An analysis of the radiation from cesium lamps has shown that the spectrum of such lamps is determined by the recombination continuum. This spectrum is close to the spectrum of the Sun not only in the visible, but also in the  ultraviolet in the A and B ranges. This makes it possible to create environmentally friendly energy-efficient lighting systems with constant UV radiation based on these lamps to compensate for the lack of ultraviolet radiation at high  latitudes and when working indoors without natural light. The advantages of such systems are considered in comparison with existing dual systems using conventional visible light sources and special erythemic fluorescent mercury  lamps.