Daily Archives:August 20th, 2016

No trouble at mill

No trouble at t'mill

We paddled from home, through Grantchester, past Byron’s Pool and out towards Hauxton before breakfast this morning. Most enjoyable. This is the mill at Grantchester, taken from just beside Jeffrey Archer’s garden.

Saw kingfishers, ducklings, a comorant… Enjoyed a cup of coffee up a little tributary before turning for home.


Power pricing

Here’s a very rough rule of thumb which I find exceedingly useful:

If something uses 1W of electricity, and it’s switched on all the time (24 x 7), it will cost about £1/year in electricity.

So, for example, I have an elderly Mac Mini next to my television which used to be on all the time because it was my ‘media centre’ – it recorded things from the TV onto disk, etc. It takes about 80-100W, so it costs me roughly that many pounds per year, which means that if I turn it off I can get my Netflix subscription for free!

All sorts of calculations become pretty straightforward.

  • I have a second display for my iMac, which uses about 60W. (I’ve just measured it.) So that would be £60/year, but it’s only on for about 8hrs/day, so £20/year.

  • If a salesman tells you a new fridge will save you an average of 40W compared to your current fridge, but costs £400, you can work out easily that it’ll pay for itself in about 10 years.

In case you’re curious, this rule assumes you pay about 11.5p/kWh for your electricity, which is close enough for most UK residents. I forget who first pointed the convenient annual multiplication out to me, but I find myself using it all the time, so I thought I’d pass it on!

© Copyright Quentin Stafford-Fraser