With the global population expected to reach 11 billion by the end of this century, the imperative of enhancing crop productivity per unit of land while conserving resources is paramount. This paper presents a novel approach to achieving these goals through Extended PAR-based photosynthesis (EPBP) methodology, specifically tailored for standalone Photovoltaic Greenhouses (PVGHs). By leveraging LED technology and extending photosynthesis during dusk and dawn periods, this methodology aims to enhance crop yield without substantial additional infrastructure investment. A comprehensive real-field experiment, conducted over a complete tomato crop cycle of 96 days, demonstrates a significant increase in crop yield, with a 51.29 % improvement compared to conventional PVGH without additional photosynthesis. Through meticulous analysis of key performance indicators such as leaf area index, specific leaf area, and dry matter weight, this study substantiates the efficacy of EPBP in optimizing crop growth within PVGHs. Further, the ROI of 14.11 % and 12.54 % have been observed for tomato crop grown with and without EPBP under the PVGH environment. It not only reduces crop growth period but also enhances both quality and yield quantity without additional operational expenses. The scope of the presented work is limited to the quantitative measurement; however, its impact on the quality of the crop yield could be further explored.