Before converting the building to solar power, SACE first invested in numerous energy efficiency measures (see series of blogs from January or and watch this video for a virtual tour!) to reduce the energy needs of our Asheville office since moving in last July 2013. As the building was being made more efficient, we began exploring options for powering our facility with clean energy by enrolling in the Solarize Asheville program (now called Clean Energy for Us). Solarize campaigns have proven extremely effective at lowering costs and complexity for homeowners (and in some cases businesses) interested in going solar. Asheville’s campaign was no exception with over 370 enrolled, at least 50 contracts signed, and over 230 kilowatts installed to date!
Modules (a.k.a., solar panels)
As if the modules aren’t impressive enough, all 24 of them (laid out on a rack that’s 25’ x 25’) are mounted on a single dual-axis tracking system. The AllSun Tracker uses a built-in GPS system to track the sun for both azimuth and altitude throughout the day… in other words, if the sun is out the tracker will find it and point the modules in that direction. This feature allows the modules to produce up to 45% more electricity than a fixed system of the same size.
Inverter and Monitoring
The projected annual output – based on PVWatts – of SACE’s Asheville system is 14,941 kilowatt hours (kWh). Despite being 2 kW smaller than our Knoxville solar system, Asheville will be generating nearly 3,500 kWh more on an annual basis. The projected output equates to about half the average annual energy consumption used by the previous owners/tenants. However, due to the short history SACE has had in the building and all the efficiency improvements that have been made, we’re hopeful the solar system may make our new office a net zero-energy building!
As we celebrate Black History Month, SACE is highlighting stories at the crossroads of energy and equity. Through my own work to design and install my own solar rooftop photovoltaic (PV) system on my home, I’ve become very familiar with the challenges in Tennessee. I've also reflected on how current utility policy in Tennessee is unfair and inconsiderate of the poor, low, and limited income customers. Here I share my experience, lessons learned, and hopes for a more equitable system.