; (2) an estimate of the energy conservation achieved as a result of the program; (3) a description of challenges encountered in implementing projects described in subsection (c)(1); and (4) recommendations as to additional legislative measures to increase the use of renewable energy in territories of the United States, as appropriate. (f) Authorization of appropriations There are authorized to be appropriated such sums as may be necessary to carry out this section. 3. GAO study and report (a) In general (1) Study and report Not later than 180 days after the date of enactment of this Act, the Comptroller General of the United States shall— (A) conduct a study regarding renewable energy and energy efficiency in territories of the United States; and (B) submit to Congress a report containing— (i) the findings of the study; and (ii) related recommendations. (2) Components The study conducted under paragraph (1) shall consider, in relation each territory of the United States, the potential— (A) to modify existing electric power systems to use renewable energy sources; (B) to expand the use of microgrids; and (C) to improve energy resiliency. (b) Authorization of appropriations There is authorized to be appropriated $1,500,000 to carry out this section. 4. Definitions In this Act, the following definitions apply: (1) Covered entity The term covered entity means a not-for-profit organization determined eligible by the Secretary of Agriculture for purposes of this Act. (2) Department of Energy national laboratories The term Department of Energy national laboratories has the same meaning as the term National Laboratory under section 2 of the Energy Policy Act of 2005 ( 42 U.S.C. 15801 ). (3) Microgrid The term microgrid means an electric system— (A) that serves the local community with a power generation and distribution system; and (B) that has the ability— (i) to disconnect from a traditional electric grid; and (ii) to operate autonomously when disconnected. (4) Renewable energy