Thinking About Smart Home Power Usage
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Thinking About Smart Home Power Usage
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Re: Thinking About Smart Home Power Usage
#2> The real shocker was when I decided to measure only the Wemo mini smart plug with nothing connected was costing me $0.31/day.
I can't buy this. That's 3,100 Wh each day, or roughly 130W constant usage. That much energy being dissipated in the plastic housing would be burning hot to the touch, or melt it.
I'd wager he's off by a couple orders of magnitude. 1.3W is much more likely for a smart plug to draw.
The 55W his Echo is drawing is suspect for the same reason. That's more power than almost any idling laptop.
Re: Thinking About Smart Home Power Usage
#3I never understood the claim that smart switches on LED lightbulbs will conserve energy. The duty cycle of the average light bulb is fairly low; I would guess they are switched on for If so, adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50%. You must be fairly sloppy to make that a gain, compared to a manually operated switch.
Re: Thinking About Smart Home Power Usage
#4The problem of saving power with small household devices is similar to the problem with micro-transactions. The overhead of connecting devices into a smart system is far greater than the recovered cost in terms of both money and energy. A smart switch can easily run to $100 to purchase and install and $10 a year to run. So it needs to save you ~$20 a year to be worthwhile. For large appliances that are regularly used such as swimming pool pumps, air conditioners, scooter or car chargers then it can be worthwhile.
I'd like to see smart blinds and curtains become more popular as windows can act like a giant highly efficient solar panel heating your home up when the conditions are right. Sadly again the cost of setting up and maintaining such a system could be ~$100 a year so only certain buildings would actually see a return on investment.
Re: Thinking About Smart Home Power Usage
#5I never understood the claim that smart switches on LED lightbulbs will conserve energy. The duty cycle of the average light bulb is fairly low; I would guess they are switched on for If so, adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50%. You must be fairly sloppy to make that a gain, compared to a manually operated switch.
> adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50%
Shouldn't that be 5%, not 50%?
Re: Thinking About Smart Home Power Usage
#6We used to use those Kill-a-Watt probes at work to classify smart home device power draw.
Emphasis on "used to". They are not very accurate at all, and the sampling interval over which they take data on wall power draw is slow enough that you will miss important changes in current draw on your DUT. We have since switched over to expensive, calibrated Agilent power analyzers with better time resolution.
The post is well intentioned, but I challenge his data collection methods. His tools are not up to the task he has set himself to. It is not nearly as simple as the folks who sell Kill-a-Watt's would have you believe.
Re: Thinking About Smart Home Power Usage
#7I never understood the claim that smart switches on LED lightbulbs will conserve energy. The duty cycle of the average light bulb is fairly low; I would guess they are switched on for If so, adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50%. You must be fairly sloppy to make that a gain, compared to a manually operated switch.
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Re: Thinking About Smart Home Power Usage
#8I never understood the claim that smart switches on LED lightbulbs will conserve energy. The duty cycle of the average light bulb is fairly low; I would guess they are switched on for If so, adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50%. You must be fairly sloppy to make that a gain, compared to a manually operated switch.
> adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50% Shouldn't that be 5%, not 50%?
they are assuming the 10W is only running 10% of the time and the smart switch is running all of the time. That puts the average use for the light at 1W and 0.5W for the smart switch.
Re: Thinking About Smart Home Power Usage
#9> The real shocker was when I decided to measure only the Wemo mini smart plug with nothing connected was costing me $0.31/day. I can't buy this. That's 3,100 Wh each day, or roughly 130W constant usage. That much energy being dissipated in the plastic housing would be burning hot to the touch, or melt it. I'd wager he's off by a couple orders of magnitude. 1.3W is much more likely for a smart plug to draw. The 55W h…
Yeah this is likely caused by the poor accuracy of the current sensor at very low power and switch mode power supplies can mess with the way the data is sampled.
Re: Thinking About Smart Home Power Usage
#10Earlier quoted context omitted.
> adding a ‘smart switch’ that uses 0.5W to a lighting fixture that has a 10W LED light bulb increases its average power usage by about 50% Shouldn't that be 5%, not 50%?
they are assuming the 10W is only running 10% of the time and the smart switch is running all of the time. That puts the average use for the light at 1W and 0.5W for the smart switch.
Ah, got it, thanks!