A heat driven liquid close-loop automatic circulating system is provided. This system circulates the liquid in a close-loop by the collected heat in the loop. The system may operate without external power for the pump. The heat driven liquid close-loop automatic circulating system may employ a modified self-powered pump for heated liquid. The pump includes an airtight container for containing the heated liquid, a inlet and a outlet of the heated liquid, further more the modified self-powered pump has a breathing channel with a liquid vapor condensing and reflux structure. The heat driven liquid close-loop automatic circulating system may be a solar heated liquid close-loop automatic circulating system with a solar heat collector.

A thermoregulation apparatus for a solar thermal energy capture system comprising a piping infrastructure in fluid communication with a fluid storage tank and one or more solar thermal energy collectors. The thermoregulation apparatus comprises: (i) a thermostatically actuated valve interposed the piping infrastructure downstream from the one or more solar energy collectors and upstream from the fluid storage tank, and (ii) piping for interconnecting the thermostatically actuated valve with the piping infrastructure, and the fluid storage tank. The thermostatically actuated valve can be configured for diverting the flow of working fluid away from the fluid storage tank when the temperature of the working fluid is below a selected set point for actuating the valve, and for diverting the flow of working fluid to the fluid storage tank when the temperature of the working fluid is about or greater than the selected set point.