Since we are consuming too much electricity I wanted to monitor and record the power consumption in our house. This is compexified by a solar power plant which we installed mid last year. So we have two electrical meters: One that measures the production of the solar panels, the other one is a two-way meter that measures how much energy we are delivering to or retrieving from the public energy grid. It should be noted that from the solar production we only deliver the excessive electricity into the grid after our house is served.
A detailed description (in german) is given at http://sebastians-blog.wangnick.de/index.php?/archives/2-Solaranlage-und-Eigenstromverbrauch.html.