[Part 3 of 3]

The aim should be for the virtuous circle of solar-power production to turn as fast as possible. That is because it offers the prize of cheaper energy. The benefits start with a boost to productivity. Anything that people use energy for today will cost less—and that includes pretty much everything. Then come the things cheap energy will make possible. People who could never afford to will start lighting their houses or driving a car. Cheap energy can purify water, and even desalinate it. It can drive the hungry machinery of artificial intelligence. It can make billions of homes and offices more bearable in summers that will, for decades to come, be getting hotter.

But it is the things that nobody has yet thought of that will be most consequential. In its radical abundance, cheaper energy will free the imagination, setting tiny Ferris wheels of the mind spinning with excitement and new possibilities.

This week marks the summer solstice in the northern hemisphere. The Sun rising to its highest point in the sky will in decades to come shine down on a world where nobody need go without the blessings of electricity and where the access to energy invigorates all those it touches.