Some ideas spring up overnight. Others take root more slowly, waiting for the right conditions to thrive. Agrovoltaics, a system in which solar arrays and food crops coexist on the same land, falls into the latter category.

Adolf Goetzberger, founder of the Fraunhofer Institute for Solar Energy Systems, and Armin Zastrow pioneered the idea back in 1981. At the time, photovoltaics was expensive, and computers were rare. So the pair worked out the equations for a dual-use system on programmable pocket calculators and published a paper titled Kartoffeln unterm Kollektor (Potatoes under Panels)—which Goetzberger later noted was apt because potatoes grow better with a bit of shade.

Thirty-five years later, it seems the world is ready for their idea. The price of solar panels has plummeted—by more than 50 percent since 2010 alone—and many farmers find it more lucrative to grow crops for fuel instead of food, or to put their land under vast solar arrays. For any one farmer, the switch makes economic sense. But cumulatively it sets up a zero-sum game that could undermine food security around the world.

Agrovoltaics is one way out of the dilemma. That is, if it can work at a scale commensurate with the world’s voracious appetite for food and energy. And therein lies the pivotal question: Can farmers get the same food production under solar panels that they currently do growing lettuce for your dinner table the old-fashioned way—directly under the sun? There’s an increasing body of research suggesting that they can.