DIY Kyoto Wattson and Holmes electricity smart meter

Have you ever wondered how much power your PC and other home appliances are using?

DIY Kyoto’s attractively designed Wattson monitors your electricity consumption and gives you a constantly updated readout through a built-in display.

The downloadable Holmes software lets you view your consumption data from Wattson on your PC.

Installation is simple ­ a sensor clips to a cable running between your electricity supply meter and fuse box, and is accurate to between one and two per cent. You can set its 433MHz AM wireless transmitter to update the Wattson display at one of three rates.

Once the sensor’s in place, Wattson can start monitoring. The red LED display is visible across a room, and displays your current usage in Watts or how much your current consumption will cost you over a year. Just tilt the unit to switch between the two.

The unit has different modes ­ colours, numbers or numbers and colours. In the ‘colours’ modes, Wattson glows blue during low power usage, purple when consumption is average and red when you use a lot of power. Night mode continues to store data but turns off the display, reducing the colours mode lighting and power consumption from about 4W to 1W.

The Holmes software can represent your consumption data in several ways: your energy usage in kilowatt hours (kWh), your power usage in watts, the cost based on your electricity price and the amount of CO2 your electricity usage produces. Holmes plots your usage in a choice of timescales. You can also share your electricity usage and energy-saving tips through DIY Kyoto’s online community.

If you have children, the colours mode will appeal to younger ones as a night light and they’ll enjoy watching the numbers change as you switch on appliances. Older ones will love working out exactly how much power appliances are using.