DNV KEMA: Accuracy of wind farm energy assessments improving

DNV KEMA Energy & Sustainability, a global energy consulting firm and authority in testing, inspection and certification, said a study it conducted found that performance predictions for large-scale North American wind energy projects placed in service between 2010 and 2012 were substantially more accurate than for wind farms placed in service between 2001 and 2009.

The firm recently published the 2013 update to its study “Actual versus Predicted Wind Power Project Performance.” The study indicates that wind energy projects entering service since 2010 have produced an average of 97% of the energy predicted, an improvement of six percentage points over wind farms that went on line between 2001 and 2009. According to DNV KEMA, “Additional improvement is anticipated when data is available from projects for which energy estimates include recent changes in energy assessment techniques.”

“To minimize the cost of energy from wind energy projects, investors need to have confidence in the energy production estimates made before the projects are built,” said Robert Poore, a Senior Advisor at DNV KEMA. “While DNV KEMA energy assessments have historically been more accurate than the industry average, we found that in the last three years improved methodologies for assessing project energy production have lowered the average variance between pre-construction energy estimates and actual plant performance for the entire industry. As confidence is gained in the improved methods, we expect to see less discounting of pre-construction estimates when investors evaluate wind projects. In the long run, this should help reduce the cost of energy from wind.”

According to the study, robust wind assessment campaigns, more comprehensive curtailment risk analysis and further research into wake and flow modeling are key elements in further reducing uncertainty in wind project energy assessments. “Our work with clients has demonstrated that an enhanced energy assessment program is one of the best investments a developer can make. When we plan and execute a better than average site measurement program, including the use of remote sensing, the reduced uncertainty in the energy assessment frequently results in more favorable financing terms, higher project value and higher confidence when bidding for power purchase agreements,” said Mr. Poore.