Tommy O'Neill drives his SUV south on a dune in a moonlit view of Polk County. He shut off the engine, took out the key and opened the gate that led into the old phosphate mine.
O'Neill is a Florida environmental specialist at Duke Energy. As we made our way along the sandy paths around the lake, we saw a flock of hawali swimming in the water, reflecting off the expanse of clouds and blue-white sky.
Next to them floated an amazing platform the size of eight Olympic swimming pools. From a distance, it looks like a pile of blocks stuck together on one side of the dam, turning it into a giant raft.
"The center," O'Neill pointed out to me as we drove, "is an actual floating solar panel."
As we exit the quad, O'Neill explains that this is a pilot project that produces only a fraction of the energy produced by a large power plant nearby.
“We are located in the Hines Energy Complex, a natural gas combined cycle power plant. And attached to the power plant is a Hines cooling pool, which is a glorified factory cooler,” O'Neill said. “It's a 1,200-acre man-made cooling pond that was a former phosphate pit. And on top of that, we're building a three-quarter megawatt, or two-acre, solar system on top of the cooling pond.”
Here are the benefits
Project manager Shayna White says such solar panels on water have several advantages. They do not need to lease new land from other property owners, and the impact on the environment is minimal.
"We are also looking at other benefits of floating solar, which include increasing the efficiency of the PV modules," White said. “The water in the reservoir needs to have a cooling effect so it can generate electricity more efficiently. On a larger scale, it will also prevent evaporation and help the dam maintain its level."
And it has another benefit: putting one of the former phosphate mines to good use that has haunted the region for more than a century.
If the project is successful after its completion in August, the 1872 module may be expanded with additional arrays.
This system will provide energy for about 100 houses. That contrasts with the Hines power plants, which run on natural gas and can power 1.5 million homes. But it will reduce the need for more generations from there on sunny days.
The pilot program is part of Duke Energy's Florida Vision program, which is designed to test innovative projects like microgrids and battery energy storage, among other things, to prepare the electric grid for a cleaner energy future.
This creates several problems
Duke spokeswoman Audrey Stasko said it complements another "microgrid" project the company is working on.
"He is a pilot. That's why we do it on a very small scale, Stasko said. - We want to see the problems, limitations, as well as advantages. And that will help us decide whether we want to do it on a larger scale and be more agile."
The floating sun was popular in Asia.
The world's largest in China can provide electricity to about 52,000 homes. The largest in the US can provide electricity to about 1,500 homes in New Jersey.
O'Neill said one of the problems with being on a former mine site is that clay and silt tend to wash into the ponds during heavy rains.
There are other problems as well.
Too many solar panels covering the surface of a lake or pond can cause dissolved oxygen levels and water temperatures to drop, endangering marine life. And in other countries, research is ongoing into whether emerging electromagnetic fields can harm aquatic ecosystems.
White said that's not a problem in this troubled neighborhood.
"It's definitely something I would look at as a pilot project in the future," White said. “But one of the advantages of putting it in a cooling pond is that that pond is not being used for that.
"So this is not a place for water recreation. There is definitely wildlife here. But it is not used to eat or sell any fish or anything that is here.'
What they're doing, White says, could turn one of Florida's worst landscapes into something that could make for a cleaner environment in the future.
