Why Do I Have Cellphone Service, But No Power?

Many people are able to use their cell phones, despite widespread power outages. CREDIT: Instagram: @hdshots View full size image

In the wake of Hurricane Sandy, millions of people on the East Coast — and 2 million in New York alone — are without power. No lights and no heat is available — yet tweets, Facebook posts, texts and voice calls continue. Many people have cellphone service. Why?

Most cell phone towers are equipped with batteries or generators to provide power when other utilities go down. Carriers realized the need for emergency electricity after Hurricane Katrina in 2005, according to digital news site Quartz.

Verizon, for example, said it had installed some form of emergency backup power on 90 percent of its cell towers. Further, cell tower signals are designed to overlap one another, so that when one tower is damaged, others nearby pick up some of the load.

But emergency power can't overcome damaged towers or flooded equipment. Over the weekend, the company readied portable towers — the type used at the Super Bowl and other huge events — to replace damaged ones.  The storm also caused up to 3 feet of flooding at Verizon central offices that hold telecom equipment in Lower Manhattan, Queens and Long Island. Water is being pumped out and engineers are assessing the damage.

[READ MORE: One in Four Don't Have Cellphone Service in Sandy-Affected Areas ]

It may be several days or longer until service is fully restored. AT&T issued a statement that they are "deploying personnel and equipment as soon as it is safe to do so." Verizon, Sprint and T-Mobile are also in the process of assessing the damage and marshaling repair crews.

This story was provided by TechNewsDaily, a sister site to LiveScience.