Owl Monitor, Google PowerMeter, Efergy Shower Timer and Firefly windup light

John Adams
Monday, 1st February 2010

John goes on an energy efficiency drive and tests out the latest monitoring equipment from Google, as well as regulating his showers and kitchen lights

Back in PM51 I reviewed the Owl Monitor. I still have it, and it has proved to be the best energy saving device I have tried. In the meantime energy monitors have evolved and Owl have responded by updating their product with the addition of a memory function. So now it displays (current and historical): electricity (kW), greenhouse gas (CO2), cost (£/$), plus the current time, date and temperature. I still love it and it remains my first glance guide to my household energy consumption.

Google AlertMe hubHowever, when I read that Google had brought out a PowerMeter so that electricity usage could be monitored online I was intrigued to give it go. To make it work you need to buy 'AlertMe' which wirelessly monitors the electricity being drawn through your meter in the same way as the Owl does, but instead of displaying the data it sends it to the internet via an ethernet connected hub. This is then displayed as a real time and historical display of electricity usage in graphical form on your iGoogle home page. It shows peaks in usage and baseline (always on constant loads), kW used and approx cost per annum. It also displays trends, the relationship between current usage and the expected usage based on past data. The data can also be downloaded as a spreadsheet if you need it for further analysis. Logging into your AlertMe account (£2.95 per month) shows you the same information but in a pure data log form.

AlertMe computer displayWhat has it done for me? Well, its certainly added a lot to my knowledge of how and when power is used. It is amazing the things you notice like the increase in usage during the cold weather despite the fact the house is heated by gas. This was caused by a change in habits as a reaction to the weather; more hot drinks, toast, roast dinners, etc, plus lots of extra washing, drying and ironing as the backlog got cleared by the stir-crazy wife.

The great thing about this system over other monitors is that you don't have to get up at 3 in the morning to see what your base load is, and it is easier to pin down appliances to power events. I think it is a really useful tool, but whether I renew my subscription next year or not, we will have to wait and see.

Efergy shower monitorShower water usage

Another bit of metering I have tried is the Efergy Shower Timer, which once calibrated sounds an alarm when the set amount of water has been used. A great idea which in theory should save both water and the energy used to heat it - my only problem was persuading the family to use it. It has, however, raised awareness and caused some discussion so it is probably well worth the modest investment.

One thing monitoring my electrical usage showed me, was that the kitchen lights were rarely off and being a large kitchen that was a significant amount of power over a year. So I have changed them to two banks of lights. The main lights now use less than half the old ones did, but don't provide work light. The working lights are low voltage spots over the work surfaces and under the cupboards, wired to a Bye Bye Standby Plug Module and triggered wirelessly by a Bye Bye Standby Motion Sensor on the wall. Now we have more light than before for food prep and cooking, but only while its being done; walk away and the work lights go out. Brilliant.

Firefly windup lightWindup LED light

Another brilliant idea is the Power Plus Firefly Dynamo Light. This compact light has 19 LEDs (16 white and 3 red) and recharges by hand cranked dynamo or any powered USB socket. It has four modes, White low, White high, Red constant, and Red flash. It will stand on its side, can be hung by the hook on the folding D handle, carried as a torch or attached to a flat metal surface by the magnets on the back. Fully charged it will provide several hours of light. Easily bright enough for personal camping and festival use, flashing red LEDS should run for about 24 hours and would make a useful marker light. Its compact, versatile and has a very good light output.

Since I wrote the above I have used the Firefly as emergency lighting during a power cut and was very impressed that it provided enough light to see what you were doing in a large room even in low mode. In high power mode it was quite possible to read or carry out precision tasks like threading a needle in the main pool of light below the Firefly (see picture). I have also used it to do some wiring work under by dashboard which went surprisingly well as the lighting couldn't have been better. Highly recommended as a portable light source with a wide range of uses.