Ecology & Environment
Solar Energy Production Calculator
Calculate average daily production, annual production, annual electricity value, and implied capacity factor. The sun-to-meter diagram traces solar resource through the array and performance losses into usable annual energy and value.
Average daily production-
Estimated annual production-
Estimated annual electricity value-
Implied capacity factor-
Decision view
Sunlight to annual solar value
Sunlight to annual solar valuePeak sun resource passes through array capacity and modeled performance losses before annual energy and electricity value are reported.
Exact scenario comparisonAverage peak sun hours per day changes while all other entered assumptions remain constant.
| Average peak sun hours per day | Average daily production | Estimated annual production | Estimated annual electricity value | Implied capacity factor |
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How to use Solar Energy Production Calculator
- Enter the rated DC array size and a site-appropriate average peak-sun-hours value for the modeled orientation.
- Use a performance ratio that represents temperature, inverter, wiring, mismatch, soiling, availability, and other system losses.
- Value production using the tariff or avoided-cost rule that actually applies to self-consumption and exported electricity.
Calculator guide
Understanding Solar Energy Production Calculator
Solar production is driven by array size, solar resource, and system performance. The result is an annual planning estimate; it does not replace a site-specific shade study, hourly production simulation, or utility interconnection analysis.
Calculation method
How the calculation works
Multiply array capacity by peak sun hours and performance ratio, then annualize across operating days. Multiply array kW by average peak sun hours and performance ratio for average daily kWh. Multiply by operating days for annual production, multiply annual kWh by entered electricity value, and divide annual production by array kW times 8,760 hours for implied capacity factor.
Energy value
Production and bill savings are not the same number
Financial value depends on the path each solar kilowatt-hour takes.
Worked situations
Practical examples
- An 8 kW array with 4.6 peak sun hours has 36.8 kWh/day before performance losses.
- At a 78% performance ratio, modeled average output is about 28.7 kWh/day and 10,478 kWh/year.
- At $0.21/kWh, simple annual electricity value is about $2,200 before tariff timing, degradation, financing, or maintenance.
Better inputs
Useful tips
- Use orientation- and tilt-specific solar resource rather than a citywide annual average when possible.
- Separate electricity consumed on site from exported electricity if the utility values them differently.
- Check inverter AC capacity, clipping, shading, and module degradation in a detailed production model.
Before relying on the result
Limitations and common mistakes
- The calculator uses one average solar-resource value and one blended performance ratio.
- Hourly weather, shading, orientation, snow, soiling, clipping, curtailment, downtime, and degradation are not simulated.
- Electricity value assumes one constant rate and excludes demand charges, time-of-use periods, export rules, taxes, and incentives.
Reference
Key terms
- Peak sun hour
- Solar irradiation equivalent to one hour at 1 kW per square meter.
- Performance ratio
- Entered share of ideal resource-based production retained after system losses.
- Capacity factor
- Annual energy divided by rated power multiplied by all hours in the year.
- Self-consumption
- Solar energy used on site rather than exported to the grid.
Important note
Calculated from the entered environmental values using the displayed model. Measurement quality, local conditions, system boundaries, and source data affect interpretation.
Frequently asked questions
Is peak sun hours the same as daylight hours?
No. It compresses varying sunlight intensity into equivalent full-power hours.
Why is performance ratio below 100%?
Real systems lose energy through temperature, inverter conversion, wiring, mismatch, soiling, shading, and availability.
Can annual production be larger than array size?
Yes. Array size is power in kW, while annual production is accumulated energy in kWh.
Does electricity value equal bill savings?
Not necessarily. Savings depend on self-consumption, export credit, time-of-use rates, fixed charges, and utility rules.