Wind turbine prices in the U.S. have fallen by nearly one-third on average since 2008, according to a new report from the Lawrence Berkeley National Laboratory. However, this turbine price decline since 2008 began from elevated levels, after turbine prices had doubled in the period from 2002 through 2008.

The report examines seven drivers of wind-turbine prices in the U.S., with the goal of estimating the degree to which each contributed to the doubling in turbine prices from 2002 through 2008, as well as the subsequent decline in prices through 2010. The seven drivers include changes in labor costs, warranty provisions, manufacturer profitability, turbine scaling, raw-materials prices, energy prices and foreign exchange rates.

Turbine scaling – the rapid increase in average turbine capacity, hub height and rotor diameter over this period – is found to have been the largest contributor to the turbine price doubling from 2002 to 2008 and has continued to pressure prices higher, according to the report. An extended period of U.S. dollar weakness – which likely increased the dollar-denominated price of turbines and components imported into the U.S. – is estimated to have been the second-largest contributor to the turbine price doubling through 2008.

The report was funded by the Wind & Water Power Program in the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy. The full report, “Understanding Trends in Wind Turbine Prices Over the Past Decade,” can be downloaded here.