According to data from the Energy Information Administration (EIA), more than 20 gigawatts (GW) of battery capacity have been added to the US electric grid in the last four years. This rapid expansion is equivalent to the production of 20 nuclear reactors and is crucial for averting power disruptions, especially in states that rely significantly on intermittent renewable energy sources such as wind and solar.
That’s what 1c means. If it were designed to provide 25GW but only lasted 1hr, then it’d be 25c.