For many years, the HVAC (Heating, Ventilation and Air Conditioning) systems have been used in buildings or industrial premises. The HVAC systems use thermal energy exchange to control temperature inside the buildings. Chillers can produce ice or cold water when the electricity is cheap. They can subsequently be used to cool buildings during peak electricity consumption. Ice Energy company which is active in the Czech Republic as well, has come with an idea to produce ice using solar energy at times of excess generation.