A control mechanism for controlling an air conditioning system includes an optical sensor and an energy controller. The air conditioning system includes a solar power module, an outdoor unit, a fan, and a storage device containing a first liquid. The optical sensor detects sunlight received by the solar power module. The energy controller controls the outdoor unit based on luminance and temperature of the sunlight, an operation state of the fan, an operation state of the outdoor unit, a temperature of the first liquid, a flow speed of a second liquid in a conduit between the storage device and the fan, and temperatures of the second liquid at different portions of the conduit.