Monthly Archives: February 2012

Halving our electricity usage

I learnt something interesting today: between 2007 and 2011, we halved the amount of electricity we use in our house:


In 2007, we used 6783 kWh of electricity (for electricity, a kilowatt hour is the same thing as a ‘unit’ on your bill). In 2011, by contrast, we used 3332 kWh (or ‘units’). 2007 was slightly on the high side (compared with 2006) because we had no gas fire in the living-room during the winter of 2006-7 so we’d used an electric oil heater during the coldest weeks (we don’t have central heating in that room) 1.

That’s an average of 19 kWh per day in 2007 compared with 9 kWh per day in 2011. Which is quite a difference. So what changed?

In early 2008, I got a plug-in Maplin meter (similar to this one) and one of the very early Current Cost monitors, which display in real-time how much electricity is being used in your whole house:

Current Cost monitor

Aside from the fun of seeing the display numbers shoot up when we switched the kettle on, it informed us more usefully that when we went to bed at night or out to work, our house was still using about 350 Watts (which is 3066 kWh per year)2 of electricity. That’s when the house is pretty much doing nothing. Nothing, that is, apart from powering:

  • Fridge
  • Freezer
  • Boiler (gas combi boiler with an electricity supply)
  • Hob controls and clock
  • Microwave clock
  • Infrared outside light sensor
  • Print/file server (basically a PC)
  • Wireless access point
  • Firewall and Internet router
  • DAB clock radio
  • ADSL modem
  • MythTV box (homemade digital video recorder; basically another PC)

And that’s the thing, this ‘baseline’ often makes a lot of difference to how much electricity a house uses overall. 3066 kWh per year was 56% of 2007’s total electricity usage.

The first six items on that list draw less than 100 Watts (876 kWh per year) altogether. They’re the things that we can’t really switch off. But there were clearly things that we could do something about.

Over the next couple of years, we reduced our baseline by about 100 Watts by getting rid of some of the excessive computer kit, buying more efficient versions when we replaced the old print/file server and MythTV box, and replaced most of our lightbulbs with energy-efficient equivalents. We also, importantly, changed our habits a bit and just got more careful about switching lights off when we weren’t using them (which wouldn’t affect the baseline but does affect the overall energy usage), and switching off, say, the stereo amplifier when we’re not using it.

That brought our baseline down to about 230 Watts (2015 kWh per year), which is a lot better, though it’s still relatively high considering that the ‘essentials’ (eg fridge and freezer) contribute less than half of that.

And that’s about where we are now. We tended to make changes in fits and starts but none of it has been that arduous. I don’t think we’re living much differently; just more efficiently.

1The complementary gas usage graph shows lower gas for that year for the same reason; I’ll blog about gas when I have a complete set of readings for 2011).
2350 Watts divided by 1000, then multiplied by 8760 hours in a year.
Photo of the Current Cost monitor was by Tristan Fearne.
Thanks also to @andysc for helping create the graph from meter readings on irregular dates.

UX hack at London Green Hackathon

At the London Green Hackathon a few weeks ago, the small team that had coalesced around our table (Alex, Alex, Andy, and me) had got to about 10pm on Saturday night without a good idea for a hack, in this case a piece of cool software relevant to the theme of sustainability. We were thinking about creating a UK version of the US-based Good Guide app using on their API to which we had access. The Good Guide rates products according to their social, environmental, and health impacts; the company makes this data available in an API, a format that programmers can use to write applications. Good Guide uses this API itself to produce a mobile app which consumers can use to scan barcodes of products to get information about them before purchase.

Discussing ideas
Discussing ideas

The problem is that the 60,000 products listed in the Good Guide are US brands. We guessed that some would be common to the UK though. We wondered if it would be possible to match the Good Guide list against the product list so that we could look up the Good Guide information about those products at least. Unfortunately, when we (Andy) tried this, we discovered that Amazon uses non-standard product IDs in its site so it wasn’t possible to match the two product lists.

The equivalent of the Good Guide in the UK is The Good Shopping Guide, of which we had an old copy handy. The Good Shopping Guide is published each year as a paperback book which, while a nicely laid out read, isn’t that practical for carrying with you to refer to when shopping. We discovered that The Ethical Company (who produce the Good Shopping Guide) have also released an iPhone app of the book’s content but it hasn’t received especially good reviews; a viewing of the video tour of the app seems to reveal why.

Discussing ideas
Quite late at night

By this point it was getting on for midnight and the two coders in our team, Andy and Alex, had got distracted hacking a Kindle. Alex and I, therefore, decided to design the mobile app that we would’ve written had we (a) had access to the Good Shopping Guide API and (b) been able to write the code needed to develop the app.

While we didn’t have an actual software or hardware hack to present back at the end of the hackathon weekend, we were able to present our mockups which we called our ‘UX hack’ (a reference to the apparently poor user experience (UX) of the official Good Shopping Guide mobile app). Here are the mockups themselves, along with a summary of the various ideas our team had discussed throughout the first day of the hackathon:

I’ve decided to get a Kindle

On Wednesday, I downloaded my first paid-for ebook: An Introduction to Social Constructionism by Vivien Burr. I’d just finished reading Incidents in the Life of a Slave Girl Written by Herself, which I found free on the Kindle Store when I installed the Kindle for Android app on my phone. I wasn’t sure whether I’d happily read a whole book from my phone but we seemed to get on pretty well, even reading from a small, backlit screen.

I rather like the crisp freshness of physical new books and the battered usedness of secondhand books, with their mysterious inscriptions from owners (or libraries) past. I also quite like having physical books on shelves; I grew up in a household full of bookcases and I’m easily distracted, when visiting friends, by the contents of their bookcases. But our current small house can’t really take many more shelves.

I’ve found that having a pile of books-to-read by my bed doesn’t actually make me read them any more quickly. And the weight and bulk of them prevents me carrying one around with me on the off-chance that I might have a spare moment to read it. I read Incidents in the Life of a Slave Girl whenever and wherever I had the chance: on the train, on the station platform, on car journeys, at my in-laws, in the living-room waiting for tea, in the kitchen whilst cooking tea, in bed, in the middle of the night when I couldn’t sleep. In short, anywhere I had my phone and some free time. And I carry my phone everywhere.

The problem with my phone is that it’s not that comfortable to hold for a long time and I’m a bit wary of straining my eyes focusing on such a small, backlit screen. Handily the Kindle automatically syncs your reading position (in the book; not your posture) to the Amazon server and your other registered Kindle devices. So if I had a Kindle, I could read it at home or on the train, and then, when I don’t have the Kindle with me (eg waiting to be served at the takeaway), I could carry on reading the same book from my phone.

So a Kindle is now on my Amazon wishlist. I’m not keen on the closedness of it as a system but I do like the user experience. Just got to patiently wait for my birthday to come round now…