A review of studies of photovoltaic chromatic devices for regulating the transparency of glass and simultaneous generation of electrical energy through an internal photoelectric effect is given. Devices based on thin-film heterostructures with kesterite as a photocell are considered in detail. Kesterite is an absorbing material consisting of copper, tin, zinc, sulfur and selenium, a new promising material for creating "smart" glazing with adjustable transparency. The energy characteristics of coatings based on kesterite are compared with coatings of other types. The prospects of kesterite as a basis for creating effective autonomous photovoltaic windows of adjustable transparency are shown.

Keywords: photoelectric effect, transparency, glass, kesterite, perovskite, silicon, window, energy efficiency, electrochromic effect

The radiation-temperature dependence for fresh water in the temperature range of 30-50 degrees Celsius is experimentally investigated. It is established that the radiation temperature of the water surface on the waves of the millimeter range is determined exclusively by the effective temperature of the skin layer.

Keywords: radiation temperature, skin layer, water, emissivity,radiation temperature, skin layer, water, emissivity, heat exchange, atmosphere, air

The dependence of the radio brightness temperature of water on the kinetic temperature in the temperature range of 50-90 degrees Celsius in the gigahertz frequency range has been experimentally investigated. It is established that the change in the radio brightness temperature of the water surface, depending on the kinetic temperature, is essentially nonlinear. The radiocontrast in the studied temperature range makes it possible to effectively detect thermal contrasts of the surfaces of hydro-objects.

Keywords: nonlinearity, kinetic temperature, radiation temperature, water, emissivity, radiocontrast, gigahertz range