CPS Energy is encouraging customers to voluntarily reduce their electricity use today. The utility declared today the second Yellow Day in a row, according to its color-coded conservation awareness notification system. The move was prompted by forecast high temps of 100 degrees or more this week. Customers are encouraged to bump up their thermostats, use fans, turn off unnecessary lights, and avoid using appliances such as washing machines and ovens, especially during the peak usage hours of 2 to 7 p.m.