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One of the main goals of the solar energy industry is making solar technologies cost-competitive with other forms of energy. In particular, balance-ofsystem (BoS) costs associated with the installation of photovoltaic (PV) systems require significant cost savings to stay competitive with conventional energy sources. Significant potential for cost savings exists through increasing the productivity of the labor force installing the system. A gap in knowledge exists regarding approaches to measuring and improving solar installation labor productivity. The objectives of this research are to design a proper method for conducting time and motion studies for solar contractors, collect and aggregate data related to installation practices, and examine factors that affect solar installation labor productivity. In order to achieve these objectives, the Georgia Technology Research Institute (GTRI) laboratory, in partnership with the Rocky Mountain Institute (RMI), conducted time and motion studies on residential and commercial projects sites to collect and document data on the steps in the installation process of PV systems. An aggregation and analysis of data recorded for each step in these studies was performed to estimate the time to accomplish each task and identify the patterns that affect labor productivity. For this research, the proposed time and motion study approach was examined on two residential and commercial solar installation projects. The findings of the research show that conducting proper time and motion studies can determine the time spent on solar PV installations activities, in order to better understand which activities consume the most labor time and what types of contextual variables have greater impacts on installation labor productivity.

Significant cost reductions for solar photovoltaic systems can be realized through aerodynamic design improvements for ground mounted and rooftop installations. Current practices in the solar industry are based on ASCE-7 codes created for buildings and do not fully account for wind reduction strategies. Numerical simulation is one of the tools that can be used to evaluate wind loads and improve system designs while maintaining reliability and durability. As a first order analysis, we have numerically simulated a solar photovoltaic panel as a flat plate with an aspect ratio of 0.5, which includes the simulation of turbulence experienced by panels. The flow is simulated using the incompressible Navier-Stokes equation and the turbulent process is simulated using k–ε model. The numerical model and boundary conditions are derived from similar experimental wind tunnel experiments. The aerodynamic force is calculated from the integration of the normal and tangential pressure forces. The result of the numerical simulation shows that the wind load on a solar panel can be successfully simulated numerically and the simulation data can be used to evaluate redesigns of the system, allowing for the effective customization of solar arrays based on local conditions.