Intro
Part of my home automation project I would have some controllable lights, of course. On one hand, I used quite a few LED strips, controlled by dimmer modules. On the other, current technology allows for a plethora of wireless light bulbs. Philips HUE is probably the biggest and best known because it has existed for quite a long time, but I am not that attracted due to the price. Once Ikea came up with the Tradfri, I decided to grab a bulb and dimmer kit. It worked quite well, so I got more bulbs and a gateway about 2 years ago.
The devices
Don’t think of this as a large scale test, but I hope the conclusions are sufficient to get an idea of the system. So, overall I got 4 bulbs, 4 dimmers and the gateway:
- A 5W GU10 light
- A 5.3W E14 light
- A 12.5W E27 light
- A 12W E27 that can change color temperature
- Two round dimmers – not sold anymore
- One 0/1 dimmer
- one 5 button dimmer
- the gateway
The system is constantly changing
As I write this, the ikea website does not seem to have the exact products anymore, the two types of E27 lights I have seem to have slimmed 1W for the same light output. The round dimmers are gone, replaced by the 0/1 dimmers, good thing since they were crap. It’s very likely they are constantly chaining the product line, improving the light bulbs and dimmers. As far as I can tell, there is only one type of gateway that has ever existed.
At first it was… bad (late 2017)
Not everything, I was able to link the dimmers to the lights in one go and be done with it. But…
The round dimmer should be a simple concept. You can dim the light with it by turning it. It’s magnetic or comes with a simple base to stick it to anything. The light switch can now be where you want to use it or take it with you turn it around and dim the light. Only, it does not work so well. You would think you can continuously dim the light, but no, you only have 5 levels: full, 3 dimm levels, off, each controllable by rotating the disk 90 degrees. Many times, out of standby, the dimmer does not respond right away and you need to turn it around a bit before it starts controlling the bulb. There is no way to know when the battery is about to die, and it dies quite fast, maybe every 4-6 months. So you don’t know if the dimmer is not working because the battery is dead or it has not picked the command yet. Frustrating, probably why they removed it from the product line.
The app and gateway just did not work at first. For 2 lights I was able to pair them with the gateway, 2 just did not work. I did resets, checked for updates, swapped dimmers, tried it a few times over the course of a couple of months and nothing. So i gave up and shelved the gateway and app and used only the bulbs with dimmers.
Now (july 2020)
Things have improved, but are not perfect. For a few months i got the thing to work… mostly.
The good
I could finally hook up all the devices to the gateway, but not without multiple dimmer resets and retries.
The 0/1 dimmer and the 5 button dimmer are working fine.
I can control the lights through node-red with node-red-contrib-tradfri.
The gateway seems to have decent range it can reach any bulb in the house (max 8m away, 1 wall), without any other one being powered (normally they should form a mesh network)
The bad
Pairing a bulb to the gateway does not always work. I mean most of the times it does not work and you need to do multiple tries, reset the app, reset the gateway.
The rooms thing does not work, I cannot assign multiple lights to the same room in the app.
The round dimmers are quite crappy still, even though now connected to the gateway they have been updated.
The lowest dim level is too high.
No direct support for the dimmers in node red (they only work directly with the bulbs). I am not really sure I would need that, but the cost is attractive as wireless buttons.
About the power consumption and cost
I got the ikea lights specially because they use Zigbee, which is much lower power than WiFi. So technically they should have very low power consumption for the radios, in stand by when the light is off, but the bulb is still powered. This would be the way I intend to use them, always powered with control from node red/app/dimmers. This teardown confirms the lights and dimmers and gateway use EFR32MG1 Zigbee SOCs. The datasheet reports <10mA current in receive mode, with 5mA for the CPU running at full speed. TX mode can be higher but transmissions should occur only very sporadically. So that would mean the standby consumption for the SOC is less than 50mW, at 3.3V supply. But measuring the bulbs, they are sleeping at around 0.3 W for the E14 bulb and 0.4W for the others. That’s a 13% efficient power supply. Not good, not good, probably a lot of cost cutting.
