• Energy Research
• Open Access close

Trends for heating energy in European Cities are the decarbonization of energy sources and the reduction of heat loads. District heating (DH) networks are key systems to reach the targets due to the cost competitiveness and high performance levels they show. However, DH networks require a conversion to adapt for the need of the future. It is necessary to reduce the operation temperature so that it is possible to increase the performance of renewable systems and operation criteria needs to be adopted for the introduction of weather-dependent, distributed heat sources such as solar systems. In this paper is presented the RELaTED, a novel DH networks scheme with decentralized Ultra-Low Temperature performance. This way, it is possible the adaptation of new and existing networks to several operational schemes. Transitory phases for the conversion of actual DH and how this affects the whole system are discussed along the paper.

Trends for heating energy in European Cities are the decarbonization of energy sources and the reduction of heat loads. District heating (DH) networks are key systems to reach the targets due to the cost competitiveness and high performance levels they show. However, DH networks require a conversion to adapt for the need of the future. It is necessary to reduce the operation temperature so that it is possible to increase the performance of renewable systems and operation criteria needs to be adopted for the introduction of weather-dependent, distributed heat sources such as solar systems. In this paper is presented the RELaTED, a novel DH networks scheme with decentralized Ultra-Low Temperature performance. This way, it is possible the adaptation of new and existing networks to several operational schemes. Transitory phases for the conversion of actual DH and how this affects the whole system are discussed along the paper.

Please refer to "Ma Q, Wang P, Fan J and Klar A. Underground solar energy storage via energy piles: an experimental study. 2021." for details.

Sweden is only utilizing half of the available excess heat. To utilize more of the excess heat a seasonal thermal energy storage could be implemented to store excessed heat from the summer when the demand is lower to the winter when the demand is higher. This can be achieved by an integration of a seasonal thermal energy storage to the district heating system. A seasonal thermal energy storage may also reduce the need of the system’s peak load, which often is economically costly and adversely affect the environment. The purpose of the paper is to investigate the possibility for Skövde Värmeverk to implement a seasonal thermal storage. The paper is performed by a literature collection and calculations are made by software programs. The result shows that it is technically possible to implement a pit thermal energy storage and a borhole thermal energy storage, but no outcome shows a profitability within 20 years. A pit thermal energy storage can replace the system’s peak load up to 79 percent and a borhole thermal energy storage up to 2,8 percent. The most suitable case for Skövde Värmeverk is to install a pit thermal energy storage with a storage capacity of 4 GWh.

Sensible Heat Storage is the most common method of thermal energy storage, particularly in the form of hot water tanks. Essentially, sensible heat storage systems work by charging them with heat from a higher temperature source to raise the temperature of the thermal store, and by extracting heat to discharge them. On a larger scale, these sensible heat stores should be designed to store heat long term over seasons, which allow the thermal storage systems to be charged using solar thermal systems to then supply heat over colder periods and can be applied in an array of buildings, including individual dwellings and larger buildings. These seasonal storage systems consist of: Tank Thermal Energy Storage (TTES), Pit Thermal Energy Storage (PTES), Borehole Thermal Energy Storage (BTES) and Aquifer Thermal Energy Storage (ATES). The aim of this report is to provide useful information about the different construction techniques for the mentioned systems in addition to FP7 Einstein Project, where a big information research has already been done, analysing the main characteristics that interfere in the various proceedings. In addition, a general study for the three different CHESS-SETUP pilots is done regarding the availability and constraints of every case to introduce the different technologies. Finally, in order to ensure the correct operation of the installations, some guidance of the different types of maintenance is done as well as maintenance plans for the different elements of the system.

Global trends in the efficiency, safety of energy systems and energy conservation actualize the task of developing new technologies for energy storage and transportation. The article considers current technologies of storage and accumulation of thermal energy, which can be used in central heating systems, and draws conclusions about the feasibility of their use. Also, the classification of energy storage systems is presented. The most perspective thermal energy storage, which can be used to equalize the load on the energy source to ensure the peak demand for heat with a high coefficient of utilization of the equipment capacity, is noted.

All local minima upon the liquidus surface for multicomponent Chloride systems.