I previously wrote about how to to get data out of a Current Cost energy monitor. I've now got mine, the appropriate data cable, a serial-USB converter and some Processing code to read and graph the data (see above for the energy consumption of our house one Sunday afternoon).
But I've discovered that I have an old version of the Current Cost - it transmits data at 2400 baud and that data is only the current energy usage and temperature at that moment in time. It doesn't include any of the historical data (which the device obviously keeps because it displays it) described here (i.e. the bits in the <<>hist<>> tag).
So I asked around and according to Andy Stanford-Clark: "there are two models of currentcost meter in circulation - the slightly older one runs at 2400 baud and doesn’t store history. The newer one runs at 9600 baud and does have history. The power companies have the older ones in stock at the moment..."
I bought mine through the ecogadgetshop but williamt left a comment on the original post saying "Just to note you can actually get the Current Cost monitor FREE, as I just have, if you signup up to the Southern Electric "Better Plan" (which is a hydro-electric green energy tariff).".
So if you're planning on doing any hacking with the Current Cost then it sounds like you might want to hold off until you can guarantee yourself a new model.