Ocean basin scale wind-driven currents provide a possible source of renewable energy using ocean turbine technology to convert kinetic energy of the flow to electricity. The Gulf Stream System in the North Atlantic Ocean is part of one of the largest subtropical gyres in the world. Within these gyres, the western intensification due to the Coriolis force produces some of the largest and most persistent ocean currents. This chapter discusses the potential for generating energy from the Gulf Stream System with a particular focus on the Florida Current portion. The overall characteristics related to the energy potential of the Gulf Stream are described based on 7 years of model simulations and 30 years of volume flux observations across the Florida Straits. Within the Florida Current portion of the Gulf Stream System, the mean kinetic power is found to be over 22 GW with a standard deviation near 6 GW. However, this variability was found to be contained within the top 100 m of the water column. Assessments based on the undisturbed flow indicate that deployment on the order of 5000 turbines could average over 5 GW of power. To quantify the effects of the energy extraction on the circulation to obtain a better estimate of the available power, idealized and realistic modeling of the ocean circulation are presented. The idealized model indicates that a mean of 5 GW of power could be dissipated within the Florida Straits, with much more power dissipated if broader regions are considered for energy extraction. However, the practical constraints on ocean current energy extraction, such as the acceptable range of impacts on the flow as seen in a realistic 3D ocean model simulation, lead to a reduction in the assessment of the power available.