Performance analysis of a solar-aided waste-to-energy system based on steam reheating

Highlights: • Solar thermal energy is used to heat the working steam of a waste-to-energy plant. • The steam reheating of the cycle is achieved by the solar-aided thermal system. • The steam cycle performance is significantly improved with a higher efficiency. • High solar-to-electricity efficiencies are expected under various solar conditions. • The thermodynamic and economic feasibilities of the new design were evaluated. An innovative hybrid solar-municipal solid waste power system has been proposed for advancing the waste-to-energy and solar thermal energy technologies. The integration is realized by exploiting the useful heat harvested from sunlight in the parabolic trough collectors to reheat the working steam of the incineration plant and promote the steam temperature. Consequently, the steam cycle performance can be remarkably improved with the efficient utilization of solar energy. The hybrid design was thermodynamically and economically assessed based on a 500 t/d incineration plant, and the performance enhancement mechanism was revealed. Furthermore, a sensitivity analysis was conducted to examine the performance of the hybrid system under various solar conditions. The results indicated that the ideal steam cycle efficiency is boosted by 0.93 percentage points when adopting the proposed solution. The solar energy contributes to producing 1.17 MW net power with a solar-to-electricity efficiency of 21.59% at the design point. The integrated system performs excellently for most of the year, and the annual solar-to-electricity of 16.19% is achieved. Regarding a lifespan of 30 years, the levelized electricity cost of the solar-aided reheating system is as low as 0.1202 $/(kW∙h). Hence, the novel design is thermodynamically and economically suitable.