> Yes, Germany has plenty of coal reserves.

I don't care, I was talking about power stations. Look at charts linked in previous comment.

> For example you disregard transmission, demand for electricity, costs of stabilization of the energy grid, costs of backup - dunkelflaute.

I literally said the word "dunkelflaute" on the first line; and I have absolutely accounted for that, that's why I said what I said about batteries, and why even with those renewables are cheaper.

Transmission and demand are approximately identical for all power sources, modulo only where the specific power lines go. Well, that and that in principle one can be off-grid for PV+batteries at a reasonable cost (especially for new builds given how much a grid connection costs in the first place), which is itself rather novel, but IMO will only be worth accounting for when almost all vehicles are EVs and/or literally all new houses come with PV and it's no longer optional (last I checked this was not yet the case).

If you want to go off-grid I would recommend in addition to PV+batteries also a passive house. In the long-term costs nothing beats good thermal insulation. https://en.wikipedia.org/wiki/Passive_house

The grid connection cost are so high because the high electric system costs, which are distributed to the market participants using grid connection cost: the transmission costs (upgrade costs of electric lines - digging earth is surprisingly costly, overhead power lines are cheaper but they are not for free, upgrade costs of transformers), costs of backup - Germany plans to build new gas power plants, which will have a very low utilization.