An electrothermal energy storage and discharge system is provided including a charging cycle and a discharging cycle. The charging cycle includes a refrigeration unit and a thermal unit, and the discharging cycle includes a power unit. The refrigeration unit is driven by an excess electric power and is configured to generate a cold energy storage having a solid carbon dioxide. The thermal unit is driven by a thermal energy and is configured to generate a hot energy storage and/or provide a hot source. The power unit operates between the cold energy storage and at least one of the hot energy storage and hot source so as to retrieve the energy by producing a high pressure carbon dioxide and a hot supercritical carbon dioxide, and generating an electric energy using the hot supercritical carbon dioxide.