Renewable energy advocates have long argued that subsidies for wind, solar and other forms of clean power would eventually drive down their costs and allow them to be competitive with conventional, dirty energy (itself often subsidized).

It looks like they could be right – to an unexpected degree.

An analysis by financial advisory and asset management firm Lazard has found that the levelized cost of energy from wind power has plunged by more than 50 percent in the past four years.

“While many had anticipated significant declines in the cost of utility-scale solar PV, few anticipated these sorts of cost declines for wind technology,” the report said.

Wind isn’t the only clean energy technology making remarkable progress, according to the Lazard analysis. Solar is on a winning trend as well:

The current and anticipated costs of all forms of utility-scale solar PV continue to decline;  the study estimates that the LCOE of leading technologies has fallen by more than 50 percent in the last four years. Utility-scale solar PV is a competitive source of peak energy as compared with conventional generation in many parts of the world, without any subsidies (appreciating the important qualitative differences related to dispatch characteristics and other factors).