((a)) In procuring energy systems the Secretary of a military department shall procure systems that use solar energy or other renewable forms of energy whenever the Secretary determines that such procurement is possible, suited to supplying the energy needs of the military department under the jurisdiction of the Secretary, consistent with the energy performance goals and energy performance plan for the Department of Defense developed under , and supported by the special considerations specified in subsection (e) of such section.
((b)) The Secretary of Defense shall from time to time study uses for solar energy and other renewable forms of energy to determine what uses of such forms of energy may be reliable in supplying the energy needs of the Department of Defense. The Secretary of Defense, based upon the results of such studies, shall from time to time issue policy guidelines to be followed by the Secretaries of the military departments in carrying out subsection (a) and .