In Del Norte, Colo., Public Works Supervisor Kevin Larimore shows off solar panels that provide electricity for the town's water supply. Despite generating its own solar energy, the town is still at risk of a blackout if its main power line goes down. Dan Boyce/Inside Energy hide caption

itoggle caption Dan Boyce/Inside Energy

Part of the Robert Moses Niagara Power Plant in Lewiston, N.Y., is seen from the air on Aug. 14, 2003, during a massive power outage that stretched from New York to Detroit and into Canada. David Duprey /AP hide caption

itoggle caption David Duprey /AP

A street light and utility pole brought down by Hurricane Sandy lay on the street in Avalon, N.J. About 2.5 million customers had no power Tuesday in New Jersey. Mark Wilson/Getty Images hide caption

itoggle caption Mark Wilson/Getty Images