Anjana Ahuja has her eyes opened

Whenever I turn off for the night and see, through the darkness, the crimson LED twinkling at me from the corner of the television, I grit my teeth.

My husband has done it again. He’s put the telly on standby instead of turning it off.
This will trigger a predictable sequence of events – I will mention it, in a slightly piqued manner, and he will point out the number of halogen lights in the kitchen.  With that marital score settled, we can get back to the important things: bedtime reading, cocoa and Radio 4.

Revealing all
Other people’s environmental shortcomings always seem so much worse than one’s own. I’ve always hated waste – I recycle, drive a fuel-efficient car, don’t leave the tap running while brushing my teeth, never fill the kettle when I’m making just one or two cups of tea, have never owned a tumble drier and would balk at getting a takeaway when there are leftovers in the fridge.

So it was a shock to have an outsider come into my home and reveal my profligacy, as happened in 2004, for a feature in the Times. I met the makers of Wattson, a little gadget that clips to the electricity cables entering a house and measures that household’s usage. Before I had even let Richard Woods into my house for a cup of tea, Wattson, attached to cables in the porch, had already detected unexplained energy usage. At this rate, Wattson’s display informed me, my electricity bill would be £70 a year. And I hadn’t even switched anything on!

The gadget measures the surge in electricity that occurs every time an appliance is turned on. It displays the result either as the number of watts being used or, more painfully, as an estimated cost if the same output continued for a year. This is how Woods, an industrial design graduate from the Royal College of Arts, was able to tell me that the bright lamp in the corner of my kitchen costs a whopping  £30 a year to run.

Switched-off profligacy
Woods left Wattson with us for a day, and what an eye-opener it was. At 9pm, with the lights, telly, dishwasher and washing machine on, Wattson was registering a staggering £3,000. But what shocked me most was the power being drawn from the mains when my appliances were switched off. ‘Digital clocks still draw power, and most appliances are designed to be most efficient when in full use,’ Woods explained later.

Woods also told me how Wattson had affected the behaviour of his three housemates when it spent a week in their sitting room. Woods recalls: ‘One of them was a hi-fi nut who read somewhere that, to get the best sound quality, you had to leave your hi-fi on so that the circuits were always warmed up. After he saw how much power it was using, he switched it off for the first time in years.’ And if Wattson showed a surge of 2,700 watts, Woods would know that somebody had put the kettle on. ‘I'm not sure what it did for energy efficiency but it was fascinating socially,’ he said.
And how has Wattson fared since that 2004 article? Woods and Corke set up a company called DIY Kyoto, which received £35,000 from Nesta last year. The company’s mission is to provide products that allow individuals to comply with Kyoto at a personal level. The company is at the final stages of preparing Wattson for the market, and is hoping to turn it into a covetable product desired by environmentalists and design buffs alike. The final selling price hasn’t been settled, but is expected to be at least £150.

Standby for a billion
Wattson certainly changed my short-term behaviour (although I fear that my continuing fondness for halogen lights may be letting me down). I try to do less washing but, with a toddler keen on cooking and gardening, there is only so long you can hold out.

And what of that twinkling standby light? A government website informs me that this twilight state, neither on nor off, consumes between 3 and 20 watts. In America, the collective cost of the television standby button could be as high as a billion dollars a year. Perhaps I should deliver this statistic to my beloved, along with the cocoa.

Anjana Ahuja is a science columnist for the Times