Monday, November 06, 2023

Smart Meters and electricity use at Tribble Towers

We first got moved over to a smart meter some years ago. It partially worked great for about a day, then stopped.

The whole thing has been a bit of a shambles. It wouldn't take electricity readings, the in-home display (IHD) wouldn't communicate with the meter, our meter wasn't even registered with the supplier, and that sort of thing.

Even now, despite having a smart meter that's capable of reporting usage accurately and frequently, our supplier makes up bills that have at best only a passing familiarity with our actual usage.

Having a smart meter can, in principle, drive savings in two ways.

First, it allows very granular billing. British Gas have a half price tariff between 11 and 4 on Sundays. This sort of variable billing simply isn't possible without a smart meter. Fine, so we do most of our washing in that window, run the dishwasher, cook Sunday dinner, wait until just after 11am for our morning coffee and make sure we boil the kettle for tea in the afternoon just before 4pm.

At one stage they had a variety of short-notice periods of cheap electricity too.

I'm guessing the advantage of this to the suppliers is that they can do a bit of demand management, shifting load from peak times to idle times, although I think it'll have to be rather more dynamic to really do any good. And if we save a bit of money in the process we're not going to complain.

The second saving is if the consumer can use the smart meter to track usage in real time and identify what's actually using all their electricity. That's proved to be a bit trickier.

After far more work that I expected, I now have a much better handle on where all the electricity in Tribble Towers is going. The smart meter itself wasn't much help in providing answers, although it did provoke a lot of questions (I think I've turned *everything* off that I can, why are we still using 200W?) - so having the smart meter was a benefit.

In our house, the heaviest usage comes from the kitchen. That's where the oven, grill, hob, microwave, toaster, and kettle are. They aren't on for that many hours a day, but when they are their usage is huge. There's also the fridge freezer - we've recently replaced ours (because the old one failed over the summer) with something that's actually pretty energy efficient, but it's obviously on 24 hours a day, every day.

The next biggest room is the living room. All that electronics - the TV and friends. What I did learn was that the Sky boxes are incredibly power hungry, and they don't vary that much between on and standby (25W, all year long). So much so that we pulled the plug on the Sky box and TV in the guest room because nobody has watched anything on it for years.

The broadband router is another big contributor. Again, it's power usage is modest, but it's on all the time (and necessarily so).

Another thing I learnt is that lighting pulls a lot of power. We have a mix of lighting types, some very efficient low energy bulbs, a number of specialist bulbs we can't get low energy versions of, and some pretty inefficient bulbs. In particular, the uplighters in the living room pull 80-100W each. Unfortunately they're already a low-energy variant (low here being a relative term). They give very good quality light, and we're not going to sit in the dark. But what we now do is leave a very low energy side light on if we're out, rather than the main light.

I was a little surprised that my office and all the computers in it wasn't consuming all that much power, in relation to some of the items mentioned above. My main monitor draws more power than the computer it's connected to. And while my array of servers pull a lot of power when on, they're not on all that many hours. My entire array of systems and network, which is basically what I use all day, is maybe 15% of our total household usage.

And there's the long tail of things in standby, chargers, and the like. Each consumes very little power, but there can be so many of them, and they tend to on all the time, so that adds quite a bit.

We have managed to identify a few inefficiencies and waste, and have reduced our electricity consumption overall by maybe 10% over the last year or so (we had already largely transitioned to low energy light bulbs, which would have been maybe another 10%). That seems to me to be the sorts of savings one might expect; anything much larger requires more radical change, especially in how we cook.