Middle-temperature solar heat can be used to preheat feed water before it enters the boiler in a coal-fired power plant. Previous studies have shown that this approach can improve the performance of coal-fired power plants. The present study estimates the first solar–coal hybrid power plant in the Inner Mongolia Region. It will have a potential net solar power output of 10MW on the basis of the operating data of a traditional 200MW coal-fired power plant. Economic feasibility analysis is then performed on the solar–coal hybrid power plant. The appropriate feed-in tariff prices are provided on the basis of different financing scenarios, solar field cost, collector area size, and other conditions. The results obtained in this study are expected to provide suggestions for the further development of solar–coal hybrid technology.

Conclusions

The Chinese government offers incentives to solar power projects depending on its economic performance conditions. The study revealed the required government subsidy for a demonstration project taken on a 200MW coal-fired power plant hybridized with solar heat at approximately 300℃. The cash flow method is utilized to simulate the NPV of the solar–coal hybrid power project in Zhuozi City, Inner Mongolia, China, and to analyze the IRR and required FiT of this project.

The outcomes revealed that the government must offer a FiT value of at least 1.21 RMB/kW h under the circumstance of 1550 kW h/m² local annual solar radiation, 58,860 m² limited solar field area size, and 1325 RMB/m² domestic collector price. The investment can then earn a rate of return to offset the inflation of approximately 8% for the investors to have the possibility to make a profit. When financing scenarios from several projects in China adopted, the required FiT can be further decreased, such as a FiT of 0.99 RMB/kW h with low-interest rates of 3% loans and half-reduced VAT. Sensitivity analysis shows that the key variables affecting the economic performance of the solar–coal hybrid power plant are solar radiation (±50% variation: 0.99–3.46 RMB/kW h), collector cost (±50% variation: 0.79–1.63 RMB/kW h), and collector area size (±50% variation: 1.17–1.53 RMB/kW h).

To promote the development of solar–coal hybrid power technology, government support policies must be implemented and investors should utilize low-interest loans, cost-effective collectors, and appropriate solar field size. The results of this study are expected to provide beneficial suggestions for developing the solar–coal hybrid technology.

The results have been published on Applied Thermal Engineering 108 (2016) 378–387.