The rating printed on a module (610 W, for example) is an instantaneous value under laboratory conditions; it does not tell you the annual yield. The same module gives three different numbers on a southern rooftop, on a high-altitude site and on a north-facing surface. Yield is a property of the installation, not of the panel.
Annual solar resource varies markedly by region. The same module produces considerably more in the south than in the north; the calculation starts from the site's irradiation data.
A south-facing module set at the tilt suited to its latitude gives the highest figure. An east-west layout lowers the total but spreads generation across the day.
A chimney, a tree, a neighbouring building or the row in front: even partial shade can cause a disproportionate loss across the string.
Cabling, inverter efficiency, temperature, soiling and mismatch. Together these account for a share that is far from negligible on most sites.
The rough approach is module rating × the region's annual peak sun hours × system efficiency. That gives an order of magnitude, not a quotation.
The real calculation is hourly: the sun's position at every hour of the year, the irradiation at that moment, the component falling on the module plane, temperature-dependent efficiency and shading are processed together. The sum of 8,760 hours gives the annual yield.
P50 is the yield expected to be exceeded in half of all years — the median scenario. P90 is the more cautious figure, expected to be exceeded in 90% of years.
Banks and investors usually look at P90; seeing both figures in the feasibility lets you read the optimistic and the cautious end at once.
Yield is not a separate tool; it is a step in the design workflow.
In Türkiye a well-oriented module of that size is expected to give roughly 850-1,100 kWh per year. Region, tilt, orientation and shading decide where in that range you land; the exact figure comes from the hourly simulation.
Roughly 1,400-1,800 kWh per year, depending on region and installation. This ratio is known as “specific yield” and is the soundest way to compare plants.
Days shorten and the sun sits lower; monthly output falls well below the summer peak. The simulation shows the monthly distribution, so the netting calculation is built on realistic figures.
Near-shading analysis computes, hour by hour, how much each module is shaded across the year; the loss is deducted directly from annual yield and carried into the feasibility at the same value.
Build the layout and let the 8,760-hour simulation run itself. Runs in the browser, no installation.