Real-World Solar Production in Los Angeles: Measured on 264 Rooftop Systems
In 2023–2025, a kilowatt of rooftop panels in the Los Angeles area produced a median 1,386 kWh a year — 569 complete system-years on 257 systems monitored by two platforms, Enphase and SolarEdge. The middle half ran from 1,278 to 1,480, about 3.8 kWh per kW a day. Those were dim years by Los Angeles standards: 2023 was the least sunny year since 2001, and in a year of average sunshine the same roofs would have made about 1,430. The sunnier years 2019–2022, measured on our SolarEdge fleet, ran higher, about 1,540.
How much 1 kW of solar produces in LA
Each system’s median year in 2023–2025, 257 systems.
| Measure | p10 | p25 | Median | p75 | p90 |
|---|---|---|---|---|---|
| 2023–2025, all system-years | 1,184 | 1,278 | 1,386 | 1,480 | 1,566 |
| 2023–2025, per system (each system’s median year) | 1,179 | 1,276 | 1,382 | 1,477 | 1,577 |
| 2023–2025, adjusted to average sunshine | 1,212 | 1,313 | 1,430 | 1,522 | 1,616 |
| 2019–2025, both platforms, all system-years | 1,203 | 1,302 | 1,422 | 1,532 | 1,641 |
| 2019–2025, SolarEdge only | 1,220 | 1,311 | 1,456 | 1,557 | 1,666 |
| Average per day, 2023–2025 | 3.2 | 3.5 | 3.8 | 4.1 | 4.3 |
| kWh per kW of DC panel capacity. 2023–2025: 569 system-years, 257 systems. | |||||
https://cali-energy.com/research/los-angeles-solar-production. Aggregated data are free to use under CC BY 4.0 with a link to this page.Read it as a benchmark: if your system made less than 1,184 kWh per kW in a full calendar year of 2023–2025, it did worse than 9 in 10 of the system-years we measured. That is worth a look — shade that has grown, panels or an optimizer offline, or an inverter fault. Above 1,480 is better than three-quarters of them, usually a south- or west-facing roof with little shade.
To get your own number, divide a full year of production from your monitoring app by your system’s DC size in kW (the size on your contract or permit). Compare it with the same year here: a year’s sunshine moves every roof together.
In kilowatt-hours: a 6 kW system at the 2023–2025 median made about 8,316 kWh a year (7,668–8,880 for the middle half). Other sizes, single panels and sizing from your usage are in output by system size and output of one panel.
Year by year: sunlight, and something else
Median per year, both platforms combined.
| Year | System-years | Median, both platforms | SolarEdge | Enphase* | Sunshine vs 2001–2025 average | Median adjusted to average sunshine |
|---|---|---|---|---|---|---|
| 2019 | 11 | 1,478 | 1,478 | — | −2.9% | 1,523 |
| 2020 | 35 | 1,503 | 1,498 | — | +0.3% | 1,499 |
| 2021 | 66 | 1,560 | 1,554 | 1,619 | +1.7% | 1,534 |
| 2022 | 91 | 1,568 | 1,550 | 1,621 | +2.2% | 1,535 |
| 2023 | 147 | 1,404 | 1,416 | 1,381 | −5.2% | 1,481 |
| 2024 | 217 | 1,373 | 1,396 | 1,368 | −1.7% | 1,397 |
| 2025 | 205 | 1,396 | 1,410 | 1,390 | −2.1% | 1,426 |
| *Shown where at least 10 Enphase system-years exist. Sunshine: NASA POWER yearly solar radiation for Los Angeles against its 2001–2025 average. | ||||||
Sunlight explains the first step down. 2023 was the least sunny year in Los Angeles since 2001, 5.2% below the 2001–2025 average, and output fell with it. On the same SolarEdge systems, output per unit of sunlight in 2023 matched 2022 within a few percent. Then the sun came back: 2024 and 2025 were 3.9% and 3.3% sunnier than 2023 — but output did not follow. On the same SolarEdge systems, output per unit of sunlight was 5% lower in 2024 and 5% lower in 2025 than in 2023, and the Enphase fleet showed a similar shortfall.
Panel aging explains part of it: a median 1.3% a year in our study of how fast systems lose output. Dust after the long dry spell from April 2024 to January 2025 is one hypothesis — output jumped after several first rains — but other dry years did not show the same loss. The 2023–2025 median is the measured level of those years; the sunshine-adjusted figure is the better guide for a typical year. How to read your own year-to-year change: why did my solar production drop.
Area by area
Each system’s median year in 2023–2025, grouped by ZIP code.
| Area | Systems | Median | Middle half | p10–p90 |
|---|---|---|---|---|
| San Fernando Valley & Burbank | 116 | 1,397 | 1,288–1,511 | 1,220–1,591 |
| Rest of Los Angeles County | 89 | 1,352 | 1,227–1,421 | 1,125–1,488 |
| Elsewhere in Southern California | 30 | 1,425 | 1,317–1,509 | 1,298–1,716 |
| Santa Clarita Valley | 11 | 1,514 | 1,435–1,567 | 1,397–1,617 |
| Ventura County | 11 | 1,403 | 1,299–1,469 | 1,276–1,483 |
| Areas with at least 10 systems. Santa Clarita Valley and Ventura County have few systems; read their medians as rough. | ||||
Location matters less than the roof. Area medians ran from 1,352 to 1,514, while systems within the San Fernando Valley alone spread from 1,220 to 1,591 (p10–p90). Direction, tilt and shade decide most of a roof’s result; see east-west versus south-facing and shade and trees.
