(a)  There is authorized to be appropriated to the Secretary to carry out this chapter (1) for the fiscal year ending September 30, 1981, the sum of $100,000,000 (of which $10,000,000 shall be available exclusively for purposes of section 9206 of this title), and (2) for each fiscal year beginning after that date, such sum as may be authorized by legislation hereafter enacted.

(b)  In each of the five years of the small wind energy systems program, at least 25 per centum of the total authorization for appropriations under subsection (a) shall be for small wind energy systems activities, including supporting activities.