1) Big quantity of juice 2) Mass power generation unit 1) Gw 
One billion watts, a watt being a unit of measure of power, or how fast energy is used. Gigawatts are typically used to describe very large quantities of power, such as the power carried by a major section of the U.S. electrical grid.
<radiobiology> Unit of power equal to 10^9 watts, 1000 megawatts, or 1 million kilowatts. 1 gigawatt is a typical size for a nuclear fission reactor, and is expected to be the typical size of a fusion reactor. ... (09 Oct 1997) ... 
A unit of measure for electrical energy equal to 1 Billion watts. Gigawatts are the preferred measure of utility scale power plants. A Gigawatt is enough electricity to power 5000 homes for a year.
(GW) A unit of power equal to 1 billion Watts; 1 million kilowatts, or 1,000 megawatts.