What is peak sun hours and why does it matter?

Peak sun hours is the equivalent number of hours per day at full 1000 W per square metre irradiance that delivers the same energy as the real, variable daylight. It bundles latitude, climate, and seasonality into one daily figure, so a panel in a sunny region produces far more than the same panel in a cloudy one.

What does the performance ratio represent?

The performance ratio captures real-world losses between nameplate capacity and delivered energy: inverter inefficiency, wiring and soiling losses, temperature derating, and downtime. Well-designed systems run 0.75 to 0.85; the tool defaults to 0.8. Lower it for dusty sites or older equipment.

How is annual kWh calculated?

Annual kWh equals capacity in kWp, times peak sun hours per day, times the performance ratio, times 365 days. It is a standard first-pass estimate; a full yield study models hourly irradiance, tilt, shading, and inverter clipping, but this captures the bulk of the result.

What is agrivoltaics?

Agrivoltaics combines solar panels with farming on the same land — grazing sheep under panels, growing shade-tolerant crops, or keeping pollinator habitat. It lets land earn both energy and agricultural income, and panel shade can reduce crop water stress in hot climates.

What rate should I use for revenue?

Use the price you would actually receive per kWh: a feed-in tariff, a power purchase agreement rate, or your retail electricity price if the energy offsets on-farm consumption. Self-consumption is usually worth more per kWh than export, so model the split if both apply.

Solar Farm Yield Estimator for Agricultural Land

Putting solar on agricultural land can earn energy income alongside crops or grazing — but only if the numbers work. This estimator turns installed capacity, local sun, and system losses into an annual kWh figure and values it at your tariff so you can compare against current land use.

How it works

The standard first-pass yield formula is:

annual kWh = capacity (kWp) x peak sun hours/day x performance ratio x 365
revenue    = annual kWh x rate (per kWh)

Peak sun hours rolls latitude, climate, and seasonality into one daily number. The performance ratio (typically 0.75–0.85, default 0.8) accounts for inverter, wiring, soiling, and temperature losses between nameplate and delivered energy. The tool ships representative regional sun-hour averages you can override.

Example

A 500 kWp array at 4.5 peak sun hours/day and a 0.8 performance ratio yields 500 x 4.5 x 0.8 x 365 = 657,000 kWh/year. At a 0.10 per-kWh PPA rate that is 65,700 of annual revenue, before subtracting lease, O&M, and financing.

Notes

This is a screening estimate, not a bankable yield study. A full assessment models tilt, azimuth, shading, inverter clipping, and degradation over the asset life. For agrivoltaics, also value the retained agricultural income, since the point is to earn from both layers.