A geothermal power plant operating on geothermal fluid includes a source of low pressure geothermal steam, and a turbo-generator including a low pressure steam turbine to which the geothermal steam is applied, and a generator coupled to the steam turbine. The low pressure geothermal steam is applied to the turbine, wherein expansion takes place driving the generator, and producing expanded steam that is exhausted from the turbine. A condenser for condensing the expanded steam includes a steam heat exchanger for receiving the expanded steam, a coolant, an air cooled heat exchanger, and a pump to exchange coolant during the steam heat exchanger and the air cooled heat exchanger, in a closed secondary coolant cycle. Preferably, the coolant is water.