In 2015 Lazard estimated unsubsidised costs for on-shore wind across the USA of US$32–77/MWh. An independent empirical study by US Department of Energy (Fig. 46) found levelised power purchase agreement prices in 2014 for wind in the US interior (region with the highest wind speeds) of US$22/MWh, and in the west (region with lowest wind speeds) about US$60/MW. The US government subsidises wind with a Production Tax Credit of US$23/MWh over 10 years, so this must be added to the DoE figures to obtain the actual costs. In Brazil in 2014, contracts were awarded at a reverse auction for an average unsubsidised clearing price of real/MWh (US$41/MWh).