The paper contains the economic analysis of the carried out modernisation of the facilities of a water-park consisting in fitting solar collectors for heating of tap hot water and central heating system. The article presents the data showing investment outlays, operating costs and the calculations concerning the payback time.

The paper contains the technical analysis of the carried out modernisation of the facilities of a water-park consisting in fitting solar collectors for the heating of tap hot water and central heating system. The article includes information on the modernisation carried out with a particular emphasis on analysing the way in which the equipment has been selected and technical solutions employed.

The Exodus method is applied to solve Fourier-Kirchoff's equation in heat transfer problems for flat plate solar collectors. Probabilistic models have been presented for the steady and non-steady conditions. The mathematical description of these models has been derived on the basis of the analogy between the conduction difference equation and the equation describing walking particle movement. The results of computations performed by the Exodus method have been compared to the results obtained by the Equivalent Thermal Network and the Finite Difference methods. The Exodus procedure allows the influence of changeable weather and operating conditions to be considered in calculations.

The article herein presents a new technique of controlling the system of collecting, storing and processing the information from the solar collectors, which might be applied to heating the industrial and domestic compartments for hot water supply. The most profitable usage of the solar collectors in the industry is replacement of a human interference with wireless sensor nets. The solar collector standard system consumes in average 30% of the heat due to poor control and configuration. Our monitoring and control system allows upgrade the performance of heating the industrial and domestic premises by means of solar collector for hot water supply.

The proposed Trombe wall design is an innovative and effective solution for addressing issues related to building energy efficiency. The Trombe wall can help reduce a building’s energy consumption, provide optimal indoor temperature, and minimize the building’s environmental impact by utilizing renewable energy sources.The article deals with the study of the heat-air characteristics of the Trombe Wall, which performs the functions of external protection of a modular house, with the aim of further evaluating the possibility of using it as a hybrid protection with additional heating and ventilation functions assigned to it. The results of experimental research conducted on one of the elements of external protection of a modular house in the form of the Trombe Wall are presented. The experimentally obtained graphic dependences were compared with the calculated data and the convergence was evaluated. The proposed design allows you to organize air exchange in the premises with a multiplicity within 1–1.5 h ^-1, and also provides an opportunity to provide additional thermal power in the amount of 250 W/m ². The article presents the results of experimental studies that allow to evaluate the thermal characteristics of the proposed design of external protection for a modular house. These results indicate that with the given geometric dimensions, in particular with a volume of 14 m ³, the thermal power utilized by the Trombe wall is within 0.2–0.7 kW

Solar photovoltaic (PV) and concentrated solar power (CSP) systems are the present worldwide trends in utilizing solar energy for electricity generation. Solar energy produced from photovoltaic cells (PV) is considered the main common technology used due to its low capital cost; however, the relatively low efficiency of PV cells has spotlighted development and research on thermal engine applications using concentrated solar power. The efficiency of concentrated solar power is greater than that of PV and considering the solar potential for Sudan. Therefore, this study has been performed in an attempt to draw attention to the utilization of CSP in Sudan since the share of CSP is insignificant in comparison with PV, besides the suitability of CSP applications to Sudan’s hot climate and the high solar energy resource, the study presents a design model of 1 MW parabolic trough collectors (PTC) using the Rankine cycle with thermal energy storage (TES) in Sudan, by adopting reference values of the Gurgaon PTC power plant in India. The design of a 1 MW Concentrated Solar thermal power plant using parabolic trough collectors (PTC) and thermal energy storage is proposed. The simulation was performed for a site receiving an annual direct normal irradiance (DNI) of 1915 kWh/m2, near Khartoum. The results showed that the plant can produce between nearly 0.6 to 1 MWh during the year, and around 0.9 MWh when it encompasses thermal energy storage with an average thermal efficiency of 24%. These results of the PTC Power plant encourage further investigation and the development of CSP technologies for electricity generation in Sudan.

Solar collectors are used increasingly in single-family housing. Their popularity depends on many factors, including the price-to-productivity ratio, which in turn results from the development of solar collector technology as well as entire systems. This development consists of many aspects, including those related to the modernization of control systems and measuring of solar collector systems. Currently used systems offer, among others, the ability to determine the approximate solar heat gains using the sensors necessary for normal control of the sensor system. The paper analyzes, on the example of one facility, how such installations work in Polish conditions. An installation consisting of 3 solar collectors has been selected for analysis, supporting the preparation of hot utility water for a single-family residential building. The detailed analysis concerned days with high heat gains compared to the average heat demand for hot water preparation in the building. The temperature verification method (TVM) of the calculated solar heat gains by the solar system controller has been proposed. Then, differences in measurements according to two methods (controller and TVM) have been presented at various characteristic moments of the installation’s operation (start- -up, stop) and during continuous operation. It has been shown that during the day gains measured by the controller can be 15% lower than gains measured by the TVM method. The check has been carried out at a daily sunlight value higher than 4.8 kWh/m2 measured on a horizontal plane. The ratio of heat energy supplied to the domestic hot water storage tank to the measured insolation has been 34%. The sum of annual solar heat gains measured by the controller and TVM differed by 5.2%.

By the emergence of distributed energy resources, with their associated communication and control complexities, there is a need for an efficient platform that can digest all the incoming data and ensure the reliable operation of the power system, which can be achieved by using digital twins. The paper discusses the advantages of using digital twins in the development of control systems and operation of distributed heat and electric power generation facilities. The possibilities of using the digital doubles for increasing the efficiency of the considered objects is presented as the example of optimizing the configuration of a control system of solar collectors in the presence of heat losses in pipelines of the external circuit. Further, the total balance consumed and generated electric and heat energy are presented. Examples of algorithms for protecting equipment to improve security are given, and the possibilities of improving the reliability of distributed power systems are considered. The system use of the digital twins provides the possibility of developing and debugging control algorithms, which increase the efficiency, reliability and safety of control objects, including distributed thermal and electrical power generation complexes.

The present work involved an extensive outdoor performance testing program of a solar water heating system that consists of four evacuated tube solar collectors incorporating four wickless heat pipes integrated to a storage tank. Tests were conducted under the weather conditions of Baghdad, Iraq. The heat pipes were of 22 mm diameter, 1800 mm evaporator length and 200 mm condenser length. Three heat pipe working fluids were employed, ethanol, methanol, and acetone at an inventory of 50% by volume of the heat pipe evaporator sections. The system was tested outdoors with various load conditions. Results showed that the system performance was not sensitive to the type of heat pipe working fluid employed here. Improved overall efficiency of the solar system was obtained with hot water withdrawal (load conditions) by 14%. A theoretical analysis was formulated for the solar system performance using an energy balance based iterative electrical analogy formulation to compare the experimental temperature behavior and energy output with theoretical predictions. Good agreement of 8% was obtained between theoretical and experimental values.