Lightweight plastic mirrors drop cost of solar thermal energy by 40%

Is there really that much cost associated with the mirrors themselves? That doesn't seem right.

> as much as 40%

"As much as" makes me think that the estimate is optimistic. Although the 50% lighter weight would make the mirror aiming equipment less expensive so maybe they could in fact reach that point.

They are going to have to do better than that to beat PV at less than half the cost of concentrated solar, but if you are just generating heat and not electricity it could be economically viable.