COLUMBIA — Work started Monday on what will be the largest solar energy array in Missouri.
When it is complete, the 3,500-panel solar array at the COLT Transload facility near Route B and Brown Station Road in northeast Columbia, will be rated for producing 1,000 kilowatt-hours of energy per hour. It is the second phase of the solar energy project at the building.
By comparison, the city’s current solar installations — at the West Ash Pumping Station, the Quaker Oats factory and Bright City Lights — are rated at 36.8 kilowatts.
Renewable energy — a combination of solar, wind, gas and waste wood — accounts for 5.9 percent of the city’s total power supply, said Tina Worley, utility services manager for Columbia Water and Light. Solar energy thus far provides less than 1 percent of the city’s total power usage of more than 1.1 million megawatt hours per year.
The city entered into a 20-year agreement in December 2010 to purchase solar-produced electricity from Omaha-based Free Power Co. Under the agreement, Free Power buys and installs the solar panels; the city is responsible for site preparation and for connecting the solar panel array to the city’s electricity grid.
Dane Glueck, president of the Missouri Solar Energy Industries Association, said the new array would be by far the largest in Missouri. Most of the larger installations he knows about are in the 100- to 200-kilowatt range, he said. An installation of about 1,000 panels on the roof of the transload facility building, which represented the first phase of the project, is being tied into the power grid and is rated at 375 kilowatts.
City of Columbia employees using backhoes, bulldozers and dump trucks began clearing the field east of the transload building Monday morning.
Jay Hasheider, energy services supervisor with Columbia Water and Light, said the field where the array is being built has been in need of remediation since the city bought the property, and the cost of clearing and grading the site will be paid for with the city's solar project money.
The other project sites will not require this "remediation," Hasheider said.
The site should be ready by the end of the week, Hasheider said, and the array should be installed and operational by October. Several other sites are being considered for future Free Power arrays, he said.
“We hope to have this one done in October, and then we hope the rest of them start going like dominoes,” Hasheider said.
When all the projects are completed, an estimated 12,000 megawatt-hours could be delivered to the city, according to the city’s 2012 Renewable Energy Report, issued in February. A megawatt is 1,000 kilowatts.
Stormwater runoff from the site is a concern, but city engineers have a plan to deal with it, said Public Works Department engineer Tom Wellman.
"The whole array is basically one big rooftop," Wellman said. "There's already a detention basin on site to help slow the water down, but we're planning to handle it mostly with native plants and grasses."
The solar panels sit on pilings about 6 feet off the ground, which allows enough ambient light to filter beneath them to nourish the native grass.
After three or four years, he said, the root system of the plants would be well established, and "with the whole field covered with native grasses," Wellman said, "that's as good a stormwater runoff management system as you can get."
For more information about the city’s solar energy projects, visit Columbia Water and Light.