Power Generation via an Autonomous Solar Tower Coupled to a Supercritical CO2 Brayton Cycle

Abstract

In the context of sustainable development, concentrated solar energy is an unavoidable alternative for many countries though the attenuation of the solar irradiation is a serious obstruction. In addition, the population demands a non-stop energy supply. In this paper, a process is presented. It is made up of a double supercritical CO2 Brayton cycle coupled to the concentrated solar tower plant, associated with a hydrogen combustion chamber and a solid oxide electrolyzer cell (SOEC) device. In order to produce power supply of 50MW, the exceeding solar energy is managed to produce and accumulate hydrogen for a self-consumption during the night and the moments of insufficiency/absence of solar irradiation. The power production is therefore autonomous around-the-clock in the whole year. In the next phase, a new parameter large solar multiple (L.S.M) is introduced in this paper to size the plant, taking into account five Moroccan regions. Depending on the climate, two rainfall periods are considered, regular and irregular. A one unit of the L.S.M accords 1km 2 of heliostat area in the clear and dry sky conditions. The obtained results demonstrate that for 100% hydrogen self-consumption, the more the atmosphere is clear sky and dry, the more the production of hydrogen is 5790 tons/km 2 /a and the less surface of the heliostat is (1 km²). On the other hand, in the most turbid conditions, the least hydrogen production drops to (2000 tones/km 2 /a) associated with more surface of the heliostat (1.77km²) as L.S.M value increases twice the unity.