Design and fabrication of a containerized micro-grid for disaster relief and off-grid applications

Rapid solutions are needed throughout the world to meet electrical demands for disaster relief, stabilizing development, industrial or research centers, exploratory drilling and mining, military stationing, and other off-grid or weak-grid applications. This need for on-demand power requires a mobile, modular, and self-sufficient power system designed for rapid deployment and seamless integration. This paper describes a mobile power solution specifically designed for disaster response situations like the Haiti earthquake in 2010, the primary motivating case for this work. A public-private partnership between Arizona State University and NRG Energy was formed to complete the use-inspired design. The mobile system was scoped to meet electricity requirements for a command center, clinic, cellular communications, kitchen, short-term lodging and public lighting, and other critical loads needed to stabilize development in the wake of natural or anthropogenic disaster that destroys the local electrical infrastructure. Deploying modular and self-contained microgrids has the potential to reduce human harm following disaster by providing a decentralized network of electrical generation assets designed to meet critical loads for human survival and well being. In addition, since no two emergency situations are alike, the proposed solution provides flexibility and scalability to meet constraints for local renewable resources, fuel availability, and physical deployment space. The final system includes a 20 kW solar photovoltaic (PV) array, 10 kWh of lithium-ion battery storage, a 10 kW inverter system, a control computer, and a 20 kW diesel generator for supplemental power. The solar array is packed within a 20' steel shipping container for ease and safe transport, thereby making the solution "containerized." Components must be firmly mounted or secured to the walls and floors of the container for transport via a cargo freighter or helicopter. A second room was created inside the container to separate the generator from the batteries for safety purposes. The prototype can be fully deployed and functional in less than one hour's time, and was tested against a load bank during various times of the day to illustrate how the power system controls shift operation between batteries, solar PV, and the generator. Sustainability, ethics, health, and safety features were considered in relation to the design specifications, manufacturability, and design scalability. These considerations included the lifecycle of the container, maintenance, modularity, intuitive operation, accessibility, and component temperature regulation, among others. Integration of other technologies such as wind power generation and water purification have the potential to bring further benefit through the plug-and-play containerized micro-grid solution.