From Cleanup to Clean Energy Inverter Inverter Aerial Photograph Showing Solar Array on Mine Waste Cap How Solar Works 1. Sunlight falls on high-capacity solar panels during daylight hours. Photon energy from the sun excites electrons in the solar panel material, generating Direct Current (DC) electricity. At the Elizabeth Mine, the maximum potential energy of the entire solar array in full sunlight is 7 megawatts (M W) DC per hour. 2. The DC electricity is then sent to an inverter which converts it into Alternating Current (AC) electricity. At the Elizabeth Mine, the total power output of the inverters is 4.99 MW AC. 3. The low-voltage AC electricity from the inverter is sent to a transformer to step up the voltage for transmission through utility lines to provide power to regional homes and businesses. The Elizabeth Mine went from "Superfund" to "Super Solar." The U.S. Environmental Protection Agency designed the mine waste cap water drainage system to promote runoff and to create an open surface area suitable for beneficial reuse. In 2017, a solar energy partnership including the Strafford Energy Committee, Wolfe Energy, Brightfields Development and Greenwood Energy outfitted the mine waste cap with 19,998 photovoltaic, or "solar" panels. This solar panel "array" generates an average of 8.7 million kilowatt-hours (kWh) of electricity each year, enough to power 1,333 typical Vermont homes. In addition, this project helps defray the State of Vermont's mine waste cap maintenance costs for the life of the solar project. Solar panel operation is guaranteed for 25 years, and with proper maintenance, the array could provide power for generations to come. Clean Energy Reducing Carbon Emissions: Each year, this solar array will offset generation of 7,136 tons of carbon dioxide "greenhouse gas." This is equivalent to the amount of carbon generated by 1,368 fossil fuel-powered passenger vehicles—or the carbon that could be sequestered by 6,128 acres of forest* Solar energy has additional benefits. The solar array generates tax revenue for Vermont and the towns of Strafford and Thetford. It is a good neighbor—that creates no pollution!! ~ * Source: www.epa.gov/energy/greenhouse-gas-equivalencies-calculator Solar Panels Ballasts v GraveK X n TT „ TT n Vegetative Support Soil Drain Net Geomembrane Soil Mine Waste Protecting the Cap. The solar panels are mounted on racks held in place by concrete weights or "ballasts." These ballasts are laid on gravel beds so they do not penetrate the protective barrier capping the mine waste below. The layers of soil and buried geomembrane barrier constructed by EPA are designed to drain clean surface water away from the mine waste. J ° J mi inn hi i in ------- |