Germany, Spain and Poland each set new solar generation records this year. In the same stretch, all three also saw sharp electricity price swings, including hours of negative prices at midday and price spikes in the evening.

The negative midday prices: when solar generation floods the grid around midday and demand doesn't rise to match it, wholesale prices can go negative, a known, growing effect of adding solar capacity faster than storage or flexible demand can soak it up.

The evening price spikes: as solar output drops away at dusk, the grid needs fast-ramping backup, currently gas, and in some systems coal or imported power, to cover the gap. That's where diesel and gas generation still plays a genuine, currently necessary role.

The bottom line: the real story is a mismatch between how fast solar capacity is growing and how fast storage and grid flexibility are catching up to use it, not a simple "solar causes chaos" or "solar is flawless" story.