For the 2020 ATB, commercial PV systems are modeled for a 200-kWDC fixed-tilt (5°), roof-mounted system. Flat-plate PV can take advantage of direct and indirect insolation, so PV modules need not directly face and track incident radiation. This gives PV systems a broad geographical application, especially for commercial PV systems.
Distributed-scale PV is assumed to be configured as a fixed-tilt, roof-mounted system. Compared to utility-scale PV, this reduces both the potential capacity factor and amount of land (roof space) that is available for development. A recent study of rooftop PV technical potential (Gagnon et al. 2016) estimated that as much as 731 GW (926 TWh/yr) of potential exists for small buildings (< 5,000 m2 footprint) and 386 GW (506 TWh/yr) for medium (5,000–25,000 m2) and large buildings (> 25,000 m2).
The following references are specific to this page; for all references in this ATB, see References.
Gagnon, Pieter, Margolis, Robert, Melius, Jennifer, Phillips, Caleb, & Elmore, Ryan. (2016). Rooftop Solar Photovoltaic Technical Potential in the United States: A Detailed Assessment. (No. NREL/TP-6A20-65298). National Renewable Energy Laboratory. https://www.nrel.gov/docs/fy16osti/65298.pdf