In January 2025, solar generated 1.5TWh of electricity in Germany (in June it generated 10TWh): https://www.energy-charts.info/downloads/electricity_generat...
In January 2025, Germany burned about 236 TWh of fossil fuels.
You cannot even mostly replace fossil fuels with solar.
Germany will need a total of 1,867 TWh per year in 2030, so an average of 155 TWh/month.
fossil fuels are very inefficient when used in most applications (especially ICE and oil for heating). As countries use more and more electricity instead of fossil fuels to generate motion and heat, total energy demand will decrease accordingly.
Currently, Germany imports almost all of its fossil fuel from abroad. Mainly Norway, USA, Gulf countries, etc. Russia used to play an important role and we paid dearly for that. As we are for the reliance on the US, I guess.
We could actually bring our energy dependence closer to home and make it cheaper by substituting fossil fuel imports with solar + battery with the PV part being distributed across northern African countries. But most likely it will be more convenient (if less efficient) and politically desirable to create a mix of domestic and souther European sources, with specialized stuff like H2/Green NG imports from Iceland and other energy rich places being mixed in.
Also, Germany will (and does) a large share of it energy requirement not from solar, but from wind. Already, renewable energy has very much softened the effects of the Iran war on electricity prices. They never exceeded the highest levels of 2025, while fossil fuels jumped to levels last seen immediately after Russia's invasion of Ukraine and are still elevated over 2025 levels.
> we paid dearly for that
And if you had invested in Drake Landing https://en.wikipedia.org/wiki/Drake_Landing_Solar_Community solar setup instead of PV, then neither the Russian invasion of Ukraine nor Hormuz blockade would have been a huge deal. The cost of energy is destroying your industrial base.
> Also, Germany will (and does) a large share of it energy requirement ... from wind
15TWh in January 2025. Again, you burned about 230 TWh of fossil fuels. Nearly every heating system is over 80%, electricity closer to 50%, so lets say 150TWh. Do you have an order of magnitude more land and water you're able to put wind generation on? And are you willing to base your life and economy on not having Dunkelflaute?
> Do you have an order of magnitude more land and water you're able to put wind generation on?
Actually yes. We currently use less than 0.5% of our agricultural land for PV (and some agricultural use is technically possible below PV). We could of course dedicate 5% or even 10% of land use to PV, if we really needed to (which we don't). We also could still expand PV to large swathes of build-up area (car parks and the like).
And Wind turbines actually don't need much space at all, the main issue is distance to settlements because of noise/shadow concerns.
> And are you willing to base your life and economy on not having Dunkelflaute?
I think there is an interesting discussion to be had. If we could i.e. half the cost of energy but have to live with drastically reducing energy consumption every few years for a couple of weeks in winter, would that be worth it?
We actually did so in the first winter after the Russian invasion of Ukraine, because energy prices rose dramatically and people and businesses reacted accordingly. That was painful (and had no upside whatsoever), but I think if it didn't come completely by surprise but would be a designed part of the system, it might be worth it.