In order to reduce fossil energy consumption

lower greenhouse gas emissions

and improve the capacity of renewable energy consumption

aiming for both the high efficiency and flexible regulation

this paper proposes a new solar-aided coal-fired power generation system integrated with the thermal storage unit

along with its operation strategy. A smaller heat storage system is integrated to improve the flexibility of coal-fired power generation system

broaden the unit operation range

and increase the capacity of renewable energy consumption. Based on a 660 MW ultra-supercritical coal-fired power generation unit

this paper compares the performance of the new system and the traditional solar-aided coal-fired power system without/with the thermal storage unit. The results indicate that the coal consumption rate of the coal-fired power generation system coupled with 30 MWth of parabolic trough solar is reduced significantly

and the reduction of standard coal consumption rate can reach 12 g/(kW⋅h) under low load condition. The coal saving and carbon reduction benefit of the new system reaches 12.85 million RMB at the local solar resource level. When the load of the new system is reduced by extracting main steam under the condition of 30% BMCR (boiler maximum continuous rating)

the peaking capacity and the peaking depth are 18.22 MW and 2.8%

respectively

and the annual income of extraction steam peak regulation reaches 6.75 million RMB. Considering the coal saving revenue

carbon reduction revenue

peak shaving revenue

solar field cost

and heat storage cost

the net present value of the new system is 58.06 million RMB

and the payback period is 10 years

which is much less than that of the traditional solar-aided coal-fired power generation system. The proposed system has a significant engineering application value

which can be used as a reference for the flexibility improvement of coal-fired power generation units.