Explicit checks passed
2 explicit checks passed for the entered values. This does not replace independent verification where the decision is safety-critical, contractual, statutory, financial or medical.
2 pass
🔆
Irradiance → Energy
PV energy produced from measured irradiance.
PerformanceCore inputs only — quick sizing with engineering defaults.
Inputs (SI units)
Instantaneous plane-of-array power density.
Results
✓ PASS — Irradiance within a physically typical clear-sky range (≤1200 W/m²).
✓ PASS — Module efficiency within the current commercial silicon range.
Solar PV decision support
PV design decision summary
This section organises the existing calculator output into design checks, governing criteria and comparison cases. Core solar formulas and the calculator's original results are unchanged.
Governing criterion
POA irradiance × active area × module efficiency
850 W/m²
This is an instantaneous/interval energy conversion using the entered irradiance, aperture area, efficiency and duration.
Design checks
Solar engineering check 1
pass✓ PASS — Irradiance within a physically typical clear-sky range (≤1200 W/m²).
Structured directly from this solar calculator's own runtime alert.
Current compatibility
pass✓ PASS — Module efficiency within the current commercial silicon range.
Structured directly from this solar calculator's own runtime alert.
Next design actions
Engine recommendation 1
Use plane-of-array (POA) irradiance for tilted arrays, not global horizontal irradiance (GHI) — mixing the two silently understates yield.
Engine recommendation 2
System-loss and PR adjustments here use a single representative point-in-time efficiency; annual energy needs an hourly or monthly irradiation series.
Engine recommendation 3
Engineering-grade preliminary calculation. Final design must be verified against project-specific site conditions, manufacturer datasheets, applicable standards and utility requirements.
Primary design output
3,570 W
Use as a preliminary result and verify the project-specific limits listed below.
Methodology & limit
Decision support is structured from the existing solar calculator engine and the current user inputs. PASS/FAIL is shown only where the engine or entered project criteria support an explicit check. Final PV design still requires site survey, exact module/inverter datasheets, structural/electrical design and applicable statutory approval.
Engineering Recommendations
- →Use plane-of-array (POA) irradiance for tilted arrays, not global horizontal irradiance (GHI) — mixing the two silently understates yield.
- →System-loss and PR adjustments here use a single representative point-in-time efficiency; annual energy needs an hourly or monthly irradiation series.
- →Engineering-grade preliminary calculation. Final design must be verified against project-specific site conditions, manufacturer datasheets, applicable standards and utility requirements.
Detailed Calculation Log
Irradiance (W/m²) is instantaneous power density; irradiation (kWh/m²/day) is the daily energy dose; energy (kWh) is the resulting output over the stated duration — kept distinct throughout.
Save & Load Project
Designs are stored privately in this browser — nothing is uploaded.
Engineering Formula
- P_DC = G(W/m²) × A(m²) × η_module [W]
- E_DC = P_DC × t / 1000 [kWh]
- E_AC = E_DC × (1 − systemLoss%)
- E_PR = E_DC × PR%
Instantaneous DC power equals plane-of-array irradiance × aperture × module efficiency.
Step-by-step Calculation
- 1.Incident solar power on array
G × A17,000 W - 2.DC power output
G·A·η3,570 W - 3.DC energy
P_DC·t/10003.57 kWh - 4.Cross-check: daily energy from irradiation dose
H(kWh/m²/day) × A × η23.1 kWh/day - 5.AC energy after system loss chain
E_DC×(1−loss%)3.07 kWh - 6.PR-adjusted energy
E_DC × PR2.856 kWh
How to use this calculator: Irradiance → Energy
PV energy produced from measured irradiance. The example below is calculated by this page's real engine from the displayed inputs.
- 1Confirm that the Irradiance → Energy matches the quantity or design check you need.
- 2Enter Irradiance, Daily irradiation (optional cross-check), and Array area using the units printed beside each field.
- 3Check every value before calculating, especially decimal points and measurement units.
- 4Calculate, then follow the substituted equations in the worked example and compare the result with any stated limit.
- 5Read the assumptions, warnings and cited references before using the result for a financial, medical or engineering decision.
Input guide and example values
Use values from the same measurement basis and time period. Conditional fields appear only when the related option is selected.
| Input | Example value | Why it matters |
|---|---|---|
| Irradiance | 850 W/m² | Instantaneous plane-of-array power density. |
| Daily irradiation (optional cross-check) | 5.5 kWh/m²/day | Distinct from instantaneous irradiance — this is the daily energy dose per m². |
| Array area | 20 m² | Measured or known array area used by the calculation engine. |
| Module efficiency | 21 % | Measured or known module efficiency used by the calculation engine. |
| Duration | 1 h | Measured or known duration used by the calculation engine. |
| DC-to-AC system loss chain | 14 % | Wiring, inverter, soiling, mismatch combined (0 skips AC-energy calculation). |
| Performance ratio | 80 % | 0/blank skips the PR-adjusted energy result. |
Formula inputs & variables for Irradiance → Energy
These are the named quantities used by this calculator. When the source formula does not define a mathematical symbol, OneCalcApp keeps the real input label instead of inventing one.
