Internet-enabled devices only consumed 2 percent of global energy usage according to a scientist of Indian-origin and his colleague.
Barath Raghavan, researcher at an International Computer Science Institute, Berkeley, and Justin Ma, at the University of California, estimated that the Internet consumes between 170 and 307 GW.
The pair came up with their total by conducting a rough Internet census.
By drawing on previously published research, they estimate that our planet is home to 750 million laptops, a billion smart phones and 100 million servers.
They also put figures on the energy that it costs to produce each of these devices (4.5 GJ and 1 GJ for a laptop and smartphone respectively) and the period for which each is used before being replaced (three years for a laptop, two for a smart phone).
Their total estimate also includes the energy that cell towers and optical switches use when transmitting Internet traffic, plus similar calculations for wi-fi transmitters and cloud storage devices.
A gigawatt is a billion watts, so running and maintaining the Internet is like illuminating several billion 100W bulbs simultaneously, they stated.
That figure is 16 terawatts, so the internet is responsible for less than 2 per cent of the energy used by humanity.
But Raghavan and Ma suggested that attempts to create more energy-efficient Internet devices would not do much to lower global energy consumption.
Instead, they propose that we should think about how the Internet can replace more energy-intensive activities.
Their research will be presented next month at the Workshop on Hot Topics in Networks in Cambridge, Massachusetts.