Systems and methods for producing energy from a geothermal formation. A heat exchanger can be disposed within a well to absorb heat from a geothermal formation. The heat exchanger can be supported within the well using a high thermal conductivity material. The heat exchanger is connected to an organic Rankine cycle engine including a secondary heat exchanger and a turbine. The primary and secondary heat transfer fluids are chosen to maximize efficiency of the organic Rankine cycle.