| Variable / input | Unit | Meaning in this calculation |
|---|---|---|
| Irradiance | W/m² | Instantaneous plane-of-array power density. |
| Daily irradiation (optional cross-check) | kWh/m²/day | Distinct from instantaneous irradiance — this is the daily energy dose per m². |
| Array area | m² | Measured or known array area used by the calculation engine. |
| Module efficiency | % | Measured or known module efficiency used by the calculation engine. |
| Duration | h | Measured or known duration used by the calculation engine. |
| DC-to-AC system loss chain | % | Wiring, inverter, soiling, mismatch combined (0 skips AC-energy calculation). |
| Performance ratio | % | 0/blank skips the PR-adjusted energy result. |
How the Irradiance → Energy works
The Irradiance → Energy uses Irradiance, Daily irradiation (optional cross-check), Array area, Module efficiency, Duration, DC-to-AC system loss chain, and Performance ratio to calculate Incident irradiance, DC power output, DC energy over duration, Daily irradiation (context), Cross-check daily DC energy, AC energy (after system losses), and PR-adjusted energy estimate. Its engine applies P_DC = G(W/m²) × A(m²) × η_module [W]; the worked values below come from that same live calculation rather than a separately typed example.
With Irradiance 850 W/m², Daily irradiation (optional cross-check) 5.5 kWh/m²/day, Array area 20 m², Module efficiency 21 %, Duration 1 h, DC-to-AC system loss chain 14 %, and Performance ratio 80 %, the main worked-example result is Incident irradiance = 850 W/m².
How each Irradiance → Energy input is used
Irradiance
The Irradiance → Energy worked example uses Irradiance = 850 W/m². This value is passed directly into the calculation, with an allowed minimum 0 and maximum 1500. Instantaneous plane-of-array power density.
Daily irradiation (optional cross-check)
The Irradiance → Energy worked example uses Daily irradiation (optional cross-check) = 5.5 kWh/m²/day. This value is passed directly into the calculation, with an allowed minimum 0. Distinct from instantaneous irradiance — this is the daily energy dose per m².
Array area
The Irradiance → Energy worked example uses Array area = 20 m². This value is passed directly into the calculation, with an allowed minimum 0.1.
Module efficiency
The Irradiance → Energy worked example uses Module efficiency = 21 %. This value is passed directly into the calculation, with an allowed minimum 1 and maximum 40.
Duration
The Irradiance → Energy worked example uses Duration = 1 h. This value is passed directly into the calculation, with an allowed minimum 0.01 and maximum 24.
DC-to-AC system loss chain
The Irradiance → Energy worked example uses DC-to-AC system loss chain = 14 %. This value is passed directly into the calculation, with an allowed minimum 0 and maximum 40. Wiring, inverter, soiling, mismatch combined (0 skips AC-energy calculation).
Performance ratio
The Irradiance → Energy worked example uses Performance ratio = 80 %. This value is passed directly into the calculation, with an allowed minimum 30 and maximum 100. 0/blank skips the PR-adjusted energy result.
Irradiance → Energy formulas and result interpretation
Formula 1: relationship used
In the Irradiance → Energy, P_DC = G(W/m²) × A(m²) × η_module [W]. The quantities in this relationship come from the named inputs or from an earlier calculation step shown in the worked example.
Formula 2: relationship used
In the Irradiance → Energy, E_DC = P_DC × t / 1000 [kWh]. The quantities in this relationship come from the named inputs or from an earlier calculation step shown in the worked example.
Formula 3: relationship used
In the Irradiance → Energy, E_AC = E_DC × (1 − systemLoss%). The quantities in this relationship come from the named inputs or from an earlier calculation step shown in the worked example.
Formula 4: relationship used
In the Irradiance → Energy, E_PR = E_DC × PR%. The quantities in this relationship come from the named inputs or from an earlier calculation step shown in the worked example.
Incident irradiance
For the displayed Irradiance → Energy worked example, Incident irradiance is 850 W/m². Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
DC power output
For the displayed Irradiance → Energy worked example, DC power output is 3,570 W. Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
DC energy over duration
For the displayed Irradiance → Energy worked example, DC energy over duration is 3.57 kWh. Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
Daily irradiation (context)
For the displayed Irradiance → Energy worked example, Daily irradiation (context) is 5.5 kWh/m²/day. Distinct quantity from instantaneous irradiance above Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
Cross-check daily DC energy
For the displayed Irradiance → Energy worked example, Cross-check daily DC energy is 23.1 kWh/day. Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
AC energy (after system losses)
For the displayed Irradiance → Energy worked example, AC energy (after system losses) is 3.07 kWh. Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
PR-adjusted energy estimate
For the displayed Irradiance → Energy worked example, PR-adjusted energy estimate is 2.856 kWh. PR = 80% Verify Irradiance, Daily irradiation (optional cross-check), and Array area and their units before relying on this output.
