COUNTRY-WIDE POWER GENERATION WITH RENEWABLES ONLY

A good example is Germany with ambitious targets:

• 65 % of the energy supply shall be generated by renewables by 2030
• Germany shall become less dependent on oil and gas imports.
  Most imports are coming from the Russian Federation, Norway and the Netherlands.
• Coal-fired electricity generation will be shot down by 2038.
• The greenhouse gas neutrality shall be reached by 2045.

By End of year 2021, Germany has taken three nuclear power plants off the grid.

The remaining three plants will be shot down by End of 2022.

What is the actual impact?

Since purchasing electricity from neighbour countries is more costly than own generation, energy prices are rapidly increasing. As long as the neighbours still have sufficient power, it's a matter of money only. The situation might become worse, once there is a general supply bottleneck.
Let's look at some graphics.

We look only at the red horizontal line. It indicates the nuclear power generation, and we see by End of December an abrupt reduction by about 50 %. That matches with shooting down the nuclear plants. Coal-firing was also reduced, most likely due to the Christmas holidays.

Now, in January 2022 we see a significant increase of natural gas fired plants (orange colour) and nice wind-energy production (green-grey) until January 10. Means, no wind.
The black line indicates the load, so energy production is missing.

Looking only on the renewables, we see the same thing. Neither off-shore nor inland power generation from wind. The solar plants (yellow) are contributing marginal.

The missing energy had to be purchased from other countries. (Everything above the zero-line is import.)

Seems to work fine, Germany has in average still more electricity export than import. Now imagine that more countries are following the same concept. In case of doldrums, there will be nothing available for purchase.

Is the way good?

Hard to say now, we need to monitor closely. Maybe you can share the experience with renewable energy in your country.
Thank you for reading.

References:

Nuclear Power Plant image by Pexels (Markus Distelrath)
Graphics by Fraunhofer Institute