Hybrid system with micro gas turbine and PV (photovoltaic) plant: Guidelines for sizing and management strategies

• A methodology for sizing and managing hybrid systems with PV and MGT is presented.
• Two management strategies are presented to grant a defined day-ahead power output.
• The impact of the size of the PV plant on CO and NOx emission is evaluated.
• Natural gas savings and electricity specific cost reduction are assessed.

This paper presents a hybrid system consisting of a 100 kWe micro gas turbine (MGT) that juxtaposes the energy production of a photovoltaic (PV) plant whose yearly yield is available by on field measurements. The aim of the work is to model and investigate the behavior and the performance of a hybrid MGT-PV system under the topical constraint of firming renewable power and hence of guaranteeing a reliable power production to the grid. We propose a solution for the sizing of the PV plant and two strategies for the management of the hybrid system in order to guarantee a reliable day-ahead hourly forecast of the electric power that can be actually produced by the plant under whatever ambient condition. The results ascertain the advantages of the upgraded system in terms of natural gas consumption (−16%) and and NOX (∼ −33%) with a higher local emission of CO. In particular, the proposed hybrid system: i) solves the problem due to the unpredictability of PV energy production; ii) grants a significant reduction of the primary fuel usage and specific energy cost; but iii) increases the level of local pollutants, since it internalizes the emissions previously generated in a centralized power plant to produce the amount of electricity of the hybrid system.