HLRP Method as a Tool for Optimizing Energy Solutions Options

Abstract

The HLRP method is combined with optimization techniques to determine the best combination of a tri-generation system composed of a hybrid fuel cell system and alternative energy sources such as wind and solar energy. Solar thermal and photovoltaic systems with short term storage are used in this study. A small commercial site in Southern Europe is investigated. The HLRP method is based on using the ratio of the thermal load to the required power as the scaling parameter to analyze a hybrid fuel cell based tri-generation system in terms of performance parameters. The performance parameters, energy utilization factor, carbon dioxide and exergy destruction per total energy load, are reported in a series of graphs. The HLRP analysis is based on ideal performance of the power producing devices and practical performance parameters of all heat transfer devices. The alternative energy systems included in this analysis include state-of-the art performance measures. The previous publications on the HLRP method have focused on its development with short examples that illustrate how it operates as an effective, initial screening tool and limited cost factors. In this paper the application of the HLRP method as an early screening tool to determine the general outline of an efficient, total energy solution is detailed. The tool will be used to compare different solutions based on the fuel consumption (energy utilization factor), carbon dioxide production, exergy destruction and costs. The tradeoffs of reducing costs or increasing carbon dioxide production are illustrated. The solutions are based on a process using regression curves of the generalized graphs. The correlation coefficient for these regression relationships is greater than 0.996. In addition, refinement of the HLRP technique that reports carbon dioxide production and exergy destruction in terms of total energy rather than thermal loads has been adopted. Combining the generalized performance of the fuel consuming components with renewable energy sources leads to a solution based on balancing cost, minimizing fuel consumption or carbon dioxide production.