Estimating the electricity generated by a photovoltaic system involves several key factors. The process begins by determining the solar panel’s power rating, typically expressed in watts (W) under Standard Test Conditions (STC). These conditions include a cell temperature of 25C (77F) and solar irradiance of 1000 W/m. To refine this figure for real-world application, adjustments must be made for location-specific solar irradiance, panel efficiency, system losses (due to wiring, temperature, and shading), and the tilt and orientation of the panels. For example, a 300W panel in an area receiving an average of 5 peak sun hours daily, experiencing 15% system losses, will yield an estimated daily output calculated by: (300W 5 hours) (1 – 0.15) = 1275 Wh or 1.275 kWh.
Accurate prediction of energy production is crucial for informed decision-making regarding renewable energy investments. This estimation enables consumers and businesses to determine the financial viability of solar installations, optimize system design for maximum efficiency, and accurately project energy cost savings over the system’s lifespan. Historically, the process relied on complex calculations and generalized data. However, modern software tools and readily available solar irradiance data provide more precise and location-specific estimations, increasing the reliability and accessibility of solar energy planning.