First up let’s take a physical walk around the unit. It needs power (which costs around 5p per month to operate), and it includes a small plastic stand so it can stand upright.

Physically, the in-home display is around the size of a small novel (The Accidental Time Machine by Joe Haldeman in particular).

The 9V power adaptor goes into the side, and don’t worry if you need to switch the device off from time to time, as the engineer assured me it doesn’t lose any information after being switched off.

There are no other buttons or connectors on the sides or the back but there are quite a few on the display so let’s take a look at that next.

There is a grey LCD display around 3” by 3” which, together with its dreary grey colour, feels a little step back in time particularly if you have been using the other bright white energy monitor with colour display.

However, it does the job and was “considered a good example” of keeping the user experience simple in a 2011 Consumer Focus report (“Getting to grips with smart display”).

On the top row of the display is the current temperature and the current time which alternate every few seconds, a mode icon indicating electricity, gas, and emissions (a small tree shaped icon). At the bottom of the display is a small usage bar chart showing a number of previous readings (based on readings of 15 second intervals for electricity and 30 minute intervals for gas). Next to the display are four large contrasting grey buttons: Select, Readings/Costs, Usage, and Emissions and we’ll take a look through those shortly.

Below the main display is a clear plastic cover which folds down to reveal a small panel with a traffic light warning system (Red, Amber, Green) to indicate electricity energy usage and a blue light for system messages.

Red indicates high usage (4+ kW), Amber medium usage (2-4 kW), whilst green indicates low usage (up to 2 kW).

The Red/Green system could be a problem for people with red-green colour blindness but at least the positions are fixed with the first position being green, and third being red (which usually indicates high usage).

If the blue light is lit you can use the row of buttons below the traffic light system to read the message.

To read the message open the flap at the bottom and press the envelope button.

You can also press the envelope button at any time to access the last received message.