Potential, trend and economic assessments of global wave power

Renewable energies with reasonable structure are required to replace traditional fossil energies to against the global anthropogenic warming and energy crisis. Hydropower has provided the largest resource of renewable energy during the last decades; however, only less than 27.6% is potentially available in Southern Hemisphere countries. Here, we found that wave power can remarkably supplement hydropower at the global scale, and wave power can supply more than half of the electricity demands in 44 coastal countries. During the period from 1979 to 2018, wave power is generally increasing along 71.3% of the coast (especially along 88.9% of the southern coast); but hydropower generation in 54% of coastal countries has decreased recently. In the basic scenario, the cost of developing wave power in 72 and 70 coastal countries is less than their half prices of national household and business electricity, respectively; even in the pessimistic scenario, economically exploitable wave power potential is about 82% of theoretical potential. Our finding highlights the potential wave power in maintaining the international security of energy budget in future.