Absolutely loving the idea of the smart bulbs, and after using the plugs for a long time, jumped on one to try it out. But something kept bothering me, what is the bulb’s power consumption? And more importantly what is the standby power consumption like? After all there would be a draw of some kind to keep the wifi on, but what is it? So I went around looking and ended up on an experiment. Get a cheap £7 wall plug for e27 socket and stick it into one of the plugs to see what happens! The results were far more interesting than I expected.
So here is the tl;dr for those in a hurry:
- Standard (white and yellow) light is very much identical, so only white is shown in the results
- About 30% reduction in output power resulted in about 60% lower power consumption
- Non-standard colours follow similar trend as stars for their heat output (red is cooler and blue is hot)
- Non-standard colours are always lower in their consumption than standard
So the experiment, as I have recently moved to a place with a completely random array of B22 and E27 sockets, I was interested in rewiring it into a common standard, and while there figured, this would be a great opportunity to test out smart lightbulbs and get a bunch to use. Due to the move, I haven’t yet setup home assistant, so all the measurements are completely not scientific in any meaningful way, basically change a setting and look at the values for half a minute to see what changes. Measurements are done using our favourite localbytes plug, in a random £7 wall light socket. Wall socket itself did not consume anything visible by the plug.
Here is the setup, pretty basic and completely unscientific. Using the web interface of the plug and the light to control (and validate the power setting via requests).
And the results, hopefully the table posting would work (if not il add an image of what the table should have looked like:
+------------------+--------------------+-------+------------------------------------------------------------------------------------------------+
| Power State | Colour | W | Notes |
+------------------+--------------------+-------+------------------------------------------------------------------------------------------------+
| Standby | White | 0-1 | When its on standby it hovers somewhere around 0-1W with 1 being most common value, I suspect its probably around 0.95W or there about, given how often it displays 1 |
| 100% | White | 10-11 | Full power on white channel - 10-11W, its most likely to be just over 10W, as it rarely goes into 11W |
| 95% | White | 8-9 | Hovers 40-60%. |
| 90% | White | 7-8 | Hovers 45-55%. |
| 85% | White | 6-7 | Hovers 50-50%. |
| 80% | White | 5-7 | Hovers 45-45-10% |
| 70% | White | 4 |
| 60% | White | 3 |
| 50% | White | 2 |
| 40% | White | 1-2 | Hovers 25-75%. |
| 25% | White | 1 |
| Custom Colours | - | - | Going from left to right on the Tasmota colour chart at 100% |
| 100% | Red | 2-3 |
| 100% | Orange | 3-4 |
| 100% | Yellow | 4-5 |
| 100% | Yellow-green | 4 |
| 100% | Light blue-green | 4 |
| 100% | Light blue | 6-7 |
| 100% | Dark blue | 3-4 |
| 100% | Pink | 5-6 |
| 100% | Red | 3 |
+------------------+--------------------+-------+------------------------------------------------------------------------------------------------+
Had a bit too much fun for one evening with this, but it brings an interesting point, what is the standby power usage for a range of smart things? For instance, 1w might be inconsequential, but what if you have replaced all your bulbs with smart ones? Over the course of an always on year, one, would on standby consume a bit under 9kwh.
Okay, what if you have 10 bulbs? 90kwh, what about the plugs themselves? They report 0 but of course there will be some kind of draw (should measure that!). One of my ideas was to convert all the bulbs to smart bulbs, so you could have a “go to sleep” button for the whole house and whatever lights you have forgotten would go off, automated curtains drawn, ect. But in the days of expensive electricity, its an interesting thought experiment.
Standby power draw for smart devices - for the bulbs is just under 1W, so just under 9Kwh per year, which is at my electricity price is a bit more than £2 per year to keep the light off! You’d be safe to multiply that per each smart device you have to have an annual cost of having your home smart do nothing! On an interesting point, when I discovered these plugs and got a few, I measured as many home appliances as I could find so for anyone else looking to optimise their background power usage, I suggest measuring standby of your TV. I was actually surprised by some of the findings enough to add a script to home assistant to switch a TV off at the wall when it detected standby power usage as it was costing £31 per year just to keep the bloody thing off! So check larger devices on standby first before worrying about the bulbs, they are good and I love the variable brightness!
PS, saw a post asking about lifespan of the plugs, what is the expected lifespan of the bulbs? Since now they have an always on component, at least for power?
