All those extra hours pay off in record surplus.

WASHINGTON, DC—Energy Secretary Samuel W. Bodman announced Monday that the country's seven-month-long effort to conserve sunshine has resulted in the largest national daylight surplus since October 2005....

Bodman said the surplus will be stored in the Strategic Daylight Reserve—a system of opaque, sealed-off underground tanks located in Arizona—and only tapped in the case of the sun burning out or a particularly rainy afternoon.