Tangible heat magazines. This type of thermal energy storage is still the most common. The heat is stored in materials with a high heat capacity, which is related to their specific mass and specific heat. Materials, which are used in this type of warehouse, must be available, cheap and easy to associate with a solar system. The most commonly used storage substance is water (etylina, glycol). Their main advantages are: ease of purchase, non-toxicity, good heat conduction, possibility of circulation throughout the solar energy use system, the disadvantages are corrosion and the ability to work at temperatures ranging from 0 do 100°C. Water for thermal energy storage in short-term storage is collected in tanks with a total capacity of 4 into 20 thousand. l for a single-family house, which depends mainly on the calculated heat storage time.
Solids can also be used to store heat, such as stones, bricks, concrete, iron, etc.. Their specific heat, however, is low, and the required volume of the deposit twice as large as water storage for the same amounts of heat. So, warehouses for single-family houses have deposits of stones with a total weight from 15 into 120 t, depending on the calculated time and capacity of the tray.