Energy and exergy efficiencies enhancement analysis of a family of integrated photovoltaic fuel cell systems

Integrated Energy Systems offer pathways to improve the overall efficiency and reliability of renewable energy technologies as efforts are made to decarbonise the energy sector. Here, energy and exergy efficiencies enhancement analysis (E4A) were applied to investigate the optimal configuration out of eleven modularised Integrated Photovoltaic Fuel Cell (IPVFC) systems. MATLAB was used to simulate the systems based on actual solar radiation and temperature data of Abuja, Nigeria. Cost-efficiency-complexity interrelationships were considered to understand the link between the efficiency and cost of the systems as the evolving complexities result from an attempt to reduce energy and exergy losses through recovery with additional energy conversion and storage components. The results indicated that System 2 (Integrated photovoltaic-thermal-converter-inverter-battery system) had the optimal energy and exergy efficiencies of 30.89% and 10.96%, respectively. Although the cost of the systems increased with increased complexity, there was no direct correlation between increasing efficiency of the IPVFC systems as their complexity increased. However, there was an apparent diminishing return in energy and exergy efficiencies of the IPVFC systems as the complexities increased. Yet, systems that used hydrogen as energy vector offer more reliability and possible application in a hydrogen economy. These findings underscore the importance of targeted component-level improvements when attempting to improve the overall efficiency of IPVFC system using exergy centred design approach.