What is seasonal solar thermal storage?

Seasonal solar thermal storage using PCMs as the thermal storage medium is usually done in two ways. One is to store the PCMs directly in the thermal storage unit, similar to the seasonal thermal energy storage of sensible heat, i.e., the direct-type. One is to use the supercooling of the PCMs for thermal storage, i.e., the supercooling-type.

Can solar thermal energy be used for cross-seasonal heating?

The increase in the tank temperature at the end of the heating period was beneficial for shortening the duration of the heat storage period for the following year. The feasibility of utilizing solar thermal energy and cascaded phase change heat storage for cross-seasonal heating has been demonstrated in this study.

How can cross-seasonal thermal storage improve solar energy utilization?

As heat storage volume increases, hot water preparation costs and heat loss per unit volume decrease. Thus, developing large-scale cross-seasonal thermal storage systems is an effective solution to improve the thermal efficiency and solar energy utilization of solar heating systems.

What is seasonal storage?

Seasonal storage is defined as the ability to store energy for days, weeks or months to compensate for a longer term supply disruption or seasonal variability on the supply and demand sides of the energy system (e.g., storing heat in the summer for use in the winter via underground thermal energy storage systems) [ 12 ].

What are construction concepts for large or seasonal thermal energy storage systems?

Fig. 1. Construction concepts for large or seasonal thermal energy storage systems and their advantages and disadvantages . 2.1.1. Tank thermal energy storage (TTES) A tank thermal energy storage system generally consists of reinforced concrete or stainless-steel tanks as storage containers, with water serving as the heat storage medium.

How to use PCMs as seasonal thermal energy storage media?

There are two ways to use PCMs as seasonal thermal energy storage media, one is the direct-type, which directly uses the performance of PCMs, and the other we can call the supercooling-type, that is, using its supercooling capacity for thermal storage, the latter way is also the main way to use PCMs for seasonal thermal energy storage.