The International Energy Agency published a report from Paris saying the 14 billion electronic devices used globally to access the internet are hugely beneficial, but they come at a substantial cost.
"Consumers are losing money in the form of wasted energy, which is leading to more costly power stations and more distribution infrastructure being built than we would otherwise need -- not to mention all the extra greenhouse gases that are being emitted," IEA Executive Director Maria van der Hoeven said in a statement.
IEA's report said an online device wastes a huge amount of energy when left in a standby mode that maintains network connectivity. If better energy efficiency measures were incorporated in online devices, consumers could save the equivalent of closing down 200 standard coal-fired power plants.
"Just by using today's best available technology, such devices could perform exactly the same tasks in standby while consuming around 65 percent less power," van der Hoeven said.
A do-nothing model would put the cost of wasted energy at $120 billion by 2020, the IEA's report said.