Did you read more than the headline? The problem is explained in a very straightforward quote, below. The grid isn’t always capable of transmitting as much energy as the wind and solar generators can produce at peak, so there have been times when they have not been able to deliver power to meet demand despite having the generation capacity to produce it. So no, electrical current isn’t being yeeted into deep space but generation capacity that’s already been invested in is sitting idle even as demand goes unmet, and that is a waste.
Our analysis shows that on days with more wind and solar generation and strong system electricity demand, limited transmission line capacity restricted wind and solar generation flows, and curtailments occurred. These types of curtailments account for 36% of the projected curtailments in 2035, which could be reduced by upgrading the transmission system.