Optimised autonomous power system

Renewable energy sources are increasingly playing a key role in the operation and evolution of the power electric systems. However, their incorporation bring with it diverse concerns. A very important issue has to deal with the fluctuations of the renewable resources. Compressed air-based energy storage systems (CAES), with favorable characteristics are a sound means for allowing the efficient integration of the intermittent renewable-based sources. This paper is focused on evaluating the economical and environmental effects of incorporating a CAES plant within an autonomous power electric system composed of a combined heat and power plant (CHP) and a high penetration of generators based on renewable sources (wind and photovoltaic). The CHP plant uses a gas turbine as the prime mover and an external boiler for the thermal peak load demand. The stored compressed air is used to partially or totally drive the gas turbine of the CHP plant. In order to properly evaluate the impact of incorporating CAES within the APS, the energy production costs as well as the environmental benefit of using electric energy storage systems - expressed in terms of CO₂ equivalent- are estimated. Sensitivity analyses regarding the fuel prices as well as the sizing of the CAES plant and of the renewable resources-based generators are performed.