Technoeconomic optimization of coaxial hydrokinetic turbines

Tethered coaxial dual-rotor turbine technology shows promise in the global shift towards renewable energy to address climate change. To assess its economic feasibility, a low-order technoeconomic optimization framework is proposed based on a levelized cost of energy (LCOE) model specially tailored for this device. This framework can predict the optimal size of the turbines and farms that minimize LCOE for given resource characteristics. To demonstrate the functionality and robustness of the proposed tool, the effects of varying device numbers and sizes on capital and operational expenditures, annual energy production, wake effects, and the convergence behavior of the optimization algorithm are investigated. Additionally, two case studies in the Gulf Stream off the coasts of North Carolina and Florida are performed to facilitate informed decision-making towards the economic viability of TCDT deployment in those locations. The results show that while the Florida coast demonstrates economic feasibility under current capital and operational costs, the North Carolina coast faces higher LCOE values, necessitating significant cost reductions, and government support to enhance feasibility and competitiveness against alternative energy sources. This tool offers a quick and easy method for preliminary assessments of the economic viability of this new technology at desired deployment sites.