For normalization of microclimate in the cabs of mobile power units, it is necessary to introduce a particular technology of solar protection. The modern cabs have a high degree of light transmission, which enables intensive irradiation of operator on all sides. It results in a hyperthermia leading to the adverse health consequences for operator. The insolation flow also has impact on the electronic equipment, plastic parts and various elements of the cab. The applied means of protection, such as tinted glasses, films, covers and curtains, could not completely solve the problem. The study aim is the analysis of intensity of insolation, assessment of its value in form of quantitative characteristics, and search of the ways of its neutralization by acceptable technical means. One of the rational means limiting the impact of insolation flow is the use of blinds. The blinds designed according to the proposed scheme are able to limit significantly the direct solar flux, providing simultaneously an acceptable visibility during the movement of mobile power unit. This is achieved by the positioning of slats of blinds in the direction of sighting lines at different angles. The major efficiency characteristic of blinds is the transmission bandwidth of direct beams. It shows the design efficiency and allows to quantify the value of transmitted solar flux. For assessment, the geometric approach is proposed. The quantitative relationships received in the course of calculations are compared with experimental geometrical measurements, having a very close convergence of numerical results. The evaluation of blinds effectiveness is presented in form of the protection factor indicating the value of reduction of direct insolation. The proposed protection has a high efficiency and reduces the direct insolation by 1,75-170 times.