This Time Self-Hosted
dark mode light mode Search

Energy Usage: It’s Not What You Think It Is

You may remember that I used to write about energy back in the days when I was living in Italy (since I had a lot more control about energy usage there, than ever since), and back then just like now, I was just as naive about stuff as the best of us. Over time, though, I started gaining a little bit more knowledge, which as they say, is dangerous.

Thankfully, besides learning from people with actual experience, we now have a lot of ways to monitor our energy usage to figure out where expenses actually end up. And that made me realize just how off the mark we are, sometimes, when looking by instinct at what is using energy in our lives.

Take for instance the following tweet by the QI Elves:

I love QI and I think that the Elves (the researchers, and the whole production staff) are doing great both in terms of finding interesting content, and providing discussion points to stimulate curiosity of adults and kids. But in this particular case, I think they are quite off the mark.

The first thing to consider, is that this is a study that is from 2006 in the United States. LED lights have made leaps and bounds since! Sure in 2006 they weren’t completely unknown (my infamous blog post that I posted just before nearly dying from pancreatitis is from 2008 — in 2007 Christmas light tubes were already LEDs), but they were definitely less overall useful. Heck, even in 2021, Alec is unsatisfied by them! But also, these need to be put into significant proportion!

I’m not talking to put it into the proportion of the astounding trash fire that are all cryptocurrencies. I’m thinking about putting it into proportion on the small scale that can be a two bedroom flat! Here’s for example a screenshot from my Home Assistant energy dashboard:

When you look at this graph, the Christmas tree lights we have in the flat (and that are turned on on average for 16 hours a day) only exceeds the power of the bedroom air freshener (which is only turned on for about six!) making it fairly cheap in terms of power. Indeed, in this graph it’s dwarfed by the UniFi Gateway, which alone consumes nearly as much as the two access points combined! I knew that the USG is a very old and inefficient design, but it took looking at its general consumption to realize just how much.

But let me share the graph for a different day:

On this one the Christmas Tree is head-to-head with… my washing machine? Did I discover the secret of free energy, and got the most efficient washing machine in the world? Will I be open sourcing it? Nope. This is what happens when you don’t turn the programme handle back to “off” after running the cycle on our washing machine (Zanussi ZKG 71×5). Turns out, I didn’t use to do that at all! The standby mode only showed a two digits eight segment display, and otherwise make it react to button presses, the programme handle is also a soft, digital selector, it’s not going to trigger a physical switch, I never thought much about it. Turns out instead that leaving it in that mode ends up consuming just shy of 20Wh per day. It’s not a lot, but as you can see it compares to a Christmas Tree on for most of the day. With current energy prices that alone takes around £2/year.

Incidentally, the WiFi Smart Plugs should consume around the same amount of power, which means there’s no real incentive, just because of that particular phantom load, to use one for a washing machine. But the reason why we have it there is a bit more complicated: I set up Home Assistant to remind us when to take out the laundry, knowing that the washing machine finished its cycle. I have not tried to make the heuristics even smarter and remember that the door won’t open right after the drying ends, but it at least shows us a notification when we come home, and when we’re about to sit down to watch TV.

So if a Christmas Tree is not going to be the main driver of phantom load in a house, what would it be? Well, that’s a good question for which I have no answer. Short of integrating BLE or ZigBee power monitors into all type of chargers and DC adapters, there isn’t an easy solution to keep track of various loads without constellating your house of smart plugs. I can definitely see myself in a few years using more smart power strips so that the vast majority of our appliances stay completely off while we’re not home. And I’m already considering moving more of my desk’s gadget to use Power-over-Ethernet (as the Home Assistant Blue above does thanks to an adapter, and the Home Assistant Yellow does out of the box), which thanks to my modified UniFi integration (which I’m trying to get merged upstream bit by bit) I can not only account for the power usage, but also control on and off state.

All of this is not helped by the number of changes in the way energy labels are applied to items nowadays. The change from the ever-higher A++ ratings to the current “Everything looks terrible” has not made things any clearer for people deciding what to buy, and the fact that the label only references a specific configuration does not help: both my recently bought monitor and TV come with default settings that are very aggressive on powersaving, but to the extent that you wouldn’t really be using it in that configuration. Turning on HDR on the monitor, for instance, makes it lose its Energy Star compliance. I don’t think this is particularly useful to consumers, just like it wasn’t obvious that the setting that turned off the TVs LED during standby was not magically making them unplug themselves when turning them off on the remote control.

Also for those who are wondering, my current solution to reducing the energy usage of fresheners is to use better fresheners: the AirWick ones are actually difficult to notice in a room after the first couple of days even when at maximum, while the Yankee Candle ones are currently much stronger even towards the end of the bottle. While the Yankee Candle fresheners don’t change their power consumption when changing intensity (instead of using a variable resistor they seem to just bring the heating elements closer or further away from the wick, mechanically — a choice that makes sense in retrospect) it means we don’t need to run them throughout the whole day to smell them. Indeed, turning up one in the bedroom a few minutes before setting the alarm is all it takes to wake up and be welcomed by them.

As such, I set up “bouncer” automations, that turn the freshener off after a set amount of time (as well as, obviously, make sure they turn off when we leave the apartment), and set it up to turn on in certain conditions (when we come home, when we’re about to wake up, …) reducing the daily power consumption significantly and making even the stronger fragrance not be such a slap in the face of strength.

Does anybody know if ZigBee smart plugs also can report power consumption? those appear to be both less needy of power themselves and a better deal in terms of price. Maybe I should just get a pair to check out with the fresheners, that otherwise don’t really need to report their energy that badly — I’d be more interested in knowing the power consumption of some of the office equipment at the end.

Comments 4
  1. I have a few smart plugs from Aqara (SP-EUC01) and they report the power consumption over Zigbee. Integrates nicely with HomeAssistant and has worked like a charm for a few months here. Only annoyance is that they default to Off if the power goes out, so they have to be toggled on again (either via the button or HA)

    1. Oh those look great! Too bad they don’t seem to do them for UK style plugs 😥

      I’ll see if I can figure out what’s available over here,at least if it’s possible.

  2. I don’t know about the usage of holiday but I’m shocked at the argument you’re making. You’re assuming:

    – in-use christmas lights make use of current techology. A large amount of residential christmas lights will be the same ones pulled out of the same box a decade ago
    – you’re assuming your usage is typical but say the lights _in_ your _flat_ for 16 hours. Lots of people have lights outside running through the night.
    – you’re assuming your might be a suitable mean average without considering that light usage might grow exponentially with the size of residence. You have lights in your flat. A small two bed house might have them hanging some more outside. But drive past a residential area with large houses, the displays get massively more extravagant.
    – you’re assuming residential usage is a good enough measure. This is like measuring firework usage by people’s backyard rockets, and disregarding the thousands displays across the world with millions of pounds spent

    And aside from the main point of the article, environmental cost isn’t just running cost. It’s manufacturing, shipping, and storage too. Holiday lights have a low usage for their cost relative to other things.

    > And that made me realize just how off the mark we are, sometimes, when looking by instinct at what is using energy in our lives.

    With energy, and with anything. Would advise pondering on this statement some more 🙂

    1. I totally agree with the environmental costs, but the source statement was about the energy consumption!

      And I’m not expecting my *usage* is typical, but my *proportion* is. The people leaving lights on overnight are likely also having a much larger energy footprint.

      As for the commercial usage, that’s where I’m ready to disagree fully: commercial usage actually updates a lot faster than homes where the lights are often reused. That adds to the environmental impact, but not to the energy usage.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.