May 18 (Renewables Now) - A new analysis of wind farm performance degradation in the US suggests that supportive policies, like the production tax credit (PTC), may have a significant impact on maintenance planning and spending.
The Lawrence Berkeley National Laboratory (Berkeley Lab) studied the performance of 917 onshore wind farms in the US and concluded that US fleet maintains 87% of peak performance after 17 years in operation, and newer parks register almost no decline over the first 10 years.
Berkeley Lab compared its findings to these of studies conducted in Europe and announced that the performance decline per year for wind power plants in the US is at the low end of the range for European wind. What is more interesting is that in Europe the wind farm performance is declining linearly over time, while in the US there is a more abrupt change in performance after 10 years of operation.
Under the PTC, wind farms get a production-based tax credit for their first ten years of operation.
“We hypothesize that after wind plants lose eligibility for the PTC, they may choose to spend less on maintenance overall and their performance may therefore drop,” said Dev Millstein, an author on the paper published recently in Joule.
Berkeley Lab points out that understanding that performance decline in wind farms will depend both on physical degradation and on "maintenance cost-benefit trade-offs", which can be policy-driven, is important for modelling wind power costs and generation.