Techno-Economic Assessment and Fuel Flexibility Analysis of Micro-Combined Heat and Power (Micro-CHP) Systems for Sustainable Domestic Energy Applications

This doctoral research provides a detailed examination of the background, motivation, aims, objectives, scope, and limitations of the study, along with the research framework, flowchart, and thesis structure. It introduces micro-Combined Heat and Power (micro-CHP) systems, emphasising their role in improving energy efficiency and reducing carbon emissions. An in-depth review is conducted on four primary prime movers commonly employed in residential micro-CHP systems: internal combustion engines (ICE), Stirling engines (SE), fuel cells (FC), and microgas turbines (MGT). These technologies are critically assessed in terms of their characteristics, operational performance, and suitability for household integration.

The study further explores the properties, efficiency, and operational flexibility of micro-CHP systems, with particular emphasis on MGT and FC technologies. It investigates the integration of these systems with biofuel-based renewable energy sources to enhance sustainability. Process simulations and energy-exergy analyses were carried out using Aspen Plus (Advanced System for Process Engineering), while GasTurb software was utilised for performance evaluation.

Two case studies were analysed: one combining an MGT-based CHP system with a Proton Exchange Membrane (PEM) electrolyser and fuel cell, and another featuring a standalone residential MGT. Hydrogen showed strong environmental and efficiency benefits, while hythane offered a balanced transitional fuel. Natural gas (NG) and methane delivered higher efficiencies but faced emission challenges. Recuperator integration improved performance via lean combustion. The findings confirm micro-CHP systems’ fuel flexibility and potential for low-emission, highefficiency residential energy aligned with net-zero goals.

Furthermore, the research explores strategies to improve the environmental performance of MGT and FC systems by examining biofuel production methods such as biomass conversion and anaerobic digestion (AD). Key technical challenges, risk factors, and economic implications are evaluated using Political, Economic, Social, Technological, Legal, and Environmental (PESTLE) analysis and Multi-Criteria Decision Analysis (MCDA) to identify the most viable micro-CHP configurations for residential applications.

This doctoral project serves as a detailed resource, offering a comparative analysis of diverse micro-CHP technologies and presenting a road map for their advancement.