With two laptop-loving children and a Jack Russell terrier hemmed in by an electric fence, Peter Troast figured his household used a lot of power. Just how much power did not really hit him until the night the family turned off the overhead lights at their home in Maine and began hunting gadgets that glowed in the dark.

“It was amazing to see all these lights blinking," Troast said.

As goes the Troast household, so goes the planet.

Electricity use from power-hungry gadgets is rising fast all over the world. The fancy new flat-panel television sets everyone has been buying in recent years have turned out to be bigger power hogs than some refrigerators.

The proliferation of computers, iPods, cellphones, game consoles and all the rest amounts to the fastest growing source of power demand in the world. Americans now have around 25 consumer electronic products in every household, compared with just three in 1980.

Worldwide, consumer electronics now represent 15% of household power demand, and that is expected to triple over the next two decades, according to the International Energy Agency, making it more difficult to tackle the greenhouse gas emissions responsible for global warming. To satisfy the demand from gadgets will require building the equivalent of 560 coal-fired power plants, or 230 nuclear plants, according to the agency.

Most energy experts see only one solution: mandatory efficiency rules specifying how much power devices may use.

Appliances such as refrigerators are covered by such rules in the US. But efforts to cover consumer electronics such as TV and game consoles have been repeatedly derailed by manufacturers worried about the higher cost of meeting the standards. That has become a problem as the spread of such gadgets counters efficiency gains made in recent years in appliances.

In 1990, refrigerator efficiency standards went into effect in the US. Today, new refrigerators are fancier than ever, but their power consumption has been slashed by around 45% since the standards took effect. Likewise, thanks in part to standards, the average power consumption of a new washer is nearly 70% lower than a new unit in 1990.

Part of the problem is that many modern gadgets cannot entirely be turned off; even when not in use, they draw electricity while they await a signal from a remote control or wait to record a television programme.

“We have entered this new era where essentially everything is on all the time," said Alan Meier, a senior scientist at the Lawrence Berkeley National Laboratory and a leading expert on energy efficiency.

People can, of course, reduce this waste—but to do so takes a single-minded person.