This study explores the design, efficiency, and sustainability of photovoltaic (PV) power plants, emphasizing their growing role in renewable energy systems. Photovoltaic power plants convert sunlight directly into electricity, offering a clean, renewable energy source, yet face efficiency and intermittency challenges. Key factors influencing PV efficiency include material type, weather, temperature, orientation, and technological advancements. Current commercial PV cells demonstrate an average efficiency of 15-20%, with monocrystalline cells achieving up to 22% efficiency under ideal conditions, while polycrystalline cells reach around 18%. These efficiency rates indicate that a 1 MW PV plant, with optimal sunlight exposure, generates approximately 4,380 MWh annually; however, in practice, real-world factors can reduce this output by 10-15%. Efficiency improvements are made possible through advanced technologies like bifacial panels, which capture sunlight from both sides, improving output by 6-9%, and solar tracking systems, which increase efficiency by 15-25% by adjusting panel orientation to follow the sun. Additionally, concentrated photovoltaics (CPV) offer potential efficiencies of up to 40%, though they are suitable only for high-sunlight regions. Life-cycle assessments show that PV plants have a CO₂ emission factor of 20-60 g CO₂-eq/kWh, significantly lower than fossil fuels, underscoring their environmental benefits. However, challenges such as high initial costs (up to $1,000/kW for utility-scale systems) and land use (up to 4 acres per MW) require careful planning for large-scale implementations. This study concludes that while PV plants are pivotal for sustainable energy, ongoing innovations in cell efficiency and energy storage will be essential to maximize their impact.