It provides real-time information taken directly from your electricity meter helping you to control your electricity consumption and make energy saving easier. It works by using a sensor cell placed next to your electricity meter, which wirelessly feeds all relevant information to Wattson's display up to 30 meters away. It emits a colour that changes depending on your usage; a cool blue for low usage up to beaming red for high usage. Numerically, Wattson displays the amount your electricity bill would be for the year, based on your usage that second. Your consumption information can be stored for up to 4 weeks on the device but can also be downloaded via the supplied software, to your pc for further analysis.

Once you've lived with Wattson you will never again overfill the kettle or leave on unused lights, which is good for your bank balance as well as the planet.

£125 from www.diykyoto.com.