  Among critical infrastructures, power grids and communication infrastructure
are identified as uniquely critical since they enable the operation of all
other sectors. Due to their vital role, the research community has undertaken
extensive efforts to understand the complex dynamics and resilience
characteristics of these infrastructures, albeit independently. However, power
and communication infrastructures are also interconnected, and the nature of
the Internet's dependence on power grids is poorly understood.
  In this paper, we take the first step toward characterizing the role of power
grids in Internet resilience by analyzing the overlap of global power and
Internet infrastructures. We investigate the impact of power grid failures on
Internet availability and find that nearly $65\%$ of the public Internet
infrastructure components are concentrated in a few ($< 10$) power grid failure
zones. More importantly, power grid dependencies severely limit the number of
disjoint availability zones of cloud providers. When dependency on grids
serving data center locations is taken into account, the number of isolated AWS
Availability Zones reduces from 87 to 19. Building upon our findings, we
develop NetWattZap, an Internet resilience analysis tool that generates power
grid dependency-aware deployment suggestions for Internet infrastructure and
application components, which can also take into account a wide variety of user
requirements.
