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DVRs, Cable Boxes Top List of Home Energy Hogs
Hugh Pickens writes "Elisabeth Rosenthal writes that cable setup boxes and DVRs have become the single largest electricity drain in many American homes, causing an increase of over $10/month for a home with many devices, with some typical home entertainment configurations eating more power than a new refrigerator. The set-top boxes are energy hogs mostly because their drives, tuners and other components are running full tilt, 24 hours a day, even when not in active use. 'People in the energy efficiency community worry a lot about these boxes, since they will make it more difficult to lower home energy use,' says John Wilson, a former member of the California Energy Commission. 'Companies say it can't be done or it's too expensive. But in my experience, neither one is true. It can be done, and it often doesn't cost much, if anything.' The perpetually 'powered on' state is largely a function of design and programming choices made by electronics companies and cable and Internet providers, which are related to the way cable networks function in the United States. Similar devices in some European countries can automatically go into standby mode when not in use, cutting power drawn by half and go into an optional 'deep sleep,' which can reduce energy consumption by about 95 percent (PDF) compared with when the machine is active. Although the EPA has established Energy Star standards for set-top boxes and has plans to tighten them significantly by 2013, cable providers and box manufacturers like Cisco Systems, Samsung and Motorola currently do not feel consumer pressure to improve box efficiency."
At least in the colder regions of the country, "heating" doesn't usually show up on the electric bill. Electric heating is extremely convenient to install, and good for point work; but the inefficiency of burning something, converting it to electricity, running that through transmission lines, just to dump it into a big resistor at the other end is a bit much.
Air conditioning is likely a lot worse; but, because everybody knows that it is extremely energy intensive, thermostatic regulation has been standard since the mechanisms for achieving it were bimetallic, and microproccessor based scheduling systems creep in pretty quickly once you get away from the nastiest of basic window units.
By contrast, it sounds like team STB has somehow managed to miss Every Single Development in computer and embedded device power management in the last decade. Ironically, they've probably even managed to achieve an outcome where Intel muscling in with their x86 (barely) SoC designs would actually be more efficient than highly-integrated task specific media SoCs; because at least they would incorporate their laptop power management techniques more or less for free. Impressive work.
Obtaining the precise numbers would be a bit hairy; but I suspect so.
Depending on the fuel in use, your heat->mechanical energy conversion will always live in the shadow of that spoil-sport Carnot, along with any engineering limitations. In practice, I'm told that you get something in the vicinity of 30-50 percent(of the fuel at the plant, it still has to be shipped there, though at least bulk shipping is easier, per unit goods, than household delivery). After that, you still have the generator that the turbine is driving, along with the power transmission apparatus.
By contrast, since heat is the desired product, the only 'waste' heat in an onsite burn is whatever goes up with the stack gasses and whatever goes to the delivery truck. At least with oil heat, in the northeast, we had about one delivery a year. Unless the truck managed to burn half its payload getting to us, I suspect that we came out ahead.
Peripheral electrical generation, with heat engines, is something you do only for backup purposes; because small heat engines pretty much inevitably suck more than huge ones; but when all you want is heat, the only real efficiency issues are the engineering problems of cooling the exhaust gasses before they leave the premises.
Actually you have calculated average watts (which is what is really relevant). Your numbers are "watt hours per hour", cancelling to watts, not watt hours.
Because a watt-second is so small a unit it's practically useless outside academia.
Now get outta here before I start converting everything to BTUs!
=Smidge=