Research Shows Solar Panel Efficiency Per Acre Is Increasing

Research shows a big improvement in generating capacity per acre of solar panels, with implications for how much land is needed for an energy transition.

Utility-scale solar power today is much more efficient than it was a decade ago in how much land it uses, according to new research.

The paper, by lead author Mark Bolinger of Lawrence Berkeley National Laboratory, is timely because utility-scale solar is a big part of plans to make a transition to carbon-free electricity, and because there have been few recent studies about solar’s efficiency in land use.

“It just seems a little bit odd to still be relying on data that was almost a decade out of date,” Bolinger told me.

He found an increase of more than 40 percent in the median generating capacity per acre of solar panels between 2011 and 2019. This includes both “tracking” solar systems, in which the panels shift during the day to follow the sun, and “fixed-tilt” systems, which are stationary. The paper was published in the IEEE Journal of Photovoltaics.

To help put this in more understandable terms, a 100-megawatt tracking solar array would have needed about 600 acres in 2011, but would only have needed about 420 acres in 2019, based on median figures.

That’s a huge shift, which means that the massive deployment of utility-scale solar that is likely to happen in the coming decades will need less land than previously thought.