Calculated results
Monthly AC energy output
Chart rendering is unavailable. Use the monthly performance table below.
Monthly solar radiation
Chart rendering is unavailable. Use the monthly performance table below.
Monthly performance breakdown
Renton, WA · TMY3 weather data| Month | Solar radiation (kWh/m²/day) | Plane of array (kWh/m²) | DC energy (kWh) | AC energy (kWh) |
|---|---|---|---|---|
Optimal orientation
Find the tilt and azimuth that deliver the most annual AC energy for your current system. PVWatts supplies one year of hourly weather, your browser searches every orientation with the same fixed-array model, and PVWatts confirms the winner.
Comparison baseline
- Location
- Renton, WA
- System size
- 4 kW DC
- System losses
- 14.08%
- Module / array
- Standard · Fixed (open rack)
- Current orientation
- 20° tilt · 180° azimuth
Advanced model settings are inherited from the current simulator inputs. Only tilt and azimuth vary.
How the search works
- 1 request fetches hourly weather and the official result at your current orientation.
- Your browser checks its model against that result, then evaluates about 1,500 orientations without contacting PVWatts.
- 1 request confirms the best orientation with official PVWatts.
Works for fixed open-rack and fixed roof-mount arrays with monofacial modules.
Your system inputs changed after this search. Run it again to update the result.
Run the search to map annual energy across every tilt and azimuth.
View accessible orientation data
Model check and method
The local model reimplements the fixed-array path of PVWatts v8 from the open-source SAM Simulation Core: sun position, the Perez sky model, row-to-row self-shading, soiling, cover and spectral losses, cell temperature, the single-diode module model, DC losses, and the inverter. One factor scales every local value so it matches the official result at your current orientation. The optimum itself always comes from an official PVWatts request.
Seasonal tilt schedule
The sun's declination swings from +23.45° at the June solstice to −23.45° at the December solstice, so the tilt that faces the noon sun changes by about 47° over a year. An adjustable rack can follow part of that swing. Compare one fixed tilt with re-tilting 2, 4, or 12 times a year at the optimal azimuth.
Run the optimal orientation search above. The schedules reuse its weather and calibrated model, so they need no extra API requests.
Chart rendering is unavailable. Use the schedule data table below.
Schedule
Your system inputs changed after the search. Run it again to update the schedules.
View accessible schedule data
| Month | Mean declination | Noon-sun tilt | Best tilt | AC at best tilt (kWh) | Schedule tilt | AC on schedule (kWh) |
|---|
Official grid comparison
Run 77 tilt and azimuth combinations entirely through official PVWatts, holding the same baseline constant. Use it to check the local search or to compare the classic grid.
Quota checkpoint
A personal NLR key is recommended. The sweep runs in 7-request batches so cancellation prevents unsent batches from consuming quota.
Acknowledge the request count to enable the sweep.
Run the comparison to see official results for all 77 orientations.
View accessible comparison data
Module overview
Calculated from the values in your table, not verified specifications.
Rated power · STC
Maximum power at standard test conditions.
Module efficiency
From rated power and overall module area.
Module area
Overall height × length, including the frame.
Fill factor · STC
Maximum-power output relative to Voc × Isc.
From specification sheet to module performance
Open a manufacturer’s PDF from the panel to begin. The reader finds the specification page and keeps it here while you review the values.
- Read the module valuesSelect the right power class when a sheet lists several models.
- Check against the sourceCorrect any misread values. Missing specifications stay blank, never guessed.
- Inspect the calculationsReview efficiency, fill factor, power tolerance, and consistency checks, then export.
No PDF? Enter values manually to work the same calculations.
Source page
Check every value against this page before you rely on a calculation. Collapse the source page to bring calculations closer.
Calculations
Updates with every edit| Quantity | Result | Formula |
|---|
Consistency checks
Each check compares two numbers the datasheet states independently. A disagreement means one of them is wrong — re-read that row on the page.
Photovoltaic news
Headlines from photovoltaic publishers, research journals, and public agencies. Every entry links to the publisher's own page: this view reads one pre-built list rather than contacting those sites, so no publisher sees traffic from it. The list is rebuilt on a six-hour schedule, and filtering and search run locally on the last rebuild.
Topic All topics
Source All sources
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