Thanks for the replies.
I have managed to get Envi-R working with my Weather Display Software by Brian Hamilton. I can therefore post my current wattage and the day's cumulative wattage to the internet with all my other weather data. See
http://bobhewitt.co.uk/pictures/Weather ... /Erith.htm and scroll down to the first graph. On the centre plot (the wind direction) there is a black plot of the usage. It may not be that sophisticated but at least it works now. The problem I had was of my own making it that I didn't fully understand the method of pairing the display with the transmitter. I held the down button while doing this process and it paired itself to Appliance 9. I realised that this wasn't correct so I finally managed to get it to pair with the 0 default.
It's possible that improvements may be made the the WD software in the future. The link on my website to the Live from the home page shows a ten second update but this can be longer if it just misses the 6 second update from the Envi-R.