Sprint says it is the only wireless carrier to be awarded a $7.3 million grant from the U.S. Department of Energy as part of the American Recovery and Reinvestment Act funding earmarked for fuel cell technology.

It is the largest single grant awarded by the Department of Energy for this round of grant funding, which totaled $41.9 million, the carrier says.

The grant funding will be used to expand Sprint’s hydrogen fuel cell program at cell sites throughout the United States, creating more network resiliency, especially during emergencies and natural disasters.

Specifically, the grant funding will be used to expand the number of Sprint cell sites that rely on hydrogen fuel cells for backup power. The fuel cells are activated when service from the local electric utility is disrupted during severe weather or other natural disasters.

Most deployed hydrogen fuel cells are paired with low-pressure hydrogen tanks that provide about 15 hours of backup power before needing refueling.

As part of the grant, Sprint says it will work with hydrogen fuel cell manufacturers, tank providers and hydrogen suppliers to extend the unassisted run-time to 72 hours.