The Owl Wireless Electricity Monitor

The Owl is a small two-part kit for monitoring how much electricity your home is using.

There is a transmitter, which clips on to your mains supply cable (it’s quite safe but you will need access to your home’s electricity meter), and a receiver which shows usage on its screen.

The transmitter is a fairly small, unobtrusive device that can be screwed to the wall to keep it in place. Both it and the receiver are battery-powered so there is no further wiring to connect. The receiver battery lasts for about 10 months and the transmitter lasts about 18. It was all easy to set up, with a clear picture-led guide that explained what to connect where.

The receiver shows current usage in watts as well as how much money you are spending each second in pounds and how much carbon dioxide is being produced. It also shows data for the last day, month, quarter or year, with two years of data stored. The meter is quite handy for checking single appliances – about three seconds after turning our kettle on the display shot up, which was quite instructive.

To calculate costs you need to input the data for your tariff. It can cope with up to four tariffs, with different ones for night and day. This is useful if you are an Economy 7 customer.

The house in which we tested the kit uses a British Gas electricity tariff that has different rates for the first few units of electricity each quarter. The Owl cannot cope with that so we used an average of the two which gave a fair approximation to the true cost (in fairness, no other current meter can cope with such tariffs either).

Setting up the cost data and using the meter was quite simple. The buttons are clear and the printed guide helps, although the beep every time a button is pressed gets irritating quickly.

Besides the monitor we are looking at, the company also supplies a cheaper Micro monitor, priced at £25, which lacks features such as the historical data and the Economy 7 mode, and a PC connection kit if you want to analyse your usage even further.