A cooling system comprising: - a thermosyphon cooler configured to transfer heat from a cooling fluid to ambient air through dry cooling and comprising: - a first heat exchanger configured to transfer heat from the cooling fluid to a refrigerant circulating through the first heat exchanger; - a second heat exchanger configured to transfer heat from the refrigerant to the ambient air; and - piping sized to circulate the refrigerant between the first heat exchanger and the second heat exchanger based on natural convection, wherein the cooling fluid and the refrigerant are fluidly separate from one another; - a cooling tower disposed downstream of the thermosyphon cooler with respect to the cooling fluid and configured to transfer heat from the cooling fluid to ambient air through evaporative cooling; and - a controller comprising an input for obtaining water cost or electricity cost or both by an operator or over a network connection, the controller being configured to determine a thermosyphon economic power consumption limit, TEPCL, value below which it is cost effective to operate the thermosyphon cooler, based on the obtained water cost, or the obtained electricity cost, or both, the controller being further configured to determine whether operation of the thermosyphon cooler should be enabled or disabled based on the TEPCL value and to control the operation of the thermosyphon cooler based thereof; and - a valve system (24, 60, 62, 66, 97) operably coupled to the controller, and wherein the controller is configured to adjust the valve system (24, 60, 62, 66, 97) to stop the flow of refrigerant within the piping in response to detecting a refrigerant temperature that is below an evaporator temperature set point. - a thermosyphon cooler configured to transfer heat from a cooling fluid to ambient air through dry cooling and comprising: - a first heat exchanger configured to transfer heat from the cooling fluid to a refrigerant circulating through the first heat exchanger; - a second heat exchanger configured to transfer heat from the refrigerant to the ambient air; and - piping sized to circulate the refrigerant between the first heat exchanger and the second heat exchanger based on natural convection, wherein the cooling fluid and the refrigerant are fluidly separate from one another; - a first heat exchanger configured to transfer heat from the cooling fluid to a refrigerant circulating through the first heat exchanger; - a second heat exchanger configured to transfer heat from the refrigerant to the ambient air; and - piping sized to circulate the refrigerant between the first heat exchanger and the second heat exchanger based on natural convection, wherein the cooling fluid and the refrigerant are fluidly separate from one another; - a cooling tower disposed downstream of the thermosyphon cooler with respect to the cooling fluid and configured to transfer heat from the cooling fluid to ambient air through evaporative cooling; and - a controller comprising an input for obtaining water cost or electricity cost or both by an operator or over a network connection, the controller being configured to determine a thermosyphon economic power consumption limit, TEPCL, value below which it is cost effective to operate the thermosyphon cooler, based on the obtained water cost, or the obtained electricity cost, or both, the controller being further configured to determine whether operation of the thermosyphon cooler should be enabled or disabled based on the TEPCL value and to control the operation of the thermosyphon cooler based thereof; and - a valve system (24, 60, 62, 66, 97) operably coupled to the controller, and wherein the controller is configured to adjust the valve system (24, 60, 62, 66, 97) to stop the flow of refrigerant within the piping in response to detecting a refrigerant temperature that is below an evaporator temperature set point.