When I got the lights I remember ikea reporting <0.5W in sleep, which I thought was just the peak maximum during TX, i expected the bulbs to be much less on average. They are not, which is disappointing. Today, that parameter is not specified on the website anymore. I have no idea why it’s gone, it could be that they have made it worse with newer models or even with improvements is still high enough that it is bad.
What does this mean? If you keep the lights on for an average of 3h a day, the smart bulbs add up to 50% more energy consumption for the E14 and 27% more for the E27 bulbs, compared to having the same bulbs without remote control. If you want to look at it another way, at 3h of operation per day the bulb should last over 13 years during which time it consumes 48kWh of standby electricity. At cheap european rates (0.1 EUR/kWh) that is 4.8 EUR, at expensive rates it can be 20 euros. That is money that can buy you a much more efficient power supply, but the consumer probably does not know and the manufacturer wants to get it as cheap as possible.
But wait, there is more: the smart light bulbs are in the order of 90 lm/W while the dumb one (both from ikea) are around 105 lm/W, so they are further less efficient by about 15% when ON.
I think this is overall quite bad. New EU regulations state that external power supplies under 50W should consume less than 100mW without load. Here we are looking at a 50mW load that can be as low as 20mW with the recent family of wireless SOCs. As far as I know, there are no regulations for the sleep power consumption for light bulbs, but I suspect there is not technical reason why they could not be reduced to 0.1W or less.
The gateway consumes 1.1W. It’s not much overall if you eventually have a lots of light bulbs in the house and use them around 3h per day.
So let me draw a line and combine everything: roughly, expect the Tradfri smart light bulbs to cost you 50% more to run than dumb lights from ikea. Whether that is worth it, is up to you.
The competition
Philips Hue is the established competition which has existed long before ikea. Their devices that seem to work a bit better: I have little direct knowledge on this and have been looking at reviews, same pairing and operational problems as ikea, but maybe a little less frequent. 2-3 years ago before ikea launched, the prices were significantly higher, but now they have gone down quite a bit (maybe the ikea competition) and are comparable to the tradfri system, but stil more expensive.
There are also a plethora of WiFi based light bulbs from multiple companies. It’s no wonder, the low cost WiFi/bluetooth chips make them cheap and it’s much easier for the user to get one working without a gateway. There are multiple highly inefficient ones, but the TP-Link one I tested seems surprisingly good: same standby power as the ikea ones, much smoother setup. A compromise with the WiFi bulbs is that there is no battery powered remote control, just an application.
Conclusions – about using the smart bulbs in general
There is clearly some work to do on the software side, paring is difficult and erratic. Limit yourself to just bulbs and dimmers and it all works well. Add the app and gateway and it starts to squeak. I did not find any problem with node red interfacing with the gateway, so far the pairing problems seem to be strictly related to the system. Cost wise, they are more expensive than traditional bulbs, but I think tradfri is the least expensive system with bulbs and physical remote controls that works quite ok now. The bulbs are both less efficient while running and have an added energy cost due to the standby consumption, costing roughly 50% more to run.
If you forget about system and just get WiFi bulbs and apps, there are good options too. The TP link bulb i tried is comparable to the ikea bulbs, but more expensive. It does not require either a dimmer or gateway. It’s worth it if you want just remote control from the app/smart home and use only a few. Considering the components, the difference between WiFi and Zigbee bulbs is the controller inside. Zigbee should be slightly more expensive but less energy hungry. However, if the manufacturer of Zigbee bulbs blows it by using an inefficient power supply, they lose the energy advantage of Zigbee. This is exactly what is happening with the ikea bulbs, which consume as much as the WiFi bulbs. So then the difference comes between how you want to control them and how many you want: if you want remote controls you have to get a system, if you want many, a system seems worth it because quality WiFi bulbs seem more expensive than Zigbee ones.