Near Bartow, Florida, nearly 1,872 solar panels float on a power plant’s 1,200 acre cooling pond, and the basin was first gouged out decades ago for phosphate mining
A cooling pond is supposed to do one job, soak up waste heat and send the water back a little cooler.
At a power complex outside Bartow, the surface looks nothing like it should.
Tidy rows of dark panels stretch toward the horizon, riding the water instead of sitting on dry ground.
That history explains why the water was available at all, since a 1,200 acre pond is far larger than any utility would build fresh just to cool a few turbines.
Nothing touches bottom, nothing touches shore.
The panels drift in place, tethered to cables and anchors spread across a basin dug out long before anyone thought to put solar here.
So why did this stretch of water turn out right for nearly 1,872 solar panels?
Why a cooling pond turned out to be perfect for panels
The pond at the Hines Energy Complex was never meant to be scenic. It began as a phosphate mining pit, one of thousands gouged into central Florida’s landscape over the last century to feed the fertilizer industry.
When mining stopped, the pit filled with water and sat idle. Engineers later saw a use for it, a reservoir big enough to cool a generating station’s equipment around the clock.
That history explains why the water was available at all, since a 1,200 acre pond is far larger than any utility would build fresh just to cool a few turbines. The excess space let engineers add a second use without taking an acre of farmland or forest, so the panels float on water the plant already needed anyway.
What the panels actually look like up close
Walk the bank and the array looks less like a conventional solar farm and more like a raft city. Each panel sits on a buoyant mounting platform, clipped into a flexible lattice engineered to shift with wind and waves rather than fight them.
Crews built sections on dry land first, then floated them out and locked them together like a dock expanding across open water. That construction method matters because a floating array cannot go up piece by piece under a fixed frame the way a ground mounted one does.
“It’s an efficient use of space,” said Don Keyes, Duke Energy construction supervisor. “No need for land, no offsetting crops. We’re just making smart use of what we’ve got.” Keyes called the structure a lattice style system, firm enough to hold its shape but loose enough to flex when the pond moves beneath it.
The detail that makes this different from a rooftop array
The panels themselves are not the type most homeowners would recognize. Traditional, or monofacial, panels capture sunlight on one side while the rest reflects away.
Floating in Bartow’s pond are bifacial solar panels that absorb light from both sides, which can produce 10 to 20 percent more power than single sided versions, since the water beneath them works like an accidental mirror, bouncing stray light back up into each panel’s underside.
That bifacial gain is larger here than over dirt or grass, because water scatters more usable light upward than soil does. Pair that with the pond’s natural cooling effect on the hardware, and the setup squeezes more output from the same panel count than a comparable array on land ever could.
Even so, floating solar remains rare in American power generation, used extensively in Asia but making up only about 2 percent of solar installations in the United States.
Why open water beat clearing more land, again
The economics echo a pattern showing up elsewhere. On a twelve acre reservoir in Ohio, officials found it cheaper to float panels than to clear nearby farmland for the same output.
Bartow’s engineers faced a similar calculation at a much larger scale. Permitting an array on water the utility already owned moved faster than acquiring and clearing new ground nearby, though that is not a universal rule.
A reservoir has to be deep enough, calm enough and accessible enough to carry the anchoring system. A working cooling pond adds another layer of complexity, because water temperature and flow cannot be disrupted, which is why such multi-year planning still shapes projects like this one.
What the pond’s second life suggests for the next one
None of this makes floating solar a universal fix for land constrained power companies. Every site needs its own water depth survey, its own anchoring design and its own agreement with regulators before panels go near a reservoir.
What Bartow shows is narrower. A cooling pond built for an entirely different purpose can carry a second industry on its surface without compromising the first, and that lesson is already traveling elsewhere, as the utility’s own announcement of the completed project makes clear.
Developers chasing the same logic have floated panels over a Mendocino winery pond rather than giving up a row of vines, proof that idle water keeps finding new tenants.
The quarry pit that once fed a fertilizer plant now feeds a grid instead. The pond itself never had to change jobs to do it, which leaves one open question, how many more ponds like it are sitting unused across the country’s industrial landscape, waiting for someone to notice the water was never really finished working.
Hugo is an engineer with strong technical expertise. Multilingual from an early age, his writing combines technical clarity with a strong interest in science and energy.
