Home

In the Press

Solar UpgradeSolar Upgrade

metalarchitecture.com/articles/magazine-features/solar-upgrade.aspx

May 6, 2011 – The University of Mississippi Center for Manufacturing Excellence was recently awarded an American Recovery & Reinvestment Act Grant through the Mississippi Development Authority, Energy Division. The design for the UM CME was completed by Jackson, Miss.-based firm, Cooke Douglass Farr Lemons Architects & Engineers, and construction had begun when CDFL Principal and Lead Electrical Engineer Jesse Browning learned of the available grant funding. "The original design of the CME already had a solar photovoltaic array integrated into the building's function as a demonstration of solar power production," says Browning. "The grant request focused on expanding the PV array to facilitate the removal of the teaching section of the Center from the electrical grid."

The CDFL team chose the lightweight, non-penetrating SolarDock system from SolarDock, Wilmington, Del., to install the photovoltaic array on the roof of the CME. The patent pending SolarDock mounting system transforms the installation of flat-roofed building photovoltaic arrays by dramatically reducing installation labor, lowering overall system costs and improving system efficiencies. This mounting system makes no roof penetrations and fits most commercially available photovoltaic modules. Holding modules in place at a 30-degree angle, the SolarDock increases annual system output by up to 15 percent when compared to a flat-mount system. Furthermore, the angled design reduces the buildup of dirt and debris, sheds snow in colder climates, and reduces heat buildup through front, side and rear ventilation.
The funding that was procured from the ARRA grant will allow additional photovoltaic capacity for the CME that will further enhance the energy efficiency of the facility. The CME is electrically divided into two sections. The energy produced from the photovoltaic array will be used in the traditional classroom spaces. Presently the project has a 13KW array of 60 solar panels that will be roof mounted. The full output of the array will provide approximately 2.5 percent of the total energy needs of the space as measured against connected load. If, however, we consider the lighting, which is the most continuous load of the building, the present array will provide 32 percent of the lighting energy needs. Enhancement to the designed 90KW array will provide 224 percent of the building lighting energy needs. This extra capacity will be available for the additional building needs, for general use loads or be redistributed to the University electrical grid for other building uses. This will reduce the present load on the University system, provide a renewable energy source for the University, and reduce the impact on the system and environment from the added load of the new facility.

The present photovoltaic array will also be an excellent teaching tool for the students at the University, to see firsthand how renewable energy systems operate. With an expected life of greater than 30 years, the system will allow many classes of students to experience and study this type of energy production. Enhancing the array will allow for greater flexibility of the system as a whole, or in parts, to contribute to the energy needs of the facility while allowing flexibility to study the system in different ways. The arrays are broken into three distinct parts. Two arrays are essentially identical in projected output. The third array is 78 percent larger than any one of the other arrays.

One year of operation at full capacity of 90KW will reduce the release of approximately 140 metric tons of carbon dioxide into the atmosphere. This calculation is assuming operation at 4.7 hours per day.

The project will consist of the installation and integration of an additional 422 photovoltaic panels with support systems on the roof of the CME and adjacent engineering school. Twelve panels will be added to the existing system of 60 photovoltaic panels, and the 13KW DC to AC inverter will be upsized to 15KW. Also, a third array of 340 panels will be added, plus an 82KW inverter. Together, the three systems compose an array of 482 photovoltaic panels using a combined 112KW of inverter power capacity for the facility. The panels will be poly-crystalline silicon based cells with 72 cells per panel for a capacity of 220W. The 482 panels at 220 watts per panel will give a total system capacity of 90KW.

The key to the efficient operation of the system will be monitoring the system and the facility for energy usage. The University is currently installing smart metering for the facilities on campus. This system will provide immediate feedback on the consumption of energy the building is using. The installed photovoltaic array is provided with a web-based energy monitoring system by Lawrence, Mass.-based Solectria Renewables LLC called SolrenView. This system already has the capability to monitor the expanded system proposed and can provide instant feedback on the energy being generated by the photovoltaic array.