Currently, high pressure sodium lamps are the light source in greenhouse vegetable growing. The most promising sources of artificial lighting are LED-based irradiators. They can provide a cooler temperature environment to bring plants closer to plants. The aim of the study is to determine the economic life of sodium and LED light sources in greenhouse vegetable growing, taking into account their degradation for the harvest. LEDs, like sodium lamps, degrade during use. This leads to a decrease in the light (photosynthetic photon) flux of light sources and, as a result, to a decrease in yield. Due to this certain functional dependence on the luminous flux level, the economically feasible life of the light is predicted.
Keywords: light sources, luminous flux, LED lamps, sodium lamps, productivity, energy efficiency, economy
On November 10, 2017, new requirements came into force that apply to lighting devices and electric lamps used in AC circuits. In connection with the newly introduced requirements, calculations of power consumption in educational institutions were carried out at different times of use of the lighting load. The purpose of the research is to determine the payback period for the implementation of LED lamps instead of fluorescent lamps for various types of premises in educational institutions. The analysis of technical characteristics of LED light sources offered on the market of the Russian Federation is carried out. Based on the results of the calculations, the payback periods were obtained for the introduction of LED lamps instead of fluorescent lamps for public premises, laboratories, training workshops, as well as lecture halls of educational institutions, with different times of use of the lighting load. This can allow already at the design stage to evaluate the effectiveness of the implementation of the selected light sources.
Keywords: light sources, led lamps, fluorescent lamps energy efficiency, electric lamps, lighting systems, educational institutions
A large number of power receivers with non-linear current-voltage characteristics with a pulsed mode of operation appeared in residential buildings, which leads to the generation of 0.38 kV higher harmonic current components into the electric network, large values of these harmonics lead to a deterioration in the shape of the network voltage curve. The purpose of the work is to study the harmonics of current generated by electrical receivers of residential buildings, and their influence on the coefficient of non-sinusoidality of the network voltage of 0.38 kV. It has been established that the greatest negative impact on the electric network is exerted by electronic devices with switching power supplies, such as PCs, laptops and netbooks, as well as dishwashers and LED lamps with a socle E14 and E27, whose total harmonic current component coefficient is 85% ≤ THDI ≤ 205%. In the Matlab Simulink program, a simulation model of a 0.38 kV network of a residential building is simulated, which allows the study of the total distortion coefficient of the current KI and voltage KU in the ASU. With the installed non-linear load power more than double the linear load, the coefficient of non-sinusoidality of the voltage in the network of 0.38 kV may exceed the values established by GOST 32144-2013.
Keywords: power supply system, electric network, quality of electric energy, voltage harmonics, current harmonics, electromagnetic compatibility, power receiver
Federal Law 261-FZ dated November 23, 2009 introduces a list of organizations subject to mandatory energy audit including development of energy passports and energy efficiency programs. However, the fact of the audit (the presence of energy certificates and energy saving program) is not an indicator of energy efficiency of the organizations surveyed. Currently, the main criteria are the specific energy consumption per square meter of floor space, the presence of meters, the availability of energy service contracts (according to the order of Ministry of Economic Development of the Russian Federation dated October 24, 2011 #591). These criteria do not allow to assess comprehensively the efforts of the staff to improve energy efficiency of the object. The authors have developed methodology allowing to determine the level of energy efficiency of the object (building, group of buildings) based on objective and subjective factors. The proposed approach makes it possible to rank different objects according to their level of energy efficiency, it allows to develop investment programs aimed at energy efficiency improvement in more efficient manner. This method can be used to monitor the energy efficiency of facilities and to assess the quality of energy efficient measures implemented at these objects. Analysis of the indicators in certain areas can detect the most "weak" places for improvement.
Keywords: Energy efficiency, energy saving, specific energy consumption, energy audits, energy efficiency measures, indicators, methodology, monitoring.