A novel methodology for life estimation and performance evaluation of offshore wind farms high voltage AC export cables is presented. The method applies Dynamic Temperature Prediction (DTP) analysis using a Thermo-Electrical Equivalent model (TEE). Furthermore, it is suggested how the cable lifetime might be inferred based on the accumulated ageing effects. Afterwards, a sensitivity analysis of the seabed temperature variations is performed. Finally, a holistic procedure for calculating more accurately the electrical power losses of the cable is presented. Results show that an important increase of the total installed power, or cross-section reduction, can be achieved compared to traditional sizing methods.