Novel concept of enhancing the performance of sloped solar collector by using natural anabatic winds

Abstract

A solar updraft power plant (SUPP) also called a solar chimney power plant is a kind of promising power generation device that operates naturally under the indoor air buoyancy at the cost of low operation and maintenance cost without use of fuel and cooling water and without need of refuse disposal. To date this SUPP technology, the feasibility of which was verified by the Manzanares prototype built and operated in 1980s, has not been commercialized mainly due to high investment per MWh of electricity. In this paper, a novel concept of extracting power from natural valley–mountain anabatic wind aided by an SUPP collector is proposed. In the system, the solar collector is built on the upper mountain slope so as to use both the heat from the solar radiation received by the collector and the extra heat from the solar radiation received by the lower bare mountain slope. In comparison with that of the conventional sloped-collector SUPP, the performance of this novel SUPP is studied based on the mathematical model developed. Results show that with an increase in the lower bare mountain slope area from 0 to 5 times the collector area, the plant efficiency increases by 183%, and the levelised electricity cost (LEC) decrease by 64.7%. This implies that the proposed power extraction from natural valley–mountain anabatic wind aided by SUPP collector is a very effective measure to enhance the performance and cost effectiveness of SUPP. This paper lays a solid foundation for studies and commercialization of SUPPs in future.