The scale of the waste finally became obvious to me after cheap domestic energy monitors appeared on the market.

I run a small computing business from my home in rural south Wiltshire. My home computer network has gradually been growing in size from a single computer and a dialup modem over a decade ago into a large collection of various beige boxes, network equipment and trailing extension leads.

For the techies reading this, there’s a Linux DNS and mailserver, a music server, a couple of Windows boxes for checking website designs work in Internet Explorer, the list goes on…

None of these are of a particularly high specification, being largely salvaged, low-end old machines that aren’t called upon for demanding tasks and don’t need to be blisteringly fast. However, although not everything is always switched on and in use, these machines have been quietly consuming between 60-110W – the same as keeping a traditional lightbulb on day in, day out.

The scale of the waste finally became obvious to me after cheap domestic energy monitors appeared on the market. These are simple devices which are simply inserted between the piece of machinery you want to monitor and the plug socket at the wall. Something like 40% of my daily electricity consumption was being spent on keeping this lot going!

Thankfully the performance of computers has increased so much in the last few years that it’s become feasible to create ‘virtual machines’ (VMs) in software. Each VM can replace an individual physical computer, and since many VMs may be run on a single computer, the potential energy (and cost) benefits are clear.

I chose to use a product called VMWare, as there is a free version available. Have a Google for “hardware virtualisation” to explore the subject if you’re interested.

Two months down the line, all of the beige boxes that used to sit around consuming power have been decommissioned, and I have a single £400 laptop that runs a collection of virtual machines instead. Plus I have a lot more room.

The added bonuses, aside from cutting my home energy consumption from 550W (base load) down to a far more reasonable 350W, are that the laptop which hosts these virtual machines has a built in battery backup for the odd occasions when the electricity grid fails, and it’s designed from the outset to be a low-power, more energy efficient device than a regular desktop computer.

It’s going to take a surprisingly short time to repay the investment in time and money that this project has taken – the energy (base load) reduction is about 5 KWh – or units – per day and at current prices that’s saving me approximately £17 a month.

So if you’re the sort of techie person like me who’s gradually built up an extensive home network over time, without really thinking about the impact, I hope this tale encourages you to see whether you can use the same kind of approach to get your electricity consumption back under control.

Even if you are not a heavy computer user, do consider conducting an experiment on your home energy consumption with easily available domestic energy monitors.

Simon Banton