I'm writing to recommend you propose a new regulation in Germany to mandate that all new large appliances come with a "Grid Chip" and "Smart Start" button. The grid chip (or governor chip) would measure frequency/voltage and respond to system reliability issues when required. The idea in a nutshell is that if frequency dipped to 49.9 Hertz your washing machine (if running) would power down until frequency recovered. We have existing load shedding protocols which you could use as a guideline for developing the frequency response logic for appliances. I believe the cost should be marginal.
The reliability rules would be hardwired into the "grid chips" but you'd also want to be able to control the appliance according to user input. This is where the Smart Start button comes in. With the feed-in rates now lower than retail electricity it is in the end-user's best interests to directly consume as much electricity from their PV system as practical. If all new appliances had governor chips and a smart start feature you'd greatly simplify the implementation of home energy management. If you can raise direct consumption from typical 30% rates up to 50% it will allow the photovoltaic industry to be more competitive and survive with significantly lower Feed in rates. Ultimately I believe you can drop the FiT down to a market based rate but to do that you need to have it so that direct consumption is maximized. People without PV system would still benefit from a Smart Start feature by utilizing time of use electricity rates.
I believe this new appliance standard would create a home market for a technology that Germany is uniquely able to develop and eventually export. I have no financial stake in any company developing any of these technologies I've recommended. I'm a grid operator in an electrical control room in Wonderland who happens to enjoy watching the progress Germany has made with wind and photovoltaics. I believe it's critical for Germany to integrate load management into your renewable energy strategy - the sooner the better. You've changed things before... Here's another opportunity.