Crowder’s Solar Green Visits the Peoria Tribe in Miami, OK

Solar Green, Crowder College’s solar energy club, went on their first trip of the spring semester, 2012. Six members, Cheyanne Baker, Matt Blair, Russell Crawford (who took the pictures), Randi Martineau, Christian Schlenker, and David Siler, and their faculty advisor, Joel Lamson, piled into a campus van and were off to do a site survey for the Peoria Tribe in Miami, Oklahoma.

                They met with Chris Owens at Peoria Tribe’s Aquatic Facility to discuss the installation of a 5.16 kilowatt grid-tied solar electric, also called photovoltaic (PV), array that will help power the facility. The Aquatic Facility has a couple of different fish hatchery projects. One project focuses on the endangered species of the Neosho Mucket, which is a freshwater mussel, and the Neosho Madtom, which is a small catfish. Another program will focus on raising bass for mussel spawning, because bass carry glochidia, which is the microscopic larval stage of the mussel, in their gills; and the production of bass for stocking ponds.

                The 5.16 kW system consists of the aluminum mounting rail system, twenty-four 215 Watt panels, a 5.1 kilowatt grid-tied inverter, and balance-of-systems (BOS) components such as a PV combiner box, breakers, lockable external disconnects, wiring, etc.

                After inventory, it was time to go outside and find an appropriate location to ground mount the array; this is commonly called a site survey. The primary function of a site survey is to try to minimize shading of the array during the 6 to 8 hours of the best sunlight of the day. Three spots were selected. One location had a utility pole and utility line that would cause some afternoon shading of the array. Another location at the side of the building was a little better, but a few yards back in the pasture was recommended as the best location.

                The array will be ground mounted on posts concreted into the ground. One reason a ground mounted solar electric array is preferred is because solar panels like to be cool; the colder the panel, the more voltage, the more power output. A ground mounted array allows maximum air flow around the panel to keep it cool.

                The array will be mounted at an angle that equals the latitude for Miami, Oklahoma, which is best for year-round solar energy production since the buildings loads will be about the same throughout the year. The solar panel angle rule-of-thumb is latitude for year-round production, latitude plus 15 degrees for winter optimization (due to a lower sun altitude) and latitude minus 15 degrees (due to a higher sun altitude) for summer optimization.

                After the club completed the inventory and site survey, they had a little time left, so they decided to troubleshoot the tribe’s 960 Watt stand-alone solar electric system. The stand-alone system consists of four 240 Watt solar electric panels, a 60 amp maximum-point-power-tracking (MPPT) battery charging controller, four 6 Volt 105 amp-hour batteries, a 1500 Watt stand-alone, off-grid, inverter along with the balance-of-system (BOS) components.

                The stand-alone solar electric system will power an atmospheric mercury monitoring system for the next nine months. It will then be used to power the pond aerators for the hatchery troughs in the Aquatic Facility.

                The Solar Green team will return later in the semester, when they have mounted the array, to help wire the grid-tied system and check on the stand-alone system.