Grid infrastructure requirements alone likely negates any ecological benefits given the amount of copper needed and the abysmal ecological conditions of copper mining.

If Germany were to split its electrical grid into two (north and south), as economists and the EU demand, things would be clearer.

The northern grid would produce more renewable energy than is required in total (hovering between 120-300% production vs usage). It'd have electricity prices around 10-15ct/kWh

The southern grid would have more pollution than even poland, as it's primarily fed with lignite, and would end up with an electricity price above 90ct/kWh.

The issues in Germany are not caused by technical or economical challenges, but by political ones. The southern states have passed laws to restrict renewables and limit construction of new power lines to gain favors with conservative NIMBYs and newage NIMBYs.