This Quick Mode On icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,400 icons, all in the same style and quality.
It's the picture of a lightning bolt to indicate electricity. It is a single bolt of lightning, with no clouds or other features. It looks like the image of an hourglass, tilted about 45 degrees up, and then stretched out until it resembles a lightning bolt.