Drifter-based global ocean current energy resource assessment

Abstract

Global electricity demand is rising daily due to economic development and population growth. To reduce greenhouse gas emissions, renewable energy is essential for meeting this increasing power demand. One promising source is the use of open ocean currents, such as the Gulf Stream, Kuroshio, and Agulhas currents, for electricity production. These currents can provide predictable and nearly continuous electricity generation along the western boundaries of ocean basins. While global evaluations using numerical models and regional assessments with direct measurements have been conducted, a comprehensive global assessment based on actual measurements is lacking. This paper fills that gap by presenting a global measurement-based assessment of ocean current energy, utilizing more than thirty years of drifter data. Results show that power densities above $1500$ W/m² were typical in the waters off Florida’s east coast and South Africa where total water depths are around 300 m, but not in other regions. The results for North America and Japan showed higher estimation accuracy, while poor or indeterminable estimation accuracy was commonly found off South Africa and South America, especially for the relatively shallow water area off northern Brazil and French Guiana. In addition, over 490,000 km² of the sea surface in these four regions exhibits power densities higher than $500$ W/m², which represents nearly 59% of the total identified high power density areas globally.