under the same conditions and comparable to the best photocatalysts and heterogeneous catalysts reported in the FA dehydrogenation so far.