Solar Electricity
Solar Performance Ratio Calculator
This page handles the arithmetic for performance ratio while leaving room to review units, limits, and source conditions.
Solar Performance Ratio inputs
Solar Performance Ratio updates live after each input change.
The Solar Performance Ratio equation
The formula uses Delivered energy, and Reference energy to produce Performance ratio. Unit mistakes usually show up as an answer that is off by a factor of 10, 100, or 1,000.
The Performance ratio value and any supporting metrics belong to this same Solar Performance Ratio case, not to a nearby run with different inputs.
Read the Solar Performance Ratio equation from the units on this page. A familiar symbol can shift meaning between DC, AC, energy, component, or billing work.
Sample Solar Performance Ratio run
Using the sample values, Delivered energy = 7200 kWh; Reference energy = 9000 kWh, the primary result is 80.00%.
This Solar Performance Ratio one-input test is a scale check, showing direction and sensitivity without turning the changed case into a recommendation.
If the changed delivered energy comes from a real measurement, keep the original Solar Performance Ratio run so the source of the difference remains clear.
Source notes for Solar Performance Ratio
Treat the Solar Performance Ratio input panel like a short measurement log. If delivered energy is assumed rather than measured, label it before copying performance ratio.
| Entry | Example | Check before use |
|---|---|---|
| Delivered energy | 7200 kWh | Enter delivered energy in kWh. |
| Reference energy | 9000 kWh | Enter reference energy in kWh. |
If the next step shifts toward Solar Azimuth Loss, keep that as a separate worksheet instead of forcing the numbers into Solar Performance Ratio.
What not to assume from Solar Performance Ratio
Define reference energy consistently across comparisons.
- Battery charge acceptance
- Controller voltage window
- Temperature derating
When performance ratio is close to a rating, use the stricter review path instead of relying on the extra decimals shown by Solar Performance Ratio.
Reading performance ratio
When performance ratio is copied into notes, include the unit and the assumption that controls the result more than display precision does.
Solar Performance Ratio should stay tied to sun-hours, array orientation, controller limits, battery voltage, and seasonal assumptions.
Audit trail for performance ratio
Save location assumptions, array tilt, controller model, battery voltage, and weather basis for Solar Performance Ratio.
If a later Solar Performance Ratio run changes only delivered energy, label it as sensitivity work. Several changed conditions deserve a new baseline.
Keep screenshots or notes only when they identify the Solar Performance Ratio source values. A saved final number without entries is hard to audit.
Help with performance ratio
What does a Check inputs message usually mean?
On Solar Performance Ratio, Check inputs usually means a required entry is missing, outside its allowed range, or creating an undefined operation.
When should this be run again?
Run a new Solar Performance Ratio case when the source condition changes, such as voltage, load, rate schedule, temperature, component, connection, or period.
Can this replace a design review?
No. Treat Solar Performance Ratio as arithmetic support; ratings, safety factors, code requirements, and manufacturer limits still need review.
Can the default values be used as a recommendation?
No. The Solar Performance Ratio defaults only demonstrate the form. Replace them with measured or rated values for the actual solar electricity case.
Why did the answer move so much after one input changed?
Many electrical relationships are proportional, inverse, squared, or tied to a denominator. A small change in reference energy can have a visible effect when the other entries stay fixed.
Why might a real measurement disagree?
A field reading for Solar Performance Ratio can include losses, tolerance, temperature effects, waveform distortion, or instrument limits that the worksheet does not model.