When the plug causes the leak

How many of the appliances in your house remain plugged in whether the gadget is on or off? The television, probably; the video definitely and quite likely a range of assorted computers, mobile phone chargers, toys, answering machines, and so on. But did

With some products this power drain – called leakage – could be as much when the appliance is off as it is when it is on.

According to a Lawrence Berkeley National Laboratory study, the total annual amount of leakage in US homes is 45TWh (45 x 1012Wh). The total annual cost to consumers from this is between $3.5billion to $5.4billion ( based on the utility rate of 7 to 12cents/kWh). Over $1 billion of this is just to keep televisions and VCRs in standby mode.

This is not just a domestic problem, energy consumption and associated leakage in the workplace is also increasing rapidly. Computers, printers and networking electronics are an essential part of the office environment and they are becoming increasingly more plentiful. Today most offices have multiple fax machines, copiers, laser printers and postage machines – most of which will be switched on all the time.

A study sponsored by German Federal Environmental Agency, Umweltbundesamt, shows the leakage from electronic products in German homes and offices costs over $2.3billion annually and makes up about 10% of the total electricity consumption. The amount of energy wasted, 20TWh, is far more than the total power requirement of 14TWh for the entire city of Berlin annually. Total carbon dioxide emissions from this waste energy is over 10million tonne. Studies in Japan also show leakage very similar to that found in US homes.

Unless solutions are found, resulting losses from energy leakage will rise sharply in the next decade. A typical household of the 1970s had a television, an am/fm stereo with a turntable and a telephone. These days many homes boast more than one television, a VCR, microwave ovens and children and teenagers’ bedrooms equipped with more computing power than it took to get men to the moon (much more). Leisure and business electronic products will continue to grow and since most of us can not even be bothered to get out of our chair to change channel, our motivation to pull plugs out of sockets is going to be low – especially in the office where we are not paying for the electricity.

Worldwide efforts to address the energy waste have produced some significant results. In Japan, legislation now mandates that electronic devices comply with specified limits on maximum power consumption. In the United States, the Energy Star program encourages manufacturers of such devices as computers, televisions and VCRs to comply with specified limits on maximum power consumption. For instance, in order to qualify for the Energy Star label, televisions and VCRs in stand-by must consume less than 3W and 4W, respectively. The EPA (Environmental Protection Agency) will soon propose expanding the Energy Star programme to home audio and Digital Video Disk (DVD) players.

Consumers are interested in buying energy efficient products as long as they do not cost more and do not have fewer features – no remote control for example. But many engineering solutions in the past have proven too costly for manufacturers to incorporate into a product without raising the purchasing price for consumers. Rapid advances in product electronics have outpaced advances in technology for the power supplies. Consequently, latest products with very sophisticated electronics such as cellular phones, DVD players, continue to use older power supply technologies due to cost.

Next month Design Engineering will be able to announce Tiny Switch, which can dramatically reduce leakage without adding cost to electrical appliances.