Open Energy Monitor

A basic intro into this wonderful world of “open source” energy monitoring and the kit you can use. If you want to give this a try, you’ll have to roll up your sleeves and get dirty 🙂 Most of the kit comes in kit form, which needs soldering together, things like resistors and capacitors. Follow the link to finding out more, check here (takes you

If you are a fan of the Raspi (Raspberry Pi), you can even put the Raspi to work as the heart of your energy monitoring. You will need to buy an expansion board for the Raspi see here (takes you to

Not frightened you off and you’re still reading! You’re either very bored or you’re a geek LOL

Why would you want to get a self assembly kit instead of buying an “off the shelf” kit that’s basically plug and play? (see efergy home hub)? I can think of a few reasons, in this case saving money isn’t one of them – apart from trying to reduce your energy bill. The kit from Open Energy can accommodate multiple sensors and you can adapt and add bits. The software you will be using can be adapted (by you) to get the results in the form that you want, basically you are in control. The Open Energy site provides a lot of wonderful information with step by step guides and pictures and has forum so if you get stuck there will usually be help available.

The “Open Source” community is largely made up of nice people and because everything is “open source” you are encouraged to add to any documentation and help others if you can. There are many “geeks” and what some of them don’t know isn’t worth knowing 🙂

One really good reason for DIY is the satisfaction in learning how to do something and especially, in this case, where you will be helping to cut down your energy consumption. I call that Win Win!

BTW, a definition of a geek that I like is “a geek is someone that is totally absorbed in computers and technology and likes it that way” 🙂

SAFETY NOTE for attaching the sensor.

In principle, when you are monitoring the “whole house” you won’t need any tools – just your eyes and fingers! In my case, the electric meter is outside in plastic box so all I had to do was find out which was the “live” cable between the meter and the fuse box. It is usually easy to see which is the live cable as it should be marked in some way. A popular method is for it to have a red plastic ring/clip round the cable. All you do is open the CT sensor (clamp) and then close it round the cable and then just connect the sensor wire to the (battery powered) transmitter, then close the meter cupboard door and start looking at the power you are using by visiting the emoncms website.

If you see any bare cables when you open the meter cupboard, close the door again and call an electrician, you don’t want to be touching bare cables because it don’t half give you a tickle :-)

If you don’t have your meter outside, you will still be able to see the cables coming from the meter to the fuse box as the meter is rarely more than about a metre away from the fuse box. Again the live cable should be marked in some way to identify it.

If you want to monitor separate circuits, I’d recommend that you ask an electrician to give you a hand. Modern fuse boxes are made to be reasonable safe even with the cover off and you should not need to touch any bare wires but it’s better to get a sparky (electrician) to give you a hand.