The International Energy Agency and climate negotiators want to set a binding target for shifting economies to run on electricity, and the argument for doing so has largely been won.

What has not been solved is the difficult part: grids were designed to carry power to consumers, not to absorb enormous injections of variable generation. Supply and demand have to be matched second by second, and that obligation is getting harder, not easier.

Transmission has become the binding constraint in most markets. Building new lines takes years of permitting, and queues for interconnection are growing faster than the capacity being added.

Storage helps, and so does demand response, but neither is cheap at scale. The transition is not primarily a generation problem; it is a network problem.