There are 'peaks and valleys' [=high and low periods] in electricity usage throughout the year.
He said I talk like a 'Valley girl'. And I said, “Like, whatever!”
the Shenandoah (River) 'Valley'
(..) He leads me beside the quiet waters. He restores my soul. He guides me in the paths of righteousness for his name's sake. Yea, though I walk through the valley of the shadow of death... ...I will fear no evil, for you are with me. Surely goodness and love will follow me all the days of my life. (..)2003 Big Fish