www.andyduffell.com

A picture of me the next time I buy light bulbs

UK electricity companies are in the habit of sending out packs of free energy saving lightbulbs to their customers. It’s one way they satisfy their climate change obligations to government. During the course of a couple of house moves i’ve ended up getting sent 3 packs of four bulbs each, so 12 bulbs in total.

Now, I already had five spare bulbs, so that means i’ve got 17 spares kicking around now. We currently use eight low-energy bulbs around the house, and i’ve yet to have one die in about three years of use. If one blew tomorrow, that would put my usage at 0.042 bulbs per year. If they all blew, that would mean 2.67 bulbs per year. So in the very worst case scenario I have 6.37 years before I have to buy stock up on bulbs again. If you take the lowest estimate, i’ve got enough for 404 years.

I mean, free stuff is great, but I think i’m pretty much sorted for light bulbs now. If you’re listening power companies: you can stop sending them now. If you feel you have to send us free stuff, alcohol will do nicely.

Electric cars: no longer glorified milk floats

Formula 1 is the cutting edge of automotive technology. A lot of the stuff in production cars today like ABS and fuel injection started out in F1. That’s why the news that the FIA is backing a new racing series using electric propulsion is exciting news. Called the EV Cup it should help accelerate the performance of alternative propulsion in cars.

It could make for some exciting racing, too. Electric propulsion has ludicrously high torque, meaning insane acceleration and crazy passing manoeuvres. If all goes to plan, look out for EV Cup races in 2011.

This might be going a little overboard...

By now, we’ve probably all heard that we should unplug or switch off any devices on standby around the house. The reward for doing so is that we get to continue having a planet to live on. Seems fair, but how true is it?

What’s the problem?

A lot of devices these days do actually consume power after they’ve been switched “off”. This can be seen from the results of my home power audit. Here’s some examples:

So in fact it does look like we’re wasting some power. On all these devices “off” is taken as being switched off with the button on the front panel. Idle in the case of the tellys is standby mode, waiting for the remote to turn the screen on, and for the hifi is switched on but not playing anything.

How much is this costing me?

Even with them all switched “off”, we looking at wasting 4.3W. At 12.5p per kWh you’re talking about £4.70-ish of electricity per year. So hardly a big deal. However, if they were all left on idle we’d be looking at £33.40, which is starting to look like a real waste of money for just three devices. And i’m betting anyone that doesn’t live in a cave has a lot more than that.

What can I do about it?

• Obviously, switch everything off whenever not in use.
• If practical, switch off at the wall whenever you can.
• Automate: buy timers that will switch off at the wall for you while you’re asleep or at work.

Tell me about these timers

They’re cheap. You can buy a plug-in timer for as little as £2. At that price it’ll pay for itself pretty quickly, and saves you the hassle of having to go around switching things off.

I sort my jumble of cables into things that have to be left on overnight (eg: router) and things that should be switched off (eg: TV) then put all the latter onto a timer that switches them on for a couple of hours in the morning and the evening. The timers have an override switch if you want to turn stuff on outside of these hours.

In my case I let the timer in my living room turn on for about 8 hours a day. That’s taken my standby wastage from 38.8W down to 28.5W, a saving of 27%. At that rate the timer pays for itself after 9 months, then everything after that is a saving. Best of all, I don’t have to actual do anything. Laziness + saving the world = win!

Savings will be even bigger on some of the more horrific standby power offenders. Mostly i’m thinking of PCs, more on that in a later post.

Most of us only get a rough idea of how much electricity we use from how hard the power company stings us each month. But do you have any idea exactly what machines in your house are slurping all that juice? The only way to find out is conduct a home power audit, and the results can be pretty interesting.

Why bother?

1. It’s easy. All you need is a plug-in power meter.
2. Green is good. Conducting an audit will show you how you can reduce your carbon footprint.
3. Money is good. You could be wasting a lot of cash each month.

Ok, how?

Plug-in meters are cheap and will pay for themselves in the savings you make

A plug-in meter does exactly what it sounds like. For my audit i’ve used a Brennenstuhl PM230 meter. You can pick one of these up for about £13 in the UK, and it does everything you need.  Another popular meter is the Kill-A-Watt, but they cost £10 more and do the same thing as the PM230.

These meters can do a lot of stuff, including calculating the actual cost of the power you use, but the main useful functions are showing watts being used by a device, and tracking usage over time in kWh.

Interpreting the results

First a bit of basic electrical theory. You’re probably aware that the power supply that comes out of the socket is rated in volts (either 230 or 110V AC, depending on what country you live in). But the measure of actual power consumption is the watt (W). Your power supplier bills you for the electricity you use in kilowatt-hours (kWh). Pretty simply: 1000W for one hour is 1kWh.

For most devices you’ll want to simply plug in your meter and note how many watts it sucks. For machines that run intermittently (such as fridges) you may want to take an average reading by leaving the meter plugged in for several hours. By dividing how many kWh by the number of hours you can get a rough average reading in watts to compare to other devices.

Important: Don’t forget to take readings of devices in their “off” and idle states. Many machines still suck juice when switched off, and anything that’s in a standby mode will certainly be slurping pennies out of your pocket the whole time.

Ok, let’s see some results!

Click here to download a PDF of my audit results.

Over the next few blogposts i’ll be taking a look at my results and discussing some of the issues, along with tips about how you can reduce your usage. Click on the tag home power audit on the right to see all the posts.