Irradiance → Energy accuracy, checks and limitations
- Irradiance → Energy units check: confirm Irradiance (W/m²), Daily irradiation (optional cross-check) (kWh/m²/day), Array area (m²), Module efficiency (%), Duration (h), DC-to-AC system loss chain (%), and Performance ratio (%) before calculating.
- Irradiance → Energy result check: compare Incident irradiance, DC power output, DC energy over duration, Daily irradiation (context), Cross-check daily DC energy, AC energy (after system losses), and PR-adjusted energy estimate with the substituted formula steps and the displayed rounding precision.
- Irradiance → Energy: Use this result for preliminary design and cross-checking. Confirm the applicable code edition, manufacturer data, site conditions and qualified-engineer approval before final design or installation.
Understanding the result
Read the main result together with supporting checks, assumptions, limits and intermediate values.
For a manual check, repeat the first equation, confirm the units and change one input at a time.
Common mistakes when using Irradiance → Energy
- Do not mix units for Irradiance (W/m²), Daily irradiation (optional cross-check) (kWh/m²/day), Array area (m²). A unit mismatch changes the input magnitude even when the typed number looks reasonable.
- Do not replace the displayed P_DC = G(W/m²) × A(m²) × η_module [W] relationship with a different convention without also changing the underlying assumptions; compare like-for-like methods when checking the result.
- Do not treat Incident irradiance = 850 W/m² from the worked example as a universal answer. It belongs to the displayed example inputs and must be recalculated for the actual case.
When the Irradiance → Energy is useful
Irradiance → Energy is designed for cases where Irradiance, Daily irradiation (optional cross-check), Array area, Module efficiency are known and you need Incident irradiance, DC power output, DC energy over duration. The page keeps the live calculator, calculation method and worked example together so the result can be checked instead of treated as a black-box number.
Use the calculator for the scope described by its inputs and notes. The displayed method is P_DC = G(W/m²) × A(m²) × η_module [W]. If the real project or decision needs factors that are not represented here, treat the result as an estimate and add the missing checks separately.
Irradiance and Daily irradiation (optional cross-check): what changes the answer
The worked example uses Irradiance = 850 W/m², Daily irradiation (optional cross-check) = 5.5 kWh/m²/day, Array area = 20 m², Module efficiency = 21 %. With those values, Incident irradiance is 850 W/m². Changing an input should be interpreted according to that field's unit, range, option and hint rather than by the number alone.
For this calculator, the main input roles are: Irradiance (W/m²): Instantaneous plane-of-array power density. Daily irradiation (optional cross-check) (kWh/m²/day): Distinct from instantaneous irradiance — this is the daily energy dose per m². Array area (m²): Measured or known array area used by the calculation engine. Module efficiency (%): Measured or known module efficiency used by the calculation engine.
How to sanity-check a Irradiance → Energy result
Start by confirming the entered values and units, then compare the substituted working with the displayed formula or calculation steps. Pay particular attention to Incident irradiance, because it is the first worked-example output shown by the live engine.
Finally, compare the result with the assumptions, warnings and related calculators on this page. A nearby calculator can be useful as a cross-check when it measures the same workflow from a different input or output direction.
Next logical calculator
Continue with Solar Generation Calculator
Useful next check because both tools use Performance ratio, while Solar Generation Calculator answers a different part of the same workflow.
Open Solar Generation CalculatorStandards, source trail and limitations
References show the method used. Check the current local edition, amendments and project specification before a regulated decision.
Design Assumptions
- • Steady irradiance for the hour.
- • STC-referenced efficiency.
Engineering Tips
- ◆Use pyranometer POA data, not GHI, for slanted arrays.
Warnings
- ▲Watch for reflections that push POA > 1200 W/m² at edges.
Standards & References
IEC 61724-1ISO 9060 (pyranometers)
Related Solar Calculators
Azimuth Deviation Loss
Annual energy loss vs deviation from true south (N-hem).
Shading Loss
Annual generation loss from partial shading.
Temperature Loss
Power derating from cell temperature above STC 25 °C.
Peak Sun Hours
Convert daily insolation to Peak Sun Hours.
Monthly Yield Split
Distribute annual generation across months (India typical).
Panel Degradation
Capacity remaining after N years at given degradation.
Related Engineering Articles
Deeper reading on the engineering behind this calculation.
How to Size a Solar PV System Correctly
A step-by-step engineering walkthrough covering load assessment, peak sun hours, performance ratio and module selection.
Read Article →Understanding LCOE and Solar Payback
Levelised cost of energy, ROI and payback period — what each metric means for a real project.
Read Article →Cable Sizing for DC and AC Solar Circuits
Voltage drop limits, derating factors and IEC-aligned conductor selection made simple.
Read Article →PV System Size Calculator: How to Calculate the Right Solar PV System Size
The full PV sizing chain — load, peak sun hours, performance ratio, required DC capacity, module count, inverter capacity and DC/AC ratio — with worked equations.
Read Article →