Sustainable off-grid residential heating and desalination: Integration of biomass boiler and solar energy with environmental impact analysis

Abstract

As global energy demand rises and the environmental impact of fossil fuel-based heating systems becomes increasingly evident, transitioning to renewable energy sources like solar and biomass for residential use is imperative. This is further underscored by the growing scarcity of freshwater resources, especially in arid urban environments. This study introduces an innovative off-grid system that effectively integrates a floor heating system with a vapor compression desalination unit. The novelty of this study lies in its approach to combining solar and biomass energies for both heating and desalination in a single off-grid system. The system's electrical and thermal energy needs are met by combining photovoltaic thermal collectors and a biomass boiler. Using TRNSYS software, the system's performance was evaluated in varying design configurations across Riyadh, Doha, and Abu Dhabi, targeting optimal thermal comfort for a standard residence with four occupants. Results show Riyadh leading in solar fraction at 48.43%, followed by Abu Dhabi (47.23%) and Doha (44.85%). The optimal equivalent heat transfer coefficient for the floor heating system varied notably between these cities, with Abu Dhabi requiring a lower coefficient to achieve thermal comfort. Additionally, a life cycle analysis revealed that the biomass boiler is the predominant source of CO2 emissions, contributing over 70% of the total in each city. Riyadh exhibited the lowest CO2 emissions, attributed to its higher solar fraction. This study demonstrates the system's versatility across different urban climates and its potential to lessen dependence on traditional energy sources, positioning it as a promising solution for future off-grid applications.