Electricity generated from solar photovoltaic (PV) panels has become a significant source of carbon-free power in the United States over the last decade. Compared to other solar-electric technologies, solar PV systems are unique in that they are highly scalable and may be deployed in configurations ranging from just a few kilowatts (kW) (residential-scale) to hundreds of megawatts (MW) (utility-scale). This report examines the comparative customer-paid costs of generating power from equal amounts of utility- and residential-scale solar PV panels in the Xcel Energy Colorado system. The report was prepared by consultants at The Brattle Group for First Solar, with support from the Edison Electric Institute. Xcel Energy Colorado provided data and technical support.