The DOE figures said the cost of installation has fallen by $795/kW from its peak at the end of the previous decade, but on par with the previous low seen in the early 2000s.
This fall in costs is partly due to the lower turbine prices, as witnessed by many OEMs this year.
The DOE said turbine pricing is in the $750-$950/kW range, down from a high of $1,600/kW in 2008.
"Early indications from a sample of projects currently under construction suggest that somewhat lower costs are on the horizon," the DOE added. Operation and maintenance costs have also fallen.
Partly as a result of the falling installation costs, the price of wind power has also fallen dramatically.
The average levelised price of wind power purchase agreements in the DOE report sample fell to "around or even below" $20/MWh, down from $70/MWh in 2009.
"Today’s low PPA prices have been enabled by the combination of higher capacity factors, declining installed costs, and record-low interest rates… The PTC has also been a key enabler over time," the DOE said in the report.