An approach to optimization of double slope solar still geometry for maximum collected solar energy

This investigation represents the optimum inclination angles of the glass cover of the double slope solar still, and orientation for maximum collected solar energy that could be captured by the solar still glass cover. The results will be displayed for different latitudes (ϕ = 24°, ϕ = 27.2°, ϕ = 30° and ϕ = 31.2°) to cover Egypt geographically. The double slope solar still has two opposite inclined surface; so it has two surfaces azimuth angles (γ1 and γ2) according to |γ1| + |γ2| = 180°, with opposite signs, these values are (γ1 = 0° and γ2 = 180°), (γ1 = 90° and γ2 = −90°), (γ1 = 45° and γ2 = −135°) which is equivalent to (γ1 = −45° and γ2 = 135°); consequently, the total energy is the summation of the collected energy by the two surfaces represents the double slope solar still surface area. The inclination angle (β) is changed from 10° to 60° on both sides of the glass cover to get independently the optimum inclination angles for each side that not necessary to be the same.