LONG-TERM OM COSTS OF WIND TURBINES BASED ON FAILURE RATES AND REPAIR COSTS

摘要

Projections of 20-year operation and maintenance (O&M) costs are presented for typical utility- scale wind turbines that are being currently installed. The costs are governed by a Weibul| statistical model that predicts failure rates of key components over the life of a project. The predictive model is adjusted based on prior field experience with similar components. Projections vary with (a) the robustness of a wind turbine design, (b) the environmental and wind conditions to which wind turbines are subjected, ? the effectiveness of lubrication of mechanical parts, and (d) maintenance practices. A Weibull analysis approach is widely used for similar purposes by NASA, the military and industry. By combining the failure rates with representative repair times and associated costs for parts and labor, unscheduled maintenance costs can be predicted. Scheduled maintenance costs are also included. The key, long-term cost drivers are generally the failure rates and replacement or rebuild costs and expenses of gearboxes, generators and hydraulic systems. Associated expenses typically include those for labor, parts and cranes. The roles of cranes, for both on-shore and off-shore wind power plants, are discussed along with potential estimates of the benefits and savings derived from tower- or nacelle-mounted cranes.