ANALYSIS OF THE CONSIDERATIONS FOR THE IMPLEMENTATION OF SEASONAL GEOTHERMAL ENERGY STORAGE USED IN SOLAR DISTRICT HEATING SYSTEMS

• Дата: 2021
• Автор: Lysak, O.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Institute of Renewable Energy National Academy of Sciences of Ukraine 2021
• Теми: renewable energy; heating; seasonal storage; geothermal energy; central solar water heating; відновлювана енергетика; опалення; сезонне акумулювання; геотермальна енергетика.
• Онлайн доступ: https://ve.org.ua/index.php/journal/article/view/311
• Назва журналу: Vidnovluvana energetika

The purpose of this article is to analyze the application of seasonal geothermal energy storage (SGES), also known as seasonal thermal energy storage (STES) or underground thermal energy storage (UTES), in solar district heating systems (SDHS). Such systems are designated in the article as SDHS-SGES, which store heat from solar collectors in hot months for space heating use when needed, including during winter months. The classification of SDHS-STES was made and the possible choice of a STES solution was analyzed. From the economical point of view, the best solution is the usage of pit thermal energy storage (PTES) systems. As for other options, they either cost more than PTES or they require some very special environment to install them. In order to show how much consumers could be supplied by SDHS-STES, there were shown some examples. With regard to the introduction of SDHS-STES, among the factors that contributed to their widespread use were: lower cost of solar collectors, high prices for fossil fuels, the exist of district heating systems, lowering the temperature regime in district heating. However, in Ukraine, at present, the implementation of SDHS-STES can be significantly complicated due to the large number of district heating (DH) systems in a very neglected state. Since SDHS-SGES is a relatively new type of DH systems, the cost of heat from them is not yet an established value, as well as the cost of the systems themselves. Due to constant improvement, development of new solutions and increasing experience in the implementation of new systems, the cost of such system has been constantly decreasing over the past decades. Therefore, the work considers the current state of research on what are the directions for reducing the cost of SDHS-SGES and what conditions are necessary for the implementation of SDHS-SGES. As shown by the conducted economic analysis, with an increase in volume, the cost of the thermal energy storage significantly decreases, which makes it possible to justify the use of DH systems in the case of a high density of heat consumption. Ref. 45, table. 1, fig. 2.