MATHEMATICAL MODEL AND SIMULATION FOR DESIGNING A COST-OPTIMIZED OFF-GRID HOUSE SOLAR ENERGY STORAGE SYSTEM

Solar power is a renewable energy source suitable for residential usage due to its affordability and the small area required for installation. However, it requires an effective energy storage system that can minimize power outages within a limited budget. This challenge was addressed by analyzing energy storage systems regarding climate and user behavior. In this study, a mathematical model has been developed to design a cost-effective energy storage system for an off-grid household. We utilized the Markov weather process and Monte Carlo simulation, considering various scenarios of available energy supply, energy consumption, and user behavior. In accordance with the outcome, the size and type of battery system from our model minimized power outages throughout the year. We applied our model to a 1600-square foot house in Rayong, Thailand, with the meteorological data and typical electricity loads from user data. For a budget threshold of 40,000 USD, our model suggests that the best battery is Tesla Powerwall+, which results in an average power outage of only around 3 hours per year, outperforming other batteries under identical economic conditions. Additionally, our model can be widely applied to real scenarios by considering a broader range of batteries, environmental impact and available space, and hybrid systems as well.