ENVI CC128 White - Energy Saving Monitor - Complete Unit With Transmitter

I purchased an ENVI CC128 Energy Monitor from Current Cost in Januar. The first one I received would not pair so did not work. After a week of exchanges they sent a replacement (after I returned the original) and that did work. This process was tedious and disappointingly long.
I also purchased the connecting cable so that I could download the data to my PC and with the aid of downloaded software from the Current Cost Website collect and analyse the energy data. This at first seems a good idea until one realises that putting PC into sleep mode loses all the data while the PC is in sleep mode, or if the PC is shut down for any reason such as an automatic 'Windows' update when the machine is automatically re booted all unsaved data is lost. In practice I could not collect more than a few days data without significant gaps due to such events where the PC interrupted for any reason.
It seems there is no meaningful data buffer in the unit to hold data when the PC is disabled so one can download when it is next back up and running again. I see this as a very significant failing as having t maintain the PC fully running to use this facility somewhat defeats the objective of saving energy.
I emailed Current Cost on this point via their website but they ignored me. I have given up on using the softare it is a waste of time.
This is a potentially very useful device but only if one can save a continous stream of data even when the PC is not runningCurrent Cost Energy Saving Monitor ENVI-CC128. The Energy Saving Monitor needs say a one month data streaming buffer capacity built into the display unit to reliably do this.

There are a number of these types of devices on the market at the moment but I chose the ENVI 128 on the basis that it will output the data as a raw XML feed over the USB serial cable (sold separately) allowing me to write my own software but this also means there is a large amount of software available on the Internet that others have created so you're not stuck with the manufacturers package. This is very useful if you use Linux like me and often get overlooked by the vendors.

It was installed very quickly and worked first time, there is a cost calculator as the name suggests that flicks between daily and monthly costs. There's a real-time wattage display, a graph showing the distribution of yesterday's usage over the day, a monthly watt-hour reading and a clock and thermometer which is about as much as you can expect. There is support for individual appliance readers too using plug-in devices sold separately (but not available at time of writing).

My only gripes so far is the quality of the build materials, the plastic casing is cheap like the kind used in the vacuum moulding machine they had back in my school days, easily broken if not left alone and the LCD display is obviously cheap but it's not easily apparent when powered up. It's also mains powered which is a plus in the sense there's no battery overheard (both environmentally and financially) and a negative in the sense it restricts where you can place it around the house, that said the power-cable is fairly generous in length.

Provided you don't expect it to do too much and lets face it - it reads and reports on power usage and that's it, then it does the job and you too can micro-manage your home electricity bill and shout at your family for leaving the lights on in another room you can't even see!

I bought one of these with the promise of the "Individual Appliance Monitoring" IAM modules.

Nearly a year on and these modules are still not on sale.

The IAM's were suppose to be plugin devices with you plug into a power point and then plug the actual device in so you could also record a devices actual power consumption e.g. your Plasma TV.

The module would transmit the readings by wireless to the Envi unit.

However still no such device and now a new Envi model is on the horiozn, the Envi R making this model obsolte.

I already had the first generation model by the way which works well but had terrible clock drift making it as a timepiece a waste of time.

IAM's also promised a true power (Watts) reading.

All of these devices like Envi rely on a clamp on device around one of the cables from your meter will ever accurately compare with the reading from your electricity meter.

Why you ask? It is because your electric meter charges you for true power used which is measured in Watts and to do this the device needs to know the power factor of an AC load and to do this it needs to examine the AC voltage waveform as well as the current waveform.

These two sinewaves, voltage and current can be out of sync and this difference needs to be measured.

With just a clamp on device which measures the amps the device can only guess what the actual wattage is and for my home for example the unit can read over 100% high.

The next model out, the Envi R talks about a meter reader add-ons which should help but what I think we need is a pro-instal option which also gets a voltage signal.

In the USA, you can buy TED, "The Energy Detective" which the makers claim is as accurate as your supply meter but alas these are still not on sale in the UK.

All of these devices will give you guidance to your homes electric consumption but other options do exist.

Plug in power monitors - The Efergy one works well and can read sub 1 watt loads.

Read your electric meter more often - each unit of electric cost you about 11 pence.

Get rid of energy eating devices that are on all the time - Typical Sky+ box in standby 24/7 over a year will cost you £19.27. A modern Foxsat-HDR alternative would cost 96 pence if also left in standby for a year.

With a plug-in power monitor you can check all the device in your home, desktop computers (if more than a few years old) can also eat a lot of power just waiting for you to press the power button on the front.

Lastly, the LCD display of the Envi is more difficult to read from certain angles than the older "Classic" model.