Cogeneration optimisation for locally integrated energy systems

Abstract

Energy Efficiency is proven to be a significant opportunity for industry, cities and society, in general, to save energy costs and harmful gaseous and particulate emissions. Locally Integrated Energy System (LIES) was introduced to promote symbiosis between industry and local area to enhance their overall system energy efficiency. LIES extends Total Site Heat Integration (TSHI) to optimise the energy system for multiple industrial processes as well as other process heat demands in proximity. This paper integrates the TSHI methodology with Power Pinch Analysis (PoPA) to sequentially optimise the thermal and electrical energy in a LIES. A Power Cogeneration Estimation Table is used to systematically identify and determine the amount of power that the thermal energy system potentially generates via backpressure and condensing steam turbines. This work evaluated the thermal and power system based on total utility cost, where the thermal requirement is fulfilled by the industrial boiler system with the potential of outsourced power demands. A case study is performed for verifying the proposed methodology. Results found that LIES with Heat and Power Integration and battery storage is recommended for low utility cost operation without the need for a heat storage system.