At some point in the last month I visited a PV company to learn about home solar installations. It was pretty great talking to the owner, who was the relative of a co-worker in California. He set me up with one of his technicians to discuss PV history within the Saarland (within the contect of the Energiewende legislation) as well as to see the monitoring systems they use to track value-added and functionality of units.
The monitoring systems track instantaneous power consumption of the home, and can present the data in a number of ways:
Solar power creates excess power during the day, and more often than not energy sold to the grid is less value than energy consumed on site. To combat this, the company also installs 10kW batteries if customers wish... these batteries allow PV owners to save more money by using their daytime energy at night. But the problem is that batteries are expensive, and the current kWh paid to PV producers is high enough to make the economics behind a battery purchase somewhat complicated.
Either way, it pays to own solar in Saarland. Here is random snippets of data presented in a paper I wrote for school:
I thought it was all very interesting... Hopefully you do to, even seeing the stats without the context of the paper.
And here are some pictures from while I was there:
