Hi Guys, many thanks for the replies so far, to help with the detail and in case anyone else in interested in a similar thing later on, I'll detail the two devices sparately.
**Current Cost energy Monitor. **
Mine is this one... Current Cost - Reducing your energy bills so you can live a greener life!
These come with RJ45 connectors on the bottom, the info in the manual says.. .
The data cable is an USB to RJ45 cable that takes serial output from the Current
Cost monitor and uses the Prolific PL-2303 chip to convert serial to USB.
The full manual can be found here... http://currentcost.com/download/InstallingthedriversfortheCurrentCostDataCable.pdf
The data from the serial output is in XML format, as shown below:
CC128-
v1.11dsb>0003712:03:5118.40<
/sensor>02723100396<
watts>0029600256
I found a useful article here... http://blog.cuyahoga.co.uk/2012/06/assembling-the-currentcost-interface/ using an XINO board and Ethernet Shield (no MAX232 so I am guessing it is TTL) to push data to cosm (www.cosm.com). Cosm is another site that allows you to upload any monitored data. He also includes a link to his code, and I also found an example in the Auduino examples, so looks pretty straight forward.
Solar Panels (Sunny Roo 4200TL Inverter):
In terms of hardware, the Inverter has a standard 9 PIN serial output, which I just plug into the 9PIN serial on my PC (set the COM settings) and run the software. The software reads the data from the serial port and stores it in an Access Database. I also have a document which details the serial output data.
Pvoutout (www.pvoutput.org) is a site that allows you to store data online showing how much energy you have produced and how much you are consuming. Then you can access it from anywhere or any device, even my iPhone. They provide software which can automatically upload the data stored in the Access Database mentioned above for my inverter directly to pvOutput. They also have detailed API instructions that provide info on creating your own.
So if my understanding is correct, it's just a case of connecting the correct wires from each source to it's own serial input (which means I need the MEGA) and start coding... or pulling my hair out... 
Add an Ethernet shield for posting the data on line.