Real rooftops versus an idealized roof model
PVWatts, the free solar model from the National Laboratory of the Rockies (formerly NREL), describes one ideal roof: facing due south, tilted 20°, never shaded.
This comparison sets every roof in the fleet against that one idealized roof. It is not a comparison with any project’s own estimate, which should reflect that roof’s direction, tilt and shade.
| Period | Measured, 2023–2025 | PVWatts ideal roof* | Measured as % of ideal |
|---|---|---|---|
| Full year, median system | 1,382 | 1,685 | 82% |
| Full year, top tenth of systems (p90) | 1,577 | 1,685 | 94% |
| April–July (monthly medians) | 581 | 646 | 90% |
| November–January (monthly medians) | 227 | 326 | 70% |
*PVWatts v8, downtown Los Angeles, 20° south-facing, 14% system losses — Cali Energy runs published in How much sun LA gets (Northridge models 1,710 kWh per kW a year). Measured: system medians, or monthly medians summed over the period.
The median roof made 82% of the ideal roof’s output; the best tenth reached 94%, which is a fair ceiling for an unshaded south-facing roof in these years. In late spring and summer real roofs come closer to the ideal (90%); the gap opens in winter (70%), when a low sun stretches shadows from trees, neighboring houses and chimneys and east- or west-facing panels lose more of the short day. If an estimate you were given assumes an unshaded south-facing roof, ask how shade was modeled. The winter study has the month-by-month picture.
Methodology
How the numbers were produced.
- Systems
- Rooftop systems in Cali Energy’s monitoring fleet on two platforms: 89 SolarEdge systems (385 complete system-years, 2019–2025) and 175 Enphase systems (387 system-years, mostly 2023–2025). Systems we service but did not install, systems expanded mid-period and systems whose output does not match their recorded size are excluded.
- Complete system-year
- One system over one calendar year with all 12 months valid, and at least 75% of the same system’s median year (years below that are treated as downtime). Enphase months are built from cleaned daily data: a month counts with at most three missing days, scaled to the full month. 2026 is incomplete and not used.
- Unit
- kWh per kW: yearly energy (AC, from the inverters or microinverters) divided by the system’s DC panel capacity. Enphase systems whose recorded capacity is a placeholder rather than the panel rating are left out of per-kW figures.
- Average sunshine
- Each system-year multiplied by the ratio of the 2001–2025 average to that year’s solar radiation, from NASA POWER for Los Angeles. NASA’s grid is coarse (one cell covers the area), which is adequate for comparing years, not neighborhoods.
- Statistics
- Medians and percentiles (p10, p25, p75, p90). “Middle half” means p25–p75.
- Geography
- Assigned by ZIP code. The fleet is weighted toward the San Fernando Valley.
- Limits
- Not a random sample of Los Angeles roofs: these are systems we monitor. Roof direction, tilt and shade vary and are not adjusted for.
- Updates
- Recalculated when a calendar year closes.
Sources: Cali Energy monitoring fleet (SolarEdge and Enphase); NASA POWER daily solar radiation (power.larc.nasa.gov); PVWatts v8, National Laboratory of the Rockies (pvwatts.nlr.gov).
Frequently asked questions
How much electricity does 1 kW of solar produce in Los Angeles?
In our measured fleet, a median 1,386 kWh a year per kW of panels in 2023–2025, with the middle half between 1,278 and 1,480. In a year of average sunshine the same systems would make about 1,430. That is about 3.8 kWh per kW a day.
How do I compare my solar system with this benchmark?
Take a full calendar year of production from your monitoring app and divide it by your system’s DC size in kW, from your contract or permit. Compare the result with the same year in the table above; for 2023–2025 the median was 1,386.
What counts as low solar production in LA?
A full year below 1,184 kWh per kW in 2023–2025 was lower than 9 in 10 of the system-years we measured. It is a screening signal: check for new shade, offline panels or inverter alerts.
Why was solar production lower in 2023–2025 than before?
2023 was the least sunny year in Los Angeles since 2001. In 2024 and 2025 sunshine recovered but output per unit of sunlight stayed about 5% lower; aging explains part of that and the rest is not yet explained.
Do Enphase and SolarEdge systems produce differently?
Not measurably. In 2023–2025 the medians were 1,407 kWh per kW for SolarEdge and 1,378 for Enphase, a gap within chance.
Does location in LA change solar output?
Less than the roof does. Area medians differed by about 162 kWh per kW, while the 10th- and 90th-percentile systems within the San Fernando Valley were 371 apart.
More research
Next steps
Below the benchmark, or planning a system?
Prepared by Cali Energy, October 15, 2026. Figures describe systems in our monitoring fleet and are not a guarantee of what any specific roof will produce; orientation, tilt, shade, equipment and weather change results. Not engineering, financial or utility advice. See our Content Disclaimer.