Design and analysis of a hybrid solar stirling engine system for power generation.

Abstract

Since the 1990s, Lebanon has faced shortages in the supply of electricity which accounted for more than 10 hours a day. In fact, these shortages have led to the wide use of back-up diesel generators that are priced at 27 ¢-kWh. Moreover, the greenhouse gas emissions from a diesel engine accounts for around 20 tons of CO2 yearly per household, which aggravates the problem even more. This project aims to decrease the Cost of Energy (COE) and achieve a continuous energy generation. In a country where the grid power is weak, the solution envisaged is the implementation of a Microgrid system based on a Hybridized Stirling Engine (HSE). In fact, the HSE runs on solar thermal energy when available, and consumes natural gas during hours of darkness or clouds. Moreover, the system is coupled to a PV plant with Li-ion battery storage. By using optimization tools such as SAM and HOMER, it appeared that a 3kW HSE coupled with a PV capacity of 4kW and a 5kWh Li-ion battery storage is the most optimal configuration. In a nutshell, the COE was accounted to be 16.3 ¢-kWh and decreased the CO2 emissions by 52percent. These numbers were compared to alternative systems such as PV-Diesel-Batteries configurations and were still found to be the finest. Because of the economic feasibility of this project, lab scale Stirling Engine prototypes were assembled and tested.