Tjin... if you make a dedicated support for your panel, whose angle to the Sun can be adjusted to match that of your location in relation to the Equator( I use a 2x4 to slide under a piece of 1/4" plywood, to change angle), a nail driven vertically will cast a shadow on itself when the Sun is directly perpendicular to the orientation of the unit.... I then place my cells under the platform to keep them cool