But Germany’s forays into negative pricing are the most frequent. At times, Germany is able to export its surplus electricity to its neighbors, helping to balance the market. Still, its experiences of negative prices are often longer, and deeper, than they are in other countries.

In one recent example, power prices spent 31 hours below zero during the last weekend of October. At one point, they dipped as low as minus €83, or minus $98, per megawatt-hour, a wholesale measure.

In other words, anyone who was able to hook up for a large blast of electricity at that time was paid €83 per unit for the trouble.

Why is supply so uneven?

The major drawback of both wind and solar power is that they wax and wane with the breeze and sunshine, and not in response to when they are most needed.

Battery storage capacity, meanwhile, is not yet advanced enough to take in all of the excess generation. And because older power plants that run on fossil fuels take a long time to ramp up and reduce electricity generation, they are not able to respond decisively enough to the shifting supply.

Like most traditional power systems, Germany’s was designed to match output to demand. However, “we now have technology that cannot produce according to the demand, but is producing according to the weather,” said Tobias Kurth, the managing director of Energy Brainpool, a Berlin-based consulting firm.

That, he said, is “one of the key challenges in the whole transition of the energy market to renewable power.”