[function_seven]

> 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.

[rconti]

He has to be off, way off. He's not using $4/mo on an Echo at 10c/kWh. We pay more than double that rate and our electric bills were frequently under $50/mo before we got an EV.

The one thing I learned using my kill-a-watt a few years back, is that "vampire draw" is likely something that only applies to VCRs from the 80s. I plugged it into a power strip full of USB and Apple chargers, and the consumption over a week is stunningly close to 0.

Every small device I measured was utterly insignificant, despite all the articles over the past decade telling you to plug all your chargers into a power strip and flip it off when not in use.

Bigger things I can understand. Our "smart TV" almost certainly draws tens of watts in spying^H^H^H^H^H^H standby mode.

[floatingatoll]

To calculate the math more correctly, a 1W smart plug is contributing $0.09/month to the $400 electrical bill quoted. This is a stellar example of a micro-optimization, in programming terms.

Focusing on big spenders like "anything with a pump" and "anything that generates heat" would contribute significantly to reductions.

I once upgraded video cards, reducing my computer's power draw by 180W and lowering my electric bill accordingly. This was back in the early days of CFLs (they were terrible) so it may not seem like much, but it was on 24/7 and that was the power at idle. I think it worked out to something like $10/month of savings, which was quite noticeable for my total bill of $50 or so.

[function_seven]

> ... and "anything that generates heat" would contribute significantly to reductions.

I never measured it, but there was one area that I quickly put a Tasmota plug on. My stereo receiver under the TV.

One day I was putting around the den and I noticed a lot of heat emanating from the credenza under the TV. It was my Sony receiver just sitting there, dutifully amplifying the null input from the turned-off TV.

So I added the plug, and told Home Assistant to turn the receiver on whenever the TV was on, and turn it off when the TV is off. My guess is that I'm saving 20-40W this way. $2-$4 a month.

(FWIW, this is the first time I've ever been glad to have a "smart" TV. The only feature I use on that TV is the ability for Home Assistant to see it)

[Relys]

Home Assistant is great! I flashed a cheap ES8266 RGB Led controller with ESPruna firmware and hooked it up to HA over MQTT. What are some of your hardware recommendations? I also have a Zigbee/Z-Wave dongle for the RPi, so I'm not limited to WiFi only.

[function_seven]

I use a Conbee II dongle with deCONZ for all my Zigbee stuff, and try to use Zigbee wherever possible.

The Hue bulbs are great, and also act as repeaters, so I have those sprinkled throughout the house. But they're expensive, so I used Sengled bulbs for most of my fixtures. The Sengleds are endpoint-only, though. So I mix those two bulbs to keep the mesh dense but also save some money.

All my door sensors are the SmartThings units. I use a mix of SmartThings and IKEA Trådfri motion sensors. One SmartThings water leak detector in the basement, a SmartThings button, and a Trådfri 5-button remote.

I started this just to have a convenient way to control lights. My house is really old, and almost all lighting is table- and floor-lamps that I would have to walk around and turn on and off. Or ceiling lamps with pull cords.

But after getting into Home Assistant, I started going a little nuts with the automations.

My favorite one: A month ago I was getting ready for bed when I realized I left my oven on all day long. For 12 hours it was keeping the oven at 375˚F. But then I realized that I already have a motion sensor in the kitchen, and if I just moved it to the door of the oven, the built-in temperature sensor could be used to remind me that the oven was left on. So now I have a rule in my automations.yaml: If the kitchen temperature exceeds the living room temperature by more than 10˚F for more than an hour, send a notification to my phone that I left the oven on.

[slantyyz]

Alternatively, you can get a $20 power bar[1] that has one outlet that determines the on/off state of the remaining plugs based on the current draw of that one outlet. No Home Assistant required.

I use one to power off a bunch of devices when my computer sleeps.

1: https://www.amazon.ca/gp/product/B01G6VTIDG/ref=ppx_yo_dt_b_...

[mixmastamyk]

I have an old radio shack power strip that shuts on/off according to a power draw in the first socket. Not sure, but is likely someone else makes one of these.

[floatingatoll]

I use an amplifier as a small space heater for a particularly cold corner of my home :)

[ip26]

1.5W is cheap to operate, but my god, for the job done that seems like a relative power glutton. Entire x86 processors can operate, not idle, at 5W.

My favorite story on the subject of relative waste:

https://reductionrevolution.com.au/blogs/news-reviews/584256...

[slantyyz]

Based on the photo in the post, the Kill A Watt is calculating his costs. He doesn't show the actual wattage reading from the Kill A Watt, so it seems to me like the price is set incorrectly on the Kill A Watt.

-- Addendum

I happened to have a Kill A Watt and Wemo lying around, and with no devices attached, the Watt reading ranges between 0.5W to 0.7W with no device attached and the Wemo set to the OFF state. When the Wemo is set to the ON state with no devices, the reading ranges from 1.2W to 1.3W, which is a noticeable jump.

[barbegal]

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.