I am a great fan of the PassivSystems monitoring systems since having a 3.96kWp solarPV system installed by M&S in March 2011 which included the Passiv solar PV monitoring. I have since added the power gauge with smart swtitch which allows me to automatically monitor excess solar electricity generated and route to an immersion which is brilliant. I chose to add the boiler control too and now have very effective ways of managing my hot water and space heating - just need a way to measure my gas and electricity consumption from the grid then I will have a complete picture of all my consumption in one place.