1. Short title This Act may be cited as the Advancing Grid Storage Act of 2018 . 2. Definitions In this Act: (1) Energy storage system The term energy storage system means a system or strategy that improves the ability to shift the dispatch of energy in time, across multiple timescales. (2) Islanding The term islanding means a distributed generator or energy storage device continuing to power a location in the absence of electric power from the primary source. (3) Loan The term loan has the meaning given the term direct loan in section 502 of the Federal Credit Reform Act of 1990 ( 2 U.S.C. 661a ). (4) Microgrid The term microgrid means an integrated energy system consisting of interconnected loads and distributed energy resources, including generators and energy storage devices, within clearly defined electrical boundaries that— (A) acts as a single controllable entity with respect to the grid; and (B) can connect and disconnect from the grid to operate in both grid-connected mode and island mode. (5) Renewable energy source The term renewable energy source includes— (A) biomass; (B) geothermal energy; (C) hydropower; (D) landfill gas; (E) municipal solid waste; (F) ocean (including tidal, wave, current, and thermal) energy; (G) organic waste; (H) photosynthetic processes; (I) photovoltaic energy; (J) solar energy