Step 1: Produce your own power
This initial setup worked great from day one and has been producing consistent results since it was plugged into the grid.
Step 2: Measure and manage your power
So my first attempt was the Wattson. A smart and good looking gizmo that clicks a sensor around your power phases and transfers real time data wirelessly to a stylish display in the living room. Great conversation piece and solid education tool for the kids. My first find was that our house had, unbeknownst to me, a "gutter heating system" which ran from November until March on a timer consuming a steady 1,000 watts. Can you believe it? 40% of our annual electricity bill (24 kW * 30 days * 5 months = 3,600 kWh) was heating the roof! Unbelievable - I immediately turned that thing off.
Next was the logical management extension of our solar array. SMA produces the home manager, which reads the power produced on the roof, but also the electricity pulled from or pushed into the grid on the main phases (it also monitors the inverters via Bluetooth for failures). This provides a complete picture of the electricity production and consumption and does a good job displaying it on the Sunny Portal. It goes one step further and allows to control consumers via Bluetooth sockets, so you can switch on certain consumers at peak solar production times only.
The only tricky bit with this product was the connectivity to the meters. Every energy company in Germany uses a different type of meter and standards are rare, so SMA cannot certify all of them as input sources. The only way to handle it is to install 2 additional suitable meters yourself (one for roof production and one bi-directional meter for grid input / output). These are relatively cheap and can be connected via S0 interface to the home manager. All worked smoothly from there on.
The home manager gave me good insights into our electricity usage patterns and in some cases lead to changes to increase self consumption.
Step 3: Add electric mobility
What does not work today as I intend is using the battery of the car to power the house at night. The concept of bi-directional charging and vehicle-to-grid electricity flow is not a reality just yet. Few EV manufacturers support / allow this, in consequence wallbox manufacturers don't support it and the utilities do not know how to handle this as a part of the existing feed-in tariff system. Approaches are emerging, but it is likely 2-3 years out before a real solution hits the market.