A simple, new way to save energy

A smart meter could encourage you to cut your power use to save money and ease up on the grid.

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A smart meter could encourage you to cut your power use to save money and ease up on the grid.

Last year, this correspondent undertook a futile exercise to go solar. Despite having a large flat roof, an unobstructed view to the south, more than 300 days of sunshine a year, and access to generous tax credits, it would have still cost me $600 a month for 10 years to repay the $65,000 needed to install the necessary solar panels, inverters and control equipment.

All that just to save $75 a month of electricity from the grid. When juice can be bought in southern California for 10.8 cents a kilowatt-hour, it is hard to make the case for becoming energy independent. If you are concerned about the pollution, buy a couple of tons of carbon offsets each year for $70 and have done with it.

But what if, instead of being charged a flat rate for every kilowatt-hour used, consumers had to pay a market price that fluctuated by the minute — as the utilities themselves have to do in the energy wholesale market? That is a distinct possibility when the much ballyhooed "smart grid" — with its two-way communication between producers and consumers — becomes a reality.

Thanks to its heavily insulated roof and double-glazed, low-emissivity glass throughout, electricity usage at my home — Mayhem Manor — is a modest 8,300 kilowatt-hours a year. Even so, your correspondent would like to know more about his pattern of electricity consumption.

He would then be able to maximize the benefit when his local power company started charging him a different rate for different times of the day. He has made a start by auditing his electrical appliances and gadgets. One of the simplest tools for doing this is the P4400 "Kill A Watt" meter made by P3 International.

To find the energy hogs, you simply plug each appliance into the meter in turn, and then plug the meter into the wall socket and leave it switched on for a fixed time. The meter's digital display gives the appliance's cumulative consumption in kilowatt-hours. It is then an easy matter of calculating the electricity bill for each piece of equipment by the day, month or year.

There were few surprises. The air-conditioning system is a killer. So are the washing machine and the dryer. Plasma television sets are brutes.

The clever little meter does other nifty things. By monitoring the line voltage, frequency and power factor, you can check the quality of the electricity you are being charged for — and yell at the utility for delivering a shoddy product if it is below specification (not that it will do you any good).

More intriguingly, the Kill A Watt meter will also tell you how much electricity you are wasting unwittingly. When switched off, many appliances do not actually kill the power but go into a standby mode instead — sucking electricity, vampirelike, from the plug.

Computer monitors and speakers, printers, fax machines, hi-fi equipment as well as televisions and set-top boxes are among the biggest electricity suckers. Consumer-electronics devices can waste as much as 25 percent of their normal power when ostensibly off. For computer systems, the figure can be as high as 85 percent.

One answer is to plug clusters of equipment (for instance, computers, monitors, printers, modems and routers) into a proper surge protector that not only guards against nasty electrical spikes coming down the line, but also shuts down all the equipment completely when you switch off.

But such approaches are only stopgaps. Far better would be to have a smart meter in the home that told you how much electricity each appliance was using at that instant, and how much it was costing you. It would then be possible to see the savings to be had from running the house at, say, 78 degrees in the summer instead of 72.

To do that, however, the appliances around the home would need to be able to respond to queries from the electricity meter and adjust themselves accordingly. Few, as yet, can do so.

Technically, it is not difficult. But politically it's a sensitive issue, with overtones of Big Brother. Indeed, there was such an uproar in California when the authorities proposed letting power companies adjust the thermostats in people's homes remotely — so as to lower overall electricity consumption at peak times — the idea was hastily abandoned.

But most consumers would be happy to allow two-way communication between their homes and the power company, provided their own fingers were on the switch. Already, a handful of meter makers have begun incorporating ZigBee transceivers into their products to do just that. The ZigBee wireless protocol was designed as a cheaper and lower-power alternative to Bluetooth and WiFi for embedding in lighting switches, thermostats, smoke detectors and other sensors. At a dollar a chip, ZigBee transceivers could even be built into toasters and coffee pots.

Unfortunately, the household-goods industry has been slow to respond. That is largely a result of the industry's innate conservatism, but there has also been some controversy about the protocol's reliability. As a result, the smart grid seemed destined to stop at the front door.

Or so your correspondent believed until he attended the recent Demo 09 in Palm Desert, Calif. The event, where selected startups are each given six minutes under the spotlight to pitch their product to an audience of investors and industry veterans, is one of the leading launch pads for emerging technologies.

Three presentations at Demo 09 lifted his spirits. One, in particular, made him feel the smart grid might even enter the home before the decade was out.

This was a demonstration of a suite of open and extensible software applications for managing energy demand and time-of-use pricing by a firm in Boulder, Colo., called Tendril. The Tendril Residential Energy Ecosystem (TREE) is designed to make life easier for consumers and utilities alike — and to do so without raising the appliancemakers from their slumbers.

Attaching appliances to a power socket via a smart plug containing sensors and a ZigBee transceiver allows information about the appliances' power consumption to be beamed automatically to a broadband router within the home, and thence to a Web server located elsewhere. Consumers can interrogate this server from a PC or iPhone to see not only the consumption pattern of various appliances attached to smart plugs around the home, but also to send instructions back to switch them on or off.

"People make 10 to 20 percent savings when they get this kind of information," says Adrian Tuck, Tendril's chief executive. "And remember every kilowatt saved in the home saves three at the generating station."

If half the households in America cut their power consumption by just 10 percent, it would be like taking 8 million cars off the road. Or doubling the amount of energy produced from renewable sources, such as expensive, rooftop solar panels.

A simple, new way to save energy 04/06/09 [Last modified: Monday, April 6, 2009 10:08am]

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