Estimating Annual Solar Electricity Output and CO₂ Avoidance

This page provides a transparent, browser-based estimate of annual solar electricity yield (kWh) and the associated CO₂ avoidance, based on basic system characteristics such as installed capacity (kWp), panel orientation and tilt, system losses, and a regional baseline yield. The intention is to make the underlying assumptions explicit and understandable, rather than to produce a black-box outcome.

The calculation follows a simplified energy balance: annual yield is derived from a regional reference yield (kWh per kWp per year), adjusted for orientation, tilt, and system losses (e.g. inverter efficiency, wiring, soiling). CO₂ avoidance is then estimated by multiplying the calculated electricity output by a user-defined CO₂ intensity factor for grid electricity. This makes the sensitivity of outcomes to both technical choices and policy-relevant assumptions immediately visible.

Quick estimate of annual electricity yield (kWh) and CO₂ avoidance based on region, tilt, azimuth and system losses (PR). This is a transparent scenario tool—useful for comparing configurations.

Region (baseline yield)

Baseline (kWh/kWp/year)

Auto-set by region unless Custom.

System size (kWp)

Tilt (°) — 0 = flat, 35 = pitched

Azimuth (°) — 0 = South, -90 = East, +90 = West, 180 = North

System losses (%) — inverter, wiring, dirt, mismatch

Typical quick estimate: 10–20%.

CO₂ factor (kg CO₂/kWh)

Adjustable (varies strongly by country/year).

Model

Annual yield ≈ kWp × baseline × f(tilt) × g(azimuth) × (1 − losses). Tilt/azimuth factors are simplified, intended for scenario comparison (not PVGIS-grade).

Estimated annual yield

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CO₂ avoidance (annual)

—

kWh × CO₂ factor

Indicative monthly profile

Normalised season curve (NW-Europe style). For intuition, not billing.

Check

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It is important to note that this tool is not a replacement for detailed engineering software or official databases. Professional tools such as PVGIS, installer-grade design packages, or utility-level models include high-resolution meteorological data, shading analysis, time-resolved irradiance, degradation over lifetime, and grid-specific marginal emission factors. None of those effects are fully represented here.

The strength of this tool lies in scenario comparison and intuition building. It allows users to explore how changing assumptions—such as tilt angle, system size, or CO₂ intensity—affects outcomes, and to discuss results in a reproducible and transparent way. The model is deliberately kept simple to avoid over-precision where uncertainty is unavoidable.

Disclaimer: This PV Yield calculator is a demonstration and scenario tool only. Results should not be used for financial decisions, subsidy applications, investment appraisal, or regulatory reporting. Actual energy yield and CO₂ impacts depend on local conditions, system design, and future grid dynamics, and should always be validated with professional assessments or measured data.