Annual performance analysis and optimization of a solar tower aided coal-fired power plant

Abstract

The integration of solar energy into coal-fired power plants has been proven as a potential approach in the utilization of solar energy to reduce coal consumption. Moreover, solar augmentation offers low cost and low risk alternatives to stand-alone solar thermal power plants. In this study, the annual performance of a solar tower aided coal-fired power (STACP) system is investigated, and the influence of thermal storage system capacity on the annual solar generating power and annual solar-toelectricity efficiency is explored. The thermal storage system capacity is optimized to obtain the lowest levelized cost of electricity (LCOE). At the same time, the influence and sensitivity of several important economic factors are explored and assessed. Results demonstrate that compared to a coal-fired power system, the reduction in the annual average coal consumption rate of the STACP system with high direct normal irradiance (DNI), medium DNI, and low DNI are 5.79, 4.52, and 3.22 g/kWh, respectively. At a minimum, the annual coal consumption can be reduced by 14,000 t in a 600 MW power generation unit. Because the same solar field is considered under different DNI conditions, the LCOE in the high DNI,

Comparative Performance Assessment of 300 MW Solar‐Coal Hybrid Power Generation System Under Different Integration Mechanisms

“…The main initial investment of the heliostat SF for estimating the economic analysis is given in Table 3 . [ 13,22,27 ] The LCOE can be estimated by the following formulas.where CC is the increased total capital cost after the SF introduced into the SCHPG system (USD); AF is the annuity factor; O&M is the annual operation and maintenance expenditure of SF (USD), and is the annual solar electricity generation (kWh).…”

“…Thermodynamic equations related to the tower-type heliostat SF subsystem are presented in detail as follows. [9,13] Direct normal irradiation (DNI) is a key parameter for performance assessment of a heliostat SF, which is prescribed as the input value for any process model of concentrated solar energy utilization.…”

“…The integration of solar energy into a coal‐fired thermal power plant is an interesting topic of solar power generation, which has been studied in the last few decades. There are many possible integration mechanisms for combining solar energy and coal‐fired thermal power plants, such as feedwater preheating, [ 12 ] feedwater evaporation and steam superheating, [ 13 ] steam reheating, [ 14 ] air preheating, [ 15 ] coal drying, [ 16 ] CO 2 capturing, [ 17 ] and flue gas treatment. [ 18 ] Numerous studies have conducted detailed investigations on the performance analysis and techno‐economic evaluation of the SCHPG system with various capacities under different operation conditions.…”

Techno-Economic Feasibility Analysis of Concentrated Solar Thermal Power Plants as Dispatchable Renewable Energy Resource of Pakistan: A case study of Tharparkar

“…Thus, reducing carbon emissions can be appreciable. The integration of CSP with the coal reduces the emissions, increases the capacity factor of Power plant and decreases the LCOE (Li et al, 2019) (Pramanik & Ravikrishna, 2017).…”

Off-design thermodynamic performances of a combined solar tower and parabolic trough aided coal-fired power plant

“…Considering the requirement of basically unchanged steam temperature, the maximum extraction percentage was indicated as 8% and 30% in the two schemes [32]. Then Zhang et al [33] and Li et al [34,35] explored the annual performance of STCG with superheaters partly replaced by molten salt-steam heat exchangers, with effects of thermal energy storage (TES) capacity considered. More recently the scheme with solar tower to reheat exhaust steam from the intermediate turbine are also performed by Li et al [36] In these studies, solar energy from parabolic troughs or the solar tower is integrated with coal-fired power plants separately, leading to a limited potential solar contribution considering boiler safety issues.…”