Innovative full-range load operation solution for solar-aided power generation system: Enhancing efficiency with coal and solar energy flexibility integration

Abstract

Solar-aided coal-fired power generation (SAPG) has emerged as an efficient method for integrating solar energy into traditional power systems. Despite its potential, the simple application of traditional coal-fired unit operation solutions to SAPG plants can adversely impact coal-side performance, an issue often overlooked in the existing literature. This study introduces a novel full-range load operation solution (FLOS) for the SAPG system, termed FLOS_SAPG, which harnesses the complementary flexibility of solar and coal energy to expand the high-efficiency valve point operating range within the governing stage. Key operational parameters, including the configuration of steam governing, initial steam pressure, solar input scale, and condenser pressure, undergo a collaborative optimization process aimed at minimizing the standard coal consumption of power supply (SCC-PS). The findings indicate that the SAPG system with FLOS_SAPG, achieves a significant average reduction in SCC-PS, achieving 8.22 g/kWh across the full load range. To further the application of FLOS_SAPG, an advanced operation strategy is proposed that surpasses conventional approaches in technical, economic, and environmental performance. The co-optimization of annual coal consumption and total capital cost identifies an optimal storage capacity of 3.5 h and a solar multiple of one. This leads to a substantial increase in annual net revenue of 2.19 × 10⁶ USD (13.61 %). Moreover, there is a reduction in annual coal consumption by 1.90 × 10⁵ tons and in CO₂ emissions by 4.67 × 10⁵ tons, respectively.