Feasibility of Transitioning from Fossil Energy to 100% Renewable Energy in Residential Buildings and a Comparative Analysis

Energy has always been an indispensable need in human life. From past to present, this need has increased and has been met through various means. Today, due to population growth and technological development, the demand for energy has risen significantly. Although energy plays an important role in our daily lives, it also brings certain disadvantages. While it improves our living standards, it simultaneously puts our future at risk. The main reason for this is the extensive use of fossil resources in energy production. The decline in air quality and the emergence of the climate crisis—both caused by harmful gases released into the atmosphere—negatively affect our future. Moreover, it is known that fossil resources will be depleted in the near future, making their continued use for energy production unsustainable. Considering all these factors, renewable energy sources emerge as the only viable alternative to fossil fuels. The clean and sustainable nature of renewable energy makes it an essential solution for our planet. Renewable sources pose no risk of depletion and allow energy to be produced without harming the environment and nature. In this study, the energy demand of a four-person household located in Ayvalık, Balıkesir, Turkey, was analyzed under four different supply scenarios: grid-only, completely fossil-fueled, renewable–fossil hybrid, and fully renewable hybrid systems. The feasibility of achieving 100% renewable energy was investigated. Four different scenarios were designed and simulated using the HOMER Pro software. These systems were also illustrated using the Unity program. Based on the analyses, the advantages and disadvantages of each scenario were evaluated, and the feasibility of renewable energy implementation was assessed.