Obviously, but economies of scale are about costs, not capacity. A plant with double the capacity costs less than twice, especially if development costs (of both the product and the machinery) are taken into account. The part of the spread of mass production in the PV price cuts in recent years is generally recognised.

Money poured into wind turbine production will help fuel increases in the size of wind turbines

As well as their price, and also the distance between two neighbouring turbines in a wind farm. It's not that easy to evaluate whether unit costs reduce. (You also confused the economies of scale from the increase of manufacturing capacity and the economies of scale from the increase of the output of a single plant.)

_{*Lunatic*, n.
One whose delusions are out of fashion.}